The intestinal uptake of paclitaxel is hampered by trans-membrane efflux transporters such as P-glycoprotein(P-gp),and paclitaxel is mainly metabolized by cytochrome P4503A4(CYP3A4)presented in the liver.Our previous ...The intestinal uptake of paclitaxel is hampered by trans-membrane efflux transporters such as P-glycoprotein(P-gp),and paclitaxel is mainly metabolized by cytochrome P4503A4(CYP3A4)presented in the liver.Our previous results demonstrated that flavonoids extracted from Taxus yunnanensis could improve the oral absorption of paclitaxel.The current study was purposed to investigate the effects of the flavonoid extracts on P-gp and CYP3A4 in vitro.The expression and activity of P-gp were detected by western blotting and intracellular rhodamine 123 accumulation assay in Caco-2 cells treated with the flavonoids extract.The expression of CYP3A4 was investigated by western blotting in mouse primary hepatocytes and the activity of CYP3A4 was detected by LC-MS/MS method using rat liver microsomes.Our results showed that the flavonoid extracts from T.yunnanensis could inhibit P-gp activity and concurrently decrease the expression and activity of CYP3A4.In conclusion,activity of P-gp and CYP3A4 could be inhibited by flavonoids extracted from T.yunnanensis which might be potential candidates for development of oral formulation of paclitaxel.展开更多
The structure of a new abietane diterpenoid, taxayunnin (1), from the barks of Taxus yunnanensis, was determined by spectroscopic analysis. A known abietane diterpenoid, taxamairin C (2), was also isolated.
A new taxane diterpenoid with a rearranged 5/7/6-membered ring system was isolated from the seeds of the Chinese pew, Taxus yunnanensis. Its structure was established as 9 alpha-acetoxy-5 alpha-cinnamoy]-11(15 --> ...A new taxane diterpenoid with a rearranged 5/7/6-membered ring system was isolated from the seeds of the Chinese pew, Taxus yunnanensis. Its structure was established as 9 alpha-acetoxy-5 alpha-cinnamoy]-11(15 --> 1)-abeotaxa-4(20), 11-diene-10 beta, 13 alpha, 15-triol on the basis of spectroscopic analysis. Its relative stereochemistry is proposed from the results of a NOESY experment.展开更多
Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experime...Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experiments.展开更多
Two new baccatin Ⅲ type taxoids, 13-Cinnamoylbaccatin Ⅲ (1) and 7-xylosylbaccatin Ⅲ(2), have been isolated from the barks of Taxus yunnanensis. The structures were elucidated by spectral means.
Three hitherto unknown taxane diterpenoids,namely baccatin Ⅷ(1),baccatin Ⅸ(2),and baccatin Ⅹ(3),along with 10 known analogues were isolated from an ethanolic extract of the twigs and leaves of Taxus yunnanensis.The...Three hitherto unknown taxane diterpenoids,namely baccatin Ⅷ(1),baccatin Ⅸ(2),and baccatin Ⅹ(3),along with 10 known analogues were isolated from an ethanolic extract of the twigs and leaves of Taxus yunnanensis.The new structures were characterized based on extensive spectroscopic analysis.Compounds 1 and 2 were tested for their in vitro cytotoxicity against five human tumor cell lines,and 1 exhibited inhibitory effects on HL-60 and MCF-7,with IC_(50) values of 3.44 and 9.67 μM,respectively.展开更多
Two new tetracyclic taxane diterpenoids----yunnanxol(1) and yunnanxamine(2)have been isolated from the bark of Taxus yunnanensis Cheng et L.K.Fu.Their structures have been established from the spectral data,mainly fro...Two new tetracyclic taxane diterpenoids----yunnanxol(1) and yunnanxamine(2)have been isolated from the bark of Taxus yunnanensis Cheng et L.K.Fu.Their structures have been established from the spectral data,mainly from MS,highfield ~1H NMR,~1H-~1H COSY, ^(13)C NMR,^(13)C-~1H COSY and ^(13)C-~1H COLOC spectroscopies.展开更多
: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is...: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is described.展开更多
A new skeleton taxane diterpene,taxayuntin,was isolated from the leaves and stems of Taxus yunnanensis.Its structure was determined by spectroscopic methods(MS,~1H NMR,^(13)C NMR, ~1H-~1H COSY,~1H-^(13)C COSY and ^(13...A new skeleton taxane diterpene,taxayuntin,was isolated from the leaves and stems of Taxus yunnanensis.Its structure was determined by spectroscopic methods(MS,~1H NMR,^(13)C NMR, ~1H-~1H COSY,~1H-^(13)C COSY and ^(13)C-~1H COLOC)and X-ray diffraction.展开更多
The phytochemical investigation on the ethanolic extracts of the barks of Taxus yunnanensis (Taxaceae) led to the isolation of two new neo-lignans, named taxuyunins A (1) and B (2), a-long with the known diterpenolign...The phytochemical investigation on the ethanolic extracts of the barks of Taxus yunnanensis (Taxaceae) led to the isolation of two new neo-lignans, named taxuyunins A (1) and B (2), a-long with the known diterpenolignan, brevitaxin (3). Their structures were elucidated on the basis of spectroscopic and chemical evidences. Compound 1 is a neo-lignan xyloside while compound 2 belongs to the rare neo-lignan possessing a ramified C3 side chain.展开更多
基金The work was supported by Foundation from Guangdong Province Science and Technology Department(Grant number:2012A080202013 and 2009A030100002)National Natural Science Foundations of China(Grant number:81202961)the National Major Projects for science and technology development from Science and Technology Ministry of China(Grant No.2012ZX09506001-004).
文摘The intestinal uptake of paclitaxel is hampered by trans-membrane efflux transporters such as P-glycoprotein(P-gp),and paclitaxel is mainly metabolized by cytochrome P4503A4(CYP3A4)presented in the liver.Our previous results demonstrated that flavonoids extracted from Taxus yunnanensis could improve the oral absorption of paclitaxel.The current study was purposed to investigate the effects of the flavonoid extracts on P-gp and CYP3A4 in vitro.The expression and activity of P-gp were detected by western blotting and intracellular rhodamine 123 accumulation assay in Caco-2 cells treated with the flavonoids extract.The expression of CYP3A4 was investigated by western blotting in mouse primary hepatocytes and the activity of CYP3A4 was detected by LC-MS/MS method using rat liver microsomes.Our results showed that the flavonoid extracts from T.yunnanensis could inhibit P-gp activity and concurrently decrease the expression and activity of CYP3A4.In conclusion,activity of P-gp and CYP3A4 could be inhibited by flavonoids extracted from T.yunnanensis which might be potential candidates for development of oral formulation of paclitaxel.
基金This project was supported by the National Natural Science Foundation of China (3950081)theYoung Academic and Technical Leader Raising Foundation of Yunnan Province (awarded to H.-J.Zhang.) the Special Supported Bioscience and Biotechnique Foundation of Academic Sinica(STZ-11).
文摘The structure of a new abietane diterpenoid, taxayunnin (1), from the barks of Taxus yunnanensis, was determined by spectroscopic analysis. A known abietane diterpenoid, taxamairin C (2), was also isolated.
基金described here comes from the Ministry of Education, Scienceports, and Culture of japan through a grant-in-aid for scientifi
文摘A new taxane diterpenoid with a rearranged 5/7/6-membered ring system was isolated from the seeds of the Chinese pew, Taxus yunnanensis. Its structure was established as 9 alpha-acetoxy-5 alpha-cinnamoy]-11(15 --> 1)-abeotaxa-4(20), 11-diene-10 beta, 13 alpha, 15-triol on the basis of spectroscopic analysis. Its relative stereochemistry is proposed from the results of a NOESY experment.
文摘Four new taxane diterpenoids were isolated from the bark of Taxus yunnanensis.Their structures were elucidated as the new skeleton with 5/7/6/4 membered rings by spectral analysis and 2D NMR shift correlation experiments.
文摘Two new baccatin Ⅲ type taxoids, 13-Cinnamoylbaccatin Ⅲ (1) and 7-xylosylbaccatin Ⅲ(2), have been isolated from the barks of Taxus yunnanensis. The structures were elucidated by spectral means.
基金financially supported by the "Large-scale Compound Library" project of National DevelopmentReform Commission of China and the"Western Light" talents training program of Chinese Academy of Sciences.
文摘Three hitherto unknown taxane diterpenoids,namely baccatin Ⅷ(1),baccatin Ⅸ(2),and baccatin Ⅹ(3),along with 10 known analogues were isolated from an ethanolic extract of the twigs and leaves of Taxus yunnanensis.The new structures were characterized based on extensive spectroscopic analysis.Compounds 1 and 2 were tested for their in vitro cytotoxicity against five human tumor cell lines,and 1 exhibited inhibitory effects on HL-60 and MCF-7,with IC_(50) values of 3.44 and 9.67 μM,respectively.
文摘Two new tetracyclic taxane diterpenoids----yunnanxol(1) and yunnanxamine(2)have been isolated from the bark of Taxus yunnanensis Cheng et L.K.Fu.Their structures have been established from the spectral data,mainly from MS,highfield ~1H NMR,~1H-~1H COSY, ^(13)C NMR,^(13)C-~1H COSY and ^(13)C-~1H COLOC spectroscopies.
文摘: The microbiological transformaion of a natural taxoid 10-deacetylbaccatin III into its C-7 epimer, 10-deacetylbaccatin V with Microsphaeropsis onychiuri, a fungus isolated from the inner bark of Taxus yunnanensis is described.
文摘A new skeleton taxane diterpene,taxayuntin,was isolated from the leaves and stems of Taxus yunnanensis.Its structure was determined by spectroscopic methods(MS,~1H NMR,^(13)C NMR, ~1H-~1H COSY,~1H-^(13)C COSY and ^(13)C-~1H COLOC)and X-ray diffraction.
基金Project supported by the National Natural Science Foundation of China(No.3950081),the Young Academic and Technical Leader Raising Foundation of Yunnan Province(awarded to Hong-Jie Zhang),and the Special Supported Bioscience and Biotechnique Foundation of
文摘The phytochemical investigation on the ethanolic extracts of the barks of Taxus yunnanensis (Taxaceae) led to the isolation of two new neo-lignans, named taxuyunins A (1) and B (2), a-long with the known diterpenolignan, brevitaxin (3). Their structures were elucidated on the basis of spectroscopic and chemical evidences. Compound 1 is a neo-lignan xyloside while compound 2 belongs to the rare neo-lignan possessing a ramified C3 side chain.
