Black-eyed Susan vine (Thunbergia alata): chemical and antifungal potential evaluation of an invasive plant species in Colombia

Abstract

Thunbergia alata (Black-eyed Susan) is a plant species from East Africa and grows in tropical regions worldwide, including Colombia, being considered an invasive species in some countries. Even though it is used by local communities to treat several illnesses, including malaria, there are few biological and chemical studies on T. alata. Therefore, this study aimed to explore the chemical composition and in vitro antimycotic (against Candida strains) activity of T. alata crude ethanolic stem and leaf extracts. This was achieved via phytochemical analyses and chromatographic profiling (HPTLC, UPLC-DAD, and LC-MS). A two-fold serial microdilution method was used to determine the minimum inhibitory concentration (MIC) against selected Candida strains. Results showed the presence of saponins, terpenes, and flavonoids in the T. alata crude ethanolic stem and leaf extracts, although rutin and chlorogenic acid were the main components of stem and leaf extracts, respectively. Concerning biological assays, T. alata leaf extracts demonstrated moderate antimycotic activity, with MIC values between 5:00 mg mL-1 and 1:25 mg mL-1 against C. albicans and C. auris strains. The results indicate that T. alata extracts, including some of their major identified compounds, possess promising antifungal properties against two significant microorganisms.