Phytochemistry of Syzygium polycephalum

Syzygium polycephalum is a plant that grows in several parts of Indonesia and belongs to Myrtaceae family. This research aims to reveal the isolation and structure elucidation of the bioactive compounds in this plant's fruit, seeds and leaves as part of overall research on the genus Syzygium. The isolation process included extraction, separation and purification, while the structure elucidation of isolated compounds was executed using the spectroscopic method. As a result, 1,5-dimethylcitrate and trimethyl citrate were isolated from the dichloromethane extract of the fruit, while from the ethyl acetate extract of the seeds, methyl gallate and gallic acid were isolated and identified. From the dichloromethane extract of the leaves, 3,4,3'-tri-O-methylellagic acid was isolated and identified. Determination of antioxidant activity was executed using the ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) approach, with Trolox as a standard. Gallic acid showed the best antioxidant activity among the five isolated compounds with an IC50 of 29.6 g/mL. From this study, five secondary metabolites were isolated. Some showed strong activity and some were inactive as antioxidant.