Abstract: A kind of peptide was isolated from flesh of artificial raised Andrias davidianus via enzymolysis.Molecular weight of the peptide was measured as 1 422,1 521,1 746,1 828 and 1 879 with a tandem time-of-flight MS system (MALDI-TOF/TOF).All the molecular weight values are lower than 2 000;and showed that the enzymolysis product is a kind of oligopeptide.The peptide extracted from Andrias davidianus was applied in formulation of toothpaste,and its antioxidation activity was examined based on method for determination of free radical scavenging activity.Results showed that when mass fraction of the peptide extract in the toothpaste formulation achieves 0.1%,rather good antioxidation effect can be obtained.Aqueous solution of the toothpaste is capable to scavenge DPPH free radicals,hydroxyl free radicals,superoxide anion radicals and ABTS free radicals.

Key words: toothpaste, peptide from Andrias davidianus, antioxidation