Four interesting sequoiatones stereoisomers(1-4) were isolated from a wetland soil-derived fungus Talaromyces flavus by chiral HPLC.On the basis of comprehensive NMR and mass analyses,their planar structures were eluc...Four interesting sequoiatones stereoisomers(1-4) were isolated from a wetland soil-derived fungus Talaromyces flavus by chiral HPLC.On the basis of comprehensive NMR and mass analyses,their planar structures were elucidated as the same as that of sequoiatone B.Among them,1 and 3(or 2 and 4)were a pair of enantiomers,and 1 and 2(or 3 and 4) were a pair of stereoisomers with epimerization at C-12,which indicated that sequoiatione-type metabolites exist as enantiomers rather than as optically pure compounds in some strains.With the quantum chemical ECD calculations,the absolute configurations of C-8 in 1-4 were determined,which is the first report to establish the absolute configuration of C-8 in sequoiatones.However,the absolute configurations of C-12 in sequoiatones are still unsolved.展开更多
基金financially supported by grants from the National Natural Science Foundation of China(Nos.81422054 and81172945)the Guangdong Natural Science Funds for Distinguished Young Scholar(S2013050014287)+1 种基金Guangdong Special Support Program(2014TQ01R420)Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme(Hao Gao,2014)
文摘Four interesting sequoiatones stereoisomers(1-4) were isolated from a wetland soil-derived fungus Talaromyces flavus by chiral HPLC.On the basis of comprehensive NMR and mass analyses,their planar structures were elucidated as the same as that of sequoiatone B.Among them,1 and 3(or 2 and 4)were a pair of enantiomers,and 1 and 2(or 3 and 4) were a pair of stereoisomers with epimerization at C-12,which indicated that sequoiatione-type metabolites exist as enantiomers rather than as optically pure compounds in some strains.With the quantum chemical ECD calculations,the absolute configurations of C-8 in 1-4 were determined,which is the first report to establish the absolute configuration of C-8 in sequoiatones.However,the absolute configurations of C-12 in sequoiatones are still unsolved.
