Seedy bananas contain stilbenes that inhibit α-glucosidase and acetylcholinesterase

Abstract Seedy bananas are used as a traditional medicine in many Asian countries. Even though evidence for the presence of compounds with declared bioactivity in seedy bananas exists, direct assays to ascertain and identify bioactive compounds have not been undertaken so far. In this study, the effect-directed analysis after thin-layer chromatography was used to evaluate the anti-α-glucosidase and anti-acetylcholinesterase activity of seedy banana extracts. High-performance thin-layer chromatography (HPTLC)‒bioautography revealed that the extracts indeed contained inhibitors of both studied enzymes. Four main compounds were isolated, and their structures were determined by mass spectrometry and nuclear magnetic resonance spectroscopy. Piceatannol, scirpusin A, scirpusin B, and cassigarol E (or its isomer, maackin) were confirmed. This study establishes the bioactivity of seedy bananas on the basis of the stilbenes, which strengthens the evidence for the folk medicine use of this plant.