gamma-sitosterol and flavan-3-ol

Antioxidant activity in edible fruits is an important characteristic in the choice of fruits for human consumption, and has profound influence on nutrition and health. Two pharmacologically active triterpenoids, β-sitosterol and lupeol, and the powerful flavan-3-ol antioxidant, (+)-catechin, were isolated from the edible fruits of Harpephyllum caffrum while a mixture of cardanols, an alkyl p-coumaric acid ester, and (+)-catechin were isolated from the stem bark. This is the first report of these compounds being isolated from this plant. The antioxidant capacity of (+)-catechin was higher than the other isolated compounds as well as the known antioxidant, ascorbic acid.

Topics: Anacardiaceae; Antioxidants; Coumaric Acids; Flavonoids; Fruit; Magnetic Resonance Spectroscopy; Molecular Structure; Pentacyclic Triterpenes; Phenols; Plant Bark; Plants, Medicinal; Propionates; Sitosterols

This paper examines the antiprotozoal activity of the dichloromethane-MeOH extract, fractions and pure compounds from the roots of Geranium mexicanum on Entamoeba histolytica and Giardia lamblia. The result indicated that the extract, organic fraction and a pure flavonoid were active against both protozoa with IC50 values ranging from 1.9 to 79.2 microg/ml for Entamoeba histolytica and from 1.6 to 100.4 microg/ml in the case of Giardia lamblia. The main active compound was the flavan-3-ol, (-)-epicatechin. In addition, the moderate active compounds (+)-catechin, tyramine and beta-sitosterol 3-O-beta-D-glucopyranoside, also were isolated. These results support the anecdotal reports for the traditional use of Geranium mexicanum roots in the management of diarrhoea and dysentery, illnesses caused in some cases by enteric protozoa.

Topics: Animals; Antiprotozoal Agents; Catechin; Drug Evaluation, Preclinical; Entamoeba histolytica; Ethanol; Flavonoids; Geranium; Giardia lamblia; Glucosides; Inhibitory Concentration 50; Methylene Chloride; Plant Extracts; Plant Roots; Sitosterols