Gypsogenin Battling for a Front Position in the Pentacyclic Triterpenes Game of Thrones on Anti-Cancer Therapy: A Critical Review—Dedicated to the Memory of Professor Hanaa M. Rady

In the last decade, gypsogenin has attracted widespread attention from medicinal chemists by virtue of its prominent anti-cancer potential. Despite its late identification, gypsogenin has proved itself as a new anti-proliferative player battling for a frontline position among other classic pentacyclic triterpenes such as oleanolic acid, glycyrrhetinic acid, ursolic acid, betulinic acid, and celastrol. Herein, we present the most important reactions of gypsogenin via modification of its four functional groups. Furthermore, we demonstrate insights into the anti-cancer activity of gypsogenin and its semisynthetic derivatives and go further by introducing our perspective to judiciously guide the prospective rational design. The present article opens a new venue for a better exploitation of gypsogenin chemical entity as a lead compound in cancer chemotherapy. To the best of our knowledge, this is the first review article exploring the anti-cancer activity of gypsogenin derivatives.