Abstract:
α-Mangostin has been identified as a major chemical constituent in the pericarps of mangosteen (Garcinia mangostana Linn.) Over time, dried pericarps of mangosteen have been subjected to studies in literature. This study aimed to explore isolation of α-mangostin and other chemical constituents from the fresh pericarps of mature mangosteen fruits and investigate their relative antioxidant and anticancer activities. Repeated column chromatography on ethyl acetate and methanol extracts of fresh mature mangosteen pericarps led to the isolation of α-mangostin (33.25% of crude extracts) as the major compound, beta-mangostin (0.225%) and gartanin (7.57%). Their antioxidant scavenging activity was investigated against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. α-Mangostin, β-mangostin and gartanin showed IC50 values of 322.57, >589 and 8.42 µM respectively, while the IC50 of Trolox was 5µM. α-Mangostin, β-mangostin and gartanin exhibited anticancer activities against SH-SY5Y neuroblastoma cell line with IC50 values of 9.0, 8.4 and 7.0 µM respectively. The idea of juxtaposing two extraction methods (maceration and ultrasonic-assisted extraction) with the dried pericarp, and as well as the fresh pericarps was also studied using methanol, ethanol, and ethyl acetate as solvents to maximize the antioxidant potency of the dried mangosteen pericarp extracts and their respective yields. This study established α-mangostin as a major antioxidant xanthone in mature mangosteen fresh pericarps, also compared the antioxidant and anticancer activities of the compounds and in the same vein predicted a synergistic antioxidant activity of α-mangostin and gartanin present in the three solvent extracts.
