Increased potency of a novel D-beta-naphthylalanine-substituted antimicrobial peptide against fluconazole-resistant fungal pathogens.

The antifungal activities of the known antimicrobial peptide, P-113, as well as a new type of Trp-rich peptide, Ac-KWRRWVRWI-NH(2), Pac-525, and its modified peptide, D-Nal-Pac-525, were determined using the broth microdilution method in three different media. All peptides had similar activities against yeast pathogens in low-salt LYM media. However, only D-Nal-Pac-525 retained its antifungal activity in the media containing high concentrations of salt. Hence, D-Nal-Pac-525 has the potential of becoming a promising antifungal agent, especially for fungal pathogens with intrinsic resistance to fluconazole.