A microbial natural product fractionation library screen with HRMS/MS dereplication identifies new lipopeptaibiotics against Candida auris.

The rise of drug-resistant fungal pathogens, including Candida auris, highlights the urgent need for novel antifungal therapies. We developed a cost-effective platform combining microbial extract prefractionation with rapid MS/MS-bioinformatics-based dereplication to efficiently prioritize new antifungal scaffolds. Screening C. auris and C. albicans revealed novel lipopeptaibiotics, coniotins, from Coniochaeta hoffmannii WAC11161, which were undetectable in crude extracts. Coniotins exhibited potent activity against critical fungal pathogens on the WHO Fungal Priority Pathogens List, including C. albicans, C. neoformans, multidrug-resistant C. auris, and Aspergillus fumigatus, with high selectivity and low resistance potential. Coniotin A targets β-glucan, compromising fungal cell wall integrity, remodelling, and sensitizing C. auris to caspofungin. Identification of a PKS-NRPS biosynthetic gene cluster further enables the discovery of related clusters encoding potential novel lipopeptaibiotics. This study demonstrates the power of natural product prefractionation in uncovering bioactive scaffolds and introduces coniotins as promising candidates for combating multidrug-resistant fungal pathogens.