Antibacterial and antifungal screening of natural products sourced from Australian fungi and characterisation of pestalactams D-F

作者：Beattie Karren D; Ellwood Nicola; Kumar Rohitesh; Yang Xinzhou; Healy Peter C; Choomuenwai Vanida; Quinn Ronald J; Elliott Alysha G; Huang Johnny X; Chitty Jessica L; Fraser James A; Cooper Matthew A; Davis Rohan A^*

来源：Phytochemistry, 2016, 124: 79-85.

DOI：10.1016/j.phytochem.2015.12.014

• Pestalotiopsis
• Amphisphaeriaceae
• Fungal natural products
• Pestalactams A-F
• Pestalactam
• Caprolactam
• X-ray crystal structure
• Antibacterial
• Antifungal
• MIC screening

Eighteen natural products sourced from Australian micro- or macro-fungi were screened for antibacterial and antifungal activity. This focused library was comprised of caprolactams, polyamines, quinones, and polyketides, with additional large-scale isolation studies undertaken in order to resupply previously identified compounds. Chemical investigations of the re-fermented culture from the endophytic fungus Pestalotiopsis sp. yielded three caprolactam analogues, pestalactams D-F, along with larger quantities of the known metabolite pestalactam A, which was methylated using diazomethane to yield 4-O-methylpestalactam A. The chemical structures of the previously undescribed fungal metabolites were determined by analysis of 1D/2D NMR and MS data. The structure of 4-O-methylpestalactam A was confirmed following single crystal X-ray diffraction analysis. The antibacterial and antifungal activity of all compounds was assessed, which identified three compounds, (1S,3R)-austrocortirubin, (1S,3S)austrocortirubin, and 1-deoxyaustrocortirubin with mild activity (100 mu M) against Gram-positive isolates and one compound, 2-hydroxy-6-methyt-8-methoxy-9-oxo-9H-xanthene-1-carboxylic acid, with activity against Cryptococcus neoformans and Cryptococcus gattii at 50 mu M.

• 出版日期2016-4