Antifungal properties of peptidomimetics with an arginine-[β-(2,5,7-tri-tert-butylindol-3-yl)alanine]-arginine motif against Saccharomyces cerevisiae and Zygosaccharomyces bailii

Due to increased occurrence of infections and food spoilage caused by yeast, there is an unmet need for new antifungal agents. The arginine-β-(2,5,7-tri-tert-butylindol-3-yl) alanine-arginine (R-Tbt-R) motif was previously proved useful in the design of an antifungal tripeptide. Here, an array of peptidomimetics based on this motif was investigated for antifungal and hemolytic activity. The five most promising modified tetrapeptide analogues (6 and 9–12) contain an additional C-terminal hydrophobic residue, and these were found to exhibit antifungal activity against Saccharomyces cerevisiae (MIC 6 and 12 μg mL−1) and Zygosaccharomyces bailii (MIC 6–25 μg mL−1). Four compounds (6 and 9–11), had limited hemolytic activity (