Systematic Assessment of the Impact of Targeted Selection Methods and Environment-Mimicking Culture Conditions on Fungal Natural Product Libraries.

Natural products are a rich source of bioactive molecules and undiscovered chemical scaffolds with significant potential for drug discovery. Among producers of natural products, fungi are particularly promising, offering diverse metabolites and undiscovered structural motifs. Large, well-curated collections of crude extracts, or "libraries", are central to fungal natural product discovery, serving as starting material for bioassay-guided isolation of new compounds. However, the systematic influence of fungal selection strategies, culturing methods, and environmental factors on chemical diversity remains underexplored. In this study, we analyzed several large fungal libraries to assess how geographic origin and phylogenetic classification shape fungal chemical profiles. We also evaluated whether culturing conditions that more closely mimic natural environments can enhance metabolite diversity. Our findings offer practical guidelines for optimizing fungal natural product library design, improving drug development efficiency and accessing novel chemotypes for future drug discovery.