α -Glucosidase Inhibitory and Antimicrobial Benzoylphloroglucinols from Garcinia schomburgakiana Fruits: In Vitro and In Silico Studies

α-Glucosidase plays a role in hydrolyzing complex carbohydrates into glucose, which is easily absorbed, causing postprandial hyperglycemia. Inhibition of α-glucosidase is therefore an ideal approach to preventing this condition. A novel polyprenylated benzoylphloroglucinol, which we named schomburgkianone I ( ), was isolated from the fruit of , along with an already-reported compound, guttiferone K ( ). The structures of the two compounds were determined using NMR and HRESIMS analysis, and comparisons were made with previous studies. Compounds and exhibited potent -glucosidase inhibition (IC of 21.2 and 34.8 µM, respectively), outperforming the acarbose positive control. Compound produced wide zones of inhibition against and (of 21 and 20 mm, respectively), compared with the 19 and 20 mm zones of compound , at a concentration of 50 µg/mL. The MIC value of compound against was 13.32 µM. An in silico molecular docking model suggested that both compounds are potent inhibitors of enzyme α-glucosidase and are therefore leading candidates as therapies for diabetes mellitus.