ISOLATION OF 5,7-DIHYDROXY, 6,8-DIMETHYL FLAVANON AND ANTIOXIDANT ACTIVITY WITH XANTHINE OXIDASE INHIBITORY ACTIVITY ASSAY OF WATER APPLE LEAVES EXTRACT (Syzygium aqueum Burm.f. Alston)

• Main Author: Mega Ramadhania, Zelika
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/45357
• Institution: Institut Teknologi Bandung

Xanthine oxidase produces free radicals when converting xanthine into uric acid. They cause oxidative stress, which cause several diseases. Usually, many compounds which inhibit xanthine oxidase also exist as an antioxidant. Some researches have proven several plants of Myrtaceae family that had antioxidant activity, but there are still very lack of informations that those plants have xanthine oxidase inhibitory activity. This aim of the research was to determine the antioxidant activity and xanthine oxidase inhibitor activity from several plants of Myrtaceae family. Then, from the selected plants the active compound was isolated. In order to achieve these objectives, the isolation steps of active compound have been done trough a series of separation methods included extraction, fractionation, detemination of antioxidant activity with radical diphenyl picrylhydrayl/DPPH scavenging method, determination of xanthine oxidase inhibitory activity, purification and characterization of active compound. Extraction was performed by Soxhlet apparatus, followed by fractionation and purification by vacum liquid chromatography and radial chromatography. The active compound was characterized using spesific spraying reagents, Ultraviolet- Visible spectrophotometry, Nuclear Magnetic Resonance (NMR)- 1 H, and NMR13 C. From this study, the methanol extract of Syzygium aqueum leaves had antioxidant activity with IC50 value which was 20,24 ?g/mL and its xanthine oxidase inhibitory activity was 47,22%, it was the highest amongst all plants. Compound X has been isolated from methanol extract of Syzygium aqueum, that was flavonoid, the purposed structure was 5,7,-dihydroxy,6,8-dimethyl flavanone.