Conversion of Beta Sitosterol to Cholesterol Blocked in an Insect by Hypocholesterolemic Agents

Abstract
Two vertebrate hypocholesterolemic agents (triparanol and 22,25-diazacholesterol) block the conversion of β-sitosterol to cholesterol in the larva of the tobacco hornworm, Manduca sexta (Johannson). A primary site of inhibitory action is the terminal step in this conversion—the reduction of desmosterol (24-dehydrocholesterol) to cholesterol. This is also the site at which these compounds inhibit de novo cholesterol biosynthesis in higher animals. Both agents severely inhibit growth and maturation of the tobacco hornworm.