Anti-inflammatory terpenoid derivatives from the twigs of Syringa oblata var. dilatata

Abstract

As a part of our ongoing search for bioactive constituents from Korean medicinal sources, chemical investigations of Syringa oblata var. dilatata twigs were carried out, leading to the isolation and characterization of two new terpenoid derivatives (1-2) and five known compounds (3-7). The chemical structures of the compounds 1 and 2 were determined by extensive NMR data (H-1 and C-13 NMR, H-1-H-1 COSY, HSQC, HMBC, and NOESY), HRMS, and chemical methods. These compounds (1-7) were evaluated for their nitric oxide (NO) inhibitory effects in lipopolysaccharide (LPS)-activated microglial cells (BV-2). Compounds 2 and 4 exhibited significant anti-inflammatory activities, with IC50 values of 23.3 and 13.9 mu M, respectively, which displayed similar activity to the positive control, N-G -monomethyl-(L)-arginine ((L)-NMMA, IC50 20.7 mu M), without any cell toxicity.