This family of antibacterial peptides are secreted from the granular dorsal glands of the Green and Golden Bell Frog Litoria aurea, Southern Bell Frog L. raniformis, Blue Mountains tree-frog Litoria citropa (genus Litoria) and frogs from genus Uperoleia. They are a part of the FSAP peptide family. Amongst the more active of these are aurein 1.2, aurein 2.2 and aurein 3.1; caerin 1.1, maculatin 1.1, uperin 3.6 [1]; citropin 1.1, citropin 1.2, citropin 1.3 and a minor peptide are wide-spectrum antibacterial peptides [2].

1: The antibiotic and anticancer active aurein peptides from the Australian Bell Frogs Litoria aurea and Litoria raniformis the solution structure of aurein 1.2. Rozek T, Wegener KL, Bowie JH, Olver IN, Carver JA, Wallace JC, Tyler MJ; Eur J Biochem 2000;267:5330-5341. PMID:10951191

2: Host defence peptides from the skin glands of the Australian blue mountains tree-frog Litoria citropa. Solution structure of the antibacterial peptide citropin 1.1. Wegener KL, Wabnitz PA, Carver JA, Bowie JH, Chia BC, Wallace JC, Tyler MJ; Eur J Biochem 1999;265:627-637. PMID:10504394