Antimicrobial and Antioxidant Polyketides from a Deep-Sea-Derived Fungus Aspergillus versicolor SH0105

Abstract

Fifteen polyketides, including four new compounds, isoversiol F (1), decumbenone D (2), palitantin B (7), and 1,3-di-O-methyl-norsolorinic acid (8), along with 11 known compounds (3–6 and 9–15), were isolated from the deep-sea-derived fungus Aspergillus versicolor SH0105. Their structures and absolute configurations were determined by comprehensive spectroscopic data, including 1D and 2D NMR, HRESIMS, and ECD calculations, and it is the first time to determine the absolute configuration of known decumbenone A (6). All of these compounds were evaluated for their antimicrobial activities against four human pathogenic microbes and five fouling bacterial strains. The results indicated that 3,7-dihydroxy-1,9-dimethyldibenzofuran (14) displayed obvious inhibitory activity against Staphylococcus aureus (ATCC 27154) with the MIC value of 13.7 μM. In addition, the antioxidant assays of the isolated compounds revealed that aspermutarubrol/violaceol-I (15) exhibited significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity with the IC50 value of 34.1 μM, and displayed strong reduction of Fe3+ with the ferric reducing antioxidant power (FRAP) value of 9.0 mM under the concentration of 3.1 μg/mL, which were more potent than ascorbic acid.

New Drimane Sesquiterpenes and Polyketides from Marine-Derived Fungus Penicillium sp. TW58-16 and Their Anti-Inflammatory and α-Glucosidase Inhibitory Effects

“…Polyketides are a large family of natural products that are derived from acetate building blocks [ 22 ]. Due to their diverse activities, especially antibiotic, anti-tumor, immunosuppressive, etc., polyketides such as doxorubicin, erythromycin A, and rapamycin, have attracted much attention and been applied in the clinic [ 22 , 23 , 24 , 25 ]. In this study, we report the isolation and characterization of 11 polyketides, including six new compounds ( 3 – 8 ), from the marine-derived fungus Penicillium sp.…”

Marine natural products

“…Further Aspergillus strains yielded meroterpenoids 397–399 , 169 xanthenone 400 , 170 aromatic ether 401 , 171 polyketides 402–405 , 172 nucleoside derivatives 406 and 407 and bisabolane sesquiterpenoid 408 , 173 xanthone derivatives 409–411 , 174 412–417 , 175 triols 418 and 419 (ref. 176) and ophiobolins 420–424 .…”

Polyketides and Meroterpenes from the Marine-Derived Fungi Aspergillus unguis 158SC-067 and A. flocculosus 01NT-1.1.5 and Their Cytotoxic and Antioxidant Activities

“…DPPH radical scavenging assay was performed according to the previously described method with minor modification [ 3 , 15 ]. The samples and a positive control, ascorbic acid, were dissolved in DMSO with final concentrations of 6.25, 12.5, 25, 50, 100, and 200 µg/mL.…”

“…The EtOH and DMSO were used as a blank and negative control, respectively. The IC 50 values were determined by the software of GraphPad Prism 8 (GraphPad Software Inc., San Diego, CA, USA) [ 3 ].…”

“…The genus Aspergillus is one of the most ubiquitous genera of filamentous fungi, and they are the major contributor to marine-derived fungal natural products [ 2 , 3 ]. A great number of secondary metabolites with structural diversity, such as polyketides, alkaloids, terpenes, steroids, and peptides, have been isolated from this genus, and many of them display potent biological activities [ 2 ].…”