A　peptide　with　antioxidant　activity　was　purified　from　Chinese　leek　seeds　by　successive　chromatographic　methods.　The　sequence　was　determined　as　Gly-Ser-Gln　(290.10　Da)　by　LC-MS/MS.　This　purified　peptide,　discovered　for　the　first　time　from　Chinese　leek　seeds　and　designated　as　CLP-2,　could　efficiently　quench　free　radicals　and　exhibit　moderate　reducing　power.　The　concentrations　for　50%　activities　for　its　radical　scavenging　effect　against　DPPH,　ABTS+　and　O2-　were　0.61,　0.04　and　0.70　mg/mL,　respectively.　In　addition,　the　peptide　protected　LO2　cells　against　hydrogen　peroxide-induced　damage　at　a　concentration　of　10　μg/mL.　Furthermore,　CLP-2　inhibited　growth　of　Gram-negative　and　Gram-positive　bacteria.　©　2014　Elsevier　Ltd.