3-Geranyl-4-hydroxy-5-(3 '-methyl-2 '-butenyl)benzoic acid as an anti-inflammatory compound from Myrsine seguinii

Bioassay-guided isolation of anti-inflammatory compounds from the methanol extract of Myrsine seguinii yielded an anti-inflammatory compound (1). The structure of compound 1 was elucidated to be 3-geranyl-4-hydroxy-5-(3'-meth yl-2'-butenyl)benzoic acid on the basis of its spectroscopic data. Compound 1 strongly suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced i nflammation on mouse ears at a dose of 500 mu g (inhibitory effect (IE): 65 %). The acetate and the methyl ether of 1 showed moderate activity at a 500 -mu g application, with IE 38% and 27%, respectively. However, the methyl e ster and the dimethyl derivative of 1 did not show activity at the same dos e. The related compounds of 1, o-, m- and p-hydroxybenzoic acids also did n ot exhibit notable activity. These results indicate that the carboxylic aci d and lipophilic terpene moieties of 1 were significant structural features for anti-inflammatory activity.