Seven indole alkaloid glycosides containing a 1′-(4″-hydroxy-3″,5″-dimethoxyphenyl)ethyl unit(1-7)were isolated from an aqueous extract of Isatis indigotica leaves(da qing ye).Their structures were determined by s...Seven indole alkaloid glycosides containing a 1′-(4″-hydroxy-3″,5″-dimethoxyphenyl)ethyl unit(1-7)were isolated from an aqueous extract of Isatis indigotica leaves(da qing ye).Their structures were determined by spectroscopic data analysis combined with enzymatic hydrolysis as well as comparison of their experimental CD(circular dichroism)and calculated ECD(electrostatic circular dichroism)spectra.Based on analysis of[α]D20 and/or Cotton effect(CE)data of 1-7,two simple roles to assign location and/or configuration ofβ-glycopyranosyloxy and 1′-(phenyl)ethyl units in the indole alkaloid glycosides are proposed.Stereoselectivity in plausible biosynthetic pathways of 1-7 is discussed.Compounds 3 and 4 and their mixture in a 3:2 ratio showed activity against KCNQ2 in CHO cells.The mixture of 5 and 6(3:2)exhibited antiviral activity against influenza virus H1 N1 PR8 with IC5064.7μmol/L(ribavirin,IC5054.3μmol/L),however,the individual 5 or 6 was inactive.Preliminary structure-activity relationships were observed.展开更多
基金Financial support of the National Natural Science Foundation of China(81630094,21732008,and 81730093)CAMS Innovation Fund for Medical Science of China(2017-I2M-3-010 and 2016-I2M1-010)the Drug Innovation Major Project(2018ZX09711001001-001,China)
文摘Seven indole alkaloid glycosides containing a 1′-(4″-hydroxy-3″,5″-dimethoxyphenyl)ethyl unit(1-7)were isolated from an aqueous extract of Isatis indigotica leaves(da qing ye).Their structures were determined by spectroscopic data analysis combined with enzymatic hydrolysis as well as comparison of their experimental CD(circular dichroism)and calculated ECD(electrostatic circular dichroism)spectra.Based on analysis of[α]D20 and/or Cotton effect(CE)data of 1-7,two simple roles to assign location and/or configuration ofβ-glycopyranosyloxy and 1′-(phenyl)ethyl units in the indole alkaloid glycosides are proposed.Stereoselectivity in plausible biosynthetic pathways of 1-7 is discussed.Compounds 3 and 4 and their mixture in a 3:2 ratio showed activity against KCNQ2 in CHO cells.The mixture of 5 and 6(3:2)exhibited antiviral activity against influenza virus H1 N1 PR8 with IC5064.7μmol/L(ribavirin,IC5054.3μmol/L),however,the individual 5 or 6 was inactive.Preliminary structure-activity relationships were observed.
