Triterpene sapogenins with oleanene skeleton: chemotypes and biological activities.

Critical survey of a selected class of pentacyclic triterpenes--the oleanane family, is presented based on current literature in order to underline their value for medicinal chemistry and drug development potential. Oleanenes may be considered as a renewable resource of valuable research materials which are structurally diverse, inherently biocompatible and have built-in affinity for many categories of functional proteins. Although availability of particular compounds from natural sources may be very low, synthetic methods elaborated by generations of chemists, secure a way to obtaining desirable structures from commercial starting materials.