... biosynthesis of triterpenesaponins is required, including the enzymes catalyzing the sequence of reactions and the genes encoding theseenzymes. The biosynthesis of triterpene saponins involves the initial ... range of structural diversity produced by asequence of biosynthetic reactions. Cyclization of oxidosqualene is the ini-tial origin of structural diversity of skeletons in their biosynthesis, and ... cyclization of 2,3-oxidosqualene, a common pre-cursor of all the sterol and triterpene biosyntheses, intovarious cyclic triterpenes, followed by oxidative modifi-cation of these carbon skeletons and...