Ring-Modified Triterpene Derivatives as Potential Pharmacological Active Compounds

Pentacyclic triterpenes represent an important class of intensively studied substances in the past two decades due to their wide spectrum of pharmacological effects. Even though this class is being thoroughly researched for the development of new drugs, to date, no representative has qualified to become a suitable candidate for various therapies. Although a large part of past and ongoing studies focuses on triterpene chemical derivatization or formulation to increase its bioavailability, other researchers are focused on obtaining semisynthetic derivatives not necessarily with increased hydrophilicity but with a superior biological effect compared to their parent compound. The current review aims to report the biological assessment of several ring-modified pentacyclic triterpene derivative series.