Alkaloids of NIRAM, natural dye from Polygonum tinctorium, and their anti-inflammatory activities

Abstract

Phytochemical investigation of EtOH extract of NIRAM, natural dye from Polygonum tinctorium, resulted in the purification of nine alkaloid compounds (1-9) including four new compounds (1-4). Structures of these new compounds were elucidated by 1D and 2D NMR (H-1 and C-13 NMR, H-1-H-1 COSY, H-1-C-13 HSQC, H-1-C-13 HMBC), IR, UV, HR-ESI-MS, and ECD spectra. Isolated compounds (1-9) were tested for their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated BV-2 cells. Compounds 1-3, 5, and 7 showed potent NO production inhibitory activities, with IC50 values of 3.88-22.87 mu M. (C) 2019 Elsevier Ltd. All rights reserved.