A review of 13C NMR spectra of drimane sesquiterpenes

Drimane sesquiterpenes are important group of phytochemicals with a wide range of medicinal properties including antibacterial, antifungal, anti-inflammatory, antioxidant, antiplasmodial, antileishmanial, molluscicidal, antifeedant and insecticidal features. Due to their wide range of medicinal activities, scientists are prompted to continuously search for novel drimane sesquiterpenes since most of the currently available anti-infective agents have drawbacks such as drug resistance and side effects. Structure determination of new compounds relies on accurate interpretation of spectroscopic data which is quite challenging but can be simplified by comparison with the data of known related compounds from the reliable databases. A large number of drimane sesquiterpenes have been examined by 13C NMR spectroscopy but such data are scattered in the literature making it hard for researchers to use them. This paper provides a review on previously reported drimane sesquiterpenes and a compilation of their 13C NMR data. It also provides a brief discussion on the substituent effect on the 13C shielding of the drimane sesquiterpenes.