A new acylated quercetin triglycoside with anti-inflammatory activity from the leaves of Camellia flavida var. flavida

Abstract

Phytochemical investigation of the leaves of Camellia flavida var. flavida led to the isolation of a previously undescribed acylated quercetin triglycoside (1), together with three known constituents (2–4). Their structures were established by HR-ESI-MS with 1D and 2D NMR analyses and, for the known compounds, by comparison with reported spectroscopic data. Compound 1 was elucidated as quercetin 3-O-[β-D-glucopyranosyl-(1→3)]-[α-L-rhamnopyranosyl-(1→6)]-[2-O-(E)-p-coumaroyl]-β-D-glucopyranoside. Compounds 1–3 inhibited lipopolysaccharide-induced nitric oxide production in RAW 264.7 macrophages, with IC50 values of 14.9 ± 1.7, 13.4 ± 2.6, and 37.7 ± 2.9 μM, respectively, while their CC50 values were >64 μM. 4 was cytotoxic (CC50 10.9 ± 0.7 μM) and was therefore not evaluated for nitric oxide inhibition. These findings expand the known chemical diversity of C. flavida var. flavida and identify 1 and 2 as moderate inhibitors of nitric oxide production.