Improved method for the synthesis of trans-feruloyl-beta-sitostanol

Phytosterols and phytostanols are known to lower low-density lipoprotein-cholesterol (LDL-C) levels in humans by up to 15%, and at least two products, Benecol and Take Control, are now on the market as naturally derived fatty acid esters of phytostanols (stanol esters) and phytosterols (sterol esters), respectively. A synthetic process was developed to synthesize gram quantities of trans-feruloyl-beta-sitostanol from ferulic acid and beta-sitostanol, with high purity and yields of approximately 60%. The process involves (a) condensation of trans-4-O-acetylferulic acid with the appropriate phytostanol or phytostanol mixture in the presence of N,N-dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine, (b) separation of the trans-4-O-acetylferuloyl products by preparative liquid chromatography, (c) selective deacetylation of the feruloyl acetate, and (d) chromatographic purification of the feruloylated phytostanols. The process was successfully applied to synthesize stanol trans-feruloyl esters from "Vegetable Stanols", a mixture of approximately 70:30 beta-sitostanol and beta-campestanol, in comparable purity and yield.