Penapisan Senyawa Aktif Bunga dan Daun Temulawak (Curcuma xanthorrhiza) sebagai Antioksidan

Abstract

This study aimed to screen antioxidant compounds on leaves and flower of C. xanthorrhiza using DPPH (2,2-diphenyl-1-picrylhydrazil) method. The flower and leaves were extracted with n-hexane, ethyl acetate, and methanol. Essential oil of the leaves was obtained through water distillation. Each extract and essential oil were determined for theirs antioxidant activities. The ethyl acetate extract of leaves had the best radical scavenging activity with IC50 41.50±7.80 μg/mL but not as good as ascorbic acid as the positive control with IC50 3.36±0.29 μg/mL. Fractionation performed on ethyl aceate leaves extract using silica gel column chromatography by step gradient elution with n-hexane, ethyl acetate, and methanol. Fractionation resulted 13 fractions (F1-F13) and the most active fraction was the F11 fraction (IC50 24.05±2.38 μg/mL). Fraction F11 was separated further by preparative thin layer chromatography and gave 8 fractions (F11.1-F11.8). Fractions F11.1 had the highest antioxidant activity with IC50 of 28.22±7.35 μg/mL. Phytochemical assay and infrared spectroscopy on F11.1 showed that the active compound as the antioxidant was flavonol. Keywords: C. xanthorrhiza, leaves, antioxidant, flavonol