Tyrosinase Inhibitory Activity of Chemical Constituents of Euphorbia macrostegia

Abstract

The chloroform extract of the aerial parts of E. macrostegia has yielded a new compound, 2-(4-hydroxyphenyl)-ethylhentriacontanoate (1), along with hentriacontan-1-ol (2), lupenone (3), cycloart-22-ene-3,25-diol (4), 3,3-,4--tri-O-methylellagic acid (5), cleomiscosin (6), and glucoclioniasterol (stigmast-5-en-3-O-beta-glucopyranoside) (7), and from the ethyl acetate extract of aerial parts of the plant isoquercetin (8), quercetin-3-O-alpha-arabinofuranoside (avicularin) (9), and rutin (10) have been isolated. Compounds 1-10 were tested for their tyrosinase inhibitory activity, and 2 exhibited an IC50 value of 71.4 mu M, almost comparable to standard kojic acid (IC50 58.2 mu M). Compounds 1-4 also showed good activity with IC50 values of 77.2, 78.6, 71.4, and 77.5 mu M, respectively.