Antimicrobial Metabolites from the Freshwater Fungus Tubeufia longihelicospora Strain GZCC 23-0405

In this study, five metabolites were successfully isolated from the culture medium of Tubeufia longihelicospora strain GZCC 23-0405, comprising two dimeric naphtha-γ-pyrones (1–2), two dimeric coumarins (3–4), and one alkaloid (5). The elucidation of their chemical structures relied on a combination of NMR, MS, and optical rotation methods. Interestingly, these compounds represent the first instances of such metabolites being isolated from helicosporous hyphomycetes. Additionally, compounds (1) and (2) exhibited significant antimicrobial potential, with MIC and MBC values of 62.0 μg mL-1 and 248 μg mL-1, respectively, against Pseudomonas aeruginosa. This study provides a comprehensive account of the extraction, isolation, structural characterization, and antimicrobial properties of these compounds, shedding light on their potential significance in the field of natural product research.