Three previously undescribed cytochalasins,named xylariasins A‒C(1‒3),together with six known ones(4‒9)were iso-lated from Xylaria sp.CFL5,an endophytic fungus of Cephalotaxus fortunei.The chemical structures of all n...Three previously undescribed cytochalasins,named xylariasins A‒C(1‒3),together with six known ones(4‒9)were iso-lated from Xylaria sp.CFL5,an endophytic fungus of Cephalotaxus fortunei.The chemical structures of all new compounds were elucidated on the basis of extensive spectroscopic data analyses and electronic circular dichroism calculation,as well as optical rotation calculation.Biological activities of compounds 1,4‒9 were evaluated,including cytotoxic,LAG3/MHC II binding inhibition and LAG3/FGL1 binding inhibition activities.Compounds 6 and 9 possessed cytotoxicity against AGS cells at 5μM,with inhibition rates of 94%and 64%,respectively.In addition,all tested isolates,except compound 6,exhibited obvious inhibitory activity against the interaction of both LAG3/MHC II and LAG3/FGL1.Compounds 1,5,7,and 8 inhibited LAG3/MHC II with IC50 values ranging from 2.37 to 4.74μM.Meanwhile,the IC50 values of compounds 1,7,and 8 against LAG3/FGL1 were 11.78,4.39,and 7.45μM,respectively.展开更多
A chemical investigation of the 95%EtoH extract of the seeds of Cephalotaxus fortunei var.alpina led to the isolation of nine new cephalotane-type norditerpenoids,ceforalides A-I(1-9),and two known analogues(10 and 11...A chemical investigation of the 95%EtoH extract of the seeds of Cephalotaxus fortunei var.alpina led to the isolation of nine new cephalotane-type norditerpenoids,ceforalides A-I(1-9),and two known analogues(10 and 11).Compounds 1-8 belong to a rare class of A-ring-contracted cephalotane-type norditerpenoids,of which compound 8 incorporates a unique tetrasubstituted 2,5-cyclohexadienone A-ring.Compound 9 is a rare 13,14-seco-17-nor-cephalotane-type diterpenoid.Their structures were determined based on NMR,HRESIMS,ECD,and X-ray diffraction analysis.Biological tests revealed compounds 10 and 11 displayed moderate antimalarial activity.展开更多
基金supported financially by the National Natural Science Foundation of China(No.21778027)the Natural Science Foundation of Gansu Province(No.18JR4RA003).
文摘Three previously undescribed cytochalasins,named xylariasins A‒C(1‒3),together with six known ones(4‒9)were iso-lated from Xylaria sp.CFL5,an endophytic fungus of Cephalotaxus fortunei.The chemical structures of all new compounds were elucidated on the basis of extensive spectroscopic data analyses and electronic circular dichroism calculation,as well as optical rotation calculation.Biological activities of compounds 1,4‒9 were evaluated,including cytotoxic,LAG3/MHC II binding inhibition and LAG3/FGL1 binding inhibition activities.Compounds 6 and 9 possessed cytotoxicity against AGS cells at 5μM,with inhibition rates of 94%and 64%,respectively.In addition,all tested isolates,except compound 6,exhibited obvious inhibitory activity against the interaction of both LAG3/MHC II and LAG3/FGL1.Compounds 1,5,7,and 8 inhibited LAG3/MHC II with IC50 values ranging from 2.37 to 4.74μM.Meanwhile,the IC50 values of compounds 1,7,and 8 against LAG3/FGL1 were 11.78,4.39,and 7.45μM,respectively.
基金This work was supported by the National Natural Science Foundation of China(Nos.81872758,21907099)Science and Technology Commission of Shanghai Municipality(19YF1457000)。
文摘A chemical investigation of the 95%EtoH extract of the seeds of Cephalotaxus fortunei var.alpina led to the isolation of nine new cephalotane-type norditerpenoids,ceforalides A-I(1-9),and two known analogues(10 and 11).Compounds 1-8 belong to a rare class of A-ring-contracted cephalotane-type norditerpenoids,of which compound 8 incorporates a unique tetrasubstituted 2,5-cyclohexadienone A-ring.Compound 9 is a rare 13,14-seco-17-nor-cephalotane-type diterpenoid.Their structures were determined based on NMR,HRESIMS,ECD,and X-ray diffraction analysis.Biological tests revealed compounds 10 and 11 displayed moderate antimalarial activity.
