A new racemic xanthone, garmckeanin A (1), and eight known analogs 2–9 were isolated from the ethyl acetate (AcOEt) extract of the Vietnamese Garcinia mckeaniana leaves. Their structures were determined by MS and NMR spectral analyses and compared with the literature. The AcOEt extract showed good cytotoxicity against cancer cell lines KB, Lu, Hep‐G2 and MCF7, with IC50 values of 5.40–8.76 μg/mL, and it also possessed α‐glucosidase inhibitory activity, with an IC50 value of 9.17 μg/mL. Garmckeanin A (1) exhibited inhibition of all cancer cell lines, with an IC50 value of 7.3–0.9 μM. Allanxanthone C (5) successfully controlled KB growth, with an IC50 value of 0.54 μM, higher than that of the positive control, ellipticine (IC50 1.22 μM). Norathyriol (8) was a promising α‐glucosidase inhibitor, with an IC50 value of 0.07 μM, much higher than that of the positive control, acarbose (IC50 161.0 μM). The interactions of the potential α‐glucosidase inhibitors with the C‐ and N‐terminal domains of human intestinal α‐glucosidase were also investigated by molecular docking study. The results indicated that bannaxanthone D (2), garcinone E (4), bannaxanthone E (6), and norathyriol (8) exhibit higher binding affinity to the C‐terminal than to the N‐terminal domain through essential residues in the active sites. In particular, compound 8 could be assumed to be the most potent mixed inhibitor.

Two new sesquiterpenes, namely fissistinone (1) and fissistinol (2), along with ten known compounds (3-12), were isolated from the fruits of Fissistigma villosissimum. Their structures were elucidated on the basis of spectral data analysis, including one-dimensional (1D), two-dimensional (2D)-nuclear magnetic resonance (NMR), and high-resolution-electrospray ionization-mass spectrometry (HR-ESI-MS). Compounds 1-8 were evaluated for their cytotoxic activities against KB cell line; however, all these compounds did not show cytotoxic activity.

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A phytochemical investigation of the methanolic extract of Garcinia mackeaniana leaves led to the isolation, and determination of five secondary metabolites, including one benzophenone 4,3',4'-trihydroxy-2,6-dimethoxybenzophenone (1), two flavone C-glucosides vitexin (2) and its 2''-O-acetyl derivative (3), one biflavone amentoflavone (4), and one mono-phenol methyl protocatechuate (5). The chemical structures of these compounds were characterized by the NMR-spectroscopic method. These isolated compounds were isolated from G. mackeaniana species for the first time. Benzophenone derivative 1 has shown to be associated with a significant IC50 value of 14.97±0.8 µg/mL in the DPPH-antioxidant assay.

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