Ani, Tri MurniTeruna, Hilwan YudaYuharmen2016-05-162016-05-162016-05-16wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/8382Isolation of methanol extract of the stem bark Goniothalamus sp. (Annonaceae) have been conducted and DPPH method using microplate reader has been performed for antioxidant activity assay. The methanol extract was fractionated by vacuum liquid chromatography (VLC) and produced nine fractions called FG1 to FG9. FG4 was recrystallized and generated a pure compound FG4, light yellow crystals. HPLC analysis showed FG4 compound is pinocembrin. FG6 was fractionated by using Chromatotron to give five fractions called FG6A to FG6E. Analysis of the FG6C fraction showed FG6C was not pure indicated by multiple peak in HPLC chromatograms. FT-IR spectrum showed OH, C=O, C-O, CH aromatic and CH aliphatic group. In addition, the FG6C gave a distinctive odour. The results showed that the methanol extract, FG6, FG8 and FG6C have antioxidant activity with IC50 value of 331; 201; 259; and 341.68 μg/mL for each sample, while FG4 fraction and pure compound FG4 was inactive as an antioxidant (IC50 >1000 μg/mL).enGoniothalamus spmethanol extractantioxidant activity assaystudent Paper Post Degree