New α‐Glucosidase Inhibitors from Vietnamese Garcinia schomburgkiana Fruits

The chemical investigation of the fruits of Garcinia schomburgkiana growing in Vietnam led to the isolation of a new anofinic acid derivative, 5‐hydroxy‐8‐methoxyanofinic acid (1), a new xanthone, xanthoschome C (2), and a known synthetic phenolic analogue, 4‐(2‐hydroxybenzyl)‐2‐(4‐hydroxybenzyl) phenol (3), along with seven known xanthones (4–10). The structures of all isolated compounds were determined using spectroscopic techniques (NMR and MS), in conjunction with comparison to existing literature data. All isolated compounds were assessed for their α‐glucosidase inhibitory activity and showed significant inhibition, with IC50 values ranging from 12.1 to 65.7 µM, surpassing the potency of the positive control, acarbose (IC₅₀ 179 ± 6.02 µM). Among them, compound 8 exhibited the strongest inhibitory activity, with an IC50 value of 12.1 ± 0.44 µM.