Triterpenoids from Frankincense and Boswellia: A focus on their pharmacology and C-NMR assignments.

Here we report for the first time the entire C-NMR spectral assignments of 119 (out of 127) triterpenoids from the oleo-gum resins of the medicinally important genus Boswellia, which includes the culturally highly valuable Frankincense species. The complete C-NMR resonances of these triterpenoids isolated between 1998 and 2024 and their biological activities are presented. C-NMR spectroscopy is a highly powerful tool for the characterization of these bioactive natural products. The compounds are arranged according to their skeletons, i.e., ursane, oleanane, lupane, dammarane, and tirucallane triterpenes. This review will be a future reference for the identification of these compounds, which have key medicinal properties in the areas of cytotoxicity and inflammation.