Isatindolignanoside A, a glucosidic indole-lignan conjugate from an aqueous extract of the Isatis indigotica roots

A glucosidic indole-lignan conjugate with a novel carbon skeleton, named isatindolignanoside A (1), was isolated from an aqueous extract of the Isatis indigotica roots ban Ian gen. Its structure was elucidated by comprehensive analysis of spectroscopic data, includingJ- and NOESY correlation-based configurational analysis, circular dichroism (CD) data, enzyme hydrolysis, and theoretical ECD calculation. In a preliminary assay, compound 1 showed antiviral activity against Coxsackie virus B3. This compound is the first example of natural product having a structural feature of conjugation between indole and lignan units, and its biosynthetic pathway is postulated. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.