Anti-free-radical properties of the peptide fractions isolated from string bean by immobilized metal ion affinity chromatography.

In this study, peptides and proteins extracted from string bean with 1% TCA were separated by chromatography on columns with copper ions immobilized through IDA and o-phosphoserine OPS. Protein and peptide concentrations and the anti-free-radical properties of the isolated fractions were determined. Identification was obtained using mass spectrometry. The anti-free- radical activity of all analyzed samples was determined using the DPPH test, and was found to depend on reaction time, choice of chelating agent and the order in which the fractions were eluted from the column.