Detection in extracts of bovine brain of lipophilic complexes of sulfate esters of cholesterol and beta-sitosterol.

Evidence indicating that there exist in bovine brains hitherto-unrecognized lipophilic conjugates of sterol sulfates is presented. These conjugates are soluble in nonpolar solvents and, when heated in methanol containing pyridine, yield polar sterol conjugates. These polar substances have the chromatographic mobility of sterol sulfates and are cleaved to free sterols when subjected to a solvolytic process known to be specific for sulfate esters. The brain sterols that have been identified in this way are cholesterol and beta-sitosterol.