IDENTIFIKASI DAN UJI AKTIVITAS ANTIOKSIDAN FRAKSI DARI EKSTRAK N-HEKSANA DAUN TUMBUHAN Goniothalamus sesquipedalis

Abstract

In Indonesia, Goniothalamus sesquipedalis could be found in Hutan Lindung Bukit Suligi, Rokan Hulu Regency, Riau Province where the leaves of G. sesquipedalis were collected. An antioxidant activity determination of G. sesquipedalis leaves extracts had been done by using DPPH (1,1-diphenyl–2–picryl hydrazyl) method. The results showed that methanol extract was more active as antioxidant (IC50 = 88,0722 μg/mL ) compared to n-hexane extract (IC50 = 754,7705 μg/mL). The extract was obtained by 3 times macerating dried leaves powder of G. sesquipedalis by using n-hexane and methanol respectively. The n-hexane extract was fractionated by vacuum liquid chromatography (VLC) and the second fraction (F2) of VLC was continued to be fractionated by using Chromatotron. Fractions of F4-F8 of Chromatotron were combined to be one fraction because of same number of retardation factor (Rf) on thin layer chromatography (TLC) determination. Analysis and identification of chemical components in combined Chromatotron fraction of the n-hexane leaves extract were determined by using high performance liquid chromatography (HPLC) and gas chromatography-mass spectroscopy (GC-MS). The main components of this fraction were α-humulene; (-)-sinularene; germacrene-D; δ-cadinene; α-selinene and neophytadiene. DDPH method was also used to determine antioxidant activity of this fraction. The result showed that combined Chromatotron fraction had the lowest antioxidant activity with %inhibition = 17,0421% (1000 μg/mL).