Two new drimane sesquiterpenes isolated from Drimys winteri (Canelo). Antifungal activity and molecular docking effect of winterdial against Botrytis cinerea

Drimys winteri (Canelo) is an endemic tree of Chile, belonging to the Winteraceae family, with significant ethnocultural importance among the Mapuche people. Recently, the antifungal activity of drimenol (1) and polygodial (2), the main drimane sesquiterpenes isolated from Canelo, against Botrytis cinerea, the fungus responsible for gray mould disease, has been demonstrated. In this study, we report the isolation and subsequent characterisation of two new sesquiterpenes: a drimane sesquiterpene with a lactone structure (4), and a novel sesquiterpene dialdehyde (6), along with three known compounds. Their structures were elucidated through comprehensive analysis of spectroscopic data. Additionally, we evaluated the antifungal activity of winterdial and the ethyl acetate fraction against Botrytis cinerea. The results demonstrated that both compounds moderately inhibit the mycelial growth of the fungus. Finally, a molecular docking analysis was conducted to gain insights into the potential mechanism of action of winterdial (5).