Phytochemical Studies and Antioxidant Activities of Artocarpus scortechinii King

Six known compounds identified as 4',5-dihydroxy-6,7-(2,2-dimethylpyrano)-2'-methoxy-8-γ,γ-dimethylallyflavone (1), cudraflavone A (2), artocarpin(3), cycloartobiloxanthone (4), artonin E (5) and oxyresveratrol (6) were isolated from the stem barks of Artocapus scortechinii King. Another four compounds namely macakurzin C (7), flemichapparin A (8), luteolin (9) and apigenin (10) were isolated from the leaves. Structures of all pure compounds were elucidated spectroscopically using 1D NMR ( 1H, 13C, DEPT), 2D NMR (COSY, HMQC, HMBC), MS and FTIR, as well as by comparison with literature data. All isolated compounds were evaluated for their antioxidant capacities using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant potential (FRAP) assays. Luteolin (9) showed the best ability to act as DPPH free radical scavenger with IC 50 value of 9.51 µM. Luteolin (9) also exhibited the strongest scavenger and potent ferric ion reducer compared to other isolated compounds in the ABTS and FRAP assays with IC 50 value of 124.4µM and 4.07 ± 0.180 mM FRAP equivalent respectively.