beta-5 is a trimeric lipopeptoid with antifungal activity against Cryptococcus neoformans and minimal mammalian cell toxicity. beta5 is an optimized derivation of AEC5 and has improved potency towards C. neoformans and decreased toxicity towards NIH/3T3 mouse fibroblasts, with a selectivity ratio improved from 8 for AEC5 to 37 for beta5.