ABSTRACT
Sterols are high-melting alcohols with a typical structure based on the cholestane structure and are ubiquitous in nature. They perform important physiological roles in all living organisms. Information on the composition of sterols in various sources, animal as well as vegetable, has been an area of analytical interest for a long time, from both the physiological perspective and for their role as marker substances in identification. Comprehensive reviews on the different instrumental techniques for sterol analysis are collated in the book by Goad and Akihisa and the recent paper by Abidi (1,2). Sterols are classified into three main groups (“sterol classes”) based on the presence or absence of methyl moieties at the 4-position in the A ring. The most frequently occurring natural plant sterols are the desmethyl sterols β-sitosterol, campesterol, and stigmasterol (Fig. 1). Dietary intake ranges from 250 to 500mg/day with about 65% of intake as β-sitosterol, 30% as campesterol, and 5% as stigmasterol and low amounts of other sterols (3-5). Recently, the efficacy of plant sterols, predominantly the 4-desmethyl sterols, in lowering blood cholesterol levels has drawn renewed interest. This also resulted in a renewed interest in their analysis. Reviews on the cholesterol-lowering properties of plant sterols and stanols, being the fully saturated sterol analogues, focus on this cholesterol lowering effect
