Roles of Hydroxyl Ions in Water-Based Solvents to Isolate Antioxidant Constituents of Natural Products

Roles of hydroxyl ions in water-based solvents to isolate antioxidant constituents of natural products were studied in present research. Sarang semut (Myrmecodia pendens) tuber as the model material of the study was considered to be the strategic natural product based on its biochemical and therapeutical effects. Water with pH of 3.0, 5.0, 7.0, 9.0, 11.0, and 13.0 were used as the solvents in macerations. Results showed that water with various working pH applied yielded the pH of each resulting extracts equaled to 7. The antioxidant levels of the resulted extracts indicated that higher the working pH, higher antioxidant activity of the resulted extracts. The extents of the antioxidant activities mimicked their antibacterial activities. The study also found that higher pH of the working solvent, higher amounts of the antioxidant/antibacterial extracts. In conclusion: the hydroxyl ions of water-based solvents applied in a maceration technology play critical role to promote the concentrations of extracts isolatable from the natural products as well as the antioxidant and/or antibacterial activity of the isolated extracts.