Research advances of pentacyclic triterpenoid natural products

Pentacyclic triterpenoids are a class of widespread natural compounds containing six isoprene structures with a wide range of pharmacological activities, including antibacterial, anti-inflammatory, antiviral, antitumor, immune regulation, etc. The structural modifications of pentacyclic triterpenoid natural products and the drug development have always been a hot research topic. This article reviews the recent progresses in the structural modifications, pharmacological effects, and clinical studies of different kinds of pentacyclic triterpenoid natural products.