Indole alkaloid glucosides from the roots of Isatis indigotica

Abstract

Five new indole alkaloid glucosides named isatindigotindolosides A-E (1–5), along with three known analogs (6–8), were isolated from an aqueous extract of the Isatis indigotica roots. Their structures including the absolute configurations were determined based on comprehensive spectroscopic data analysis, combined with chemical methods and electronic circular dichroism spectra calculations. In the preliminary assays, compounds 1, 6 and 7 showed antiviral activity against influenza virus A/Hanfang/359/95 (H3N2) with IC₅₀ values of 14.6–33.3 μM. Compound 1 also exhibited inhibitory effect against nitric oxide (NO) production in microglial cell BV2 with an inhibition ratio of 93.0% at 10 μM.

Keywords:

• Cruciferae
• Isatis indigotica
• indole alkaloid glucoside
• isatindigotindolosides A–E
• antiviral activity
• inhibition activity against nitric oxide production

Acknowledgment

We thank Chinese Academy of Medical Sciences and Peking Union Medical College High Performance Computing Platform for supporting the calculation of the ECD spectra.