Secondary metabolites of a marine-derived Penicillium ochrochloron

Abstract

Extremophilic fungi have received considerable attention recently as new promising sources of biologically active compounds with potential pharmaceutical applications. This study investigated the secondary metabolites of a marine-derived Penicillium ochrochloron isolated from underwater sea sand collected from the North Sea in St. Peter-Ording, Germany. Standard techniques were used for fungal isolation, taxonomic identification, fermentation, extraction, and isolation of fungal secondary metabolites. Chromatographic separation and spectroscopic analyses of the fungal secondary metabolites yielded eight compounds: talumarin A (1), aspergillumarin A (2), andrastin A (3), clavatol (4), 3-acetylphenol (5), methyl 2,5-dihydro-4-hydroxy-5-oxo-3-phenyl-2-furanpropanoate (6), emodin (7) and 2-chloroemodin (8). After co-cultivation with Bacillus subtilis, the fungus was induced to express (-)-striatisporolide A (9). Compound 1 was evaluated for antibacterial activity against Staphylococcus aureus, Acinetobacter baumannii, Mycobacterium smegmatis, and M. tuberculosis, as well as cytotoxicity against THP-1 cells. The compound, however, was not cytotoxic to THP-1 cells and had no antibacterial activity against the microorganisms tested. The compounds isolated from P. ochrochloron in this study are well-known compounds with a wide range of beneficial biological properties that can be explored for pharmaceutical, agricultural, or industrial applications. This study highlights the bioprospecting potential of marine fungi and confirms co-cultivation as a useful strategy for the discovery of new natural products.

Anthraquinones and Their Analogues from Marine-Derived Fungi: Chemistry and Biological Activities

“…Buttachon et al reported the isolation of emodin ( 1 ) ( Figure 3 ) from the culture extract of Aspergillus candidus KUFA0062, isolated from a marine sponge Epipolasis sp., which was obtained from the coral reef at the Similan Island National Park, Phang-Nga province, Thailand [ 16 ]. Compound 1 was also obtained from the ethyl acetate (EtOAc) extract of the culture of Penicillium ochrochloron , isolated from the underwater sea sand, which was collected from the North Sea in St. Peter-Ording, Germany [ 17 ]. In another study, Wang et al isolated 1 and questin ( 2 ) ( Figure 3 ) from a solid culture extract of A. flavipes HN4-13, obtained from a Lianyungang coastal sediment from Jiangsu Province, China [ 18 ].…”

“…Although a number of chlorinated anthraquinone derivatives have been isolated, together with non-haloginated anthraquinones, from the culture of marine-derived fungi with normal culture media, the brominated counterparts were only isolated from marine-derived fungi cultured in bromide-enriched media. Eze et al described the isolation of 7-chloroemodin ( 135 ) ( Figure 11 ) from the EtOAc extract of the culture of an underwater sea sand-derived Penicillium ochrochloron [ 17 ], while Luo et al reported the isolation of 2-chloro-1,3,8-trihydroxy-6-(hydroxymethyl)anthracene-9,10-dione ( 136 ) ( Figure 11 ) from the culture extract of a sea sediment-derived Penicillium sp. SCSIOsof101 [ 46 ].…”