An appetite suppressant from Hoodia species

Abstract

Two new pregnane glycosides were isolated by fractionation of the dried stems of Hoodia gordonii. Their structures were determined as 3beta-[beta-D-thevetopyranosyl-(1→4)-beta-D-cymaropyranosyl-(1→4)-beta-D-cymaropyranosyloxy]-12beta-tigloyloxy-14beta-hydroxypregn-5-en-20-one (1) and 3beta-[beta-D-cymaropyranosyl-(1→4)-beta-D-6-deoxy-3-O-methylallopyranosyl-(1→4)-beta-D-cymaropyranosyl-(1→4)-beta-D-cymaropyranosyloxy]-12beta-tigloyloxy-14beta-hydroxypregn-5-en-20-one (2) on the basis of spectroscopic studies and conversion to known compounds. Compounds 1 and 2 were also isolated from Hoodia pilifera. Compound 1 was tested for its appetite-suppressant properties in rats by oral gavage at 6.25 to 50 mg/kg and the results showed that all doses resulted in a decrease of food consumption over an eight day period and a body mass decrease when compared to the control sample receiving only the vehicle. In a comparative study against a fenfluramine control sample, compound 1 resulted in a reduction in food intake over the study period, with a concomitant overall decrease in body weight while fenfluramine resulted in a small decrease in food intake, but an increase in body weight (though less than control group) over the same period of time.