The Biosynthesis of Plant Sterols

Abstract

The great variety of plant sterols and related compounds have for many years been a source of interest to natural products chemists because of the challenges they have offered in structural determination and development of analytical techniques. Interest in the biosynthesis of animal sterols spans the past thirty years, but plant sterol biosynthesis has been extensively investigated only since about 1965. Apart from the additional mechanisms required for the introduction of the extra carbon atoms into the side of typical plant sterols, there was probably the expectation that the pathway in plants would be much the same as the animal route leading from acetyl-CoA through mevalonic acid, squalene, and lanosterol to cholesterol. It soon became apparent, however, that such is not the case, and the studies of phytosterol biosynthesis have been rewarded by the recognition of several intriguing mechanistic differences not only between animals and plants but also between particular classes of plants. Moreover some of these differences appear to correlate with other evidence showing phylo-genetic relationships of various classes of lower and higher plants.