The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Riming Huang - One of the best experts on this subject based on the ideXlab platform.
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natural products from the genus Tephrosia
Molecules, 2014Co-Authors: Yinning Chen, Riming HuangAbstract:The genus Tephrosia, belonging to the Leguminosae family, is a large pantropical genus of more than 350 species, many of which have important traditional uses in agriculture. This review not only outlines the source, chemistry and biological evaluations of natural products from the genus Tephrosia worldwide that have appeared in literature from 1910 to December 2013, but also covers work related to proposed biosynthetic pathways and synthesis of some natural products from the genus Tephrosia, with 105 citations and 168 new compounds.
Abhay Kumar Singhai - One of the best experts on this subject based on the ideXlab platform.
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wound healing potential of Tephrosia purpurea linn pers in rats
Journal of Ethnopharmacology, 2006Co-Authors: Santram Lodhi, R S Pawar, Alok Pal Jain, Abhay Kumar SinghaiAbstract:Tephrosia purpurea is a well-known herb for its hepatoprotective, anticancer, antiulcer, antibacterial and in healing bleeding piles, etc. The present study was aimed for wound healing potential of ethanolic extract of Tephrosia purpurea (aerial part) in the form of simple ointment using three types of wound models in rats as incision wound, excision wound and dead space wound. The results were comparable to standard drug Fluticasone propionate ointment, in terms of wound contraction, tensile strength, histopathological and biochemical parameters such as hydroxyproline content, protein level, etc. Histopathological study showed significant (P < 0.05) increase in fibroblast cells, collagen fibres and blood vessels formation. All parameters were observed significant (P < 0.05) in comparison to control group.
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In vitro Evaluation of Tephrosia purpurea Pers for Antioxidant Activity
Journal of Natural Remedies, 2006Co-Authors: Avijeet Jain, Abhay Kumar Singhai, Vinod Kumar DixitAbstract:This research was taken up to investigate the antioxidant activity of leaves of Tephrosia purpurea . The in vitro antioxidant activity of ethanolic extract of leaves of Tephrosia purpurea was investigated by DPPH free radical scavenging, and nitric oxide scavenging methods. The ethanol extract showed good antioxidant activity in these above methods. This activity may be due to the presence of flavanoids.
Abou Elhamd H Mohamed - One of the best experts on this subject based on the ideXlab platform.
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estrogenic activity of chemical constituents from Tephrosia candida
Journal of Natural Products, 2011Co-Authors: Mohamed Elamir F Hegazy, Abou Elhamd H Mohamed, Ali M Elhalawany, Pierre C Djemgou, Abdelaaty A Shahat, Paul W PareAbstract:In a continued investigation of medicinal plants from the genus Tephrosia, phytochemical analysis of a methylene chloride–methanol (1:1) extract of the air-dried aerial parts of Tephrosia candida afforded two new 8-prenylated flavonoids, namely, tephrocandidins A (1) and B (2), a new prenylated chalcone, candidachalcone (3), a new sesquiterpene (4), and a previously reported pea flavonoid phytoalexin, pisatin (5). The structures of 1–4 were established by spectroscopic methods, including HREIMS, and 1H, 13C, DEPT, HMQC, and HMBC NMR experiments. The most potent estrogenic activity of these isolated natural products in an estrogen receptor (ERα) competitive-binding assay was for 3, which exhibited an IC50 value of 80 μM, compared with 18 nM for the natural steroid 17β-estradiol. Results were interpreted via virtual docking of isolated compounds to an ERα crystal structure.
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chemical constituents of Tephrosia purpurea
Pharmacognosy Research, 2010Co-Authors: Ali K Khalafalah, Afifi H Yousef, Abeer M Esmail, Mohamed H Abdelrazik, Mohamed Elamir F Hegazy, Abou Elhamd H MohamedAbstract:In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia , reinvestigation of the methylenechloride/methanol (1:1) extract of the aerial parts of Tephrosia purpurea yielded an aromatic ester 1, a sesquiterpene 2 and prenylated flavonoid 3. The structures of the compounds were established by comprehensive NMR studies, including DEPT, COSY, NOE, HMQC, HMBC, EIMS and CIMS.
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Prenylated flavonoids from Tephrosia apollinea
Chinese Chemical Letters, 2009Co-Authors: A. K. Khalafallah, Afifi H Yousef, Suleiman A. Suleiman, N. A. A. Elkanzi, Abou Elhamd H MohamedAbstract:In continuation of our chemical investigation on some medicinal plants of the genus Tephrosia, re-investigation of the methylenechloride/methanol (1:1) extract of the air-dried aerial part of Tephrosia apollinea afforded a new prenylated flavonoid 1, in addition to an aromatic ester, a sesquiterpene, a lignan and several known prenylated flavonoids. The structures were established by (1H NMR, 13C NMR, DEPT, 1H–1H COSY, HMQC, HMBC, NOESY and HRMS). Relative configurations of 9 and 10 were confirmed by X-ray analysis.
Yinning Chen - One of the best experts on this subject based on the ideXlab platform.
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natural products from the genus Tephrosia
Molecules, 2014Co-Authors: Yinning Chen, Riming HuangAbstract:The genus Tephrosia, belonging to the Leguminosae family, is a large pantropical genus of more than 350 species, many of which have important traditional uses in agriculture. This review not only outlines the source, chemistry and biological evaluations of natural products from the genus Tephrosia worldwide that have appeared in literature from 1910 to December 2013, but also covers work related to proposed biosynthetic pathways and synthesis of some natural products from the genus Tephrosia, with 105 citations and 168 new compounds.
Philip C Stevenson - One of the best experts on this subject based on the ideXlab platform.
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phytochemical analysis of Tephrosia vogelii across east africa reveals three chemotypes that influence its use as a pesticidal plant
Plants (Basel Switzerland), 2019Co-Authors: Angela G Mkindi, Steven R Belmain, Yolice Tembo, Ernest R Mbega, Beth Medvecky, Amy Kendalsmith, Iain W Farrell, Patrick A Ndakidemi, Philip C StevensonAbstract:Tephrosia vogelii is a plant species chemically characterized by the presence of entomotoxic rotenoids and used widely across Africa as a botanical pesticide. Phytochemical analysis was conducted to establish the presence and abundance of the bioactive principles in this species across three countries in East Africa: Tanzania, Kenya, and Malawi. Analysis of methanolic extracts of foliar parts of T. vogelii revealed the occurrence of two distinct chemotypes that were separated by the presence of rotenoids in one, and flavanones and flavones that are not bioactive against insects on the other. Specifically, chemotype 1 contained deguelin as the major rotenoid along with tephrosin, and rotenone as a minor component, while these compounds were absent from chemotype 2, which contained previously reported flavanones and flavones including obovatin-3-O-methylether. Chemotype 3 contained a combination of the chemical profiles of both chemotype 1 and 2 suggesting a chemical hybrid. Plant samples identified as chemotype 1 showed chemical consistency across seasons and altitudes, except in the wet season where a significant difference was observed for samples in Tanzania. Since farmers are unable to determine the chemical content of material available care must be taken in promoting this species for pest management without first establishing efficacy. While phytochemical analysis serves as an important tool for quality control of pesticidal plants, where analytical facilities are not available simple bioassays could be developed to enable extension staff and farmers to determine the efficacy of their plants and ensure only effective materials are adopted.
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highly variable insect control efficacy of Tephrosia vogelii chemotypes
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Steven R Belmain, Barbara A Amoah, Stephen P Nyirenda, John F Kamanula, Philip C StevensonAbstract:Tephrosia vogelii has been used for generations as a pest control material in Africa. Recently, two chemotypes have been reported based on the occurrence (chemotype 1) or absence (chemotype 2) of rotenoids. This could have an impact on the efficacy and reliability of this material for pest control. We report that chemotype 2 has no pesticidal activity against Callosobruchus maculatus Fabricius (family Chrysomelidae) and that this is associated with the absence of rotenoids. We present a first report of the comparative biological activity of deguelin, tephrosin, α-toxicarol, and sarcolobine and show that not all rotenoids are equally effective. Tephrosin was less toxic than deguelin which was less active than rotenone, while obovatin 5-methyl ether, the major flavonoid in chemotype 2 was inactive. We also report that in chemotype 1 the occurrence of rotenoids shows substantial seasonal variation.
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distinct chemotypes of Tephrosia vogelii and implications for their use in pest control and soil enrichment
Phytochemistry, 2012Co-Authors: Gudeta W Sileshi, Steven R Belmain, Stephen P Nyirenda, Philip C Stevenson, Geoffrey C Kite, Gwilym P Lewis, Felix Forest, Nigel C VeitchAbstract:Tephrosia vogelii Hook. f. (Leguminosae) is being promoted as a pest control and soil enrichment agent for poorly-resourced small-scale farmers in southern and eastern Africa. This study examined plants being cultivated by farmers and found two chemotypes. Chemotype 1 (C1) contained rotenoids, including deguelin, rotenone, sarcolobine, tephrosin and α-toxicarol, required for pest control efficacy. Rotenoids were absent from chemotype 2 (C2), which was characterised by prenylated flavanones, including the previously unrecorded examples (2S)-5,7-dimethoxy-8-(3-hydroxy-3-methylbut-1Z-enyl)flavanone, (2S)-5,7-dimethoxy-8-(3-methylbut-1,3-dienyl)flavanone, (2S)-4′-hydroxy-5-methoxy-6″,6″-dimethylpyrano[2″,3″:7,8]flavanone, (2S)-5-methoxy-6″,6″-dimethyl-4″,5″-dihydrocyclopropa[4″,5″]furano[2″,3″:7,8]flavanone, (2S)-7-hydroxy-5-methoxy-8-prenylflavanone, and (2R,3R)-3-hydroxy-5-methoxy-6″,6″-dimethylpyrano[2″,3″:7,8]flavanone. The known compounds (2S)-5-methoxy-6″,6″-dimethylpyrano[2″,3″:7,8]flavanone (obovatin 5-methyl ether) and 5,7-dimethoxy-8-(3-hydroxy-3-methylbut-1Z-enyl)flavone (Z-tephrostachin) were also found in C2. This chemotype, although designated Tephrosia candida DC. in collections originating from the World Agroforestry Centre (ICRAF), was confirmed to be T. vogelii on the basis of morphological comparison with verified herbarium specimens and DNA sequence analysis. Sampling from 13 locations in Malawi where farmers cultivate Tephrosia species for insecticidal use indicated that almost 1 in 4 plants were T. vogelii C2, and so were unsuitable for this application. Leaf material sourced from a herbarium specimen of T. candida contained most of the flavanones found in T. vogelii C2, but no rotenoids. However, the profile of flavonol glycosides was different to that of T. vogelii C1 and C2, with 6-hydroxy-kaempferol 6-methyl ether as the predominant aglycone rather than kaempferol and quercetin. The structures of four unrecorded flavonol glycosides present in T. candida were determined using cryoprobe NMR spectroscopy and MS as the 3-O-α-rhamnopyranosyl(1 → 6)-β-galactopyranoside-7-O-α-rhamnopyranoside, 3-O-α-rhamnopyranosyl(1 → 2)[α-rhamnopyranosyl(1 → 6)]-β-galactopyranoside, 3-O-α-rhamnopyranosyl(1 → 2)[α-rhamnopyranosyl(1 → 6)]-β-galactopyranoside-7-O-α-rhamnopyranoside, and 3-O-α-rhamnopyranosyl(1 → 2)[(3-O-E-feruloyl)-α-rhamnopyranosyl(1 → 6)]-β-galactopyranosides of 6-hydroxykaempferol 6-methyl ether. Tentative structures for a further 37 flavonol glycosides of T. candida were assigned by LC–MS/MS. The correct chemotype of T. vogelii (i.e. C1) needs to be promoted for use by farmers in pest control applications.
