Anti-inflammatory phenylpropanoid glycosides from Clerodendron trichotomum leaves

Abstract

The chromatographic separation of MeOH extract from Clerodendron trichotomum Thunberg leaves led to the isolation of three phenylpropanoid compounds. Using spectroscopic methods, the structures of these compounds were determined as beta-(3', 4'-dihydroxyphenyl)ethyl-O-alpha-L-rhamnopyranosyl (1-->3)-beta-D-(4-O-caffeoyl)-glucopyranoside, acteoside (verbascoside) (1), beta-(3', 4'-dihydroxyphenyl)ethyl-O-alpha-L-rhamnopyranosyl (1-->3)-beta-D-(6-O-caffeoyl)-glucopyranoside, isoacteoside (2), beta-(3', 4'-dihydroxyphenyl) ethyl-O-alpha-L-rhamnopyranosyl (1-->3)-beta-D-glucopyranoside, and decaffeoylacteoside (3). We measured the anti-inflammatory activity of these three phenylpropanoid compounds both in vitro (DPPH reduction assay, TBARS assay on Cu (2+)-induced oxidized LDL, PGE(2) assay) and in vivo (acetic acid induced vascular permeability in mice and carrageenan-induced hind paw edema in rats). 80% methanol fraction and acteoside had the activity.