Untargeted Metabolomics Approach for the Discovery of Environment-Related Pyran-2-Ones Chemodiversity in a Marine-Sourced Penicillium restrictum

Abstract

Very little is known about chemical interactions between fungi and their mollusc host within marine environments. Here, we investigated the metabolome of a Penicillium restrictum MMS417 strain isolated from the blue mussel Mytilus edulis collected on the Loire estuary, France. Following the OSMAC approach with the use of 14 culture media, the effect of salinity and of a mussel-derived medium on the metabolic expression were analysed using HPLC-UV/DAD-HRMS/MS. An untargeted metabolomics study was performed using principal component analysis (PCA), orthogonal projection to latent structure discriminant analysis (O-PLSDA) and molecular networking (MN). It highlighted some compounds belonging to sterols, macrolides and pyran-2-ones, which were specifically induced in marine conditions. In particular, a high chemical diversity of pyran-2-ones was found to be related to the presence of mussel extract in the culture medium. Mass spectrometry (MS)- and UV-guided purification resulted in the isolation of five new natural fungal pyran-2-one derivatives—5,6-dihydro-6S-hydroxymethyl-4-methoxy-2H-pyran-2-one (1), (6S, 1’R, 2’S)-LL-P880β (3), 5,6-dihydro-4-methoxy-6S-(1’S, 2’S-dihydroxy pent-3’(E)-enyl)-2H-pyran-2-one (4), 4-methoxy-6-(1’R, 2’S-dihydroxy pent-3’(E)-enyl)-2H-pyran-2-one (6) and 4-methoxy-2H-pyran-2-one (7)—together with the known (6S, 1’S, 2’S)-LL-P880β (2), (1’R, 2’S)-LL-P880γ (5), 5,6-dihydro-4-methoxy-2H-pyran-2-one (8), (6S, 1’S, 2’R)-LL-P880β (9), (6S, 1’S)-pestalotin (10), 1’R-dehydropestalotin (11) and 6-pentyl-4-methoxy-2H-pyran-2-one (12) from the mussel-derived culture medium extract. The structures of 1-12 were determined by 1D- and 2D-MMR experiments as well as high-resolution tandem MS, ECD and DP4 calculations. Some of these compounds were evaluated for their cytotoxic, antibacterial, antileishmanial and in-silico PTP1B inhibitory activities. These results illustrate the utility in using host-derived media for the discovery of new natural products.

Global metabolome changes induced by environmentally relevant conditions in a marine-sourcedPenicillium restrictum

“…Host-derived media appear clearly more relevant than classical artificial culture media [21][22][23][24], as shown here by the presence of mussel FAs in the lipid composition of the fungus. We can assume that such lipids of hybrid origin are naturally produced within the bivalves, which could not have been observed otherwise.…”

“…However, the most significantly altered part of the analysed metabolism was the FA composition of lipids. This result was unexpected as in a previous study focused on specialised metabolites it was shown that, when cultured in the MES-SSW medium, P. restricum MMS417 over-produced two classes of specialised metabolites, namely pyran-2-ones and lactam macrolides [21]. It therefore appears that the most important response was firstly the induction of lipid metabolism pathways necessary for the physiological adaptation of the fungus, before the expression of more complex biosynthetic mechanisms of specialised metabolism.…”

New Cytotoxic Secondary Metabolites from Two Deep‐Sea‐Derived Fungi and the Co‐Culture Impact on the Secondary Metabolic Patterns

“…Normal and reverse phase chromatographic methods were applied to afford fractions from the AcOEt extract of fermentation of LXY140-3. Thirteen compounds, including one new organic acid 14, and 12 known compounds (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26) were isolated and purified (Figure 5). The known compounds were determined as D-pantothenic acid methyl ester (15), [16] mevalonolactone ( 16), [17] 3,5-dihydroxydecanioc acid (17), [18] (À )-annularin C (18), [19] (1'R,2'S)-LLÀ P880γ (19), [20] PC-2 (20), [20] (6S,1'S)-LLÀ P880β (21), [21] 6S,1'S,2'R)-LLÀ P880β (22), [22] atlantinone B (23), [22] isochomophilone III (24), [23,24] isochomophilone VIII (25), [25] hypocrellone A (26), [26] respectively, by comparison of their MS, NMR, and specific rotation data with those of reported compounds (Figure 5).…”

Marine natural products

“…209 Soft coral-derived Penicillium strains yielded deoxyisoaustamide derivatives 554–560 , 210 and azaphilones 561 and 562 , 211 whilst deep-sea sediment-derived strains were the source of phenylhydrazone 563–565 , and enantiomeric quinazoline 566 and 567 derivatives, 212 benzamide 568 and 569 and leucine derivatives 570 and 571 , 213 penicyrone A analogues with an epoxy tetrahydrofuran ring 572 and 573 , 213 phenol furanone 574 , octanamide derivative 575 and decanoic acid derivatives 576 and 577 . 213 An untargeted metabolomics approach to examination of a P. restrictum extract led to isolation of pyran-2-one derivatives 578–582 , of which 579 was a known synthetic but new NP and 582 was a known terrestrial NP but a first time marine isolate 214 and P. sclerotiorum yielded azaphilones 583 and 584 . 215 Solitumergosterol A 585 , is an unique 6/6/6/6/5 steroid obtained from P. solitum from deep-sea sediment, 216 as were polyketide 586 and alkaloids 587 and 588 .…”