Aromatic compounds from an aqueous extract of “ban lan gen” and their antiviral activities

A pair of new diphenyl glycerol ether enantiomers（-）-l and（+）-l and two new methyl benzamidobenzoates 2 and 3,named（-）-（R）-and（+）-（S）-isatindigotrioic acid[（-）-l and（+）-l]and isatindigoticamides A（2） and B（3）,respectively,were isolated from an aqueous decoction of the roots of Isatis indigotica（ban lan gen）.Their structures were elucidated by spectroscopic data analysis including2 D NMR experiments.The absolute configurations of（-）-l and（+）-l were assigned based on the CD exciton chirality method.Compounds 2 and 3 exhibited antiviral activities against HSV-1 with IC50values of 4.87 and 25.87μmol/L,respectively.Compound 2 was also found active against Coxsackie virus B3 and LPS-induced NO production.