Aromatic Polyketides from the Deep-Sea Cold-Seep Mussel Associated Endozoic Fungus Talaromyces minioluteus CS-138

Abstract

Five new aromatic polyketides, including a unique benzofuran derivative, talarominine A (1), and four chromone analogs talamins A–D (2–5), along with one known related metabolite, 5-hydroxy-7-methoxy-2,3-dimethylchromone (6), were isolated and identified from the Talaromyces minioluteus CS-138, an endozoic fungus obtained from the deep-sea cold seep mussel Gigantidas platifrons. Their chemical structures were elucidated by detailed analysis of their NMR spectra, HRESIMS and X-ray crystallographic data, and by comparison with literature data as well. The antibacterial and DPPH scavenging activities of compounds 1–6 were evaluated. Compounds 1–3 showed inhibitory activity against some of the tested bacteria whereas compounds 2 and 5 showed potent DPPH radical scavenging activities, which were better than that of the positive control butylated hydroxytoluene (BHT). This work is likely the first report on marine natural products of mussel-derived fungus living in cold seep environments.

Chemical Constituents and Anticancer Activities of Marine-Derived Fungus Trichoderma lixii

“…Compound 8 showed weak or no antimicrobial and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities [46,58]. In this study, it showed no antiproliferative activity against all tested cancer cell lines (IC 50 > 100 µM) as well.…”

Antibacterial Indole Diketopiperazine Alkaloids from the Deep-Sea Cold Seep-Derived Fungus Aspergillus chevalieri

“…The antibacterial activities against human pathogenic bacteria ( Escherichia coli and Micrococcus luteus ) and aquatic pathogens ( Vibrio harveyi , Edwardsiella tarda , V. anguillarum , and Aeromonas hydrophilia ) were determined by a serial dilution technique using 96-well microtiter plates with minor modifications, as described in our previous report [ 5 , 6 , 7 , 8 , 9 ]. The bacteria were cultivated overnight at 37 °C in liquid LB medium and diluted with the LB broth to a concentration of 1.5 × 10 8 CFU/mL.…”

“…Deep-sea cold seeps are special extreme environments characterized by fluid emissions rich in methane and hydrogen sulfide, developing a unique chemosynthetically-driven ecosystem that creates a unique habitat for microorganisms in sediments [ 4 ]. Recently, a batch of intriguing findings on secondary metabolites from deep-sea cold seep-derived fungi has highlighted the potential of these microbes as a source of new antibiotics [ 5 , 6 , 7 , 8 , 9 ].…”

“…In our continuous research for bioactive metabolites from deep-sea cold seep-derived fungi [ 5 , 6 , 7 , 8 , 9 ], the fungal strain Aspergillus chevalieri CS-122, which was isolated from the sulfate-reducing sediments collected at a cold seep in the northeast of the South China Sea, drew our attention. As a result, a couple of indole diketopiperazine alkaloids containing an unprecedented spiro-bicyclo skeleton were isolated and identified [ 9 ].…”

New Phenol Derivatives from the Haima Cold Seep-Derived Fungus Aspergillus subversicolor CYH-17

“…Under extreme conditions, cold seep organisms have evolved unique pathways to produce structurally diverse and biologically active secondary metabolites. According to previous reports, there were a great deal of new compounds that were found in the microorganisms derived from cold seeps, involving alkaloids [ 10 ], polyketides [ 11 ], terpenoids [ 12 ], glycosides [ 13 ], macrolides [ 14 ] and so forth. The new secondary metabolites displayed significant biological activity, including antimicrobial activity, cytotoxic activity and antioxidant activity.…”