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Defects in cell death signaling pathways are one of the hallmarks of cancer and can lead to resistance to conventional therapy. Natural products are promising compounds that can overcome this resistance. In the present study we studied the effect of six quaternary benzophenanthridine alkaloids (QBAs), sanguinarine, chelerythrine, sanguirubine, chelirubine, sanguilutine, and chelilutine, on Jurkat leukemia cells, WT, and cell death deficient lines derived from them, CASP3/7/6-/- and FADD-/-, and on solid tumor, human malignant melanoma, A375 cells. We demonstrated the ability of QBAs to overcome the resistance of these deficient cells and identified a novel mechanism for their action. Sanguinarine and sanguirubine completely and chelerythrine, sanguilutine, and chelilutine partially overcame the resistance of CASP3/7/6-/- and FADD-/- cells. By detection of cPARP, a marker of apoptosis, and pMLKL, a marker of necroptosis, we proved the ability of QBAs to induce both these cell deaths (bimodal cell death) with apoptosis preceding necroptosis. We identified the new mechanism of the cell death induction by QBAs, the downregulation of the apoptosis inhibitors cIAP1 and cIAP2, i.e., an effect similar to that of Smac mimetics. [ABSTRACT FROM AUTHOR]

A new dimeric prenylated quinolone alkaloid, named 2,11-didemethoxy-vepridimerine A, was isolated from the root bark of Zanthoxylum rhetsa, together with twelve known compounds. The structure of the new compound was elucidated on the basis of spectroscopic investigations (NMR and Mass). The interaction of the isolated compounds with the main protease of SARS-CoV-2 (Mpro) was evaluated using molecular docking followed by MD simulations. The result suggests that 2,11-didemethoxy-vepridimerine A, the new compound, has the highest negative binding affinity against the Mpro with a free energy of binding of −8.5 Kcal/mol, indicating interaction with the Mpro. This interaction was further validated by 100 ns MD simulation. This implies that the isolated new compound, which can be employed as a lead compound for an Mpro-targeting drug discovery program, may be able to block the action of Mpro. [ABSTRACT FROM AUTHOR]

Defects in cell death signaling pathways are one of the hallmarks of cancer and can lead to resistance to conventional therapy. Natural products are promising compounds that can overcome this resistance. In the present study we studied the effect of six quaternary benzophenanthridine alkaloids (QBAs), sanguinarine, chelerythrine, sanguirubine, chelirubine, sanguilutine, and chelilutine, on Jurkat leukemia cells, WT, and cell death deficient lines derived from them, CASP3/7/6-/- and FADD-/-, and on solid tumor, human malignant melanoma, A375 cells. We demonstrated the ability of QBAs to overcome the resistance of these deficient cells and identified a novel mechanism for their action. Sanguinarine and sanguirubine completely and chelerythrine, sanguilutine, and chelilutine partially overcame the resistance of CASP3/7/6-/- and FADD-/- cells. By detection of cPARP, a marker of apoptosis, and pMLKL, a marker of necroptosis, we proved the ability of QBAs to induce both these cell deaths (bimodal cell death) with apoptosis preceding necroptosis. We identified the new mechanism of the cell death induction by QBAs, the downregulation of the apoptosis inhibitors cIAP1 and cIAP2, i.e., an effect similar to that of Smac mimetics.

Strong antileishmanial and antitrypanosomal activities were highlighted for the crude methanolic extract (IC 50 = 0.61 and 2.15 μg/mL, respectively) of Zanthoxylum zanthoxyloides (Lam.) B.Zepernick & Timler root bark, as well as for its apolar partitions (cyclohexane: IC 50 = 0.66 and 5.17 μg/mL, respectively and dichloromethane: IC 50 = 0.07 and 0.22 μg/mL, respectively), with a good selectivity index (SI) towards WI-38 cells. In addition, cyclohexane and dichloromethane extracts exhibited a dose-dependent inhibition of human coronavirus HCoV-229E infection in hepatoma Huh-7 cells expressing or not the cellular protease TMPRSS2 (IC 50 values of 5.29 μg/mL and 4.87 μg/mL, respectively). Fractionation of these active extracts led to the isolation of a new racemic benzophenanthridine alkaloid named zanthoxyloithrine (1), together with 13 known compounds. Their structures were elucidated by spectroscopic techniques including IR, UV, HR-MS, 1D and 2D NMR and electronic circular dichroism. In parallel, HR-ESI-MS/MS based dereplication and molecular networking analysis were performed to identify unpurified compounds in cyclohexane and dichloromethane extracts. Zanthoxyloithrine (1) showed strong antileishmanial (IC 50 = 0.14 μM, SI = 52.0) and antitrypanosomal (IC 50 = 0.36 μM, SI = 20.8) activities. In addition, compound (1) demonstrated a high antiviral activity against HCoV-229E with IC 50 value of 6.70 μM in presence of TMPRRS2 and without significant toxicity on Huh-7 cells. Other purified benzo[ c ]phenanthridine alkaloids also showed anti-coronavirus and antiparasitic activities. [Display omitted] • Zanthoxylum zanthoxyloides demonstrated antiparasitic and anti-coronavirus activities. • An original benzophenanthridine alkaloid was isolated along with 13 known compounds. • Zanthoxyloithrine, the novel alkaloid, showed promising antimicrobial activities. • Dereplication and molecular network analyses were performed on the apolar extracts. • Alkaloids and polyunsaturated amides were putatively identified by this dereplication. [ABSTRACT FROM AUTHOR]

The nuclear receptors hepatocyte nuclear factor 4α (HNF4α) and retinoic acid receptor-related orphan receptor-β (RORβ) are ligand-regulated transcription factors and potential drug targets for metabolic disorders. However, there is a lack of small molecular, selective ligands to explore the therapeutic potential in further detail. Here, we report the discovery of greater celandine (Chelidonium majus) isoquinoline alkaloids as nuclear receptor modulators: Berberine is a selective RORβ inverse agonist and modulated target genes involved in the circadian clock, photoreceptor cell development, and neuronal function. The structurally related chelidonine was identified as a ligand for the constitutively active HNF4α receptor, with nanomolar potency in a cellular reporter gene assay. In human liver cancer cells naturally expressing high levels of HNF4α, chelidonine acted as an inverse agonist and downregulated genes associated with gluconeogenesis and drug metabolism. Both berberine and chelidonine are promising tool compounds to further investigate their target nuclear receptors and for drug discovery., (© 2024 The Authors. Archiv der Pharmazie published by Wiley‐VCH GmbH on behalf of Deutsche Pharmazeutische Gesellschaft.)

In the present study, one new benzophenanthridine alkaloid derivative, 2′ -methoxy-3′ -methyltetrahydrofuran-(5′→6)-dihydrochelerythrine (1) was separated from Eomecon chionantha Hance. The chemical structure of 1 was identified based on extensive spectroscopic data including UV, HR-ESI-MS, 1D and 2D NMR. [ABSTRACT FROM AUTHOR]

Reactive oxygen species play crucial role in biological homeostasis and pathogenesis of human diseases including cancer. In this line, now it has become evident that ROS level/concentration is a major factor in the growth, progression and stemness of cancer cells. Moreover, cancer cells maintain a delicate balance between ROS and antioxidants to promote pathogenesis and clinical challenges via targeting a battery of signaling pathways converging to cancer hallmarks. Recent findings also entail the therapeutic importance of ROS for the better clinical outcomes in cancer patients as they induce apoptosis and autophagy. Moreover, poor clinical outcomes associated with cancer therapies are the major challenge and use of natural products have been vital in attenuation of these challenges due to their multitargeting potential with less adverse effects. In fact, most available drugs are derived from natural resources, either directly or indirectly and available evidence show the clinical importance of natural products in the management of various diseases, including cancer. ROS play a critical role in the anticancer actions of natural products, particularly phytochemicals. Benzophenanthridine alkaloids of the benzyl isoquinoline family of alkaloids, such as sanguinarine, possess several pharmacological properties and are thus being studied for the treatment of different human diseases, including cancer. In this article, we review recent findings, on how benzophenanthridine alkaloid-induced ROS play a critical role in the attenuation of pathological changes and stemness features associated with human cancers. In addition, we highlight the role of ROS in benzophenanthridine alkaloid-mediated activation of the signaling pathway associated with cancer cell apoptosis and autophagy.

A new dimeric prenylated quinolone alkaloid, named 2,11-didemethoxy-vepridimerine A, was isolated from the root bark of Zanthoxylum rhetsa, together with twelve known compounds. The structure of the new compound was elucidated on the basis of spectroscopic investigations (NMR and Mass). The interaction of the isolated compounds with the main protease of SARS-CoV-2 (Mpro) was evaluated using molecular docking followed by MD simulations. The result suggests that 2,11-didemethoxy-vepridimerine A, the new compound, has the highest negative binding affinity against the Mpro with a free energy of binding of −8.5 Kcal/mol, indicating interaction with the Mpro. This interaction was further validated by 100 ns MD simulation. This implies that the isolated new compound, which can be employed as a lead compound for an Mpro-targeting drug discovery program, may be able to block the action of Mpro.

Abstract Background Cell migration is involved in several pathological processes such as tumor invasion, neoangiogenesis and metastasis. Microtubules are needed in directional migration. Methods To investigate the effects of microtubule-binding agents (paclitaxel, vinblastine, colchicine, podophyllotoxin), benzophenanthridine alkaloids (sanguinarine, chelerythrine, chelidonine) and other anti-tumor drugs (homoharringtonine, doxorubicin) on cell migration, we performed the in vitro wound healing assay. The interactions between selected alkaloids and microtubules were studied via U2OS cells expressing microtubule-GFP markers. Results The microtubule-binding natural products paclitaxel, vinblastine, colchicine and podophyllotoxin significantly altered microtubule dynamics in living cells and inhibited cell migration at concentrations below apparent cytotoxicity. The benzophenanthridine alkaloid sanguinarine, chelerythrine and chelidonine which affected microtubules in living cells, did not inhibit cell migration. Homoharringtonine (protein biosynthesis inhibitor) and doxorubicin significantly inhibited cell migration, however, they did not exert obvious effects on microtubules. Conclusion In this study, we demonstrated that microtubule-binding agents are effective anti-migrating agents; moreover, homoharringtonine and doxorubicin can be referred as anti-migrating agents, but direct microtubule dynamics are not involved in their mode of action. Our study provides evidence that some alkaloids and other microtubule-binding natural products may be interesting candidates for the development of novel agents against metastasis.

An increasing amount of evidence suggests that transmembrane member 16A (TMEM16A)-encoded Ca2+-activated Cl− channels play a crucial role in regulating tumorigenesis. Therefore, specific and potent TMEM16A inhibitors have been proposed to potentially be useful for the treatment of cancer. During drug screening, we found that benzophenanthridine alkaloids (sanguinarine, sanguinarium chloride, sanguinarine nitrate, ethoxysanguinarine, chelerythrine, and dihydrosanguinarine) potently inhibited the recombinant TMEM16A current. The IC50 and Emax values for TMEM16A inhibition of six tested benzophenanthridine alkaloids were 5.6–12.3 μM and 77–91%, respectively. These benzophenanthridine alkaloids also significantly inhibited the endogenous TMEM16A currents and proliferation, migration, and induced apoptosis in LA795 lung adenocarcinoma cells. These data demonstrate that benzophenanthridine alkaloids are novel TMEM16A inhibitors and are potentially useful in specific cancer therapies. These findings also provide new insight for the development of TMEM16A inhibitors. [ABSTRACT FROM AUTHOR]

Background: Extensive bioactivities of alkaloids from the genus Macleaya (Macleaya cordata (Willd.) R. Br. and Macleaya microcarpa (Maxim.) Fedde) have been widely reported, as well as more and more concerned from the scientific communities. However, systematic research on the phytochemical information of M. microcarpa is incomplete. The aim of this study was to rapidly and conveniently qualitative analyze alkaloids from M. microcarpa by ultra-performance liquid chromatography/quadrupole-time-of-fight mass spectrometry (UHPLC–Q-TOF-MS) using accurate mass weight and characteristic fragment ions, furthermore separate and identify the main alkaloids, test antitumor activity in vitro and antiangiogenic activity in vivo. Results: A total of 14 alkaloids from fruits of M. microcarpa were identified by UHPLC–Q-TOF-MS, including 5 protopines, 2 benzophenanthridines, 1 dimer, 1 dihydrobenzophenanthridines and 5 unknown structure compounds. Two major alkaloids were isolated by various column chromatographic methods. Their structures were determined by NMR data and related literatures. The two major alkaloids were evaluated for intro cytotoxic activities against HL-60, MCF-7, A-549, and in vivo antiangiogenic activity using transgenic zebrafish. Conclusions: Current qualitative method based on UHPLC–Q-TOF-MS technique provided a scientific basis for isolation, structural identification, and in vitro or in vivo pharmacological further study of alkaloids from M. microcarpa in the future. [ABSTRACT FROM AUTHOR]

Bloodroot (Sanguinaria canadensis) is a plant that historically has been used in medicine for its antimicrobial, antihypertensive, anti-inflammatory, and antineoplastic properties. In dermatology, bloodroot has been utilized for its cytotoxic effects; it has been marketed as black salve as an anticancer treatment, but it does not come without notable toxicities. Unwanted cosmetic outcomes and even irreversible scarring and premalignant conditions have been reported. This article aims to bring awareness to both the therapeutic potential of S canadensis as well as the potential toxicities and risks associated with this North American plant. [ABSTRACT FROM AUTHOR]

Efforts to develop the necessary biotechnologies in Greater Celandine (Chelidonium majus L.), a leading plant resource for the development of plant-derived medicines, have been hampered by the lack of knowledge about transcriptome and metabolome regulations of its medicinal components. Therefore, this study aimed to examine the effect of abiotic elicitors, methyl jasmonate (MJ) and salicylic acid (SA), at different time courses (12, 24, 48, and 72 h), on expression and metabolome of key benzophenanthridine alkaloids (BPAs) in an optimized in vitro culture. Gene expression analysis indicated the upregulation of CFS (cheilanthifoline synthase) to 2.62, 4.85, and 7.28 times higher than the control at 12, 24, and 48 h respectively, under MJ elicitation. Besides, MJ upregulated the expression of TNMT (tetrahydroprotoberberine N-methyltransferase) to 2.79, 4.75, and 7.21 times at 12, 24, and 48 h respectively, compared to the control. Investigation of BPAs revealed a significant enhancement in the chelidonine content (9.86 µg/mg) after 72 h of MJ elicitation. Additionally, sanguinarine content increased to its highest level (3.42 µg/mg) after 24 h of MJ elicitation; however, no significant enhancement was detected in its content in shorter elicitation time courses. Generally, higher gene expression and BPAs’ level was observed through longer elicitation courses (48 and 72 h). Our findings take part in improving the understanding of transcription and metabolic regulation of BPAs in cultured Greater Celandine cells.

Background: Cell migration is involved in several pathological processes such as tumor invasion, neoangiogenesis and metastasis. Microtubules are needed in directional migration. Methods: To investigate the effects of microtubule-binding agents (paclitaxel, vinblastine, colchicine, podophyllotoxin), benzophenanthridine alkaloids (sanguinarine, chelerythrine, chelidonine) and other anti-tumor drugs (homoharringtonine, doxorubicin) on cell migration, we performed the in vitro wound healing assay. The interactions between selected alkaloids and microtubules were studied via U2OS cells expressing microtubule-GFP markers. Results: The microtubule-binding natural products paclitaxel, vinblastine, colchicine and podophyllotoxin significantly altered microtubule dynamics in living cells and inhibited cell migration at concentrations below apparent cytotoxicity. The benzophenanthridine alkaloid sanguinarine, chelerythrine and chelidonine which affected microtubules in living cells, did not inhibit cell migration. Homoharringtonine (protein biosynthesis inhibitor) and doxorubicin significantly inhibited cell migration, however, they did not exert obvious effects on microtubules. Conclusion: In this study, we demonstrated that microtubule-binding agents are effective anti-migrating agents; moreover, homoharringtonine and doxorubicin can be referred as anti-migrating agents, but direct microtubule dynamics are not involved in their mode of action. Our study provides evidence that some alkaloids and other microtubule-binding natural products may be interesting candidates for the development of novel agents against metastasis. [ABSTRACT FROM AUTHOR]

Spectrophotometric, spectropolarimetric, viscometric and spectrofluorimetric analysis of the binding of the alkaloid nitidine to double- and triple-helical forms of RNA have served to highlight the ability of this drug to produce changes in the structure of RNA. The experimental data collected here confirm that nitidine is able to intercalate into the base pairs of poly(A).poly(U) and poly(U).poly(A)*poly(U) under specified conditions and the strength of interaction was of the order of 106 M−1, as calculated from UV absorption study. The binding constants showed that NIT binds more strongly to the triple-helical form of RNA than the corresponding parent duplex. [ABSTRACT FROM AUTHOR]

Background Nucleic acids are now important targets for therapeutic intervention. Alkaloids are an important class of molecules that have myriad therapeutic utility. Isoquinoline and benzophenanthridine alkaloids exhibit multiple pharmacological activities which are often related to their strong nucleic acid binding abilities. Therefore, a review of their interaction aspects with varying nucleic acid structures is essential for rational design and development as therapeutic agents. Scope of the review This work reviews the interaction of various therapeutically important isoquinoline and benzophenanthridine alkaloids with nucleic acids. The review lends insights into the molecular aspects of the interaction that is critical from the perspective of designing better therapeutics. Major conclusions This review provides a concise report on the recent developments and advancements on the interaction of various alkaloids with natural and synthetic nucleic acids. The review focuses on the mode, mechanism, specificity, conformational aspects and energetics of the interaction that will be helpful in the design and synthesis nucleic acid targeted alkaloid analogs. General significance The molecular aspects of the interaction presented here will benefit the development of effective drugs for many diseases. The fundamental results discussed in this review can serve as a database for the design and development of futuristic nucleic acid based small molecule therapeutics. [ABSTRACT FROM AUTHOR]

In this article, an attempt has been taken to endeavour the physiochemical modulation of an isoquinoline based alkaloid sanguinarine (SANG) in various nonpolar (alkane) medium and inside surfactant coated bio-mimicking nanocavity. Notably, in different alkane medium, SANG undergoes cationic iminium to neutral alkanolamine conversion. This conversion generally occurs as an outcome of nucleophilic attack by water (or hydroxyl group) at the electron deficient centre of iminium form of SANG in water at pKa >7.2. Hence, such conversion in nonpolar mediumis surprising, as alkane cannot act as a nucleophile. After investing much effort behind theoretical and experimental techniques, we have directly monitored that ‘water of crystallization’ of the alkaloid itself take part in the intranucleophilic attack at the electron deficient centre in alkane medium, which switches the fluorescence from orange (iminium) to bluish-violet (alkanolamine) even detectable by naked eye. Notably, we have employed such fluorescence switching of SANG into the detection of alkane mixed with the drinking water, and we have noticed that SANG alkaloid may be potentially useful for the detection of hazardous alkane, like, hexane, heptane, octane, decane etc. from drinking water. This kind of fluorescence switching of organic cationic fluorophore in alkane medium is rare, and such switching would be highly interesting for the application in petrochemistry, environmental and geological sciences for development of sensors to detect alkanes and other nonpolar solvents. Moreover, in presence of anionic (AOT) surfactant in nonpolar solvent (n-heptane and benzene), the newly created alkanolamine form is found to enter inside the reverse micellar (RMs) nanocavity. Intriguingly, subsequent addition of water results in the return of alkaloid into its initial cationic iminium form by second conversion inside the reverse micellar water nanopool, exhibiting an isoemissive point at ~530 nm. [ABSTRACT FROM AUTHOR]

Introduction: Prostate cancer is the most common noncutaneous cancer and the second leading cause of cancer-related mortality worldwide and the third in USA in 2017. Chelerythrine (CHE), a naturalbenzo[c]phenanthridine alkaloid, formerly identified as a protein kinase C inhibitor, has also shown anticancer effect through a number of mechanisms. Herein, effect and mechanism of the CHE-induced apoptosis via reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress in prostate cancer cells were studied for the first time. Methods: In our present study, we investigated whether CHE induced cell viability decrease, colony formation inhibition, and apoptosis in a dose-dependent manner in PC-3 cells. In addition, we showed that CHE increases intracellular ROS and leads to ROS-dependent ER stress and cell apoptosis. Results: Pre-treatment with N-acetyl cysteine, an ROS scavenger, totally reversed the CHE-induced cancer cell apoptosis as well as ER stress activation, suggesting that the ROS generation was responsible for the anticancer effects of CHE. Conclusion: Taken together, our findings support one of the anticancer mechanisms by which CHE increased ROS accumulation in prostate cancer cells, thereby leading to ER stress and caused intrinsic apoptotic signaling. The study reveals that CHE could be a potential candidate for application in the treatment of prostate cancer. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the safety of a standardized Macleaya cordata Extract Product (MCEP) containing the quaternary benzophenanthridine alkaloids, sanguinarine and chelerythrine, when fed to dairy cows. Thirty-six dairy cows were randomized into three groups with twelve cows/treatment in two replica pens for each treatment group: control (C) without MCEP added to feed, treatment 1 ( SANG-1000) with MCEP added to feed at 1,000 mg/animal/day (1.5 mg/kg bw/day) and treatment 2 ( SANG-10000) with MCEP added to feed at 10,000 mg/animal/day (15.5 mg MCEP/kg bw/day). After two weeks of acclimation, animals were observed for an 84-day experimental period, with body weight, feed intake and milk production measured daily. Milk composition was analysed every two weeks. Haematological analyses were performed on Day 0 and Day 84, and clinical chemistry analyses were performed on Day 84 of the study. There was no statistically significant difference ( p > .10) among the three groups on body condition score, milk production or milk composition over the study period. There were no significant differences in body weight gain or feed consumption among the three groups. Animals in the SANG-10000 group had significantly higher mean corpuscular volume ( MCV) than the C group ( p < .1) and lower mean corpuscular haemoglobin concentration ( MCHC) than the SANG-1000 group ( p < .1). Concentrations of sanguinarine and chelerythrine in milk samples collected on Day 84 were below the detection limit ( LOD) as measured by high-performance liquid chromatography-mass spectrometry ( HPLC- MS/ MS). In conclusion, this study presents compelling data supporting the hypothesis that the test product MCEP, when included in the TMR at up to 10,000 mg/animal/day (15.5 mg MCEP/kg bw/day), is well tolerated by dairy cows. [ABSTRACT FROM AUTHOR]

Sanguinarine is a benzo[c]phenanthridine alkaloid with interesting cytotoxic properties, such as induction of oxidative DNA damage and very rapid apoptosis, which is not mediated by p53-dependent signaling. It has been previously documented that sanguinarine is reduced with NADH even in absence of any enzymes while being converted to its dihydro form. We found that the dark blue fluorescent species, observed during sanguinarine reduction with NADH and misinterpreted by Matkar et al. (Arch. Biochem. Biophys. 2008, 477, 43–52) as an anionic form of the alkaloid, is a covalent adduct formed by the interaction of NADH and sanguinarine. The covalent adduct is then converted slowly to the products, dihydrosanguinarine and NAD + , in the second step of reduction. The product of the reduction, dihydrosanguinarine, was continually re-oxidized by the atmospheric oxygen back to sanguinarine, resulting in further reacting with NADH and eventually depleting all NADH molecules. The ability of sanguinarine to diminish the pool of NADH and NADPH is further considered when explaining the sanguinarine-induced apoptosis in living cells. [ABSTRACT FROM AUTHOR]

Present study allows us a better understanding of the interaction of nitidine, a benzophenanthridine alkaloid with single stranded polyriboadenylic acid [ss-poly (rA)]. The interaction leads to self-structure induction in ss-poly (rA) under the experimental condition of pH 7.0. Interaction of nitidine with ss-poly (rA) was ascertained by monitoring the change in absorbance, fluorescence intensity and circular dichroism values. Binding mode of nitidine with ss-poly (rA) was observed to be intercalation as confirmed from the quenching and viscometric studies. The association was characterized by both negative enthalpy and entropy changes accompanying with a moderately high binding constant of 5.10 × 10 5 M −1 . Nitidine induced double helical organization in single stranded poly (rA) under the experimental pH. [ABSTRACT FROM AUTHOR]

Six pairs of previously undescribed 6-monosubstituted dihydrobenzophenanthridine alkaloids were separated as corresponding six scalemic mixtures from the aerial part of Chelidonium majus . The elucidation for the 2D structures of these alkaloids was achieved using regular spectroscopic and chemical methods. The assignment of scalemic-mixture nature was achieved using combined examinations of their NMR data, CD spectra, calculation of specific rotations, and chiral HPLC profiles. The identification for the relative configurations of alkaloids possessing two asymmetric carbons directly connected up by a rotatable sp 3 - sp 3 carbon-carbon single bond was significantly facilitated by discussing the erythro and threo relative configurations defined by the mutuality of the orders of decreasing steric hindrances between the two sets of ligands linked to the two chiral centers. Two scalemic mixtures were assigned as (1′ R ,6 R /1′ S ,6 S )- and (1′ S ,6 R /1′ R ,6 S )-1-(dihydrochelerythrine-6-yl)ethanols, two as (1′ R ,6 R )/(1′ S ,6 S )- and (1′ S ,6 R )/(1′ R ,6 S )-1-(dihydrosanguinarine-6-yl)ethanols, one as (±)-ethyl 2-(dihydrosanguinarine-6-yl)acetate, and one as (±)-ethyl dihydrosanguinarine-6-carboxylate, respectively. The resolution of three scalemic mixtures was achieved and the absolute configurations of the three pairs of enantiomers were assigned via time-dependent Density Functional Theory calculations of electronic circular dichroism (ECD) data. The assignment for the absolute configurations of the other three scalemic mixtures was achieved via a chiral HPLC-UV/CD method plus analyzing their ECD data. The findings of this paper demonstrated that the relevant biochemical reactions concerning the construction of these 6-monosubstituted dihydrobenzophenanthridine alkaloids in the test plant are very nonselective. Scalemic mixture of (1′ R ,6 R )/(1′ S ,6 S )-1-(dihydrosanguinarine-6-yl)ethanol exhibited biological activity. It inhibited the growth of human MDA-MB-231 cell line at a moderate level with IC 50 value of 5.12 μ M. [ABSTRACT FROM AUTHOR]

Quaternary benzophenanthridine alkaloids are known to have a wide range of biological effects, including antimicrobial, antifungal, anti-inflammatory, and antitumour activities. However, only sanguinarine and chelerythrine have been studied intensively. The aim of this study was to evaluate the anti-inflammatory potential of the five minor quaternary benzophenanthridine alkaloids sanguilutine, sanguirubine, chelirubine, chelilutine, and macarpine in vitro and to compare them with more thoroughly studied sanguinarine and chelerythrine. Before making cellbased assays, the cytotoxicity of the alkaloids was evaluated. The anti-inflammatory potential of the chosen alkaloids was evaluated as for their ability to modulate the lipopolysaccharideinduced secretion of tumour necrosis factor α (TNF-α) in the macrophage-like cell line THP-1. The cyclooxygenase (COX)-1 and COX-2 inhibitory activities were also measured. The results indicate that the presence of a methylenedioxy ring attached at carbon (C)7-C8 is important for reducing the secretion of TNF-α. Interestingly, this effect did not show a simple dependence on concentration. The selected alkaloids showed little or no anti-COX activity. The results obtained from the present experiments may provide additional information useful in understanding the structure-to-activity relationship of the quaternary benzophenanthridine alkaloids. The antiinflammatory potential and the cytotoxic effect are driven by the presence of a methylenedioxy ring attached at C7-C8 and C2-C3, respectively. [ABSTRACT FROM AUTHOR]

Single stranded RNAs are biologically potent as they participate in various key cellular processes. The binding efficacy of two potent anticancer alkaloids, sanguinarine (here after SANG) and chelerythrine (here after CHEL), with single-stranded ribonucleic acids poly(rI), poly(rG), and poly(rC) were studied using spectroscopic and thermodynamic tools. Results reveal that both SANG and CHEL binds well with single stranded RNAs with affinity in the order poly(rI) > poly(rG) > poly(rC). CHEL showed slightly higher affinity compared to SANG with all the single stranded RNAs. Both SANG and CHEL showed association affinity of the lower 10 6 order with poly(rI), higher 10 5 order binding with poly(rG) and lower 10 5 order with poly(rC). The binding mode was partial intercalation due to the staking interaction between the bases and the alkaloids. The complexation of both the SANG and CHEL to the RNAs were mainly enthalpy driven and also favoured by entropy changes. Perturbation was observed in the RNA conformation due to binding of the alkaloids. In this present study we have deciphered the fundamental structural and calorimetric aspects of the interaction of the natural benzophenanthridine alkaloids with single stranded RNAs and these results may help to develop new generation alkaloid based therapeutics targeting single stranded RNAs. [ABSTRACT FROM AUTHOR]

Two new alkaloids 6-hydroxyethyldihydrochelerythrine (1) and 6-hydroxymethyl-7,8-demethylenedihydrochelerythrine (2) together with two analogues named maclekarpine E (3) and 6-hydroxymethyldihydrosanguinarine (4) were detected primarily from the leaves of Macleaya cordata by their characteristic mass spectrometry (MS) and tandem mass spectrometry (MS/MS). And then isolation of four targeted-compounds was performed by column chromatography and preparation HPLC under the guiding of MS. Finally, their structures were determined by spectrum analysis. Alkaloids 3 and 4 were isolated from this plant medicine for the first time. [ABSTRACT FROM AUTHOR]

Background Chelerythrine is widely used as a broad range protein kinase C (PKC) inhibitor, but there is controversy about its inhibitory effect. Moreover, it has been shown to exert PKC-independent effects on non-neuronal cells. Methods In this study we investigated possible off-target effects of chelerythrine on cultured cortical rodent neurons and a neuronal cell line. Results We found that 10 μM chelerythrine, a commonly used concentration in neuronal cultures, reduces PKC and cAMP-dependent protein kinase substrates phosphorylation in mouse cultured cortical neurons, but not in rat primary cortical neurons or in a striatal cell line. Furthermore, we found that incubation with chelerythrine increases pERK1/2 levels in all models studied. Moreover, our results show that chelerythrine promotes calpain activation as assessed by the cleavage of spectrin, striatal-enriched protein tyrosine phosphatase and calcineurin A. Remarkably, chelerythrine induces a concentration-dependent increase in intracellular Ca 2+ levels that mediates calpain activation. In addition, we found that chelerythrine induces ERK1/2- and calpain-independent caspase-3 activation that can be prevented by the Ca 2+ chelator BAPTA-AM. Conclusions This is the first report showing that chelerythrine promotes Ca 2+ -dependent calpain activation in neuronal cells, which has consequences for the interpretation of studies using this compound. General significance Chelerythrine is still marketed as a specific PKC inhibitor and extensively used in signal transduction studies. We believe that the described off-target effects should preclude its use as a PKC inhibitor in future works. [ABSTRACT FROM AUTHOR]

Background Chelerythrine (CHE) is a benzophenanthridine alkaloid that is a potent, selective, and cell-permeable protein kinase C inhibitor. The purpose of the present study was to examine the effect of CHE on intestinal recovery and enterocyte turnover after intestinal ischemia-reperfusion (IR) injury in rats. Methods Male Sprague-Dawley rats were divided into four experimental groups: (1) sham rats underwent laparotomy, (2) sham-CHE rats underwent laparotomy and were treated with intraperitoneal CHE; (3) IR-rats underwent occlusion of both superior mesenteric artery and portal vein for 30 minutes followed by 48 hours of reperfusion, and (4) IR-CHE rats underwent IR and were treated with intraperitoneal CHE immediately before abdominal closure. Intestinal structural changes, Park injury score, enterocyte proliferation, and enterocyte apoptosis were determined 24 hours following IR. The expression of Bax, Bcl-2, p-ERK, and caspase-3 in the intestinal mucosa was determined using real Western blot and immunohistochemistry. Results Treatment with CHE resulted in a significant decrease in Park injury score in jejunum (threefold decrease) and ileum (twofold decrease), and parallel increase in mucosal weight in jejunum and ileum, villus height in jejunum and ileum, and crypt depth in ileum compared with IR animals. IR-CHE rats also experienced a significantly lower apoptotic index in jejunum and ileum, which was accompanied by a lower Bax/Bcl2 ratio compared with IR animals. Conclusions Treatment with CHE inhibits programmed cell death and prevents intestinal mucosal damage following intestinal IR in a rat. [ABSTRACT FROM AUTHOR]

Here we have reported a detail study on the interaction of the benzophenanthridine alkaloid chelerythrine (CHL) with double stranded polyriboadenylic acid [ds poly (rA)] by exploiting various spectroscopic techniques. The alkaloid shows high binding affinity (binding constant is 1.10 × 10 5 M −1 ) towards the double stranded RNA as revealed from Scatchard plot. The binding was confirmed by hypochromic effect in the UV–vis spectrum of CHL, increase in fluorescence intensity of CHL and perturbations of the circular dichroism (CD) spectrum of ds poly (rA). Later fluorescence quenching, cooperative CD melting transition, viscometric and molecular modeling studies establish the fact that the alkaloid binds to the ds poly (rA) by the mechanism of intercalation. Thermodynamic parameters obtained from the isothermal titration calorimetric (ITC) study show that the binding is favoured by negative enthalpy and small positive entropy changes. This report may be a model for intercalation of small molecule like CHL to the double stranded RNA. [ABSTRACT FROM AUTHOR]

In this study we have reported the anionic surfactant (Sodium dodecyl sulfate, SDS) driven structural conversion of two benzophenanthridine plant alkaloids namely Chelerythrine (herein after CHL) and Sanguinarine (herein after SANG). Both the alkaloids exist in two forms: the charged iminium and the neutral alkanolamine form. The iminium form is stable at low pH (< 6.5) and the alkanolamine form exists at higher pH (> 10.1). The fluorescence intensity of the alkanolamine form is much stronger than the iminium form. The iminium form of both the alkaloids remains stable whereas the alkanolamine form gets converted to the iminium form in the SDS micelle environment. The iminium form possesses positive charge and it seems that electrostatic interaction between the positively charged iminium and negatively charged surfactant leads to the stabilization of the iminium form in the Stern layer of the anionic micelle. Whereas the conversion of the alkanolamine form into the iminium form takes place and that can be monitored in naked eye since the iminium form is orange in colour and the alkanolamine form has blue violet emission. Such a detail insight about the photophysical properties of the benzophenanthridine alkaloids would be a valuable addition in the field of alkaloid-surfactant interaction. [ABSTRACT FROM AUTHOR]

Novel syntheses of both the benzo[ b ]phenanthridine and the 6 H -dibenzo[ c,h ]chromen-6-one motif are described. Reaction of (2-(3-bromo-1,4-dimethoxynaphthalen-2-yl)phenyl)methanamine with PIFA afforded benzo[ b ]phenanthridine-7,12-dione, while the related nonbrominated precursor, (2-(1,4,5-trimethoxynaphthalen-2-yl)phenyl)methanamine on treatment with PIFA, furnished the ortho -quinone 1-methoxybenzo[ c ]phenanthridine-11,12-dione. Unexpectedly, treatment of related oxygen analogs such as (2-(1,4-dimethoxynaphthalen-2-yl)phenyl)methanol with NBS under an O 2 atmosphere, afforded a chromenone, 12-methoxy-6 H -dibenzo[ c,h ]chromen-6-one. [ABSTRACT FROM AUTHOR]

The benzophenanthridine plant alkaloid chelerythrine was recently reported to bind to single stranded polyriboadenylic acid [ss poly(A)] through an entropy driven process with remarkably high binding affinity (∼10 7 M −1 ) (Basu and Suresh Kumar, 2015). Considering the anticancer effects of chelerythrine along with its potential to be developed as an RNA targeted drug due to its high affinity to ss poly(A), here we studied the binding of chelerythrine to double stranded (ds) poly(A). The binding was characterized thermodynamically by enthalpy and entropy changes, and enthalpy-entropy compensation behaviour. The binding thermally stabilized the structure. The binding led to hypochromic and bathochromic effects in the visible absorption spectrum of chelerythrine and enhanced its fluorescence intensity. An intercalative binding mode was deduced from fluorescence quenching, anisotropy, and viscometric studies. The binding of chelerythrine to the ds poly(A) was significantly weaker than its binding to ss poly(A). The results may lead to designing RNA targeted therapeutics and a useful agent in gene regulation in eukaryotic cells. [ABSTRACT FROM AUTHOR]

Two new benzophenanthridine alkaloids enantiomers (±)-zanthonitidumines A (1) and B (2), along with seven known analogues (3 – 9), were isolated from Zanthoxylum nitidium. Their structures were elucidated on the basis of extensive spectroscopic techniques and ECD data. Compound 2 exhibited the most significant inhibition of IL-6 generation as well as TNF- α release which suggest that it may be a potential anti-inflammatory agent. [Display omitted] • Two new benzophenanthridine alkaloids enantiomers, (±)-Zanthonitidumine A (1) and B (2), were isolated from Zanthoxylum nitidium. • Absolute configuration of the new compounds was established by extensive spectroscopic and ECD analysis. • Compound 2 exhibited potent anti-inflammatory activity comparable to that of the positive control. [ABSTRACT FROM AUTHOR]

Sanguinaria canadensis, also known as bloodroot, is a traditional medicine used by Native Americans to treat a diverse range of clinical conditions. The plants rhizome contains several alkaloids that individually target multiple molecular processes. These bioactive compounds, mechanistically correlate with the plant's history of ethnobotanical use. Despite their identification over 50 years ago, the alkaloids of S. canadensis have not been developed into successful therapeutic agents. Instead, they have been associated with clinical toxicities ranging from mouthwash induced leukoplakia to cancer salve necrosis and treatment failure. This review explores the historical use of S. canadensis, the molecular actions of the benzophenanthridine and protopin alkaloids it contains, and explores natural alkaloid variation as a possible rationale for the inconsistent efficacy and toxicities encountered by S. canadensis therapies. Current veterinary and medicinal uses of the plant are studied with an assessment of obstacles to the pharmaceutical development of S. canadensis alkaloid based therapeutics. [ABSTRACT FROM AUTHOR]

Background and Purpose: Nitidine chloride (NC), a benzophenanthridine alkaloid, has various biological properties including anticancer and analgesic activities. The aim of the present study was to evaluate the role of organic cation transporter 2 (OCT2) and multidrug and toxin extrusion 1 (MATE1) in the renal disposition and nephrotoxicity of NC.Experimental Approach: MDCK cells stably expressing human OCT2 and/or hMATE1 were used to investigate the OCT2- and MATE1-mediated transport of NC. In addition, the accumulation of NC and its potential toxicity were studied in rat primary-cultured proximal tubular (rPCPT) cells and in rats in vivo.Key Results: NC was found to be a high-affinity substrate of both OCT2 and MATE1 with high cytotoxicity in MDCK-hOCT2/hMATE1 and MDCK-hOCT2 compared to mock cells. The OCT2 inhibitors, cimetidine and (+)-tetrahydropalmatine ((+)-THP), significantly reduced NC accumulation and cytotoxicity in MDCK-hOCT2, MDCK-hOCT2/hMATE1 and rPCPT cells. Severe kidney damage with high levels of blood urea nitrogen and lactate dehydrogenase (LDH), reduced levels of alkaline phosphatase (ALP) and pathological changes were found in rats after 20 days of successive i.v. doses of NC (5 mg·kg(-1) ·day(-1) ). Concomitantly, the concentration of NC in the kidney reached similar high levels at 2 h after the last dose of the 20 day treatment as those observed at 0.5 h after a single i.v. dose of 5 mg·kg(-1) .Conclusions and Implications: Our data indicate that NC-induced nephrotoxicity might be mainly attributed to OCT2-mediated extensive renal uptake and weak tubular secretion by MATE1. [ABSTRACT FROM AUTHOR]

Rumen microbiota have important metabolic functions for the host animal. This study aimed at characterizing changes in rumen microbial abundances and fermentation profiles using a severe subacute ruminal acidosis (SARA) in vitro model, and to evaluate a potential modulatory role of plant derived alkaloids (PDA), containing quaternary benzophenanthridine and protopine alkaloids, of which sanguinarine and chelerythrine were the major bioactive compounds. Induction of severe SARA strongly affected the rumen microbial composition and fermentation variables without suppressing the abundance of total bacteria. Protozoa and fungi were more sensitive to the low ruminal pH condition than bacteria. Induction of severe SARA clearly depressed degradation of fiber (P < 0.001), which came along with a decreased relative abundance of fibrolytic Ruminococcus albus and Fibrobacter succinogenes (P < 0.001). Under severe SARA conditions, the genus Prevotella, Lactobacillus group, Megasphaera elsdenii, and Entodinium spp. (P < 0.001) were more abundant, whereas Ruminobacter amylophilus was less abundant. SARA largely suppressed methane formation (−70%, P < 0.001), although total methanogenic 16S rRNA gene abundance was not affected. According to principal component analysis, Methanobrevibacter spp. correlated to methane concentration. Addition of PDA modulated ruminal fermentation under normal conditions such as enhanced (P < 0.05) concentration of total SCFA, propionate and valerate, and increased (P < 0.05) degradation of crude protein compared with the unsupplemented control diet. Our results indicate strong shifts in the microbial community during severe SARA compared to normal conditions. Supplementation of PDA positively modulates ruminal fermentation under normal ruminal pH conditions. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that the benzo[c] phenanthridine alkaloid chelerythrine chloride (CC) has inhibitory effects on various tumors. However, the anticancer activity of CC and its underlying mechanisms have not been elucidated in renal cancer cells. The present study examined the effects of CC on growth inhibition and apoptosis of renal cancer cells in vitro and in vivo. Flow cytometry and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays revealed that CC markedly suppressed the growth of HEK-293 and human renal cancer SW-839 cells in a time-and dose-dependent manner. The xenograft mouse model, which was performed in nude mice, exhibited a reduced tumor growth following CC treatment. In addition, the present study revealed that CC significantly decreased the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, which was accompanied by upregulation of p53, B-cell lymphoma 2 (Bcl-2)-associated X protein, cleaved caspase-3 and cleaved poly (adenosine diphosphate-ribose) polymerase (PARP), and downregulation of Bcl-2, caspase-3 and PARP. Furthermore, the use of PD98059, a specific mitogen-activated protein kinase kinase inhibitor, potentiated the proapoptotic effects of CC, which indicated that CC may induce apoptosis in renal cancer cells partly via inhibition of ERK activity. Overall, the results of the present study demonstrated that CC may be developed as a potential anticancer treatment for patients with renal cancer. [ABSTRACT FROM AUTHOR]

A study on the interaction of benzophenanthridine plant alkaloid chelerythrine (CHL) with low pH induced protonated form and conventional B-form DNA was carried out by using a combination of various spectroscopic and viscometric techniques. The interaction of the alkaloid with protonated form of DNA was characterized by the typical hypochromic and bathochromic shifts in the absorption spectrum, increase of thermal melting temperature, increase in solution viscosity, perturbation in circular dichroic spectrum. Binding constant for the association of CHL with protonated DNA was of the order of 10 5 M −1 . The mode of binding of CHL with protonated DNA was characterized from the absorption spectral studies, viscosity measurements and quenching experiments. The stabilization of protonated DNA upon binding with CHL was revealed from thermal melting studies. CD spectral studies revealed that CHL converted the protonated form of CT-DNA to the right handed B-form. [ABSTRACT FROM AUTHOR]

Selected benzo[c]phenathridine alkaloids were biotransformed using rat liver microsomes and identified by liquid chromatography and mass spectrometry. While the metabolites of commercially available sanguinarine and chelerythrine have been studied in detail, data about the metabolism of the minor alkaloids remained unknown. Reactions involved in transformation include single and/or double O -demethylation, demethylenation, reduction, and hydroxylation. Two metabolites, when isolated, purified and tested for toxicity, were found to be less toxic than the original compounds. [ABSTRACT FROM AUTHOR]

Cell cultures of Eschscholzia californica react to a fungal elicitor by the overproduction of antimicrobial benzophenanthridine alkaloids. The signal cascade toward the expression of biosynthetic enzymes includes (1) the activation of phospholipase A2 at the plasma membrane, resulting in a peak of lysophosphatidylcholine, and (2) a subsequent, transient efflux of vacuolar protons, resulting in a peak of cytosolic H+. This study demonstrates that one of the Na+/H+ antiporters acting at the tonoplast of E. californica cells mediates this proton flux. Four antiporter-encoding genes were isolated and cloned from complementary DNA (EcNHX1-EcNHX4). RNA interference-based, simultaneous silencing of EcNHX1, EcNHX3, and EcNHX4 resulted in stable cell lines with largely diminished capacities of (1) sodium-dependent efflux of vacuolar protons and (2) elicitor-triggered overproduction of alkaloids. Each of the four EcNHX genes of E. californica reconstituted the lack of Na+-dependent H+ efflux in a βnhx null mutant of Saccharomyces cerevisiae. Only the yeast strain transformed with and expressing the EcNHX1 gene displayed Na+-dependent proton fluxes that were stimulated by lysophosphatidylcholine, thus giving rise to a net efflux of vacuolar H+. This finding was supported by three-dimensional protein homology models that predict a plausible recognition site for lysophosphatidylcholine only in EcNHX1. We conclude that the EcNHX1 antiporter functions in the elicitor-initiated expression of alkaloid biosynthetic genes by recruiting the vacuolar proton pool for the signaling process. [ABSTRACT FROM AUTHOR]

Four Holstein steers with ruminal and duodenal cannulas were used in a 4 × 4 Latin square design to examine the effect of daily intake of 0, 2, 4 or 6 g/steer of standardized plant extract containing a mixture of quaternary benzophenanthridine alkaloids and protopine alkaloids (QBA+PA) on the characteristics of ruminal fermentation and characteristics of digestion. The basal diet consisted of a steam-flaked corn-based finishing diet that contained 62% corn and 12% sudangrass hay and the rest of diet was composed of mainly dried distillers grains, molasses, fat, and minerals. The source of QBA+PA used was Sangrovit-RS (Phytobiotics Futterzusatzstoffe GmbH, Eltville, Germany) and supplementation levels of 2, 4, and 6 g Sangrovit-RS.steer-1.d-1, which represented a net daily ingestion of approximately 6, 12, and 18 mg of QBA+PA compounds, respectively. Inclusion of QBA+PA linearly increased (P = 0.04) flow to the duodenum of nonammonia N and linearly decreased (P < 0.01) duodenal flows of ammonia N. Ruminal microbial efficiency (duodenal microbial N; g/kg OM fermented in the rumen) and protein efficiency (duodenal nonammonia N; g/g N intake) were increased (P < 0.05) as the level of QBA+PA increased. There were no effects of QBA+PA supplementation on ruminal, postruminal, and total tract digestion of OM, starch, and NDF, but postruminal and total tract digestion of N increased (P < 0.01) as the level of QBA+PA increased. Digestible energy of the diet tended to increase (linear affect, P = 0.09) with QBA+PA supplementation. Ruminal pH and total VFA molar concentrations were not different between treatments. Ruminal NH3-N concentration linearly decreased (P = 0.02) with QBA+PA supplementation. Ruminal molar proportion of acetate increased (P = 0.04) as the supplementation level of QBA+PA increased. It is concluded that QBA+PA supplementation enhances efficiency of N utilization in feedlot steers fed a steamflaked corn-based finishing diet. This effect was due, in part, to enhanced ruminal microbial efficiency, decreased ruminal degradation of dietary nonammonia N, and enhanced postruminal N digestion. [ABSTRACT FROM AUTHOR]

Background Information. Macarpine (MA) is a quaternary benzophenanthridine plant alkaloid isolated fromMacleaya microcarpa or Stylophorum lasiocarpum. Benzophenanthridine alkaloids are interesting natural products that display antiproliferative, antimicrobial, antifungal and anti-inflammatory activities, and also fluorescence properties. In a previous study, we demonstrated that thanks to its ability to interact with DNA and its spectral properties MA could be used as a supravital DNA probe for fluorescence microscopy and flow cytometry including analyses of the cell cycle. In this study, we evaluated the suitability of MA as a DNA dye for time-lapse microscopy and flow-cytometric cell sorting. Results. Living A-375 and MEF cells stained with MA were monitored by time-lapse microscopy for 24 h. Mitoses were observed at MA concentrations up to 0.5 µg/ml during the first 2-3 h. After this period of time, cells treated with MA at concentrations of 0.75 and 0.5 µg/ml underwent apoptosis. Cells cultivated with MA at concentration of 0.25 µg/ml or lower survived throughout the 24 h period. Toxicity of MA was dependent on light wavelength and frequency of image capturing. The intensity of MA fluorescence decreased during the incubation. MA concentration of 0.1 µg/ml was identified as the most suitable for live cell imaging with respect to fluorescence intensity and toxicity. MA at the concentration 10 µg/ml was used for sorting of enhanced green fluorescent protein (EGFP)- labelled neurons and fibroblasts yielding profiles similar to those obtained with DRAQ5. Contrary to DRAQ5, MA-stained cells survived in culture, and the sorted cells lost the MA signal suggesting reversible binding of the dye to the DNA. Conclusion. The results proved that MA may readily be used for chromosomes depicting and mitosis monitoring by time-lapse microscopy. In addition, MA has shown to be a suitable probe for sorting of EGFP-labelled cells, including neurons, that survived the labelling process. Significance. In consideration of the results, we highly anticipate an onward use of MA in a broad range of applications based on live cell sorting and imaging, for example, cell synchronisation and monitoring of proliferation as an important experimental and/or diagnostic utility. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the wood from Zanthoxylum quinduense Tul. allowed the isolation and identification of norchelerythrine, decarine, 6-acetonyldihydrochelerythrine, syringaresinol, evofilin C, p-hydroxybenzaldehyde, vanillic acid, a mixture of β-sitosterol, stigmasterol and campesterol and a mixture of saturated and unsaturated fatty acids, and their esters derivatives. The structures of the isolated compounds were elucidated by spectroscopic techniques and comparison with literature data and the mixture of sterols and fatty acids were identified by GC/MS. The antifungal activity of the ethanolic extract, fractions and pure compounds against Fusarium oxysporum f. sp. lycopersici was determined by bioautography. Evofilin C and nochelerytrine were the only substances that present antifungal activity.

Apoptosis is triggered by the activation of caspases and characterized by chromatin condensation and nuclear fragmentation (type II nuclear morphology). Necrosis is depicted by a gain in cell volume (oncosis), swelling of organelles, plasma membrane leakage, and subsequent loss of intracellular contents. Although considered as different cell death entities, there is an overlap between apoptosis and necrosis. In this sense, mounting evidence suggests that both processes can be morphological expressions of a common biochemical network known as "apoptosis- necrosis continuum." To gain insight into the events driving the apoptosis-necrosis continuum, apoptotically proficient cells were screened facing several apoptotic inducers for the absence of type II apoptotic nuclear morphologies. Chelerythrine was selected for further studies based on its cytotoxicity and the lack of apoptotic nuclear alterations. Chelerythrine triggered an early plasma membrane leakage without condensed chromatin aggregates. Ultrastructural analysis revealed that chelerythrine-mediated cytotoxicity was compatible with a necrotic-like type of cell death. Biochemically, chelerythrine induced the activation of caspases. Moreover, the inhibition of caspases prevented chelerythrine-triggered necrotic-like cell death. Compared with staurosporine, chelerythrine induced stronger caspase activation detectable at earlier times. After using a battery of chemicals, we found that high concentrations of thiolic antioxidants fully prevented chelerythrine-driven caspase activation and necrotic-like cell death. Lower amounts of thiolic antioxidants partially prevented chelerythrine-mediated cytotoxicity and allowed cells to display type II apoptotic nuclear morphology correlating with a delay in caspase-3 activation. Altogether, these data support that an early and pronounced activation of caspases can drive cells to undergo a form of necrotic-like regulated cell death. [ABSTRACT FROM AUTHOR]

The O 4 -benzo[ c ]phenanthridine alkaloids exhibit potent antiproliferative activity against cancer cells, which is derived from their ability to inhibit of topoisomerase I and II. It has been reported that in the alkaloids a cationic quaternary ammonium atom, which results in resonance effects between ring A and B, is necessary for increased antiproliferative activity. These findings indicate the role of their substituents at ring A on inhibition of tumor cell proliferation. In the present study, we systematically assessed the cytotoxic activities of naturally occurring alkaloids and their derivatives containing various ring A substituents against two tumor cell lines, HCT-116 colon tumor cells and HL-60 promyelocytic leukemia cells. Among the cationic iminium alkaloids, which displayed more potent activity than the corresponding neutral derivatives, and the 7,8-oxygenated benzo[ c ]phenanthridine alkaloids, chelerythrine and NK109, exhibited stronger antiproliferative activity than the 8,9- and 9,10-oxygenated alkaloids. The activity of cationic iminium alkaloids could be correlated with the bond lengths of their ring A substituents and the electrostatic potentials of their ammonium molecules by DFT calculation. [ABSTRACT FROM AUTHOR]

This work aimed to investigate benzophenanthridine from the roots of Zanthoxylum nitidum (Roxb.) DC. var. fastuosum How ex Huang for the first time. Thirteen benzophenanthridines were isolated, and our results of the cytotoxic activities indicated that compound 6 exhibited the best potency against A549, Hela, SMMC-7721 and EJ, with the IC50 values of 27.50, 37.50, 16.95 and 60.42 μM, respectively. Compounds 7 and 11 also showed strong cytotoxicity when tested against the four human cancer cell lines (A549, Hela, SMMC-7721 and EJ), while only compounds 12 and 13 displayed cytotoxicity in inhibiting BALL-1 proliferation among all the compounds. These results suggested that benzophenanthridines may become a valid alternative of potential basis for new anti-proliferative agents. [ABSTRACT FROM AUTHOR]

In this work, a novel, active tumour-targeting system (Fe3O4@OCMCS-CHE) was designed by surface-modifying superparamagnetic iron oxide nanoparticles (Fe3O4) with O-carboxymethylchitosan (OCMCS) to improve their biocompatibility and ability to target specific tumour cells. The chelerythrine (CHE) was used as the model of anti-tumour drug in this system. The optimised formulation was characterised and confirmed by scanning electron microscopy (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR),in vitrodrug release and so on. It was found that the synthesised nanoparticles were spherical in shape with an average size of 60 nm, the drug loading content and entrapment efficiency were 8.32 ± 0.25% (w/w) and 90.65 ± 0.46% (w/w), respectively, and the saturated magnetisation reached 27.06 emu/g. Thein vitrodrug-release behaviour from nanoparticles displayed a biphasic drug-release pattern with initial burst release and consequently sustained release. Also, the effect of magnetic targeted nanoparticles on the proliferation of human hepatoma cell line (HepG2)in vitrowas investigated. The results from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Hochest assays suggested that the Fe3O4@OCMCS-CHE nanoparticles could effectively inhibit the proliferation of HepG2 cells, which displayed time-dependent and concentration-dependent manner. All these results indicated that the multifunctional Fe3O4@OCMCS nanoparticles possess a high drug loading efficiency, have low cytotoxicity, and are promising candidates for targeted drug delivery. [ABSTRACT FROM AUTHOR]

Six compounds ( 1 – 6 ), isolated from the methanol extract of the roots of the African medicinal plant Zanthoxylum capense Thunb. (Rutaceae), and seven ester derivatives ( 7 – 13 ) were evaluated for their antibacterial activities and modulatory effects on the MIC of antibiotics (erythromycin, oxacillin, and tetracycline) and ethidium bromide (EtBr) against a Staphylococcus aureus reference strain (ATCC 6538). Using the same model, compounds 1 – 13 were also assessed for their potential as efflux pump inhibitors by a fluorometric assay that measures the accumulation of the broad range efflux pump substrate EtBr. Compounds 8 and 11 were further evaluated for their antibacterial, modulatory and EtBr accumulation effects against four additional S. aureus strains, which included two clinical methicillin-resistant S. aureus (MRSA) strains. Compounds ( 1 – 13 ) have not shown antibacterial activity at the concentration ranges tested. When evaluated against S. aureus ATCC 6538, oxychelerythrine ( 1 ) a benzophenanthridine alkaloid, showed the highest modulatory activity enhancing the susceptibility of this strain to all the tested antibiotics from two to four-fold. Ailanthoidiol diacetate ( 8 ) and ailanthoidiol di-2-ethylbutanoate ( 11 ) were also good modulators when combined with EtBr, increasing the bacteria susceptibility by four and two-fold, respectively. In the EtBr accumulation assay, using ATCC 6538 strain, the phenylpropanoid (+)-ailanthoidiol ( 6 ) and most of its ester derivatives ( 8 − 11 ) exhibited higher activity than the positive control verapamil. The highest effects were found for compounds 8 and 11 that also increased the accumulation of EtBr, using S. aureus ATCC 25923 as model. Furthermore, both compounds ( 8, 11 ) were able to enhance the ciprofloxacin activity against the MRSA clinical strains tested, causing a reduction of the antibiotic MIC values from two to four-fold. The EtBr accumulation assay revealed that this modulation activity was not due to an inhibition of efflux pumps mechanism. These results suggested that Z. capense constituents may be valuable as leads for restoring antibiotic activity against MRSA strains. [ABSTRACT FROM AUTHOR]

Objectives Drug combinations consisting of the DNA intercalating benzophenanthridine alkaloid sanguinarine, the chelator EDTA with the antibiotic streptomycin were tested against several Gram-positive and Gram-negative bacteria, including multi-resistant clinical isolates. Methods Microdilution, checkerboard and time kill curve methods were used to investigate the antibacterial activity of the individual drugs and the potential synergistic activity of combinations. Key findings Sanguinarine demonstrated a strong activity against Gram-positive and Gram-negative bacteria (minimum inhibitory concentrations, MIC = 0.5-128 μg/ml), while streptomycin was active against Gram-negative strains ( MIC = 2-128 μg/ml). EDTA showed only bacteriostatic activity. Indifference to synergistic activity was seen in the two-drug combinations sanguinarine + EDTA and sanguinarine + streptomycin (fractional inhibitory concentration index = 0.1-1.5), while the three-drug combination of sanguinarine + EDTA + streptomycin showed synergistic activity against almost all the strains (except methicillin-resistant S taphylococcus aureus), as well as a strong reduction in the effective doses (dose reduction index = 2-16 times) of sanguinarine, EDTA and streptomycin. In time kill studies, a substantial synergistic interaction of the three-drug combination was detected against Escherichia coli and Klebsiella pneumoniae. Conclusions The combination of drugs, which interfere with different molecular targets, can be an important strategy to combat multidrug resistant bacteria. [ABSTRACT FROM AUTHOR]

Benzophenanthridine alkaloids are strong antimicrobials of Papaveraceae and attractive lead compounds for drug development. The cytotoxicity of these compounds requires the producing plant to limit the pathogen-triggered burst of biosynthesis. Cells of Eschscholzia californica excrete early benzophenanthridines to the cell wall, followed by re-uptake and reduction in the cytoplasm by the detoxifying enzyme sanguinarine reductase. We now discovered that this enzyme is a core component of self-control in alkaloid production. RNAi-based silencing of sanguinarine reductase gave rise to mutants that either show a complete stop of elicitor-triggered alkaloid production or a burst of biosynthesis that severalfold surpasses the wild type level. These unexpected phenotypes reflect impacts of substrate or product of sanguinarine reductase: the substrate, sanguinarine, inhibits phospholipase A2 at the plasma membrane, an initial component of the signal path towards expression of biosynthetic enzymes. The product, dihydrosanguinarine, inhibits enzymes of early biosynthesis, prior to reticuline formation. By tuning these steady states, sanguinarine reductase adjusts the capacity of alkaloid biosynthesis: a minimum activity is sufficient to prevent the blockade of the induction pathway by sanguinarine, while the full activity of the same enzyme causes a limitation of the biosynthetic flow via dihydrosanguinarine. [ABSTRACT FROM AUTHOR]