Abstract:
The main objective of this work was to determine the antioxidant capacity of Plautawan which is a new specie planted in Trat, Thailand. Plautawan leave and twig were extracted by ethanol and water. Ethanol crude extract has 12.2% yield lower than 17.65% of water crude extract. The total phenolic compound determined by Folin-Ciocalten Phenol Test. Ethanol crude extract of 1st, 2nd and 3rd were 585.41±0.47, 564.52±0.20 and 533.14±0.25 mg GAE/g crude extract, respectively which were 3 times higher than that of water crude extract (176.99±0.02 mg GAE/g Crude Extract). Mean while, flavonoid content determined by Aluminium Chloride Colorimetric Assay. Ethanol crude extract of 1st, 2nd and 3rd were 28.51±0.07, 21.39±0.35 และ 20.61±0.43 mg QAE/g crude extract respectively which were 3-5 times higher than water crude extract (6.12±0.03 mg QAE/g crude extract). The 50% inhibition concentration (IC50) value of ethanol crude extract of 1st, 2nd and 3rd by DPPH were 125±0.11, 175±0.21 and 185±0.81 µg/ml which were 1.5 times lower than IC50 of water crude extract (190±0.11 µg/ml). However, Plautawan crude extract have lower antioxidant capacity when compared to IC50 of ascorbic acid (13.27±0.01 µg/ml). Also, reducing power of ethanol extract of 1st, 2nd and 3rd were 36.77±0.01, 34.7±0.01 and 23.21±0.01 µg Ascorbic Acid Equ/mg extract accordingly which were higher than aqua extract (21.34±0.02 µg Ascorbic Acid Equ/mg extract). Plautawan crude extract was applied in O/W emulsion at 3% concentration. After heating - cooling cycle test, it was found that % DPPH inhibition of the product decreased about 20%. In conclusion, Plautawan crude extract was source of natural antioxidants with relatively low antioxidant capacity comparing to standard Vitamin C.