Study on the structure and pharmacological activities of sesquiterpenoids and its adducts from Inula helenium

Its dried roots, known as “Tu-Mu-Xiang”, are extensively used in China as a versatile medicinal herb against fever, bronchitis, indigestion, lung disorders, and chronic enterogastritis. Previous phytochemical investigations revealed that the chemical constituents of Inula helenium are diverse in structure and possess rich pharmacological activities, sesquiterpenes are one of its main active components.

Sesquiterpenes can be classified into eudesmane-type, germacrene-type, guaiane-type, and other types based on their skeleton structures. In recent years, comparatively minor amount of sesquiterpenes and its dimers are being the most popular metabolites of this plant owing to their great structural variety and widely ranging of pharmacological activities, including anti-tumor, anti-inflammatory, antibacterial, and antiviral activities etc.