*2.3.7 Hymenochirins*

Hymenochirins are a class of AMPs produced by two frogs of *Pseudhymenochirus merlini* and *Hymenochirus boettgeri* with letters P and B in the second part name of these peptides indicating the producing species of the peptide, respectively [37, 182]. Hymenochirin-1B is a cationic, α-helical amphibian host-defense peptide with antimicrobial, anticancer, and immunomodulatory properties. This peptide has anti-*A. baumannii* properties against MDR isolates with MIC of 19.1 μg/ml [113]. Among the analogs of hymenochirin-1B obtained by amino acid substitution method, [E6k and D9k] hymenochirin-1B reduced human erythrocytes' toxicity and showed 3.9-folds higher activity against *A. baumannii.* [E6k and D9k] hymenochirin-1B is active against both MDR and XDR isolates and could inhibit the growth of these isolates at 4.9 μg/ml concentration [113]. Hymenochirin-1 Pa is another cationic member of this family with moderate hemolytic activity. This peptide inhibited the growth of XDR *A. baumannii* isolates at 7.5–15 μg/ml concentration [114, 182].
