A novel indole alkaloid glycoside with an unprecedented 2-(diphenylpropyl)indole skeleton, isatindigodiphindoside (1), was isolated from an aqueous extract of the roots of Isatis indigotica. The structure was determined by extensive spectroscopic studies, especially by 2D NMR data analysis combined with enzymatic hydrolysis and ECD calculations. Plausible biosynthetic pathways of compound 1 are also discussed. (C) 2017 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.