A new chlorinated sesquiterpenoid analogue of fumagillin, ligerin (1), was isolated from a marine-derived strain of Penicillium, belonging to the subgenus Penicillium, along with the known compounds penicillic acid (2), orcinol, and orsellinic acid. Chemical structures were established by an interpretation of spectroscopic data including IR, UV, and HRESIMS, together with analyses of 1D and 2D NMR spectra and X-ray analysis for the determination of the absolute configuration. Ligerin (1) displayed strong inhibitory activity against an osteosarcoma cell line. This is the first report of the isolation of a fumagillin analogue from a marine-derived Penicillium strain.

Significance and Impact of the Study: Penicillium strains isolated from bivalve molluscs produce extracts exhibiting a higher cytotoxicity than extracts from Penicillium strains isolated from the surrounding marine environment. The use of a mussel-based medium for cultures of some shellfish-derived strains enhances the cytotoxicity of extracts when compared with classical media. The production of cytotoxic compounds and of the mycotoxin patulin on such a host-derived medium highlights a potential health risk for shellfish consumers. AbstractIn order to assess the putative toxigenic risk associated with the presence of fungal strains in shellfish-farming areas, Penicillium strains were isolated from bivalve molluscs and from the surrounding environment, and the influence of the sample origin on the cytotoxicity of the extracts was evaluated. Extracts obtained from shellfish-derived Penicillia exhibited higher cytotoxicity than the others. Ten of these strains were grown on various media including a medium based on mussel extract (Mytilus edulis), mussel flesh-based medium (MES), to study the influence of the mussel flesh on the production of cytotoxic compounds. The MES host-derived medium was created substituting the yeast extract of YES medium by an aqueous extract of mussel tissues, with other constituent identical to YES medium. When shellfish-derived strains of fungi were grown on MES medium, extracts were found to be more cytotoxic than on the YES medium for some of the strains. HPLC-UV/DAD-MS/MS dereplication of extracts from Penicillium marinum and P. restrictum strains grown on MES medium showed the enhancement of the production of some cytotoxic compounds. The mycotoxin patulin was detected in some P. antarcticum extracts, and its presence seemed to be related to their cytotoxicity. Thus, the enhancement of the toxicity of extracts obtained from shellfish-derived Penicillium strains grown on a host-derived medium, and the production of metabolites such as patulin suggests that a survey of mycotoxins in edible shellfish should be considered.

Abstract:Two new tetracyclic cucurbitane-type triterpene glycosides were isolated from an ethyl acetate extract of Citrullus colocynthis leaves together with four known cucurbitacins. Their structures were established on the basis of their spectroscopic data (mainly NMR and mass spectrometry). Evaluation of the in vitro cytotoxic activity of the isolated compounds against two human colon cancer cell lines (HT29 and Caco-2) and one normal rat intestine epithelial cell line (IEC6), revealed that one of the isolated compounds presented interesting specific cytotoxic activity towards colorectal cell lines.

Fungi are talented organisms able to produce several natural products with a wide range of structural and pharmacological activities. The conventional fungal cultivation used in laboratories is too poor to mimic the natural habitats of fungi, and this can partially explain why most of the genes responsible for the production of metabolites are transcriptionally silenced. The use of Histone Deacetylase inhibitors (HDACis) to perturb fungal secondary biosynthetic machinery has proven to be an effective approach for discovering new fungal natural products. The present study relates the effects of suberoylanilide hydroxamic acid (SAHA) and sodium valproate (VS) on the metabolome of Botryosphaeria mamane, an endophytic fungus isolated from Bixa orellana L. UHPLC/HR‐MS analysis, integrated with four metabolomics tools: MS‐DIAL, MS‐FINDER, MetaboAnalyst and GNPS molecular networking, was established. This study highlighted that SAHA and VS changed metabolites in B. mamane, causing upregulation and downregulation of metabolites production. In addition, twelve compounds were detected in the extracts as metabolites structurally correlated to SAHA, indicating its important reactivity in the medium or its metabolism by the fungus. An addition of SAHA induced the production of eight metabolites while VS induced only two metabolites undetected in the control strain. This result illustrates the importance of adding HDACis to a fungal culture in order to induce metabolite production.

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In the course of investigations on marine-derived toxigenic fungi, five strains of Trichoderma atroviride were studied for their production of peptaibiotics. While these five strains were found to produce classical 19-residue peptaibols, three of them exhibited unusual peptidic sodium-adduct [M + 2 Na](2+) ion peaks at m/z between 824 and 854. The sequencing of these peptides led to two series of unprecedented 17-residue peptaibiotics based on the model Ac-XXX-Ala-Ala-XXX-XXX-Gln-Aib-Aib-Aib-Ala/Ser-Lxx-Aib-Pro-XXX-Aib-Lxx-[C(129) ]. The C-terminus of these new peptides was common to all of them, and its elemental formula C5 H9 N2 O2 was established by HR-MS. It could correspond to the cyclized form of N(δ) -hydroxyornithine which has already been observed at the C-terminus of various peptidic siderophores. The comparison of the sequences of 17- and 19-residue peptides showed similarities for positions 1-16. This observation seems to indicate a common biosynthesis pathway. Both new 17-residue peptaibiotics and 19-residue peptaibols exhibited weak in vitro cytotoxicities against KB cells.

The UHPLC/DAD-HRMS(n) method combining characteristic fragmentation patterns and the profiles of the product ions generated in the MS and MS/MS spectra is an effective technique for characterizing hirsutinolide-type SLs.