Identification of multiple peptides with antioxidant and antimicrobial activities from skin and its secretions of Hylarana taipehensis, Amolops lifanensis, and Amolops granulosus

Amphibian skin and its secretions contain many kinds of peptides with different bioactivities. In this study, a large number of peptides including antioxidant and antimicrobial peptides were identified from three East Asian frog species Hylarana taipehensis, Amolops lifanensis, and Amolops granulosus. The majority of these peptides were antimicrobial peptides, while eight antioxidant peptides were identified, which included two novel peptides taipehensin-1TP1 (TLIWEFYHQILDEYNKENKG) and taipehensin-2TP1 (CLMARPNYRCKIFKQC). These antioxidant peptides exhibited the ability to scavenge ABTS and/or DPPH free radicals. Moreover, six out of eight antioxidant peptides temporin-TP1, brevinin-1TP1, brevinin-1TP2, brevinin-1TP3, brevinin-1LF1, and palustrin-2GN1 also showed antimicrobial activity.