Chiral monoterpenoids in plants — Enantioselective chromatographic analysis, and their bioactivity

Abstract

Monoterpenoids are the components of essential oils, whichare produced and accumulated, in large amounts by plants from certain families, including Labiatae, Pinaceae, Cupressaceae, Umbelliferae and Rutaceae . They are of special interest because of their industrial applications and on account of their chemical properties and Biol.ogical activity. Monoterpenic composition can be useful in genetic and chemotaxonomic studies of coniferous species. The first reports concerning the enantiomeric separations of monoterpenoids in essential oils were published in the early nineties. These studies were concerned with the elaboration of simple analytical methods adequate for chiral separations in these complicated natural product mixtures. The enantiomeric composition of certain monoterpenoids in essential oils is now the subject of several studies. Differences in the relative amounts of enantiomers of some monoterpenoids existing between various species, as well as within ones have thus been reported. Owing to the great numbers of possible isomers within each group of monoterpenoids, their analysis presents great difficulties, which are growing significantly when a chiral discrimination is required. In this article the gas-chromatographic methods adequate for an analysis of chiral monoterpenoids are presented. Recent results on the enantiomeric composition of monoterpenoids from different species of plants are discussed. The bioactivity of selected chiral monoterpenoids is also described.