Phytochemistry and Bioactive Compounds from Garcinia cowa Roxb.

Phytochemical investigation of the roots of Garcinia cowa Roxb. resulted in the isolation of forty-four compounds. Of these, thirty-five were xanthones, two anthraquinones, two flavonoids and five terpenes. Their structures were spectroscopically elucidated using UV, IR, 1D NMR, and 2D NMR methods. Thirty compounds were reported for the first time as metabolites of G. cowa. One active isolated compound, β-mangostin, was found to show a strong antibacterial activity against Bacillus cereus TISTR 687 and methicillin resistant Staphylococcus aureus (MRSA)-SK1 with an MIC value of 4 mg/mL. Whereas α-mangostin showed stronger activity against B. cereus TISTR 687 and MRSA-SK1 (MIC 0.5 mg/mL) than that of vancomycin (MIC 1 mg/mL). Two compounds, cowanin and cowanol, exhibited strong antibacterial activities against B. cereus TISTR 687, MRSA‑SK1, and S. aureus TISTR 1466 with MICs in the range of 2-4 mg/mL. Isocudraniaxanthone B, xanthone V1, and kaempferol expressed good antioxidative activities with IC50 values of 19.75 ± 0.39, 19.70 ± 0.39, and 11.67 ± 0.12 μM, respectively. Additionally, an acetone extract showed cytotoxicity against Vero cells (African green monkey kidney) and anticancer activity against the standard cell culture BC-Breast cancer with IC50 values of 36.13 and 40.89 mg/mL, respectively.