cytellin and astilbin

Erythroxylum species have several traditional uses in different countries, including the treatment of hypertension. The ethanol extract from E. gonocladum aerial parts, a species endemic to the Brazilian cerrado, elicited a concentration-dependent inhibition of angiotensin converting enzyme (ACE) (pIC(50)=4.53+/-0.05). Extract fractionation led to the isolation of two compounds, whose structures were assigned by spectrometric data as astilbin and beta-sitosterol, along with a mixture of palmitic, stearic and linolenic acids. This is the first report on the occurrence of these compounds on E. gonocladum. Astilbin promoted significant ACE inhibition in vitro (pIC(50)=5.86+/-0.33) and its activity did not differ from captopril, when both compounds were assayed at 10 microM concentration.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Antihypertensive Agents; Brazil; Captopril; Dose-Response Relationship, Drug; Erythroxylaceae; Fatty Acids; Flavonols; Peptidyl-Dipeptidase A; Plant Components, Aerial; Plant Extracts; Rats; Sitosterols