<b>Background and Objective:</b> Various medicinal herbs and fruits in Thailand composed of many bioactive phytochemicals, which are support health and reduce the harmful of many diseases. The main objectives of this study were to extract wild grape residues obtained from wine production and fractionate them by silica column chromatography and investigate the chemical substances and antioxidant competency. <b>Materials and Methods:</b> Methanolic crude extract of wild grape pomace was fractionated by silica gel chromatography using the mixture methanol/ethyl acetate as eluting solvents. The chemical substances including total phenolic, flavonoid, saponin and condensed-tannin were investigated by colorimetric spectrophotometer. The antioxidant activities with free radical scavenging (DPPH and ABTS) and reducing power antioxidants (FRAP and CUPRAC) were tested. Finally, High Performance Liquid Chromatography (HPLC) was applied for the analysis of the individual phenolic compounds. <b>Results:</b> The fractionated extracts had higher chemical substances than crude extract, except total phenolic. Among the substances, condensed-tannins showed the highest content in the fractionated extracts. The active substances showed higher ABTS free radical scavenging activity than DPPH and metal-reducing power antioxidant by CUPRAC than FRAP assays. The dominant phenolic substances in the fractionated extracts were gallic acid, resveratrol, quercetin, epicatechin and caffeic acid. <b>Conclusion:</b> The pomace of immature wild grape fruits from wine production contained various types of chemical substances and antioxidant competency. The obtained results provide more information on the wild grape fruits in terms of phytochemical source and their activity.
Keywords: Fractionation; residues; substances; wild grape; wine.