Non-glycosidic iridoids from the roots of Patrinia scabra and their nitric oxide production inhibitory effects

Abstract

Phytochemical investigation on the 70% aqueous EtOH extract from the roots of Patrinia scabra led to the isolation and characterization of five new non-glycosidic iridoids, patriscabrins F-J (1-5), along with a known iridoid 11-ethoxyviburtinal (6). The structures of the new compounds 1-5 were determined by interpretation of spectroscopic data, particularly by 1D- and 2D-NMR and ECD studies. Thereafter, the isolates 1-6 were evaluated for their inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells. Of these, patriscabrin F (1) exhibited the most potent inhibitory effect with observed IC50 value of 14.1 mu M. In addition, patriscabrin G (2) and 11-ethoxyviburtinal (6) showed IC50 values 24.6 and 35.5 mu M, respectively.