Esterification reaction and antioxidant activity of xanthone derivative from mangosteen peel (garcinia mangostana l.)

Mangosteen peel (Garcinia mengostana L.) contains bioactive compounds from xanthone derivatives as the largest component. Xanthones are active as antioxidants, anti-inflammatory, anti-fungal, anti-cancer and anti-allergic. Mangosteen peel powder was extracted by maceration with ethanol, and then fractionated with n-hexane and chloroform. The results of the fractionation were tested for antioxidant activity and total phenolics. The xanthone derivative obtained was carried out by an esterification reaction with anhydrous acetic acid using sulfuric acid catalyst. The results of the phytochemical test of the ethanol extract of mangosteen peel contain secondary metabolites such as alkaloids, flavonoids, terpenoids, phenols, and saponins. The results of the phenol test on the chloroform fraction obtained a total phenol content of 77939.94 mg GAE/100 mL. The results of the antioxidant activity test showed that the n-hexane fraction was the most active antioxidant with IC50 114.8 µg/mL, chloroform fraction (202.59 µg/mL), water (407.36 µg/mL), and ethanol crude extract (482.36 µg/mL). Antioxidant activity after the esterification reaction decreased compared to before esterification with IC50 219.29 µg/mL. Compounds that can be identified from the esterification reaction of the chloroform fraction of mangosteen peel are manopiranoside; 1,3,6-triolate-α-mangosteen; 1,3,6-trihydroxy-α-mangosteen; 3-O-acetyl- α-mangosteen; 3,6-di-O-acetyl-α-mangosteen; 3,6,7-tri-O-acetyl-α-mangosteen.