Betulinic acid and its derivatives: a review on their biological properties.

Betulinic acid is a naturally occurring pentacyclic triterpenoid and has been shown to exhibit a variety of biological activities including inhibition of human immunodeficiency virus (HIV), antibacterial, antimalarial, antiinflammatory, anthelmintic and antioxidant properties. This article reports a survey of the literature dealing with betulinic acid related biological properties that has appeared from the 1990's to the beginning of 2003. A broad range of medical and pharmaceutical disciplines are covered, including a brief introduction about discovery, phytochemical aspects, organic synthesis, anti-HIV and cytotoxic mechanisms of action. Various structural modifications carried out and their biological and pharmacokinetic profiles are also incorporated.