Lignans and a neolignan from an aqueous extract of Isatis indigotica roots

Abstract

Four new lignans (1−4) and one new neolignan (5), along with two known lignan derivatives (6 and 7), were isolated from an aqueous extract of the Isatis indigotica root (ban lan gen). Their structures were determined by spectroscopic data analysis, chemical method, and theoretical calculation, for which 1 was proved by single-crystal X-ray diffraction. Compound 2 exhibited antiviral activity against influenza virus A/Hanfang/359/95 (H3N2) with an IC₅₀ value of 11.1 µM and a selective index (SI) > 9, while 1 and 5 are the first examples of sulfonated lignan and neolignan from nature.

Graphical Abstract

Keywords:

• Cruciferae
• Isatis indigotica
• sulfonated lignan and neolignan
• cyclolignan glucoside
• antiviral activity

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Financial support from the National Natural Sciences Foundation of China (grant nos. 81630094 and 81730093) and CAMS Innovation Fund for Medical Science (2021-I2M-1-028) are acknowledged.