Five Novel Pterocarpan Derivatives From Sophora Flavescens

Main observation and conclusion Five 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-alpha production in RAW264.7 cells, and compound 1 showed significant inhibitory activity with inhibition rate of 86.22%, IC50 = 0.79 mu mol/L (dexamethasone as positive control, inhibition rate of 71.38%).