New Small-Size Antifungal Peptides: Design, Synthesis and Antifungal Activity

The synthesis, in vitro evaluation and conformational study of small-size peptides acting as antifungal agents are reported. These peptides displayed antifungal activity against human pathogenic strains including Candida albicans and Cryptococcus neoformans. Among the peptides reported here, RQWRRWWQR-NH2 exhibited the strongest activity against Cryptococcus neoformans. Our results allowed us to reduce in size these bioactive peptides from 16 to 11 and to 9 amino acid residues in total. Despite their reduction, they still maintained and even enhanced the antifungal activity detected for penetratin. A conformational and electronic structure analysis on these peptides was also performed by using molecular mechanics calculations in conjunction with Molecular Electrostatic Potentials (MEP) maps.