Studies on the Sterol of Bombyx mori L. IV. Conversion of the Sterol in the Silkworm.

Abstract

Conversion of β-sitosterol to cholesterol in the silkworm was demonstrated using 3H-β-sitosterol. After ingestion of 3H-β-sitosterol in the larva, the ether extract of homogenized larva was fractionated on alumina. The sterol fraction was separated into cholesterol and β-sitosterol by gas chromatography and the radioactivity of each collected fraction was counted. The strong radioactivity of the larval cholesterol fraction suggested that larva is able to convert β-sitosterol in the diet to cholesterol. But in the pupa incorporation of 3H-β-sitosterol into cholesterol in free fraction was observed, while that in sterol ester fraction was not.