Chemical constituents and biological activities from Garcinia xanthochymus Hook. f.

Abstract

Phytochemical investigation of bark and twig of Garcinia xanthochymus Hook. f. led to the isolation of 22 known compounds, including 13 xanthones (GXBA-sm1 (formoxanthone C), GXBA-sm2 (euxanthone), GXBA-sm3 (pyranojacreubin), GXBA-sm4 (7-geranyloxy-1,3-dihydroxyxanthone), GXBA-sm7 (6-hydroxy-2,3-dimethoxy xanthone), GXBA-sm8 (xanthone V1), GXBA-sm10 (morusignin I), GXBA-sm11 (dulxanthone B), GXBA-sm12 (1,5-dihydroxy-3-methoxyxanthone), GXTM-sm19 (2,5-dihydroxy-1-methoxyxanthone), GXTM-sm20 (2,6-dihydroxy-1,5-dimethoxyxanthone), GXTM-sm21 (1,2,5-trihydroxyxanthone), and GXTM-sm22 (1,2,5-trihydroxy-6-methoxyxanthone)), six of flavonoid scaffolds (GXBA-sm6 (kaempferol), GXBA-sm9 ((2R,3S)-morelloflavone), GXTM-sm13 (GB-2a), GXTM-sm14 (GB-1), GXTM-sm15 ((2S,2'S,3R)-GB-1a), and GXTM-sm16 (volkensiflavone)), two of benzene derivatives (GXTM-sm17 (4-hydroxybenzoic acid) and GXTM-sm18 (4-hydroxy-3-methoxybenzoic acid)), and one anthraquinone (GXBA-sm5 (damnacanthal)). In addition, metabolite profiling by UHPLC-QTOF-MS was also investigated, resulting in the identification of 14 xanthones, 6 flavonoids, and 2 benzene derivatives. The extracts and some isolated compounds were also evaluated for their antioxidant and in vitro anticancer activities against four human cancer cell lines: MDA-MB-231 (breast), Huh-7 (liver), A549 (lung), and SW480 (colon). Antioxidant assays revealed that the methanol bark extract (GXBM) showed the highest DPPH scavenging activity (IC50 = 23.4 ± 1.0 µg/mL), while the dichloromethane bark extract (GXBD) showed the strongest activity in ABTS (IC50 = 133.8 ± 1.7 µg/mL) and FRAP (IC50 = 104.1 ± 3.2 µg/mL) assays. The isolated compound, (2R,3S)-morelloflavone (GXBA-sm9) exhibited potent antioxidant activity across all assays: DPPH (34.5 ± 0.7 µM), ABTS (298.7 ± 11.0 µM), and FRAP (92.2 ± 0.2 µM), surpassing standard antioxidants ascorbic acid and BHT (IC50 = 44.1 ± 6.6 µM and 414.3 ± 12.6 µM in DPPH assay, 129.6 ± 0.8 µM and 174.7 ± 3.4 µM in ABTS assay, and 245.4 ± 8.6 µM and 1162.1 ± 16.8 µM in FRAP assay). Cytotoxicity, apoptosis, and colony formation were assessed via MTT, Annexin V-FITC/PI staining, and colony formation assays. Among all extracts, the hexane extract (GXBH) demonstrated the strongest cytotoxicity with IC50 values of 66.9 ± 5.1 µg/mL (MDA-MB-231), 64.7 ± 14.9 µg/mL (Huh-7), 80.0 ± 11.9 µg/mL (A549), and 65.4 ± 7.8 µg/mL (SW480). 7-Geranyloxy-1,3-dihydroxyxanthone (GXBA-sm4) also showed strong activity against MDA-MB-231 (IC50 = 24.5 ± 2.31 µM). GXBH significantly induced apoptosis and inhibited colony formation in all four cell lines. These findings demonstrate the potential of G. xanthochymus as a natural source of antioxidants and anticancer agents, supporting its development as an alternative therapeutic candidate.