22 results on '"Spiteller, Michael"'
Search Results
2. Tramadol-A True Natural Product?
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Kusari, Souvik, Tatsimo, Simplice Joel N., Zühlke, Sebastian, Talontsi, Ferdinand M., Kouam, Simeon Fogue, and Spiteller, Michael
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TRAMADOL ,ANALGESICS ,NATURAL products ,MEDICINAL plants ,PLANT roots - Abstract
We have independently investigated the source of tramadol, a synthetic analgesic largely used for treating moderate to severe pain in humans, recently found in the roots of the Cameroonian medicinal plant, Nauclea latifolia. We found tramadol and its three major mammalian metabolites ( O-desmethyltramadol, N-desmethyltramadol, and 4-hydroxycyclohexyltramadol) in the roots of N. latifolia and five other plant species, and also in soil and local water bodies only in the Far North region of Cameroon. The off-label administration of tramadol to cattle in this region leads to cross-contamination of the soil and water through feces and urine containing parent tramadol as well as tramadol metabolites produced in the animals. These compounds can then be absorbed by the plant roots and also leached into the local water supplies. The presence of tramadol in roots is, thus, due to an anthropogenic contamination with the synthetic compound. [ABSTRACT FROM AUTHOR]
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- 2014
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3. Bioactive constituents of Lobostemon fruticosus: Anti-inflammatory properties and quantitative analysis of samples from different places in South Africa.
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Bedane, Kibrom Gebreheiwot, Zühlke, Sebastian, and Spiteller, Michael
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CAFFEIC acid , *QUANTITATIVE research , *MASS spectrometry , *FLOWERING of plants , *MEDICINAL plants , *LIPOPOLYSACCHARIDES , *PHENOLIC acids - Abstract
• A total of 13 compounds were identified from the leaves and twigs of Lobostemon fruticosus. • LC–LTQ-Orbitrap mass spectrometry method was established for identification and quantification of the constituents. • The anti-inflammatory activities of isolated compounds were assessed by measuring the levels of cytokines IL-1β, IL-2, IL-6, GM-CSF and TNF-α. • All the tested compounds and the extract decrease the release of the tested cytokines compared to LPS control. Lobostemon fruticosus is South Africa medicinal plant traditionally used in treatment of wounds and skin diseases. Nevertheless, there is no report on its phytochemical constituents. LC–LTQ-Orbitrap mass spectrometry was used for identification and quantification of its constituents. A total of 13 compounds were identified from the leaves and twigs of the plant using NMR, ESI-HRMS and reference substances. The identified compounds were p -hydroxybenzoic acid (1), lycopsamine-N-oxide (2), caffeic acid (3), loliolide (4), 3-indolcarbaldehyde (5), globoidnan B (6), rabdosiin (7), syringaresinol (8), pinoresinol (9), rutin (10), rosmarinic acid (11), keampferol-3- O -rutinoside (12) and globoidnan A (13). In addition, quantitative determination of 6 marker compounds in samples from 12 different locations in South Africa was established. Rosmarinic acid and globoidnan A were found in large amount in the leaves and flowers of the plant. Samples from West Cape contained relatively greater amount of the tested compounds per dry weight than the other samples. The anti-inflammatory activities of isolated compounds were assessed by measuring the levels of cytokines IL-1β, IL-2, IL-6, GM-CSF and TNF-α in the supernatant media of human peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS). At a concentration of 100 μM, compounds 7, 8 and 11 significantly decreased secretion of IL-1β, IL-2 and IL-6 compared to the LPS treated control (0.76–57.6%). All compounds significantly reduced the production of TNF-alpha compared to the LPS treated control (0.17–12.2%) and reference drug ibuprofen. [ABSTRACT FROM AUTHOR]
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- 2020
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4. Correlations between camptothecin and related metabolites in Camptotheca acuminata reveal similar biosynthetic principles and in planta synergistic effects
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Kusari, Souvik, Zühlke, Sebastian, and Spiteller, Michael
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ALGORITHMS , *ALTERNATIVE medicine , *ANALYSIS of variance , *ANTINEOPLASTIC agents , *CLUSTER analysis (Statistics) , *COMPARATIVE studies , *COMPUTER software , *DISCRIMINANT analysis , *FACTOR analysis , *LIQUID chromatography , *MASS spectrometry , *MEDICINAL plants , *MULTIVARIATE analysis , *POPULATION geography , *RESEARCH funding , *PLANT stems , *PHYTOCHEMICALS , *PLANT extracts , *DATA analysis - Abstract
Abstract: Camptothecin (CPT), 9-methoxycamptothecin (9-MeO-CPT), and 10-hydroxycamptothecin (10-OH-CPT) are potent antineoplastic metabolites. We analyzed these metabolites in Camptotheca acuminata sampled from Germany and China, using LC–MS/MS and LC-ESI–HRMS/MS, coupled with chemometrics. Multivariate analysis revealed that fresh stems of C. acuminata from China had the highest comprehensive metabolite load. Significant positive correlations of CPT with 9-MeO-CPT and 10-OH-CPT were observed by Kruskal''s multidimensional scaling and principal component analysis. Linear discriminant analysis and hierarchical agglomerative cluster analysis revealed that C. acuminata from China was separated from others. These positive correlations indicate that these metabolites are biosynthesized similarly and operate synergistically in planta. [Copyright &y& Elsevier]
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- 2011
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5. Cardenolides and dihydro-β-agarofuran sesquiterpenes from the seeds of Salacia staudtiana.
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Kamtcha, Duplex Wetadieu, Tene, Mathieu, Bedane, Kibrom Gebreheiwot, Knauer, Lena, Brieger, Lukas, Strohmann, Carsten, Tane, Pierre, Kusari, Souvik, and Spiteller, Michael
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HYDROCARBON analysis , *STEROIDS analysis , *BACILLUS (Bacteria) , *BIOLOGICAL assay , *CRYSTALLIZATION , *CRYSTALLOGRAPHY , *ESCHERICHIA coli , *GENTAMICIN , *HIGH performance liquid chromatography , *HYDROCARBONS , *MASS spectrometry , *MEDICINAL plants , *MOLECULAR structure , *NUCLEAR magnetic resonance spectroscopy , *PSEUDOMONAS , *SEEDS , *STAPHYLOCOCCUS aureus , *STEROIDS , *STREPTOMYCIN , *THIN layer chromatography , *X-rays , *PLANT extracts , *AUTOANALYZERS - Abstract
Abstract Phytochemical studies of the seeds of the Cameroonian medicinal plant, Salacia staudtiana , resulted in the isolation and identification of five new cardenolides (1 – 5) as well as a new dihydro-β-agarofuran (9), along with eight known compounds. The structures of all compounds were elucidated by 1D/2D NMR, ESI-HRMS data and comparison with literature data. The relative configurations of the new compounds were defined by X-ray crystallography analysis, NOESY correlations and coupling constants. We evaluated their antibacterial efficacy against two commonly dispersed environmental strains of Escherichia coli and Bacillus subtilis , and two pathogenic strains of Staphylococcus aureus and Pseudomonas aeruginosa , compared to the standard antibiotics, streptomycin and gentamicin. Moreover, we assessed the antibacterial activity of the crude extract of the seeds in parallel to evaluate the plausible synergistic effects of the compounds in chemical defense of the seeds during germination and plant reproduction. The isolated compounds showed moderate antibacterial activities against the tested organisms. Compounds 1 and 3 and the crude extract exhibited distinct antibacterial activities against B. subtilis and S. aureus. The isolated compounds showed weak DPPH radical scavenging properties compared to the reference standard (Trolox). Our study lends evidence to the antibacterial chemical defense of S. staudtiana seeds by seed-borne compounds. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]
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- 2018
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6. Cardenolides from the stem bark of Salacia staudtiana.
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Kamtcha, Duplex Wetadieu, Tene, Mathieu, Bedane, Kibrom Gebreheiwot, Knauer, Lena, Strohmann, Carsten, Tane, Pierre, Kusari, Souvik, and Spiteller, Michael
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ANTI-infective agents , *BARK , *ESCHERICHIA coli , *MEDICINAL plants , *PSEUDOMONAS , *STAPHYLOCOCCUS aureus , *PLANT stems , *STEROIDS , *IN vitro studies - Abstract
Seven new cardenolides, staudtianoside A−F ( 1−6 ) and staudtianogenin A ( 8 ), were isolated along with six known compounds from the stem bark of the Cameroonian medicinal plant Salacia staudtiana Loes. ex Fritsch. The structures were elucidated by means of ESI-HRMS and NMR spectroscopic methods and by comparison with literature data. The relative configurations of the new compounds were determined by X-ray diffraction analysis, NOESY correlation and coupling constants. We evaluated the antibacterial efficacy of the isolated compounds against two commonly dispersed environmental strains of Escherichia coli and Bacillus subtilis , as well as against two human pathogenic clinical strains of Staphylococcus aureus and Pseudomonas aeruginosa . Compounds 1 , 2 and 8 exhibited marked antibacterial potencies against the clinically relevant P. aeruginosa that were comparable to the standard antibiotics. Compound 2 was also active against S. aureus and E. coli . Further, compounds 5 and 8 demonstrated efficacy against E. coli as well as B. subtilis . The structure-activity relationship of the tested compounds is discussed. [ABSTRACT FROM AUTHOR]
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- 2018
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7. seco-Tiaminic acids B and C: Identification of two novel 3,4-seco-tirucallane triterpenoids isolated from the root of Entandrophragma congoënse (Meliaceae).
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Happi, Gervais Mouthé, Talontsi, Ferdinand Mouafo, Laatsch, Hartmut, Zühlke, Sebastian, Ngadjui, Bonaventure Tchaleu, Spiteller, Michael, and Kouam, Simeon Fogue
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ALTERNATIVE medicine , *ANIMAL experimentation , *ANTIMALARIALS , *ANTINEOPLASTIC agents , *ANTIPARASITIC agents , *MASS spectrometry , *MEDICINAL plants , *NUCLEAR magnetic resonance spectroscopy , *RATS , *PLANT roots , *TERPENES , *PLANT extracts , *MUSCLE cells , *IN vitro studies , *PHARMACODYNAMICS , *TUMORS - Abstract
Chemical investigation of the roots of Entandrophragma congoënse (Meliaceae) led to the isolation of two new 3,4- seco -tirucallane triterpenes, namely seco -tiaminic acids B and C ( 1 and 2 ) together with nine known compounds: 3,4-secotirucalla-21-formyl-23-oxo-4(28),7,24-trien-3-oic acid ( 3 ), methyl angolensate ( 4 ), molucensin N ( 5 ), molucensin O ( 6 ), piscidinol A ( 7 ), 7 α ,20( S )-dihydroxy-4,24(28)-ergostadien-3-one ( 8 ), 24-methylene-cholest-5-en-3 β ,7 α -diol ( 9 ), entilin A ( 10 ), and entilin B ( 11 ). Their structures were determined using extensive spectroscopic methods including 1D and 2D NMR, HRMS, and CD analyses; new results were compared to existing data in the literature. The two newly identified seco -tiaminic acids showed moderate antiplasmodial and cytotoxic activities against a chloroquine-sensitive strain of the malaria parasite ( Plasmodium falciparum NF54) and were cytotoxic toward an L6 rat skeletal myoblast cell line, respectively. [ABSTRACT FROM AUTHOR]
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- 2018
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8. Flavanones of Erythrina livingstoniana with antioxidant properties.
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Bedane, Kibrom Gebreheiwot, Kusari, Souvik, Masesane, Ishmael B., Spiteller, Michael, and Majinda, Runner R.T.
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ALTERNATIVE medicine , *ANTIOXIDANTS , *FREE radicals , *IMMUNOASSAY , *MASS spectrometry , *MEDICINAL plants , *NUCLEAR magnetic resonance spectroscopy , *PLANT extracts , *FLAVANONES - Abstract
Six new flavanones ( 1 – 6 ), together with six known compounds were isolated from Erythrina livingstoniana . Their structures were elucidated on the basis of NMR data and HRMS n fragmentation pathway and by comparison with literature data. Compounds 5 , 7 and 8 showed remarkable DPPH free radical scavenging efficacies. The compounds, however, did not demonstrate an anti-inflammatory potential when tested using a PGE 2 (prostaglandin E2) competitive enzyme immunoassay. The plausible biosynthetic pathways of the isolated compounds are described. [ABSTRACT FROM AUTHOR]
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- 2016
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9. Prenylated 2-arylbenzofuran derivatives with potent antioxidant properties from Chlorophora regia (Moraceae).
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Kyekyeku, James Oppong, Kusari, Souvik, Adosraku, Reimmel Kwame, Zühlke, Sebastian, and Spiteller, Michael
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ALTERNATIVE medicine , *ANTIOXIDANTS , *BARK , *PHYSICAL & theoretical chemistry , *DOSE-effect relationship in pharmacology , *FREE radicals , *IMMUNOASSAY , *MASS spectrometry , *MEDICINAL plants , *NUCLEAR magnetic resonance spectroscopy , *PLANT stems , *PHYTOCHEMICALS , *PLANT extracts , *FLAVONOLS , *DESCRIPTIVE statistics - Abstract
Extracts of Chlorophora regia are frequently used in Ghana in traditional medicine. There is, however, no reported data on the chemical composition of the plant. Comprehensive phytochemical investigation of the stem bark of C. regia resulted in the isolation of three new prenylated 2-arylbenzofuran derivatives, regiafuran A–C ( 1–3 ), and one new prenylated flavonol ( 4 ), together with fifteen known compounds ( 5–19 ). Their structures were elucidated by combined spectroscopic analysis of their NMR and HRESI-MS n data. Compounds 1, 2, 5, 9 and 15 exhibited remarkable free radical scavenging properties with IC 50 values of 1.9 μg/ml, 2.4 μg/ml, 2.2 μg/ml, 2.1 μg/ml and 1.8 μg/ml, respectively, compared to the standard trolox (IC 50 1.1 μg/ml). The isolated compounds did not, however, show any anti-inflammatory potential when tested using a PGE 2 (prostaglandin E 2 ) competitive enzyme immunoassay. [ABSTRACT FROM AUTHOR]
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- 2016
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10. Anti-inflammatory tirucallane triterpenoids from Anopyxis klaineana Pierre (Engl.), (Rhizophoraceae).
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Mireku, Evelyn Afua, Kusari, Souvik, Eckelmann, Dennis, Mensah, Abraham Yeboah, Talontsi, Ferdinand M., and Spiteller, Michael
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ALTERNATIVE medicine , *ANTI-inflammatory agents , *BARK , *PHYSICAL & theoretical chemistry , *CHROMATOGRAPHIC analysis , *DOSE-effect relationship in pharmacology , *FREE radicals , *IMMUNOASSAY , *MASS spectrometry , *MEDICINAL plants , *NUCLEAR magnetic resonance spectroscopy , *PROSTAGLANDINS , *PLANT stems , *PLANT extracts , *DESCRIPTIVE statistics , *IN vitro studies - Abstract
Phytochemical investigation of the stem bark extract of Anopyxis klaineana was carried out by various chromatographic techniques resulting in the isolation and characterization of three new tirucallane triterpenoids, namely 3,23-dioxotirucalla-7,24-dien-21-oic acid ( 1 ), 3,4-secotirucalla-23-oxo-4(28)7,24-trien-3,21-dioic acid ( 2 ) and 3,4-secotirucalla-4-hydroxy-23-oxo-7,24-diene-3,21-dioic acid-21-methyl ester ( 3 ), along with nine known compounds ( 4–12 ). The structural elucidation of the compounds was performed by means of high-resolution mass spectrometry (HRMS n ), nuclear magnetic resonance (NMR), and by comparison to literature data. Although none of the isolated compounds showed antibacterial efficacy against selected environmental and clinically important pathogenic Gram-positive and -negative bacteria, they demonstrated moderate DPPH free radical scavenging properties. Furthermore, compounds 1 and 7 exhibited remarkable anti-inflammatory potential in a prostaglandin E 2 (PGE 2 ) competitive enzyme immunoassay with IC 50 values of 3.63 μM and 10.23 μM, respectively. [ABSTRACT FROM AUTHOR]
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- 2015
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11. Erylivingstone A–C with antioxidant and antibacterial activities from Erythrina livingstoniana.
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Bedane, Kibrom Gebreheiwot, Kusari, Souvik, Eckelmann, Dennis, Masesane, Ishmael B., Spiteller, Michael, and Majinda, Runner R.T.
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ALTERNATIVE medicine , *ANTIBIOTICS , *ANTIOXIDANTS , *BACILLUS (Bacteria) , *PHYSICAL & theoretical chemistry , *ESCHERICHIA coli , *FREE radicals , *MASS spectrometry , *MEDICINAL plants , *MICROBIAL sensitivity tests , *NUCLEAR magnetic resonance spectroscopy , *STAPHYLOCOCCUS aureus , *STREPTOCOCCUS , *PLANT extracts , *FLAVANONES , *IN vitro studies , *PHARMACODYNAMICS - Abstract
The chemical study of Erythrina livingstoniana has led to the isolation of three new flavanones namely 5,7,3′-trihydroxy-4′-methoxy-5′-formylflavanone (erylivingstone A) ( 1 ), 5,7,3′-trihydroxy-5′-(2-hydroxy-3-methylbut-3-enyl)-4′-methoxyflavanone (erylivingstone B) ( 2 ) and 5,7,3′-trihydroxy-5′-(3-hydroxy-3-methyl- trans -but-1-enyl)-4′-methoxyflavanone (erylivingstone C) ( 3 ) together with three known compounds ( 4 – 6 ). Their structures were elucidated on the basis of NMR data, HRMS n fragmentation pathway and by comparison with literature data. We evaluated the antibacterial efficacies and free-radical scavenging potential of the isolated compounds ( 1 – 6 ). The typical environmental strains of Gram-positive Bacillus subtilis , Gram-negative Escherichia coli , as well as against the clinically important Staphylococcus aureus , Streptococcus pyogenes and E. coli (risk-group 2) were used for the antibacterial assay. Compounds 5 and 6 exhibited the most pronounced efficacy against tested environmental bacteria as well as against the pathogenic strain of E. coli . Compound 3 was also quite active against these three bacterial strains. The isolated compounds showed weak radical scavenging properties with compound 6 being the most active, followed by compounds 2 , 3 and 5 . [ABSTRACT FROM AUTHOR]
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- 2015
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12. Minor secondary metabolites from the bark of Entandrophragma congoënse (Meliaceae).
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Happi, Gervais Mouthé, Kouam, Simeon Fogue, Talontsi, Ferdinand Mouafo, Zühlke, Sebastian, Lamshöft, Marc, and Spiteller, Michael
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ALTERNATIVE medicine , *ANIMAL experimentation , *ANTIMALARIALS , *BARK , *BIOLOGICAL models , *PHYSICAL & theoretical chemistry , *DRUG resistance , *DRUG toxicity , *MASS spectrometry , *MEDICINAL plants , *MICROBIAL sensitivity tests , *NUCLEAR magnetic resonance spectroscopy , *RATS , *SPECTRUM analysis , *PLANT extracts , *DESCRIPTIVE statistics , *IN vitro studies , *PHARMACODYNAMICS - Abstract
Two new tirucallane-type triterpenoids were isolated from the bark of Entandrophragma congoënse (Meliaceae) along with five known compounds gladoral A, bipendensin, 4-hydroxymethyl-3,5-dimethyldihydrofuran-2(3 H )-one, scopoletin and 5,7-dimethoxy-6-hydroxycoumarin. Their structures were elucidated by means of spectroscopic analyses including 1D and 2D-NMR spectroscopy, high resolution mass spectrometric data as well as the comparison of data with those reported in the literature. The tested compounds ( 1 – 4 ) displayed moderated antiplasmodial activity against erythrocytic stages of chloroquine-resistant Plasmodium falciparum strain NF54 and low cytotoxicity on L6 cell lines. All the isolated compounds are reported for the first time from the genus Entandrophragma. [ABSTRACT FROM AUTHOR]
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- 2015
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13. Antimicrobial and cytotoxic constituents from native Cameroonian medicinal plant Hypericum riparium.
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Tala, Michel Feussi, Talontsi, Ferdinand Mouafo, Zeng, Guang-Zhi, Wabo, Hippolyte Kamdem, Tan, Ning-Hua, Spiteller, Michael, and Tane, Pierre
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MEDICINAL plants , *ALTERNATIVE medicine , *ANTIBIOTICS , *ANTINEOPLASTIC agents , *BIOLOGICAL models , *PHYSICAL & theoretical chemistry , *DOSE-effect relationship in pharmacology , *MASS spectrometry , *MICROBIAL sensitivity tests , *SPECTRUM analysis , *GASTROINTESTINAL tumors , *PLANT extracts , *METHICILLIN-resistant staphylococcus aureus , *DESCRIPTIVE statistics , *IN vitro studies , *PHARMACODYNAMICS - Abstract
Bioassay guided fractionation of Hypericum riparium leaves extract has resulted in the isolation and characterization of three new compounds namely chipericumin E ( 1 ), hyperenone C ( 3 ), and hyperixanthone ( 5 ), together with twenty known compounds. Their structures were elucidated based on comprehensive interpretation of spectroscopic and spectrometric data. Compounds 1 – 4 , and 6 – 8 displayed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and cytotoxic effects on the human gastric cell line BGC-823 with IC 50 values ranging from 6.54 to 18.50 μM. [ABSTRACT FROM AUTHOR]
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- 2015
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14. Flavanols from Tetrapleura tetraptera with cytotoxic activities.
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Ayoolu, Oguntimehin Samuel, Ogbole, Omonike Oluyemisi, Ajaiyeoba, Edith Oriabure, Nchiozem-Ngnitedem, Vaderament-A, Demissie, Taye B., Elbadawi, Mohamed, Efferth, Thomas, Bedane, Kibrom Gebreheiwot, and Spiteller, Michael
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MEDICINAL plants , *LEUKEMIA , *NUCLEAR magnetic resonance spectroscopy , *FLAVONOLS , *TOXICITY testing , *PLANT extracts , *MOLECULAR structure , *CELL lines - Abstract
Tetrapleura tetraptera is a medicinal plant used in East and West Africa to treat inflammation and related diseases. From the stem bark of the plant, three previously undescribed flavan-3-ol derivatives named (2 R, 3 S)-3,3′,5′,7-tetrahydroxy-4′-methoxyflavane (1), (2 R, 3 S) -3′,5′,7-trihydroxy-4′-methoxyflavane-3- O -β-D-glucopyranoside (2), and (2 R, 3 S, 4 S) -3,3′,4,5′,7-pentahydroxy-4′-methoxyflavane (3) were isolated with three known analogues. The structural elucidation of the compounds was performed based on NMR spectroscopy and HRMS data analyses. The absolute configurations around the stereogenic carbons were determined using Circular Dichroism (ECD) and density functional theory (DFT) calculations. The cytotoxicity of the isolated compounds was tested using resazurin reduction assay. Compound 1 was moderately active against both recalcitrant leukemia cell lines with IC 50 values of 21.90 μM towards CCRF-CEM and 50.80 towards CEM/ADR5000. Similar level of activity was observed for compound 3 against CCRF-CEM cell line, IC 50 = 35.50 μM. All the tested compounds were not cytotoxic compared with the standard drug, doxorubicin, with IC 50 values of 0.0075 against CCRF-CEM and 24.30 μM against CEM/ADR5000. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2022
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15. Cytotoxic compounds from the leaf of Bersama abyssinica subspecies abyssinica.
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Nyamboki, Divinah Kwamboka, Bedane, Kibrom Gebreheiwot, Hassan, Khadija, Spiteller, Michael, and Matasyoh, Josphat Clement
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SUBSPECIES , *NUCLEAR magnetic resonance spectroscopy , *CELL lines , *MEDICINAL plants - Abstract
From the leaves of Kenyan medicinal plant Bersama abyssinica Subspecies abyssinica , four previously undescribed compounds namely, three bufadienolides, 10 β -formylpaulliniogenin B, 10 β -formylpaulliniogenin A and 1 β -acetoxy-3 β ,5 β -dihydroxy-15-methoxy-16,19-dioxobufa-14(15),20,22-trienolide, and a phenolic compound 2,6,4′-trihydroxybenzophenone-4-O-(6‴-cinnamoyl)-β-D-glucoside were isolated together with four known compounds. The structural elucidation of the compounds was based on 1D and 2D NMR spectroscopy and HRMS data analyses. The relative configurations were defined by NOESY correlations. Cytotoxic activities on L929 and KB3.1 cell lines of the isolated compounds were investigated using MTT assay. The 1 β -acetoxy-3 β ,5 β -dihydroxy-15-methoxy-16,19-dioxobufa-14(15),20,22-trienolide showed significant cytotoxic activity against KB3.1 cell lines with IC 50 of 3.9 ± 0.99 μM. Bufadienolides from Bersama abyssinica (Fresen) subspecies abyssinica Melianthaceae. [Display omitted] • Cytotoxic compounds from the leaf of Bersama abyssinica subspecies abyssinica. • Previously undescribed bufadienolides are reported. • Plants of the genus Bersama have proved to be a rich source of bufadienolides. [ABSTRACT FROM AUTHOR]
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- 2022
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16. Penialidins A–C with strong antibacterial activities from Penicillium sp., an endophytic fungus harboring leaves of Garcinia nobilis.
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Jouda, Jean-Bosco, Kusari, Souvik, Lamshöft, Marc, Mouafo Talontsi, Ferdinand, Douala Meli, Clovis, Wandji, Jean, and Spiteller, Michael
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ALTERNATIVE medicine , *ANTI-infective agents , *FUNGI , *LEAVES , *MEDICINAL plants , *MOLECULAR structure , *NUCLEAR magnetic resonance spectroscopy , *SPECTRUM analysis , *IN vitro studies , *PHARMACODYNAMICS - Abstract
Three new polyketides named penialidins A–C ( 1 – 3 ), along with one known compound, citromycetin ( 4 ), were isolated from an endophytic fungus, Penicillium sp., harbored in the leaves of the Cameroonian medicinal plant Garcinia nobilis . Their structures were elucidated by means of spectroscopic and spectrometric methods (NMR and HRMS n ). The antibacterial efficacies of the new compounds ( 1 – 3 ) were tested against the clinically-important risk group 2 (RG2) bacterial strains of Staphylococcus aureus and Escherichia coli . The ecologically imposing strains of E. coli (RG1), Bacillus subtilis and Acinetobacter sp. BD4 were also included in the assay. Compound 3 exhibited pronounced activity against the clinically-relevant S. aureus as well as against B. subtilis comparable to that of the reference standard (streptomycin). Compound 2 was also highly-active against S. aureus . By comparing the structures of the three new compounds ( 1 – 3 ), it was revealed that altering the substitutions at C-10 and C-2 can significantly increase the antibacterial activity of 1 . [ABSTRACT FROM AUTHOR]
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- 2014
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17. Indolosesquiterpene alkaloids from the Cameroonian medicinal plant Polyalthia oliveri (Annonaceae).
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Kouam, Simeon Fogue, Ngouonpe, Alain Wembe, Lamshöft, Marc, Talontsi, Ferdinand Mouafo, Bauer, Jonathan O., Strohmann, Carsten, Ngadjui, Bonaventure Tchaleu, Laatsch, Hartmut, and Spiteller, Michael
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MEDICINAL plants , *ANNONACEAE , *SESQUITERPENES , *ALKALOIDS , *CAMEROONIANS , *LIQUID chromatography - Abstract
The stem bark of Polyalthia oliveri was screened for its chemical constituents using liquid chromatography high resolution mass spectrometry resulting in the isolation of three indolosesquiterpene alkaloids named 8α-polyveolinone (1), N-acetyl-8α-polyveolinone (2) and N-acetyl-polyveoline (3), together with three known compounds, dehydro-O-methylisopiline (4), N-methylurabaine (5) and polycarpol (6). The structures of the compounds were elucidated by means of high resolution mass spectrometry and different NMR techniques and chemical transformations. Their absolute configurations were assigned by ab-initio calculation of CD and ORD data (for 2 and 3) and X-ray diffraction analysis (for 2). Compounds 2 and 3 exhibited moderate antiplasmodial activity against erythrocytic stages of chloroquine-sensitive Plasmodium falciparum NF54 strain and low cytotoxicity on rat skeletal myoblast (L6) cell line. [ABSTRACT FROM AUTHOR]
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- 2014
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18. Monoterpenes with antibacterial activities from a Cameroonian medicinal plant Canthium Multiflorum (Rubiaceae).
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Kouam, Simeon Fogue, Ngouonpe, Alain Wembe, Bullach, Anke, Lamshöft, Marc, Kuigoua, Guy Merlin, and Spiteller, Michael
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ALTERNATIVE medicine , *ANIMAL experimentation , *ANTI-infective agents , *ANTIMALARIALS , *BIOLOGICAL models , *MEDICINAL plants , *MICROBIAL sensitivity tests , *NUCLEAR magnetic resonance spectroscopy , *RATS , *STAPHYLOCOCCUS aureus , *PHYTOCHEMICALS , *PLANT extracts , *DESCRIPTIVE statistics , *IN vitro studies , *PHARMACODYNAMICS - Abstract
Abstract: Investigation of the crude extract obtained from the aerial parts of Canthium multiflorum led to the isolation of a new iridoid (1) together with twelve known compounds. The structures of these compounds were elucidated by interpretation of 1D and 2D NMR spectroscopic data, accurate mass measurements and comparison with analytical data of previously known analogues. Most of the isolated compounds have been reported for the first time from C. multiflorium. The antimicrobial activities of the isolated compounds were evaluated on five different bacterial strains using agar diffusion technique. The Gram-positive bacterium Staphylococcus aureus subsp. aureus (DSM 799), and the Gram-negative bacteria Actinobacter calco-aceticus (DSM 30006), Serratia plymuthica (DSM 4540), Pseudomonas stutzeri (DSM 4166) and Escherichia coli (DSM 1116) were employed for this purpose. The new iridoid, named 6-oxo-genipin (1), demonstrated significant inhibitory activity against all microbial strains tested, especially the pathogen Staphylococcus aureus. In addition, the compounds 3, 4 and 9 exhibited antiplasmodial activity against Plasmodium falciparum strain K1 and weak cytotoxicity against L6 cell lines. [Copyright &y& Elsevier]
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- 2013
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19. Sonhafouonic acid, a new cytotoxic and antifungal hopene-triterpenoid from Zehneria scabra camerunensis
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Kongue, Michel D.T., Talontsi, Ferdinand M., Lamshöft, Marc, Kenla, Timothee J.N., Dittrich, Birger, Kapche, Gilbert D.W.F., and Spiteller, Michael
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ALTERNATIVE medicine , *BIOLOGICAL models , *CRUSTACEA , *MASS spectrometry , *MEDICINAL plants , *MUTAGENS , *NUCLEAR magnetic resonance spectroscopy , *PLANT diseases , *TERPENES , *PLANT extracts , *DESCRIPTIVE statistics - Abstract
Abstract: A new hopene-type triterpenoid, namely sonhafouonic acid 1a was isolated from Zehneria scabra camerunensis, together with eight known compounds. The structure of 1a was established by extensive NMR and high resolution MS techniques and confirmed by single-crystal X-ray crystallographic analysis. Compound 1a exhibited inhibitory activity against mycelial growth of two peronosporomycete phytopathogens Pythium ultimum and Aphanomyces cochliodes and cytotoxicity towards brine shrimp larvae (Artemia salina) at 10μg/mL. [Copyright &y& Elsevier]
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- 2013
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20. Sapelenins G–J, acyclic triterpenoids with strong anti-inflammatory activities from the bark of the Cameroonian medicinal plant Entandrophragma cylindricum
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Kouam, Simeon Fogue, Kusari, Souvik, Lamshöft, Marc, Tatuedom, Ostend Kamgue, and Spiteller, Michael
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TRITERPENOIDS , *ANTI-inflammatory agents , *MEDICINAL plants , *ENTANDROPHRAGMA , *TRITERPENES , *CHEMICAL derivatives - Abstract
Abstract: Four acyclic triterpene derivatives named sapelenins G–J (1–4), along with eight known compounds, sapelenins A–D, ekeberin D2 (5), (+)-catechin and epicatechin, and anderolide G, were isolated from the stem bark of the Cameroonian medicinal plant, Entandrophragma cylindricum Sprague, on the basis of bioassay-guided fractionation. Their structures were determined by means of high-resolution mass spectrometry and NMR spectroscopic data, as well as by comparison with the literature values of their analogs. The absolute configurations of the compounds (1–4) were assigned by the modified Mosher’s method in conjunction with NOESY experiments and chemical modifications. The anti-inflammatory activities of the sapelenins were evaluated by assessing their ability to suppress or inhibit the secretion of cytokine interleukin-17 (IL-17) by human peripheral blood mononuclear cells (PBMC) stimulated with phytohemagglutinin (PHA). The cytotoxicity of these compounds on PMBCs was further assessed for correctly interpreting their anti-inflammatory responses. The tested compounds demonstrated moderate to significant anti-inflammatory activities by suppressing the secretion of IL-17 by PHA-stimulated human PBMCs. One of them, sapelenin G (1), showed high potency in suppressing the secretion of IL-17 by PBMCs comparable to reference cyclosporine A, without causing any cytotoxic effects (negligible), and deserves further considerations towards developing an effective anti-inflammatory drug. [Copyright &y& Elsevier]
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- 2012
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21. Anti-inflammatory steroidal sapogenins and a conjugated chalcone-stilbene from Dracaena usambarensis Engl.
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Nchiozem-Ngnitedem, Vaderament-A, Omosa, Leonidah Kerubo, Bedane, Kibrom Gebreheiwot, Derese, Solomon, Brieger, Lukas, Strohmann, Carsten, and Spiteller, Michael
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ANTI-inflammatory agents , *CRYSTALLOGRAPHY , *CYTOKINES , *FLAVONOIDS , *MASS spectrometry , *MEDICINAL plants , *NUCLEAR magnetic resonance spectroscopy , *STILBENE , *TERPENES , *PLANT extracts - Abstract
Four new steroidal sapogenins, dracaenogenins C F (1 – 4), a new conjugated chalcone-stilbene, 3′′-methoxycochinchinenene H (5) together with eight known compounds namely, (25 S)-spirosta-1,4-dien-3-one (6), trans -resveratrol (7), 4,4′-dihydroxy-3′-methoxychalcone (8), N - trans -coumaroyltyramine (9), N - trans - p -coumaroyloctopamine (10), N - trans -feruloyloctopamine (11), 7-hydroxy-1-(4-hydroxy-3-methoxyphenyl)- N 2 , N 3 - bis (4-hydroxyphenethyl)-6-methoxy-1,2-dihydronaphthalene-2,3-dicarboxamide (12) and grossamide (13) were isolated from the stems of Dracaena usambarensis Engl. from Kenya. It is important to note that compounds 12 and 13 are being reported from this genus for the first time. Structural elucidation of the isolated compounds was done using spectroscopic (NMR, UV, IR, optical rotation) and spectrometric (HRESIMS) techniques. The absolute and relative configurations of the isolated compounds were determined by employing single crystal X-ray crystallography analysis, NOESY correlations and coupling constants. The anti-inflammatory potencies of the isolated compounds were evaluated by measuring the levels of four cytokines (IL-1β, IL-2, GM-CSF and TNF-α) in the supernatant media of human peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS). At the tested concentration of 100 μM, the new conjugated chalcone-stilbene 5 , the dihydrochalcone, 8 and the lignanamide, 13 were substantially more potent than the standard drug, ibuprofen, inhibiting the release of all the cytokines, IL-1β , IL-2, GM-CSF and TNF-α from 0.06–58.04% compared to LPS control. These compounds should therefore be considered for development into anti-inflammatory drug candidates. Compound 7 significantly decreased the release of GM-CSF (6.11% of LPS control) and TNF-α (18.35% of LPS control). The cytokine TNF-α was sensitive to all the tested compounds 1 - 13. Unlabelled Image • Thirteen secondary metabolites isolated from the stem bark of Dracaena usambarensis. • Four new steroidal sapogenins, 1 - 4 and a new conjugated chalcone-stilbene, 5. • The relative configuration of 1 was confirmed with X-ray analysis. • Inhibitory activity of 5 , 8 and 13 , was higher than ibuprofen against all cytokines. [ABSTRACT FROM AUTHOR]
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- 2020
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22. Anti-inflammatory norhopanes from the root bark of Fagaropsis angolensis (Engl.) H.M.Gardner.
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Mukavi, Justus, Omosa, Leonidah Kerubo, Nchiozem-Ngnitedem, Vaderament-A, Nyaga, Justin, Omole, Ruth, Bitchagno, Gabin Thierry M., and Spiteller, Michael
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ANTI-infective agents , *BARK , *CYTOKINES , *GRANULOCYTE-macrophage colony-stimulating factor , *INTERLEUKIN-1 , *INTERLEUKIN-2 , *MEDICINAL plants , *PLANT roots , *SPECTRUM analysis , *TRADITIONAL medicine , *TUMOR necrosis factors , *PAIN management , *IBUPROFEN , *PHYTOCHEMICALS , *PLANT extracts - Abstract
Two new norhopane derivatives namely 3β,6β,22-trihydroxy-7β,11α-di[(4-hydroxybenzoyl)oxy]-21αH-24-norhopa-4(23)-ene (1) and 3β,6β,22-trihydroxy-7β-[(4-hydroxybenzoyl)oxy]-21αH-24-norhopa-4(23)-ene (2) together with two previously reported compounds, including a norhopane, 3β,6β,11α-trihydroxy-7β-[(4-hydroxybenzoyl)oxy]-24-norhopa-4(23),17(21)-diene (3) and a norneohopane, (21αH)-24-norneohopa-4(23), 22(29)-diene-3β,6β,7β-triol 7-caffeate (4) were isolated from the root bark of Fagaropsis angolensis. Elucidation of their structures was achieved by spectroscopic (NMR, IR and UV) and spectrometric (HRESIMS) data and by comparison of these data with those of related compounds in the literature. Compounds 1–4 were evaluated for their anti-inflammatory activity by measuring the levels of cytokines, IL-1β, IL-2, GM-CSF and TNF-α in lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMC). All tested compounds decreased secretion of IL-1β and TNF-α. Compounds 2 and 4 caused significant decrease of the production of IL-2, GM-CSF and TNF-α compared to the reference drug, ibuprofen. These findings showed that the root barks of F. angolensis are rich source of norhopane derivatives and further provide a scientific rationale of using this plant in Kenyan folk medicine to relieve pain. Unlabelled Image [ABSTRACT FROM AUTHOR]
- Published
- 2020
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