Construction, structural modification, and bioactivity evaluation of pentacyclic triterpenoid privileged scaffolds in active natural products.

Pentacyclic triterpenoids, as important representatives of natural products, have garnered widespread attention due to their diverse biological activities, including anti-inflammatory, antiviral, and antitumor effects. Oleanolic acid (OA), betulinic acid (BA), ursolic acid (UA), triptolide, and glycyrrhetinic acid (GA) are typical examples of pentacyclic triterpenoids. Despite their significant biological activities, their poor water solubility and low bioavailability have limited further development and application.