Isolation of antioxidant compound as free radical scavenging from fruit of Bruguiera gymnorrhiza

Abstract

Antioxidants are compounds that can inhibit or prevent the oxidation of the easily oxidized substrate. One of the plants as a potential source of bioactive compounds and antioxidant is Bruguiera gymnorrhiza. This plant commonly found in the Pacific region of Southeast Asia, Ryukyu Islands, Micronesia, and Polynesia (Samoa) to subtropical regions of Australia. This study aimed to determine the chemical composition fruit of B. gymnorrhiza, isolate and determine the structure of antioxidant compounds that function as free radical scavengers from methanol extract. This study began with the sample preparation, proximate test, extraction, antioxidant activity assay, separation by chromatography and make use of the compound structure prediction by Nuclear Magnetic Resonance. Old fruit yield greater than young fruits with values respectively 9.94% and 6.83%. Old fruit has a more effective antioxidant activity (13.47 ppm) compared to young fruits (81.60 ppm) and classified as a powerful antioxidant (IC50 <50 ppm). Fruit of B. gymnorrhiza have high carbohydrate content that is equal to 29.28% with 66.39% moisture, 2.11% protein, 1.07% fat and 1.15% ash. Bioactive compounds that act as antioxidants are phenol group. By TLC chromatography technique produces the best eluent, namely methanol:water (4:1) and resulted 3 fractions. Fraction III compounds old fruit has antioxidant activity of 26.69 ppm. Flavonol, flavone, and glycosyl flavone compounds thought to have an important role as an antioxidant found in fruits of B. gymnorrhiza.