ANTIOXIDANT ACTIVITIES OF LEAVES EXTRACTS OF FOUR KINDS SYZYGIUM USING DPPH AND CUPRAC METHODS

• Main Author: Fajarwati, Kania
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40224
• Institution: Institut Teknologi Bandung

Background and purposes: Syzygium is one of the plants that widely used as a natural antioxidant by the community. Many kinds of Syzygium in Indonesia makes researcher interested to compare antioxidant activity of selected Syzygium plants. The purposes of this study were to determine the antioxidant activity of leaves extracts from four kinds of Syzygium using DPPH and CUPRAC methods, determine total phenolic and flavonoid content, analyze the correlation between total phenolic and flavonoid content with IC50 DPPH and EC50 CUPRAC, and correlation between IC50 DPPH and EC50 CUPRAC. Methods: Extraction by reflux with three different solvent polarity. Determination of IC50 DPPH and EC50 CUPRAC, total phenolic and total flavonoid content were carried out by uv-vis spectrophotometer. Correlation of total phenolic and flavonoid content with IC50 DPPH and EC50 CUPRAC and the correlation between the two antioxidant methods were analyzed using Pearson’s statistical method. Results: The highest antioxidant activity by DPPH method was ethanol leaves extract of Syzygium jambos with IC50 1.78 µg/mL and the CUPRAC method was ethanol leaves extract of Syzygium malaccense with EC50 10.31 µg/mL. The highest total phenolic content was shown by ethanol leaves extract of Syzygium jambos (64.36 g GAE/100 g) and the highest total flavonoid content was shown by ethyl acetate leaves extract of Syzygium malaccense (16.44 g QE/100 g). Total phenolic content of all samples had negatively and significant correlation with their IC50 DPPH dan EC50 CUPRAC. IC50 DPPH value of all samples gave positively and significant correlation with their EC50 CUPRAC. Conclusions: All extracts had antioxidant activities. Phenolic compounds mainly contributed in antioxidant activities of leaves aextract of S. jambos, S. samarangense, S. malaccense, dan S. aqueum by DPPH and CUPRAC methods. DPPH and CUPRAC methods showed linear results in antioxidant activities of all samples.