The Distribution of Dihydrositosterol in Plant Fats.

Abstract

In previous reports from this laboratory it has been shown that a saturated sterol, dihydrositosterol, C₂₇H₄₇OH, is a constituent of the unsaponifiable matter obtained from the bran and endosperm of corn 1 and wheat. 2 The present communication supplies some additional information on the method of isolation, its occurrence in other plant fats, and properties.

For the isolation of this saturated sterol the method of Anderson and Nabenhauer 3 has been utilized with certain modifications which result in an increased yield of dihydrositosterol. The most important change, in the method already described, is acetylation of the sterol mixture before treating its carbon tetrachloride solution with acetic anhydride and sulfuric acid. This treatment with acetic anhydride and sulfuric acid is repeated until the carbon tetrachloride layer is colorless and no green color is developed by the addition of a fresh portion of acetic anhydride and sulfuric acid. This acetylation prevents the formation of sterol sulfates or sulfonic acids which not only reduce the yield but cause the formation of troublesome emulsions during subsequent washing of the carbon tetrachloride solution.

During the past two years the unsaponifiable matter prepared from a number of plant fats has been examined and dihydrositosterol was found to be present in appreciable quantity in the oil, bran and endosperm of corn, the bran, endosperm and germ of wheat and the bran from rice.

In the case of corn and wheat a higher concentration of the reduced stlerol was found in the outer covering, but a comparison between cottonseed oil and cottonseed meal, or linseed oil and linseed meal showed no such concentration. 4