58 results on '"Nair JJ"'
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2. [Plenary Lecture] - African Ethnopharmacology: The Southern African Perspective
- Author
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van Staden, J, primary, Ndhlala, AR, additional, Mulaudzi, RB, additional, and Nair, JJ, additional
- Published
- 2013
- Full Text
- View/download PDF
3. Anti-inflammatory Principles of the Plant Family Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Animals, Humans, Mice, Plant Extracts pharmacology, Plant Extracts chemistry, Phenanthridines pharmacology, Phenanthridines chemistry, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents chemistry, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids pharmacology, Amaryllidaceae Alkaloids chemistry, Inflammation drug therapy
- Abstract
There is considerable interest in the utilisation of plants against inflammation. Over 50 species of the plant family Amaryllidaceae are known for such usage in traditional medicine. This review was undertaken to identify the chemical principles responsible for these anti-inflammatory effects. It describes the findings from in vitro, in vivo and in silico studies, as well as the probes made on the mechanisms of action. The literature search returned over 600 hits, of which around 130 were chosen for their relevance to the text. Over 140 compounds have thus far been screened for anti-inflammatory effects. These were mostly isoquinoline alkaloids but also included other classes of secondary metabolites such as chromones, flavonoids and triterpenoids. In vitro studies were carried out in mononuclear cells such as lymphocytes, monocytes, neutrophils and macrophages, against which no serious side effects were observed. The constituents were also effective against inflammation induced by physical and chemical stimuli in a variety of murine test subjects. Chief among the compounds were the isoquinoline alkaloids lycorine and narciclasine, which displayed potent effects against pain, swelling, asthma and arthritis, amongst others. From a mechanistic perspective, several of the compounds were shown to mediate in inflammatory pathways, notably via the modulation of both pro-inflammatory (such as NF- κ B, TNF- α and IL-1) and anti-inflammatory (such as IL-10 and TGF- β ) factors. Useful insights also emerged from active-site docking studies of some of the compounds. The Amaryllidaceae affords a rich and diverse platform for the discovery of potential anti-inflammatory drugs., Competing Interests: The authors declare that they have no conflict of interest. The account herein is the product of findings made independently by the authors, no part of which may be deemed liable to any other individual or organisation., (Thieme. All rights reserved.)
- Published
- 2024
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4. Anti-inflammatory effects of the plant family Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Humans, Plant Extracts pharmacology, Plant Extracts therapeutic use, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents therapeutic use, Inflammation drug therapy, Amaryllidaceae, Alkaloids pharmacology
- Abstract
Ethnopharmacological Relevance: Members of the plant family Amaryllidaceae are widely recorded in traditional systems of medicine. Their usage for inflammatory conditions is most prominent, with substantive evidence emerging from several locations around the world., Aim of the Study: This survey was undertaken to identify such plant taxa, highlight the countries from which they originate and afford details of the ailments against which they are utilized. The undertaking also sought to establish the in vitro and in vivo activities of Amaryllidaceae plant extracts in inflammation-based assays. Furthermore, it set out to unravel the molecular mechanisms used to explain these effects., Materials and Methods: Over six-hundred articles were identified in searches carried out on SciFinder, Scopus, ScienceDirect, PubMed and Google Scholar. These were condensed to around 170 that formulated the basis of the text. The keyword engaged was 'Amaryllidaceae' in conjunction with 'inflammation' or 'anti-inflammatory', as well as the names of individual genera combined with the latter two., Results: Fifty-one species from thirty-five countries were identified for their uses against inflammation. Twenty-four of such conditions were discernible, of which their applicability in wound healing and pain management was most conspicuous. The utilization of all plant parts was apparent, preparations of which were used primarily via topical application. Extracts of seventy-three species (from twenty-three genera) were examined in nearly thirty inflammation-based assays where their activities in vitro and in vivo were shown to be significant. They were effective in vivo against pain and swelling as well as wound healing, without detriment towards test subjects. The in vitro studies were carried out mainly in mononuclear cells such as macrophages, leukocytes, lymphocytes and neutrophils against which their cytotoxic effects were seen to be minimal. The modes of operation were shown to involve modulation of both pro-inflammatory (such as NF-κB, TNF-α, IL-6, IFN-γ, COX and NO) and anti-inflammatory (such as IL-10) factors., Conclusions: The Amaryllidaceae is showcased as a platform highly conducive towards studies in the inflammation arena. Potent activities in instances were observed via in vitro and in vivo models of study, bolstered by the significant amounts of information emerging from traditional forms of medicine. It is conceivable that the family may yield future anti-inflammatory chemotherapeutics, particularly those related to its alkaloid principles., Competing Interests: Declaration of competing interest These are independent findings made by the authors and none of the contents may be disputed in terms of liability to another individual or organization., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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5. Antiviral alkaloid principles of the plant family Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Humans, Antiviral Agents pharmacology, Plant Extracts pharmacology, Plant Extracts chemistry, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids pharmacology, Amaryllidaceae Alkaloids chemistry, Alkaloids pharmacology, Alkaloids chemistry
- Abstract
Background: Viral-borne diseases are amongst the oldest diseases known to mankind. They are responsible for some of the most ravaging effects wrought on human health and well-being. The use of plants against these ailments is entrenched in both traditional and secular medicine around the globe. Their natural abundance and chemical diversity have also boosted their appeal in drug discovery., Aim: The plant family Amaryllidaceae is distinguished for its alkaloid principles, some of which are of considerable interest in the clinical arena. This account is the outcome of a literature review undertaken to establish the applicability of these substances as antiviral agents., Methods: The survey utilized the search engines Google Scholar, PubMed, SciFinder, Scopus and Web of Science engaging the word 'antiviral' in conjunction with 'Amaryllidaceae' and 'Amaryllidaceae alkaloid'. The search returned over five hundred hits, of which around eighty were of relevance to the theme of the text., Results: Over eighty isoquinoline alkaloids have been screened against nearly fifty pathogens from fourteen viral families, the majority of which were RNA viruses. Potent activities were reported in some instances, such as that of trans-dihydronarciclasine against Yellow fever virus (IC
50 0.003 μg/ml), with minimal effects being manifested on host cells. There were also promising results obtained from in vivo studies, in most cases without lethal effects on test subjects. Structure-activity relationship studies afforded useful insight to the antiviral pharmacophore, with the phenanthridone alkaloid nucleus shown to be the most enabling. Although the mechanistic basis to these activities pertained mostly to inhibition of DNA, RNA and protein synthesis, evidence was also forthcoming about the inhibitory action of some of the alkaloids against viral neuraminidase, protease and reverse transcriptase. In silico methods of analysis have offered further perspectives of how some of the alkaloids interact at the active sites of their targets., Conclusion: The Amaryllidaceae offers a viable platform for plant-based antiviral drug discovery. Its cause is strengthened not only by its wide proliferation and exploitation of its members in alternative forms of medicine, but also by its rich chemical diversity which has already spawned useful antiviral drug leads., Competing Interests: Declaration of Competing Interest This account is the outcome of independent findings made by the authors and none of its content, in any shape or form, may be deemed liable to any other individual or organization., (Copyright © 2022. Published by Elsevier GmbH.)- Published
- 2023
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6. Chemical Principles of Boophone, Nerine, Crossyne, Clivia, Cryptostephanus, Haemanthus and Scadoxus of the South African Amaryllidaceae and Their Biological Properties.
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Nair JJ and van Staden J
- Subjects
- South Africa, Plant Extracts pharmacology, Plant Extracts chemistry, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids chemistry, Alkaloids pharmacology
- Abstract
The Amaryllidaceae features prominently amongst bulbous flowering plant families. Accommodating about a third of its species, South Africa affords a sound basis for Amaryllidaceae plant research. Boophone, Nerine, Crossyne, Clivia, Cryptostephanus, Haemanthus and Scadoxus have been well-represented in such endeavors. The account herein summarizes the studies undertaken between 2013 - 2020 on these genera in regards to their chemical and biological characteristics. A total of 136 compounds comprising 63 alkaloids and 73 non-alkaloid entities were described during this period from eighteen members of the title genera. The alkaloids were reflective of the structural diversity found in eight isoquinoline alkaloid groups of the Amaryllidaceae. Of these, the crinane (29 compounds), lycorane and homolycorine (11 compounds each) groups were the most-represented. The non-alkaloid substances were embracive of the same number of unrelated groups including, acids, phenolics, flavonoids and triterpenoids. A wide variety of assays were engaged to ascertain the biological activities of the isolated compounds, notably in regards to cancer and motorneuron-related diseases. There were also attempts made to determine the antimicrobial, anti-inflammatory and antioxidant effects of some of the substances. New information has also emerged on the herbicidal, insecticidal and plant growth regulatory effects of selected alkaloid principles. Coupled to the biological screening measures were in instances probes made to establish the molecular basis to some of the activities, particularly in relation to cancer and Parkinson's disease., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)
- Published
- 2023
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7. Insights to the tribe Haemantheae of the South African Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Anti-Inflammatory Agents, Ethnopharmacology, Medicine, Traditional, Phytochemicals, Plant Extracts chemistry, Plant Extracts pharmacology, Plant Extracts therapeutic use, South Africa, Alkaloids pharmacology, Amaryllidaceae chemistry
- Abstract
Ethnopharmacological Relevance: The family Amaryllidaceae has been documented in traditional systems of medicine around the globe. Its member tribe Haemantheae occurs chiefly in South Africa, where around twenty of its species are identifiable with a wide variety of functions in such practices., Aim of the Study: This account details work published from 2013 to 2020 on the tribe Haemantheae involving Clivia, Cryptostephanus, Haemanthus, Scadoxus and Gethyllis. Focus is maintained on the traditional medicinal aspects, pharmacological activities and identification of the active principles. Significant effort is also made to outline the molecular basis to some of these effects., Materials and Methods: The major search engine platforms including, SciFinder, Scopus, ScienceDirect, PubMed and Google Scholar were utilized at the literature consolidation stage. Keywords engaged in the process included 'Amaryllidaceae' and 'Haemantheae' as well as individual genera and specie names., Results: Twenty-four species of the five genera were encountered over the designated time frame. New traditional medicinal information has emerged on nine of these species, where usage ranged from the treatment of wounds and infections, circulatory and gastrointestinal issues to AIDS and TB. Significant amounts of new data also appeared in relation to the antimicrobial, anti-inflammatory, antioxidant, anticholinesterase, antidepressive and cytotoxic effects of these plants. Potent activities were observed in some instances, as they were in regards to the anti-inflammatory effects of some Gethyllis species in their cyclooxygenase-inhibitory effects. The entities behind these activities, with few exceptions, were shown to be isoquinoline alkaloids which are known to dominate the chemistry of the Amaryllidaceae. Interesting observations were also made for the mechanisms behind some of the effects, notably in the inflammatory and motorneuron disease arenas., Conclusions: The tribe Haemantheae has proved to be a rich and diverse platform for studies of the Amaryllidaceae in the key areas of traditional medicine, pharmacology and phytochemistry. Indigenous knowledge has played a significant role in guiding the biological evaluations, while identification of the active principles has been bolstered by the exceedingly rich alkaloid diversity of the Amaryllidaceae. As such, Haemantheae should continue to feature prominently in drug discovery efforts targeted at the family., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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8. Cytotoxic Agents in the Minor Alkaloid Groups of the Amaryllidaceae.
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Nair JJ and van Staden J
- Subjects
- Apoptosis, Cytotoxins, Alkaloids pharmacology, Amaryllidaceae, Amaryllidaceae Alkaloids pharmacology
- Abstract
Over 600 alkaloids have to date been identified in the plant family Amaryllidaceae. These have been arranged into as many as 15 different groups based on their characteristic structural features. The vast majority of studies on the biological properties of Amaryllidaceae alkaloids have probed their anticancer potential. While most efforts have focused on the major alkaloid groups, the volume and diversity afforded by the minor alkaloid groups have promoted their usefulness as targets for cancer cell line screening purposes. This survey is an in-depth review of such activities described for around 90 representatives from 10 minor alkaloid groups of the Amaryllidaceae. These have been evaluated against over 60 cell lines categorized into 18 different types of cancer. The montanine and cripowellin groups were identified as the most potent, with some in the latter demonstrating low nanomolar level antiproliferative activities. Despite their challenging molecular architectures, the minor alkaloid groups have allowed for facile adjustments to be made to their structures, thereby altering the size, geometry, and electronics of the targets available for structure-activity relationship studies. Nevertheless, it was seen with a regular frequency that the parent alkaloids were better cytotoxic agents than the corresponding semisynthetic derivatives. There has also been significant interest in how the minor alkaloid groups manifest their effects in cancer cells. Among the various targets and pathways in which they were seen to mediate, their ability to induce apoptosis in cancer cells is most appealing., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)
- Published
- 2021
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9. Insight to the antifungal properties of Amaryllidaceae constituents.
- Author
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Nair JJ and van Staden J
- Subjects
- Alkaloids chemistry, Alkaloids pharmacology, Amaryllidaceae Alkaloids pharmacology, Cell Wall drug effects, Phenanthridines pharmacology, Protein Synthesis Inhibitors chemistry, Protein Synthesis Inhibitors pharmacology, Amaryllidaceae chemistry, Antifungal Agents chemistry, Antifungal Agents pharmacology
- Abstract
Background: Fungal pathogenesis continues to be a burden to healthcare structures in both developed and developing nations. The gradual and irreversible loss of efficacies of existing antifungal medicines as well as the emergence of drug-resistant strains have contributed largely to this scenario. There is therefore a pressing need for new drugs from diverse structural backgrounds with improved potencies and novel modes of action to fortify or replace contemporary antifungal schedules., Aim: Alkaloids of the plant family Amaryllidaceae exhibit good growth inhibitory activities against several fungal pathogens. This review focuses on the mechanistic aspects of these antifungal activities. It achieves this by highlighting the molecular targets as well as structural features of Amaryllidaceae constituents which serve to enhance such action., Methods: During the information gathering stage extensive use was made of the three database platforms; Google Scholar, SciFinder and Scopus. In most instances articles were accessed directly from journals licensed to the University of KwaZulu-Natal. In the absence of such proprietary agreements the respective corresponding authors were approached directly for copies of papers., Results: Although several classes of molecules from the Amaryllidaceae have been probed for their antifungal effects, it is the key constituents lycorine and narciclasine which have together afforded the most profound mechanistic insights. These may be summarized as follows: (i) effects on the fungal cell wall and cell membrane; (ii) effects on morphology such as budding and hyphal growth; (iii) effects on fungal organelles such as ribosomes; (iv) effects on macromolecules such as DNA, RNA and proteins and; (v) identification of the active sites for these constituents., Conclusion: The key feature in the antifungal effects of Amaryllidaceae alkaloids is the inhibition of protein synthesis. This involved the inhibition of peptide bond formation by binding to yeast ribosomes via the 60S subunit. Related effects involved the inhibition of both DNA and RNA synthesis. These adverse effects were reflected morphologically on both the fungal cell wall and cell membrane. Such observations should prove useful in the chemotherapeutic arena should efforts shift towards the development of a clinical candidate., Competing Interests: Conflict of interest Both authors hereby jointly affirm that there is no conflict of interest attending any aspect of this undertaking., (Copyright © 2018 Elsevier GmbH. All rights reserved.)
- Published
- 2020
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10. Antiprotozoal alkaloid principles of the plant family Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Amaryllidaceae Alkaloids pharmacology, Antiprotozoal Agents pharmacology, Diterpenes chemistry, Drug Evaluation, Preclinical, Humans, Isoquinolines pharmacology, Molecular Structure, Phytochemicals chemistry, Phytochemicals pharmacology, Plant Extracts pharmacology, Structure-Activity Relationship, Trypanosoma brucei brucei drug effects, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids chemistry, Antiprotozoal Agents chemistry, Isoquinolines chemistry, Plant Extracts chemistry
- Abstract
Protozoan-borne diseases are prominent amongst diseases caused by parasites. Given their alarming morbidity and mortality statistics, there is ever growing interest in new therapies against these diseases. Whilst synthetic drugs such as benznidazole and melarsoprol have had a profound influence on the clinical setup, there has been significant interest in the phytochemical platform to also deliver such drug candidates. The plant family Amaryllidaceae is recognizable for its isoquinoline alkaloids, which exhibit attractive molecular architectures and interesting biological properties. This survey focuses on the antiprotozoal activities of 73 of such substances described in 18 different species of the Amaryllidaceae. Of these, 2-O-acetyllycorine was identified as the most potent (IC
50 0.15 μg/mL against Trypansoma brucei brucei). Also considered are structure-activity relationships which have served to modulate activities, as well as the plausible mechanisms that underpin these effects and afford insight to the Amaryllidaceae alkaloid antiprotozoal pharmacophore., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
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11. Antiplasmodial Lycorane Alkaloid Principles of the Plant Family Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids isolation & purification, Animals, Antimalarials chemistry, Antimalarials isolation & purification, Humans, Plasmodium falciparum drug effects, Structure-Activity Relationship, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids pharmacology, Antimalarials pharmacology
- Abstract
The spread of malaria is thought to have followed human expansion out of Africa some 60 - 80 thousand years ago. With its prevalence in pantropical countries of the world and epicenter localized in Africa, malaria is now considered an unnecessary burden to overworked and under-resourced healthcare structures. Plants have long afforded a fertile hunting ground for the search and identification of structurally diverse antimalarial agents, such as quinine and artemisinin. This survey examines the antiparasitic properties of the family Amaryllidaceae via the antiplasmodial activities demonstrated for its lycorane alkaloid principles. Of these, 24 were natural compounds identified in 20 species from 11 genera of the Amaryllidaceae family, whilst the remaining 28 were synthetically derived entities based on the lycorane skeleton. These were screened against ten different strains of the malarial parasite Plasmodium falciparum , wherein the parent compound lycorine was shown to be the most potent with an IC
50 of 0.029 µg/mL in the FCR-3 strain seen to be the best. Structure-activity relationship studies revealed that good activities were detectable across both the natural compounds as well as the synthetically accessed derivatives. Such studies also highlighted that there are several inherent structural features that define the lycorane alkaloid antiplasmodial pharmacophore, such as the nature of its ring systems and properties of its substituents. Mechanistically, a limited number of studies confirmed that lycorane alkaloids manifest their action by targeting enzymes associated with the plasmodial FAS-II biosynthetic pathways. Overall, these alkaloids have provided useful, convenient, and accessible scaffolds for antimalarial-based drug discovery., Competing Interests: The findings described herein are a consolidation of independent research carried out in the laboratories of the authors. As such, none of its content in any shape or form is deemed liable to any other individual or organization., (Georg Thieme Verlag KG Stuttgart · New York.)- Published
- 2019
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12. The Amaryllidaceae as a source of antiplasmodial crinane alkaloid constituents.
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Nair JJ and van Staden J
- Subjects
- Amaryllidaceae classification, Amaryllidaceae Alkaloids isolation & purification, Antimalarials isolation & purification, Molecular Structure, Phytochemicals isolation & purification, Phytochemicals pharmacology, Plasmodium falciparum drug effects, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids pharmacology, Antimalarials pharmacology
- Abstract
Malaria is prevalent in tropical and subtropical regions of the globe. With over 200 million cases reported annually, particularly in sub-Saharan Africa, it is an unnecessary burden to already overworked and ailing healthcare structures. Traditional medicine (TM) remains vibrant in most of these regions wherein plants often serve as the first line of defense against malaria. Given this fact as well as the successes elsewhere of therapies such as Artemisia annua emanating from evidence-based TM, interest in plants as a source of new antimalarial drugs has been rejuvenated. The bulbous plant family Amaryllidaceae is recognized for its structurally-diverse alkaloid constituents which exhibit interesting biological properties. This review focuses on the in vitro activities demonstrated by its crinane alkaloids against various strains of the malaria-causing parasite Plasmodium falciparum. The survey embraces the twelve genera of the Amaryllidaceae whose nineteen representative species have been examined for antiplasmodial crinane alkaloid principles. A total of seventy-two compounds were screened against nine strains of P. falciparum, with the α-crinanes reflecting better overall activities than their corresponding β-crinane subgroup congeners. In terms of potency, an ED
50 of 0.14 μg/mL (for augustine in the D-6 strain) and IC50 of 0.35 μg/mL (for haemanthidine in the K1 strain) were the lowest activity indices observed. Structure-activity relationship studies afforded useful insight on the antiplasmodial pharmacophore and the features supporting its efficacy. Overall, crinane alkaloids have provided a useful platform for the study of antiplasmodial effects, not only in terms of potency but also in terms of structural diversity., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
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13. Cell cycle modulatory effects of Amaryllidaceae alkaloids.
- Author
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Nair JJ and van Staden J
- Subjects
- Alkaloids pharmacology, Antineoplastic Agents pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Apoptosis drug effects, Cell Cycle Checkpoints drug effects, Humans, Neoplasms drug therapy, Structure-Activity Relationship, Amaryllidaceae Alkaloids metabolism, Amaryllidaceae Alkaloids pharmacology, Cell Cycle drug effects
- Abstract
The birth, growth, proliferation and death of cells involve a rigorous and continuous process in place to ensure the survival of living organisms. The cell cycle prevails at the core of this process to facilitate the division of a parent cell as well as the duplication of its genetic matter. Although checkpoints exist to steer the course of a cell from one phase to the other, malfunctions at any point of the four active phases of the cell cycle can have detrimental effects. Cancer is thought to be a consequence of such a malfunction in the cell cycle which endows a cell with enhanced replicative potential, immunity to anti-growth signals and the ability to evade apoptosis. This characteristic has been exploited in cancer chemotherapy since a significant number of anticancer drugs manifest their action via cell cycle modulatory effects. The plant family Amaryllidaceae is distinguished for its alkaloid principles which exhibit potent (at the sub-nanomolar level in some cases) and cell line specific antiproliferative activities, with apoptosis induction a key feature of these properties. As a consequence there has been sustained interest in these chemical entities as a source of new anticancer drugs. This has been matched by the large body of work that has emerged over the past two decades addressing their cytotoxic potential, establishing a structure-activity relationship basis as well as probing their mode of action. This review focuses on studies which highlight how Amaryllidaceae alkaloids modulate the cell cycle of cancer cells., (Copyright © 2018 Elsevier Inc. All rights reserved.)
- Published
- 2018
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14. Antifungal constituents of the plant family Amaryllidaceae.
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Nair JJ and van Staden J
- Subjects
- Antifungal Agents pharmacology, Humans, Amaryllidaceae chemistry, Antifungal Agents therapeutic use, Plant Extracts chemistry
- Abstract
Globalization, the modern lifestyle, immuno-suppressive agents, invasive surgical procedures, the loss of efficacies of existing drugs, and multidrug resistance are some of the factors used to explain the rise in fungal infections in recent years. Significant advances have been made in attempts to replace existing antifungal schedules, especially with synthetic targets. The identification of other platforms for drug discovery is now entrenched in research programs across the globe. Plants offer significant benefits owing to their numerical superiority, exceedingly broad chemical basis and appealing sustainability characteristics. Furthermore, plants have a long and rich historical association with traditional approaches towards fungal diseases. These have in numerous instances served as markers in the bioassay-guided identification of the active constituents. Although the plant family Amaryllidaceae is conventionally associated with cancer and motor-neuron disease chemotherapies, around 30 of its species have been examined for antifungal activities with microgram per millilitre inhibitory activities detected in several instances. This review focuses on the nearly 40 constituents from the family, mainly isoquinoline alkaloids, which have been screened against around 50 fungal pathogens. Encouragingly, microgram per millilitre growth inhibitory activities were applicable for several of the compounds with a minimum inhibitory concentration of 4 μg/ml seen to be the lowest., (Copyright © 2018 John Wiley & Sons, Ltd.)
- Published
- 2018
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15. Antibacterial constituents of the plant family Amaryllidaceae.
- Author
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Nair JJ, Wilhelm A, Bonnet SL, and van Staden J
- Subjects
- Alkaloids chemistry, Alkaloids isolation & purification, Alkaloids pharmacology, Amaryllidaceae metabolism, Anti-Bacterial Agents isolation & purification, Anti-Bacterial Agents pharmacology, Gram-Negative Bacteria drug effects, Gram-Positive Bacteria drug effects, Plant Extracts chemistry, Amaryllidaceae chemistry, Anti-Bacterial Agents chemistry
- Abstract
There is a pressing need in antibiotic drug discovery for new drugs to counterbalance the effects of multidrug resistance. Plants represent a viable platform for such endeavors owing to their traditional relevance in infectious disease therapies as well as their vast chemical resources. As many as fifty different species of the Amaryllidaceae are discernible with such functions in traditional medicine, thirty-nine of which have been subjected to pharmacological evaluations. Submicromolar antibacterial activities for several of these plants have been the driving force behind studies targeting their active constituents. This review accounts for close to a hundred of such entities, mainly isoquinoline alkaloids, which have been the focus in assays of thirty different bacterial pathogens. Promising activities were detected in several instances, although disappointingly the submicromolar level could not be breached. Also considered are structure-activity relationships which have emerged within the various groups of Amaryllidaceae alkaloids., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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16. Alkaloid Constituents of the Amaryllidaceae Plant Amaryllis belladonna L.
- Author
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Tallini LR, Andrade JP, Kaiser M, Viladomat F, Nair JJ, Zuanazzi JAS, and Bastida J
- Subjects
- Amaryllidaceae Alkaloids isolation & purification, Amaryllidaceae Alkaloids pharmacology, Antiprotozoal Agents isolation & purification, Antiprotozoal Agents pharmacology, Biosynthetic Pathways, Leishmania donovani drug effects, Parasitic Sensitivity Tests, Plant Extracts isolation & purification, Plant Extracts pharmacology, Plasmodium falciparum drug effects, Trypanosoma cruzi drug effects, Amaryllidaceae chemistry, Amaryllidaceae Alkaloids chemistry, Antiprotozoal Agents chemistry, Plant Extracts chemistry
- Abstract
The plant family Amaryllidaceae is well-known for its unique alkaloid constituents, which exhibit a wide range of biological activities. Its representative, Amaryllis belladonna , has a geographical distribution covering mainly southern Africa, where it has significant usage in the traditional medicine of the native people. In this study, A. belladonna samples collected in Brazil were examined for alkaloid content. Alkaloid profiles of A. belladonna bulbs were generated by a combination of chromatographic, spectroscopic and spectrometric methods, including GC-MS and 2D NMR. In vitro screening against four different parasitic protozoa ( Trypanosoma cruzi , T. brucei rhodesiense , Leishmania donovani and Plasmodium falciparum ) was carried out using the A. belladonna crude methanol extract, as well as three of its alkaloid isolates. Twenty-six different Amaryllidaceae alkaloids were identified in the A. belladonna bulb samples, and three of them were isolated. Evidence for their respective biosynthetic pathways was afforded via their mass-spectral fragmentation data. Improved data for 1- O -acetylcaranine was provided by 2D NMR experiments, together with new ¹H-NMR data for buphanamine. The crude extract and 3- O -acetylhamayne exhibited good antiprotozoal activity in vitro, although both with a high cytotoxic index.
- Published
- 2017
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17. Sjogren's syndrome: Review of the aetiology, Pathophysiology & Potential therapeutic interventions.
- Author
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Nair JJ and Singh TP
- Abstract
Background: Sjogren's syndrome (SS) is an autoimmune disorder characterised by lymphocytic infiltration of exocrine glands, resulting in glandular dysfunction. Objectives: This study aims to review the aetiology of Sjogren's syndrome, highlight aspects that contribute to the pathophysiology of the disease and explore treatment options that target different mediators of pathogenesis., Material and Methods: The MEDLINE/PubMed and Google Scholar databases were searched systematically with the terms "Sjogren's syndrome"; "clinical"; "treatment"; "management". Eligible studies had to meet a predefined inclusion criteria., Results: 912 identified studies were evaluated against the inclusion criteria. 25 eligible studies were included for review. Sjogren's syndrome is a multifactorial condition with genetic, environmental and hormonal factors playing a role in establishing the condition. B-cell activating factor (BAFF) is an important mediator in the induction and perpetuation of this condition. Elevated BAFF levels, found in patients with SS, promote growth of B-cells and subsequent production of autoantibody; anti-SSA/Ro. BAFF inhibitors are important potential therapeutic drugs that may be effective in patients with Sjogren's syndrome. Other potential targets include CD20 and CD22 that cause B-cell depletion., Conclusions: The pathophysiology of this exocrinopathy has not fully been elucidated. Potential therapeutic interventions include BAFF inhibitors and anti-CD20 and anti-CD22 therapy. However, no clinical trials have been conducted on subjects with Sjogren's syndrome to support existing research. Key words: Sjogren's syndrome, autoimmune, rheumatology., Competing Interests: Conflict of interest statement:The authors hereby report no conflicts of interest with regards to this work.
- Published
- 2017
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18. Distribution and Diversity of Usage of the Amaryllidaceae in the Traditional Remediation of Infectious Diseases.
- Author
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Nair JJ, Van Staden J, Bonneta SL, and Wilhelm A
- Subjects
- Humans, Phytotherapy, Plant Extracts chemistry, Plants, Medicinal chemistry, Surveys and Questionnaires, Amaryllidaceae chemistry, Infections drug therapy, Plant Extracts therapeutic use
- Abstract
Globalization and multidrug resistance are amongst the factors implicated in the resurgence of infectious diseases in recent years. This has fostered a compelling need in drug discovery to replace (or supplement) existing schedules. The floral biodiversity has been identified as a viable resource platform due to its inimitable chemical characteristics as well as the presence of numerous of its members in traditional medicinal approaches towards these diseases. Whilst the plant family Amaryllidaceae is conventionally associated with cancer and motor-neuron disease therapies, this survey shows that it has a significant presence in the remediation of infections and infection-related ailments. This verifiable indigenous knowledge could amplify efforts towards the identification of the active chemical constituents.
- Published
- 2017
19. A Clinical Study of Acute Kidney Injury in Tropical Acute Febrile Illness.
- Author
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Nair JJ, Bhat A, and Prabhu MV
- Abstract
Introduction: Tropical Acute Febrile Illness (TAFI) is one of the most common causes of morbidity within the community. Acute Kidney Injury (AKI) due to infective and non infective causes is a major complication. Presence of AKI is a major cause of mortality among patients with TAFI., Aim: To study the spectrum of tropical acute febrile illness; the proportion, spectrum and staging of acute kidney injury; Renal Replacement Therapy (RRT) initiation and in-hospital mortality., Materials and Methods: A total of 600 TAFI patients were prospectively studied at a tertiary care centre in coastal Karnataka between September 2012 and September 2014 for the aetiology of TAFI; the development and staging of AKI based on Kidney disease: Improving global outcomes (KDIGO) guidelines; the initiation of RRT and in-hospital mortality., Statistical Analysis: Data analysis was done using SPSS version 17.0 with statistical significance calculated using chi-square and Fisher's exact t-test for which p-value <0.05 was considered significant., Results: The spectrum of TAFI, in decreasing order, was vivax malaria, leptospirosis, dengue fever, falciparum malaria, mixed malaria, enteric fever, scrub typhus and the most common aetiology was malaria. The proportion of AKI was 54%. The most common cause of AKI, its stages 2 and 3, RRT initiation and in-hospital mortality was leptospirosis; and AKI stage 1 was dengue fever. KDIGO AKI stage 1, 2 and 3 was seen in 46.9%, 31.2% and 21.9% of AKI patients, respectively. RRT initiation was required in 10.2% of AKI patients and in-hospital mortality was 3% among all patients. AKI, RRT initiationand in-hospital mortality were significantly associated with older age, fever duration and other presenting complaints, examination findings, renal function and other parameters, leptospirosis, dengue fever, falciparum malaria., Conclusion: The aetiology in about half of TAFI patients in coastal Karnataka was malaria. More than 50% develop AKI with greater than one-fifth of them progressing to AKI stage 3 and one-tenth requiring RRT. The most common cause of AKI, AKI stage 2, 3, RRT initiation and in-hospital mortality was leptospirosis. AKI was present in almost all patients with leptospirosis. Therefore leptospirosis was the most nephrotoxic acute febrile illness in the present study population. Dengue fever was the most common cause of AKI stage 1. Vivax malaria was the third most common cause of AKI. The factors like age, presenting complaints, examination findings, renal function and other parameters, aetiology and RRT initiation may be used to predict AKI and in-hospital mortality.
- Published
- 2016
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20. In vivo Cytotoxicity Studies of Amaryllidaceae Alkaloids.
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Nair JJ, Bastida J, and van Staden J
- Subjects
- Alkaloids chemistry, Animals, Antineoplastic Agents, Phytogenic chemistry, Molecular Structure, Neoplasms drug therapy, Alkaloids pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Liliaceae chemistry
- Abstract
The plant family Amaryllidaceae is recognizable for its esthetic floral characteristics, its widespread usage in traditional medicine as well as its unique alkaloid principles. Few alkaloid-producing families rival the Amaryllidaceae in terms of the diversity of its structures as well as their wide applicability on the biological landscape. In particular, cytotoxic effects have come to be a dominant theme in the biological properties of Amaryllidacea alkaloids. To this extent, a significant number of structures have been subjected to in vitro studies in numerous cell lines from which several targets have been identified as promising chemotherapeutics. By contrast, in vivo models of study involving these alkaloids have been carried out to a lesser extent and should prove crucial in the continued development of a clinical target such as pancratistatin. This survey examines the cytotoxic effects of Amaryllidaceae alkaloids in vivo and contrasts these against the corresponding in vitro effects.
- Published
- 2016
21. Apoptosis-Inducing Effects of Amaryllidaceae Alkaloids.
- Author
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Nair JJ, van Staden J, and Bastida J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Animals, Antineoplastic Agents chemistry, Humans, Molecular Conformation, Neoplasms pathology, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents pharmacology, Apoptosis drug effects
- Abstract
The Amaryllidaceae occupies a privileged status amongst medicinal plants in having delivered the Alzheimer's drug galanthamine to the clinical market. Following its resounding success, there have been several positive indicators for the emergence of an anticancer drug from the family due to the potent antiproliferative activities manifested by several of its alkaloid constituents. Of these, the phenanthridones such as pancratistatin hold most promise as potential chemotherapeutics having succumbed to various phases of clinical trials. Other cytotoxic targets of the Amaryllidaceae are to be found within the lycorane and crinane groups, as exemplified by crinine and lycorine. Although the molecular targets of these alkaloids still remain elusive, much effort has gone into understanding their mode of action in cancer cells. Recent findings have shown that the apoptotic pathway may be a key factor in cancer cell death instigated by Amaryllidaceae alkaloids. As such, this review seeks to: (a) examine the apoptotic effects of Amaryllidaceae alkaloids in cancer cells; (b) explore the molecular basis to these effects; and (c) provide a pharmacophoric rationale in support of these activities., ((c) provide a pharmacophoric rationale in support of these activities.)
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- 2016
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22. Mechanistic insights to the cytotoxicity of Amaryllidaceae alkaloids.
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Nair JJ, Rárová L, Strnad M, Bastida J, and van Staden J
- Subjects
- Humans, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents, Phytogenic pharmacology
- Abstract
With over 500 individual compounds, the Amaryllidaceae alkaloids represent a large and structurally diverse group of phytochemicals. Coupled to this structural diversity is the significant array of biological properties manifested by many of its members, of which their relevance in motor neuron disease and cancer chemotherapy has attracted considerable attention. To this extent, galanthamine has evolved into a successful commercial drug for Alzheimer's disease since its approval by the FDA in 2001. Concurrently, there have been several positive indicators for the emergence of an anticancer drug from the Amaryllidaceae due to the potency of several of its representatives as cell line specific antiproliferative agents. In this regard, the phenanthridones such as pancratistatin and narciclasine have offered most promise since their advancement into clinical trials, following which there has been renewed interest in the cytotoxic properties of these alkaloids. Given this background, this review seeks to highlight the various mechanisms which have been invoked to corroborate the cytotoxic effects of Amaryllidaceae alkaloids.
- Published
- 2015
23. Cytotoxicity studies of lycorine alkaloids of the Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Animals, Humans, Liliaceae chemistry, Phenanthridines chemistry, Plant Extracts chemistry, Amaryllidaceae Alkaloids toxicity, Liliaceae adverse effects, Phenanthridines toxicity, Plant Extracts toxicity
- Abstract
The plant family Amaryllidaceae is renowned for its unique alkaloid constituents which possess a significant array of structural diversity. Several of these alkaloids are known for their interesting biological properties, of which galanthamine and pancratistatin have acquired a privileged status due to their relevance in the pharmaceutical arena. In particular, galanthamine represents the first prescription drug emanating from the Amaryllidaceae after its approval by the FDA in 2001 for the treatment of Alzheimer's disease. Following on this commercial success there have been sustained projections for the emergence of an anticancer agent related to pancratistatin due to the potency, selectivity, low toxicity and high tolerability typifying targets of this series of alkaloids. The lycorine series of alkaloids have also garnered widespread interest as cytotoxic agents and were amongst the earliest of the Amaryllidaceae constituents to exhibit such activity. To date over 100 of such naturally-occurring or synthetically-derived alkaloids have been screened for cytotoxic effects against a number of cancer cell lines. This survey examines the cytotoxic properties of lycorine alkaloids, highlights the outcomes of structure-activity relationship orientated studies and affords plausible insights to the mechanistic rationale behind these effects.
- Published
- 2014
24. Crinine-type alkaloids from Hippeastrum aulicum and H. calyptratum.
- Author
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de Andrade JP, Guo Y, Font-Bardia M, Calvet T, Dutilh J, Viladomat F, Codina C, Nair JJ, Zuanazzi JAS, and Bastida J
- Subjects
- Crystallography, X-Ray, Magnetic Resonance Spectroscopy, Molecular Structure, Alkaloids chemistry, Amaryllidaceae Alkaloids chemistry, Liliaceae chemistry, Plant Extracts chemistry
- Abstract
An ongoing search for alkaloids in the Amaryllidaceae species using GC-MS resulted in the identification of two crinine-type alkaloids, aulicine (1) and 3-O-methyl-epimacowine, (2) from the indigenous Brazilian species Hippeastrum aulicum and Hippeastrum calyptratum, respectively. In addition, two alkaloids, 11-oxohaemanthamine (3) and 7-methoxy-O-methyllycorenine (4) were both isolated from H. aulicum. Furthermore, we provide here complete NMR spectroscopic data for the homolycorine analogues nerinine (5) and albomaculine (6). The absolute stereochemistry of the 5,10b-ethano bridge in the crinine variants was determined by circular dichroism and X-ray crystallographic analysis, thus presenting the first direct evidence for the presence of crinine-type alkaloids in the genus Hippeastrum., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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25. Crinane alkaloids of the amaryllidaceae with cytotoxic effects in human cervical adenocarcinoma (HeLa) cells.
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Nair JJ, Rárová L, Strnad M, Bastida J, Cheesman L, and van Staden J
- Subjects
- Female, HeLa Cells, Humans, Molecular Structure, Adenocarcinoma drug therapy, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids pharmacology, Cytotoxins chemistry, Cytotoxins pharmacology, Uterine Cervical Neoplasms drug therapy
- Abstract
The family Amaryllidaceae has a long history of usage in the traditional medicinal practices of the indigenous peoples of South Africa, with three of its species known to be used for cancer treatment. Furthermore, the Amaryllidaceae is widely recognized for its unique alkaloid constituents, several of which exhibit potent and selective cytotoxic activities. In this study, several crinane alkaloids derived from local Amaryllidaceae species were examined for cytotoxic effects against the human cervical adenocarcinoma cell line, of which distichamine was the most potent (IC50 2.2 microM).
- Published
- 2014
26. Traditional usage, phytochemistry and pharmacology of the South African medicinal plant Boophone disticha (L.f.) Herb. (Amaryllidaceae).
- Author
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Nair JJ and Van Staden J
- Subjects
- Humans, Plant Preparations adverse effects, South Africa, Liliaceae chemistry, Phytotherapy, Plant Preparations chemistry, Plant Preparations therapeutic use
- Abstract
Ethnopharmacological Relevance: Boophone disticha is the most common member of the South African Amaryllidaceae used extensively in traditional medicine of the various indigenous population groups, including the Sotho, Xhosa and Zulu as well as the San. This survey was carried out to identify and highlight areas relevant to the traditional usage of Boophone disticha. Pharmacological aspects were examined with the purpose of reconciling these with the traditional usage of the plant. In relation to phytochemical make-up, particular attention was paid on how its alkaloid constitution might corroborate the various biological effects manifested by the plant., Materials and Methods: Information gathering involved the use of four different database platforms, including Google Scholar, ScienceDirect, SciFinder(®) and Scopus. Arrangement and detailing of this information is as reflected in the various sections of the paper., Results: Sixteen categories were identified under which Boophone disticha finds use in traditional medicine. These were shown to include general usage purposes, such as 'cultural and dietary', 'well-being', 'personal injury', 'divinatory purposes', 'psychoactive properties' and 'veterinary uses'. Furthermore, traditional usage was seen to involve six body systems, including functions pertaining to the circulatory, gastrointestinal, muscular, neurological, respiratory and urinary systems. The four remaining categories relate to use for inflammatory conditions, cancer, malaria and tuberculosis. Overall, three areas were discernible in which Boophone disticha finds most usage, which are (i) ailments pertaining to the CNS, (ii) wounds and infections, and (iii) inflammatory conditions. In addition, several aspects pertaining to the toxic properties of the plant are discussed, including genotoxicity, mutagenicity and neurotoxicity., Conclusion: The widespread ethnic usage of Boophone disticha has justified its standing as a flagship for the Amaryllidaceae and its relevance to South African traditional medicine. Furthermore, its promising pharmacological and phytochemical profiles have stimulated significant interest in the clinical realm, especially in the areas of cancer and motor neuron disease chemotherapy. These collective properties should prove useful in steering the progress of the plant towards a wider audience., (© 2013 Published by Elsevier Ireland Ltd.)
- Published
- 2014
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27. Pharmacological and toxicological insights to the South African Amaryllidaceae.
- Author
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Nair JJ and van Staden J
- Subjects
- Alkaloids chemistry, Alkaloids toxicity, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids pharmacology, Anti-Bacterial Agents pharmacology, Anti-Inflammatory Agents chemistry, Anti-Inflammatory Agents pharmacology, Antifungal Agents chemistry, Antifungal Agents pharmacology, Antiparasitic Agents chemistry, Antiparasitic Agents pharmacology, Ethnopharmacology methods, Hallucinogens chemistry, Hallucinogens pharmacology, Humans, Isoquinolines chemistry, Isoquinolines pharmacology, Mental Disorders drug therapy, Neoplasms drug therapy, Phenanthrenes chemistry, Phenanthrenes pharmacology, Plants, Toxic, South Africa, Liliaceae chemistry, Medicine, African Traditional methods, Plants, Medicinal
- Abstract
The plant family Amaryllidaceae is of provenance in the South African region which is known to harbor about a third of the global complement of around 1000 species. It has widespread usage in the traditional medicinal practices of the indigenous peoples of the region. As a consequence and given its unique alkaloid principles, its members have provided a viable platform for phytochemical based drug discovery. The medicinal potential of the family has been realized through the commercialization of galanthamine as an Alzheimer's drug due to its potent and selective inhibitory activity against the enzyme acetylcholinesterase. Further promising chemotherapeutic candidates of the family reside with the phenanthridone class of alkaloids such as pancratistatin which exhibit potent and cell line specific antiproliferative properties with significant potential for clinical development. Despite these interesting medicinal attributes, plants of the Amaryllidaceae are known to be poisonous and several of them have been classified as such. This survey taking into consideration Amaryllidaceae plants native to South Africa aims to strike a balance between the medicinal potential of the family on one hand and its adverse and toxic effects on the other., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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28. Alkaloids from Boophone haemanthoides (Amaryllidaceae).
- Author
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Nair JJ, Rárová L, Strnad M, Bastidad J, and van Staden J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Antineoplastic Agents, Phytogenic chemistry, Drug Screening Assays, Antitumor, HeLa Cells, Humans, MCF-7 Cells, Molecular Structure, Phenanthridines isolation & purification, Amaryllidaceae Alkaloids isolation & purification, Antineoplastic Agents, Phytogenic isolation & purification, Liliaceae chemistry
- Abstract
In this study, the South African Amaryllid Boophone haemanthoides was examined for its phytochemical composition and cytotoxicity. In the process eight alkaloid structures, including the new compound distichaminol, were identified in bulb ethanolic extracts. Of the isolates, lycorine and distichamine exhibited strong activities against human acute lymphoblastic leukemia (CEM), breast adenocarcinoma (MCF7) and cervical adenocarcinoma (HeLa) cells with IC50S ranging from 1.8 to 9.2 microM.
- Published
- 2013
29. Investigation of aryl halides as ketone bioisosteres: refinement of potent and selective inhibitors of human cytochrome P450 19A1 (aromatase).
- Author
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McNulty J, Nielsen AJ, Brown CE, DiFrancesco BR, Vurgun N, Nair JJ, Crankshaw DJ, and Holloway AC
- Subjects
- Benzene Derivatives pharmacology, Breast Neoplasms enzymology, Female, Humans, Hydrocarbons, Halogenated pharmacology, Isomerism, Ketones pharmacology, Models, Molecular, Molecular Conformation, Stereoisomerism, Structure-Activity Relationship, Triazoles chemistry, Triazoles pharmacology, Aromatase metabolism, Aromatase Inhibitors chemistry, Aromatase Inhibitors pharmacology, Benzene Derivatives chemistry, Hydrocarbons, Halogenated chemistry, Ketones chemistry
- Abstract
Bioisosteric replacement of cyclic ketone functionality with aryl halides was investigated on a centrally-flexible, five-component 1,2,3-triazole-containing pharmacophore, resulting in enhanced inhibition of aromatase (CYP450 19A1). Structure-activity data generated from both syn- and anti-aldol precursors provides significant insights into the requirements for enhanced potency, validating this novel ketone-to-aryl halide bioisostere hypothesis., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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30. Alkaloids of the South African Amaryllidaceae: a review.
- Author
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Nair JJ, Bastida J, Codina C, Viladomat F, and van Staden J
- Subjects
- Alzheimer Disease drug therapy, Animals, Antineoplastic Agents, Phytogenic analysis, Drug Discovery, Ethnobotany, Humans, Phytotherapy, Plant Extracts therapeutic use, Plants, Medicinal chemistry, South Africa, Amaryllidaceae Alkaloids chemistry, Liliaceae chemistry
- Abstract
The plant family Amaryllidaceae is known for its horticultural and ornamental appeal as well as its medicinal value. In relation to these characteristics, trade in Amaryllid flower varieties (especially daffodils) is a multi-million dollar revenue generator for the floriculture industry. Of greater significance are the medicinal attributes of the family, which has already spawned the Alzheimer's prescription drug galanthamine, a potent and selective inhibitor of the enzyme acetylcholinesterase, of significance in the progression of neurodegeneration associated with motor neuron diseases, with annual global sales of around $150 million. Furthermore, it is anticipated that an anticancer drug target related to the Amaryllidaceae alkaloid pancratistatin, presently under advanced clinical evaluation, will enter commercial circulation within the next decade. Members of the Amaryllidaceae are distributed through both tropical and subtropical regions of the globe, but are of prominence within three distinct geographical locations, including Andean South America, the Mediterranean basin, and southern Africa. The southern African zone is known to harbor at least a third of the worldwide complement of around 1000 species, many of which are widely utilized in the traditional medicinal practices of the indigenous people of the region. Given its therapeutic and economic value, its natural abundance in the southern African region, coupled to its widespread usage in ethnic medicine, the family Amaryllidaceae provides a diverse and accessible platform for phytochemical based drug discovery. A consolidation of its traditional usage as well as its chemical and pharmacological profiles will thus guide efforts aimed at maximizing this potential. In undertaking this survey of the Amaryllidaceae of southern African, we aimed to achieve these goals.
- Published
- 2013
31. Cytotoxic agents of the crinane series of amaryllidaceae alkaloids.
- Author
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Nair JJ, Bastida J, Viladomat F, and van Staden J
- Subjects
- Animals, Drug Screening Assays, Antitumor, Humans, Structure-Activity Relationship, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic pharmacology, Liliaceae chemistry
- Abstract
In the alkaloid galanthamine, the plant family Amaryllidaceae has endowed the pharmaceutical community with a potent and selective inhibitor of the enzyme acetylcholinestersae (AChE), of prominence in the chemotherapeutic approach towards motor neuron diseases. Following on the commercial success of this prescription drug in the treatment of Alzheimer's disease, it is anticipated that other drug candidates will in future emerge from the family. In this regard, the phenanthridones, exemplified by narciclasine and pancratistatin, of the lycorine series of Amaryllidaceae alkaloids have shown much promise as remarkably potent and selective anticancer agents, with a drug target of the series destined for the clinical market within the next decade. Given these interesting biological properties and their natural abundance, plants of the Amaryllidaceae have provided a diverse and accessible platform for phytochemical-based drug discovery. The crinane series of Amaryllidaceae alkaloids are also enriched with a significant array of biological properties. As a consequence of their close structural similarity to the anticancer agents of the lycorine series, the cytotoxic potential of crinane alkaloids has been realized through structure-activity relationship (SAR) studies involving targets of both semi-synthetic and natural origin, which has identified several members as leads with promising antiproliferative profiles. As the first of its kind, this review seeks to collate such information from the past few decades in advancing the crinane group as a viable platform for anticancer drug discovery.
- Published
- 2012
32. Apoptosis-inducing effects of distichamine and narciprimine, rare alkaloids of the plant family Amaryllidaceae.
- Author
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Nair JJ, Rárová L, Strnad M, Bastida J, and van Staden J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids isolation & purification, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic isolation & purification, Cell Line, Cell Survival drug effects, Dose-Response Relationship, Drug, Drug Screening Assays, Antitumor, HeLa Cells, Humans, MCF-7 Cells, Molecular Conformation, Phenanthrenes chemistry, Phenanthrenes isolation & purification, Stereoisomerism, Structure-Activity Relationship, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Apoptosis drug effects, Liliaceae chemistry, Phenanthrenes pharmacology
- Abstract
Several of the Amaryllidaceae alkaloids are known for their cytotoxic properties, of which the lycorine group representatives are prominent for potent and cell line specific antiproliferative activities. As a distinct niche within the lycorine group, the phenanthridones, exemplified by narciclasine and pancratistatin, have shown much promise as remarkably selective cytotoxic agents and are presently at various stages of development, with a clinical candidate likely to appear on the market within the next decade. The crinane group of the Amaryllidaceae has also spawned several molecules, such as crinamine and haemanthamine, with promising cytotoxic activities. In the present study, the β-crinane distichamine as well as the phenanthridone narciprimine, both rare constituents of the Amaryllidaceae, are revealed as novel antiproliferative agents. Apoptosis-inducing effects are demonstrated for distichamine in human acute lymphoblastic leukemia (CEM) cells. These findings provide further insights to the structural details of the apoptosis-inducing pharmacophores resident within both series of alkaloids., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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33. Alkaloids from Narcissus serotinus.
- Author
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Pigni NB, Ríos-Ruiz S, Martínez-Francés V, Nair JJ, Viladomat F, Codina C, and Bastida J
- Subjects
- Amaryllidaceae Alkaloids pharmacology, Gas Chromatography-Mass Spectrometry, Molecular Structure, Nuclear Magnetic Resonance, Biomolecular, Spain, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids isolation & purification, Narcissus chemistry
- Abstract
Narcissus serotinus belongs to the Amaryllidaceae family, a group well known for an exclusive variety of alkaloids with interesting biological activities. This study was aimed at identifying the alkaloid constituents of N. serotinus collected in the Spanish region of Valencia, using a combination of chromatographic, spectroscopic, and spectrometric methods, including GC-MS and 2D NMR techniques. GC-MS analysis allowed for the direct identification of five known compounds. In addition, the isolation and structure elucidation of six new Amaryllidaceae alkaloids are described.
- Published
- 2012
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34. Acetylcholinesterase inhibition within the lycorine series of Amaryllidaceae alkaloids.
- Author
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Nair JJ and van Staden J
- Subjects
- Animals, Enzyme Activation drug effects, Humans, Molecular Structure, Structure-Activity Relationship, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids pharmacology, Cholinesterase Inhibitors chemistry, Cholinesterase Inhibitors pharmacology, Phenanthridines chemistry, Phenanthridines pharmacology
- Abstract
The plant family Amaryllidaceae occupies a privileged status within the botanical hierarchy due to its horticultural and ornamental appeal, as well as its widespread usage in the traditional medicinal practices of indigenous peoples across the globe. Of greater significance are the unique, structurally-diverse alkaloid constituents produced by members of the family, which has spawned several biologically significant molecules. In this regard, the Alzheimer's drug galanthamine has gained much prominence due to its selective and reversible inhibitory interaction with the enzyme acetylcholinesterase (AChE), of significance in the progression of neurodegeneration associated with Alzheimer's disease (AD). The lycorine series of compounds within the family have recently emerged as novel inhibitors of AChE, in some instances with higher levels of activity compared with the commercial drug galanthamine, making them attractive targets for natural product and synthetically-driven structure-activity relationship studies. This brief survey traces the emergence of lycorine compounds over the past decade as promising leads in the therapeutic approach towards AD and their possible future advancement onto the clinical stage.
- Published
- 2012
35. Antibacterial activity of crinane alkaloids from Boophone disticha (Amaryllidaceae).
- Author
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Cheesman L, Nair JJ, and van Staden J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids isolation & purification, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents isolation & purification, Bacillus subtilis drug effects, Escherichia coli drug effects, Klebsiella drug effects, Medicine, African Traditional, Microbial Sensitivity Tests, Plant Extracts chemistry, Staphylococcus aureus drug effects, Amaryllidaceae Alkaloids pharmacology, Anti-Bacterial Agents pharmacology, Gram-Negative Bacteria drug effects, Gram-Positive Bacteria drug effects, Liliaceae chemistry, Plant Extracts pharmacology
- Abstract
Ethnopharmacological Relevance: Boophone disticha (Amaryllidaceae) is one of the most common bulbous plants used for medicinal purposes by the indigenous people of southern Africa. Its use as a narcotic substance by the Khoi/San tribes has been known for several centuries, while the Sotho, Xhosa and Zulu people are known to use the plant to treat a host of ailments, including inflammation, wounds, gynaecological conditions and psychosis., Aim of the Study: Much of the pharmacological work on the plant, such as affinity to the serotonin transporter, has been based on its reputed usage for narcotic purposes. However, its widespread use to treat wounds and infections has not been linked to a specific chemical entity. In this regard, Boophone disticha was here examined for its phytochemical composition which could shed light on the use of the plant for such purposes., Materials and Methods: The known crinane alkaloids buphanidrine and distichamine were isolated via column chromatography of the ethanolic extract of bulbs of Boophone disticha. Structural details of the compounds were determined by high field 2D NMR and mass spectroscopic techniques. Microbial activity against selected Gram-positive and Gram-negative bacteria was ascertained according to the micro-dilution assay., Results: Both buphanidrine and distichamine were uncovered as novel, broad spectrum moderately active, antibacterial agents with the best MIC value detected at 0.063mg/ml for Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. MIC values for Bacillus subtilis were two-fold less than that observed for the other three bacteria, suggesting that the extract and pure compounds were selective in their interaction with the bacterial pathogens., Conclusion: Phytochemical investigation of Boophone disticha has led to the identification of two known crinanes, buphanidrine and distichamine. Based on the reputed traditional use of the plant for wounds and infections, both compounds were screened for antibacterial activity which revealed them to be novel, broad spectrum antibacterial agents with the best MIC value set at 0.063mg/ml. Their close structural similarity may have bearing on their similar activity profiles., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2012
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36. Discovery of a novel class of aldol-derived 1,2,3-triazoles: potent and selective inhibitors of human cytochrome P450 19A1 (aromatase).
- Author
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McNulty J, Nair JJ, Vurgun N, Difrancesco BR, Brown CE, Tsoi B, Crankshaw DJ, and Holloway AC
- Subjects
- Aldehydes chemistry, Aromatase metabolism, Chemistry, Pharmaceutical methods, Drug Design, Humans, Kinetics, Models, Chemical, Models, Molecular, Molecular Conformation, Phenylacetates chemistry, Recombinant Proteins chemistry, Structure-Activity Relationship, Triazoles chemistry, Antineoplastic Agents pharmacology, Aromatase chemistry, Aromatase Inhibitors pharmacology, Triazoles pharmacology
- Abstract
The discovery of a novel five-component 1,2,3-triazole-containing pharmacophore that exhibits potent and selective inhibition of aromatase (CYP 450 19A1) is described. All compounds are derived from an initial aldol reaction of a phenylacetate derivative with an aromatic aldehyde. Structure-activity data generated from both syn- and anti-aldol adducts provides initial insights into the requirements for both potency and selectivity., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
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37. Isolation of narciprimine from Cyrtanthus contractus (Amaryllidaceae) and evaluation of its acetylcholinesterase inhibitory activity.
- Author
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Nair JJ, Aremu AO, and van Staden J
- Subjects
- Acetylcholinesterase isolation & purification, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids isolation & purification, Animals, Cholinesterase Inhibitors chemistry, Cholinesterase Inhibitors isolation & purification, Chromatography, Eels, Magnetic Resonance Spectroscopy, Mass Spectrometry, Molecular Structure, Phenanthrenes chemistry, Phenanthrenes isolation & purification, Plant Extracts chemistry, Plant Extracts isolation & purification, Plant Roots, Plants, Medicinal, Structure-Activity Relationship, Acetylcholinesterase metabolism, Amaryllidaceae Alkaloids pharmacology, Cholinesterase Inhibitors pharmacology, Liliaceae chemistry, Phenanthrenes pharmacology, Plant Extracts pharmacology
- Abstract
Ethnopharmacological Relevance: Plants of the family Amaryllidaceae are used widely in traditional medicine in South Africa. Several of these, including representatives of the genus Cyrtanthus find use in the treatment of mental illness and age-related dementia., Aim of the Study: Based on the distribution of central nervous system-activating alkaloidal constituents within the genus Cyrtanthus, Cyrtanthus contractus was here explored for such compounds which could interact with acetylcholinesterase (AChE), of significance in the progression of neurodegeneration associated with Alzheimer's disease., Materials and Methods: The known phenanthridone alkaloid narciprimine was isolated via column chromatography of the ethanolic extract of bulbs of Cyrtanthus contractus. The structure of the compound was determined by high field 2D NMR and mass spectroscopic techniques. The classical method of Ellman et al. was used in the determination of AChE inhibitory activity., Results: The isolation of narciprimine from Cyrtanthus contractus is a landmark find since it has previously only been identified in Zephyranthes, Narcissus and Lycoris, genera endemic to the Americas, Europe and Asia, respectively. Narciprimine exhibited micromolar inhibitory activity (IC(50) 78.9) against the enzyme acetylcholinesterase., Conclusion: This work represents the first isolation of narciprimine from an African Amaryllidaceae species, which may be of chemotaxonomic significance. The AChE inhibitory activity of narciprimine, taken together with activities of other structurally similar inhibitors within the series affords further insight to the structural details of the lycorine alkaloid acetylcholinesterase inhibitory pharmacophore., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2011
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38. Human cytochrome P450 liability studies of trans-dihydronarciclasine: a readily available, potent, and selective cancer cell growth inhibitor.
- Author
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McNulty J, Thorat A, Vurgun N, Nair JJ, Makaji E, Crankshaw DJ, Holloway AC, and Pandey S
- Subjects
- Alkaloids chemistry, Amaryllidaceae Alkaloids chemistry, Antineoplastic Agents, Phytogenic chemistry, Crystallography, X-Ray, Cytochrome P-450 CYP3A, Drug Screening Assays, Antitumor, Humans, Molecular Structure, Phenanthridines chemistry, Stereoisomerism, Alkaloids isolation & purification, Alkaloids pharmacology, Amaryllidaceae Alkaloids isolation & purification, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents, Phytogenic isolation & purification, Antineoplastic Agents, Phytogenic pharmacology, Cytochrome P-450 CYP1A1 antagonists & inhibitors, Cytochrome P-450 CYP3A Inhibitors, Narcissus chemistry, Phenanthridines isolation & purification, Phenanthridines pharmacology
- Abstract
The cytochrome P45O activities of the naturally occurring Amaryllidaceae alkaloid narciclasine (3), isolated from Narcissus pseudonarcissus, and synthetic derivative trans-dihydronarciclasine (5) are reported. While narciclasine was found to possess potent inhibitory activity to human CYP3A4, its dihydro analogue was inactive. This study revealed that the C1-C10b double bond is required for inhibition of this crucial metabolizing enzyme. Compound 5 also demonstrated no inhibition of the related human cytochromes CYP19 and CYP1A1. This study elevates the status of trans-dihydronarciclasine (5) as a highly privileged, readily available molecule, with potent and selective anticancer activity.
- Published
- 2011
- Full Text
- View/download PDF
39. A sol-gel-derived acetylcholinesterase microarray for nanovolume small-molecule screening.
- Author
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Monton MR, Lebert JM, Little JR, Nair JJ, McNulty J, and Brennan JD
- Subjects
- Animals, Electrophorus, Enzymes, Immobilized chemistry, Enzymes, Immobilized metabolism, Fluorometry, Kinetics, Silicon Dioxide chemistry, Solutions, Acetylcholinesterase metabolism, Cholinesterase Inhibitors pharmacology, Drug Evaluation, Preclinical methods, Nanotechnology methods, Protein Array Analysis methods
- Abstract
A fluorimetric acetylcholinesterase (AChE) assay was developed and characterized both in solution and with the enzyme entrapped in sol-gel-derived silica. The assay is based on a disulfide-thiol interchange reaction between the intramolecularly quenched dimeric dye BODIPY FL l-cystine and thiocholine generated by the AChE-catalyzed hydrolysis of acetylthiocholine (ATCh), which results in a brightly fluorescent monomeric product owing to the cleavage of the disulfide-coupled form of the dye. The new assay was validated by comparison with the Ellman assay performed under parallel conditions and was used in both kinetic and end point assays. The assay was extended to the fabrication of functional AChE microarrays using contact pin-printing of sol-gel-derived silica. A total of 392 sol-gel formulations were screened for gelation times and 192 of these were further evaluated for array fabrication on four different surfaces using a factor analysis approach. Of these, 66 sol-gel/surface combinations produced robust microarrays, while 26 sol-gel/surface combinations were identified that could produce highly active AChE microarrays. The Z' factor for the on-array assay using an optimal sol-gel/surface combination, which considers both signal variability and difference in signals between positive and negative controls, was determined to be 0.60, which is above the minimum level required for applicability to screening. By overprinting nanoliter volumes of solutions containing the dye, ATCh, and potential inhibitors, these microarrays could be used to screen two libraries of small molecules, one composed of newly synthesized alkaloids and another consisting of ∼1000 known bioactive compounds, both as discrete compounds and mixtures thereof, for activity against AChE. IC(50) values were obtained on microarrays for compounds showing significant inhibitory activity, demonstrating the utility of arrays for quantitative inhibition assays.
- Published
- 2010
- Full Text
- View/download PDF
40. Structure-activity studies on acetylcholinesterase inhibition in the lycorine series of Amaryllidaceae alkaloids.
- Author
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McNulty J, Nair JJ, Little JR, Brennan JD, and Bastida J
- Subjects
- Structure-Activity Relationship, Alkaloids chemistry, Alkaloids pharmacology, Cholinesterase Inhibitors chemistry, Cholinesterase Inhibitors pharmacology
- Abstract
The synthesis of differentially functionalized analogs of the Amaryllidaceae alkaloid lycorine, accessed via a concise chemoselective silylation strategy, is described uncovering two of the most potent inhibitors of acetylcholinesterase (AChE) identified to date in this series. Important elements of this novel pharmacophore were elucidated through structure-activity relationship (SAR) studies., (Copyright 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
41. Cytochrome P450 3A4 inhibitory activity studies within the lycorine series of alkaloids.
- Author
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McNulty J, Nair JJ, Singh M, Crankshaw DJ, Holloway AC, and Bastida J
- Subjects
- Cytochrome P-450 CYP3A, Structure-Activity Relationship, Amaryllidaceae Alkaloids pharmacology, Cytochrome P-450 CYP3A Inhibitors, Enzyme Inhibitors pharmacology, Phenanthridines pharmacology
- Abstract
A mini-panel of semi-synthetic analogs of the Amaryllidaceae alkaloid lycorine was screened for cytochrome P450 3A4 (CYP3A4) inhibitory activity, the most potent of which exhibited inhibition as low as 0.21 microM. Elements of this novel pharmacophore unravelled include bulky lipophilic substitution at C2 in conjunction with a small hydrogen bond donor/acceptor at C1, or bulky electron-rich substitution at C1 in conjunction with a vicinal hydrogen bond donor/acceptor.
- Published
- 2010
42. Potent and selective inhibition of human cytochrome P450 3A4 by seco-pancratistatin structural analogs.
- Author
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McNulty J, Nair JJ, Singh M, Crankshaw DJ, and Holloway AC
- Subjects
- Humans, Liliaceae chemistry, Models, Molecular, Structure-Activity Relationship, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids pharmacology, Cytochrome P-450 CYP3A pharmacology, Cytochrome P-450 CYP3A Inhibitors, Isoquinolines chemistry, Isoquinolines pharmacology
- Abstract
seco-Derivatives of the anticancer agent pancratistatin bearing the 2S,3S,4S,5S configuration were accessed via a novel, highly diastereoselective anti-aldol reaction. Structure-activity relationships reveal important insights into the seco-pancratistatin pharmacophore as a potent and selective inhibitor of human cytochrome P450 3A4 (CYP3A4), and highlight features of concern in advancing a potent, selective anticancer agent in the pancratistatin series., (2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
43. Isolation of flavonoids from the heartwood and resin of Prunus avium and some preliminary biological investigations.
- Author
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McNulty J, Nair JJ, Bollareddy E, Keskar K, Thorat A, Crankshaw DJ, Holloway AC, Khan G, Wright GD, and Ejim L
- Subjects
- Antifungal Agents isolation & purification, Flavanones isolation & purification, Flavones isolation & purification, Fungi pathogenicity, Sesquiterpenes, Terpenes isolation & purification, Phytoalexins, Antifungal Agents pharmacology, Cytochrome P-450 Enzyme Inhibitors, Flavanones pharmacology, Flavones pharmacology, Fungi drug effects, Prunus chemistry, Resins, Plant chemistry, Terpenes pharmacology, Wood chemistry
- Abstract
An investigation of the constituents in heartwood and resin of Prunus avium is reported. A mini-library of structurally diverse flavanones and flavones was screened for human cytochrome P450 1A1, 3A4 and 19 (aromatase) inhibition, and for antifungal activity against a panel of pathogenic fungi. The defensive role of these natural plant flavonoids as antifungal phytoalexins and phytoanticipins is discussed.
- Published
- 2009
- Full Text
- View/download PDF
44. Structure-activity studies on seco-pancratistatin analogs: potent inhibitors of human cytochrome P450 3A4.
- Author
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McNulty J, Nair JJ, Singh M, Crankshaw DJ, and Holloway AC
- Subjects
- Amaryllidaceae Alkaloids chemical synthesis, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents chemical synthesis, Antineoplastic Agents pharmacology, Cytochrome P-450 CYP3A metabolism, Humans, Isoquinolines chemical synthesis, Isoquinolines pharmacology, Structure-Activity Relationship, Amaryllidaceae Alkaloids chemistry, Antineoplastic Agents chemistry, Cytochrome P-450 CYP3A Inhibitors, Isoquinolines chemistry
- Abstract
Two total syntheses of fully functionalized seco-analogs of the anticancer compound pancratistatin are reported. Structure-activity relationship (SAR) studies identified potent and selective inhibitors of human cytochrome P450 3A4 (CYP3A4) and revealed several core pharmacophoric elements. These studies identify potential roadblocks and will guide the further development of a viable selective clinical pancratistatin derivative.
- Published
- 2009
- Full Text
- View/download PDF
45. Selective cytochrome P450 3A4 inhibitory activity of Amaryllidaceae alkaloids.
- Author
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McNulty J, Nair JJ, Singh M, Crankshaw DJ, Holloway AC, and Bastida J
- Subjects
- Amaryllidaceae Alkaloids chemistry, Cytochrome P-450 CYP3A, Drug Evaluation, Preclinical, Enzyme Inhibitors, Galantamine pharmacology, Humans, Isoquinolines pharmacology, Phenanthridines chemistry, Small Molecule Libraries pharmacology, Amaryllidaceae Alkaloids pharmacology, Cytochrome P-450 CYP3A Inhibitors, Phenanthridines pharmacology
- Abstract
A library of natural and semi-synthetic Amaryllidaceae alkaloids was screened for cytochrome P450 3A4 (CYP3A4) inhibitory activity. Of the crinane, lycorane and galanthamine representatives examined two semi-synthetic silylated lycorane analogues, accessed via a chemoselective silylation strategy from lycorine, and the natural compound narciclasine exhibited low micromolar activities. Important pharmacological features uncovered include the lack of CYP3A4 inhibitory activity seen for galanthamine and the selective activity that is seen with narciclasine over pancratistatin.
- Published
- 2009
- Full Text
- View/download PDF
46. Structure-activity studies on the lycorine pharmacophore: A potent inducer of apoptosis in human leukemia cells.
- Author
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McNulty J, Nair JJ, Bastida J, Pandey S, and Griffin C
- Subjects
- Amaryllidaceae Alkaloids chemistry, Antineoplastic Agents, Phytogenic pharmacology, Drug Screening Assays, Antitumor, Humans, Jurkat Cells, Molecular Structure, Phenanthridines chemistry, Structure-Activity Relationship, Amaryllidaceae Alkaloids chemical synthesis, Amaryllidaceae Alkaloids pharmacology, Apoptosis drug effects, Phenanthridines pharmacology
- Abstract
The direct chemoselective differential functionalization of the ring-C hydroxyl groups present in the Amaryllidaceae alkaloid lycorine is described allowing for selective manipulation of the 1,2-hydroxyl groups. A mini-library comprised of synthetic and natural lycorane alkaloids was prepared and their apoptosis-inducing activity investigated in human leukemia (Jurkat) cells. Further insights into the nature of this interesting apoptosis-inducing pharmacophore are described, including the requirement of both free hydroxyl groups in ring-C.
- Published
- 2009
- Full Text
- View/download PDF
47. Structure activity studies on the crinane alkaloid apoptosis-inducing pharmacophore.
- Author
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McNulty J, Nair JJ, Bastida J, Pandey S, and Griffin C
- Subjects
- Amaryllidaceae Alkaloids chemistry, Caspase 3 metabolism, Dose-Response Relationship, Drug, Enzyme Activation drug effects, Humans, Hydrogenation, Jurkat Cells, Phenanthridines chemistry, Phenanthridines pharmacology, Plant Extracts chemistry, Structure-Activity Relationship, Amaryllidaceae Alkaloids pharmacology, Apoptosis drug effects
- Abstract
The apoptosis-inducing ability of alpha-ethano bridged crinane alkaloids was investigated using natural and semi-synthetic derivatives uncovering novel structural requirements of this cytotoxic pharmacophore. An alpha-ethano bridge is required; an alpha- or beta-methoxy or hydroxyl H-bond acceptor are all tolerated at C-3; a small substituent (H, or OH) alone is tolerated at C-11; and a C-1 to C-2 double bond is shown to modulate, but is not a requirement for, apoptosis-inducing activity.
- Published
- 2009
48. synthesis and biological evaluation of fully functionalized seco-pancratistatin analogues.
- Author
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McNulty J, Nair JJ, Griffin C, and Pandey S
- Subjects
- Apoptosis drug effects, Drug Screening Assays, Antitumor, Humans, Molecular Conformation, Molecular Structure, Stereoisomerism, Amaryllidaceae Alkaloids chemical synthesis, Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids pharmacology, Antineoplastic Agents chemical synthesis, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, Isoquinolines chemical synthesis, Isoquinolines chemistry, Isoquinolines pharmacology
- Abstract
The total synthesis of fully functionalized polyhydroxyamide B,C- seco-analogues of the anticancer compound pancratistatin (PST) ( 1) is reported. Key steps include an Evans' MgCl 2-promoted anti-aldol reaction between a functionalized l-threose derivative and ( R)-(+)-oxazolidinone to stereoselectively form the C-1/C-10b bond and a regiospecific radical-mediated oxidative fragmentation of a 1,3-benzylidene. The B,C- seco compounds 25 and 26 exhibited low activity (ED 50 > 30 microg/mL) for inducing apoptosis in human cancer cells.
- Published
- 2008
- Full Text
- View/download PDF
49. Efficient carbonylation reactions in phosphonium salt ionic liquids: anionic effects.
- Author
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McNulty J, Nair JJ, and Robertson A
- Abstract
Application of phosphonium salt ionic liquids in the carbonylation of aryl and vinyl halides is presented. Anionic effects were uncovered with the bromide ionic liquid emerging as the superior media. Acid bromide intermediates were detected in control experiments providing an extended view on the overall catalytic cycle involved. Solvent-free product isolation and recycling of the ionic liquid containing active Pd-catalyst are also demonstrated.
- Published
- 2007
- Full Text
- View/download PDF
50. Selective apoptosis-inducing activity of crinum-type Amaryllidaceae alkaloids.
- Author
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McNulty J, Nair JJ, Codina C, Bastida J, Pandey S, Gerasimoff J, and Griffin C
- Subjects
- Amaryllidaceae Alkaloids chemistry, Amaryllidaceae Alkaloids isolation & purification, Animals, Antineoplastic Agents, Phytogenic chemical synthesis, Antineoplastic Agents, Phytogenic chemistry, Antineoplastic Agents, Phytogenic isolation & purification, Antineoplastic Agents, Phytogenic pharmacology, Cell Line, Cell Line, Tumor, Dose-Response Relationship, Drug, Humans, Molecular Structure, Amaryllidaceae Alkaloids pharmacology, Apoptosis drug effects, Crinum, Liliaceae chemistry
- Abstract
The selective apoptosis-inducing activity of Amaryllidaceae alkaloids belonging to the crinane-type is reported. A mini-library of natural and synthetic crinane alkaloids was assembled. Biological screening indicated crinamine 4 and haemanthamine 9 to be potent inducers of apoptosis in tumour cells at micromolar concentrations. Structure-activity relationships demonstrated the requirement for both an alpha-C2 bridge and a free hydroxyl at the C-11 position as pharmacophoric requirements for this activity.
- Published
- 2007
- Full Text
- View/download PDF
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