Five Novel Pterocarpan Derivatives from Sophora flavescens

Abstract

Main observation and conclusionFive novel pterocarpan derivatives (1—5) and three known pterocarpans were isolated from the roots of Sophora flavescens Ait. Their structures were elucidated based on extensive spectroscopic data (UV, IR, 1D and 2D NMR, and HR‐ESI‐MS). Notably, compounds 1—5 were the first reported natural products, which possess unique pterocarpan‐glucose‐long chain aliphatic acid structures. The kinds of aliphatic acids were determined by comparison with authentic aliphatic acids using HPLC‐ELSD analysis after acid hydrolysis. The absolute configurations of 1—5 were confirmed by analysis of their ECD spectra. All compounds were evaluated against lipopolysaccharide (LPS)‐induced TNF‐α production in RAW264.7 cells, and compound 1 showed significant inhibitory activity with inhibition rate of 86.22%, IC50 = 0.79 μmol/L (dexamethasone as positive control, inhibition rate of 71.38%).