Antifungal depsidone metabolites from Cordyceps dipterigena, an endophytic fungus antagonistic to the phytopathogen Gibberella fujikuroi

Abstract

Among thirty four endophytic fungal strains screened for in vitro antagonism, the endophytic fungus Cordyceps dipterigena was found to strongly inhibit mycelial growth of the plant pathogenic fungus Gibberella fujikuroi. Two new depsidone metabolites, cordycepsidone A (1) and cordycepsidone B (2), were isolated from the PDA culture extract of C. dipterigena and identified as being responsible for the antifungal activity. Elucidation of their chemical structures was carried out using 1D and 2D NMR spectroscopy in combination with IR and MS spectroscopic data. Cordycepsidone A displayed strong and dose-dependent antifungal activity against the plant pathogenic fungus Gibberella fujikuroi. The isolates were inactive in bioassays for malaria (Plasmodium falciparum), leishmaniasis (Leishmania donovani), Chagas’s disease (Trypanosoma cruzi), and cytotoxicity at 10 μg/mL. The compounds were also found to be inactive against several bacterial strains at 50 μg/mL.

Cordidepsine is A Potential New Anti-HIV Depsidone from Cordia millenii, Baker

“…The other signals were attributed to the lactone carbonyl at δ C 166.1 (C-11) and aldehyde function at δ C 193.9 (C-14). These data were similar to those of related depsidones previously isolated from several microorganisms [21,22,23,24] and some species of Garcinia genus [25]. The 1 H NMR spectrum (Table 1) confirmed the presence of two aromatic singlets at δ H 6.85 (1H, s , H-2) and δ H 7.08 (1H, s , H-9), suggesting two penta-substituted aromatic rings.…”

“…Allantoin ( 11 ) also displayed weak activity with an IC 50 value of 412.94 μM (Table 3). The activity of compound 1 can be justified by the fact that previous biological studies revealed that depsidones are potential antiviral agents [24]. Furthermore, with reference to compound 1 , previous studies showed that an aromatic moiety next to (at least) two adjacent oxygens appears to be a structural element that is essential for activity against HIV-1 integrase [29].…”

Bioactivity of Fungal Endophytes as a Function of Endophyte Taxonomy and the Taxonomy and Distribution of Their Host Plants

“…These metabolites encompass a diverse range of structures including alkaloids [20], terpenoids [21], quinones [22], and peptides, xanthones and phenols [23]. Bioactivity has been observed against cancer cell lines [24] [25], pathogenic bacteria [26] [27] and fungi (e.g., [28]), and against eukaryotic parasites such as the causal agents of malaria, leishmaniasis and Chagas' disease (e.g., [29] [30]). …”

Cytotoxic Cytochalasins and Other Metabolites from Xylariaceae sp. FL0390, a Fungal Endophyte of Spanish Moss

“…Figure 2) revealed that the two iso-butyl groups (see above) were attached to the adjoining carbon atoms (C-4 and C-5) of the 2(1H)-pyrimidinone ring. Thus, the structure of this metabolite was determined as 4,5-di-isobutyl-2(1H)-pyrimidinone (2). Although many nucleotides contain 2(1H)-pyrimidinone moieties carrying OH and /or NH 2 substituents, this constitutes the first report of the natural occurrence of a 2(1H)-pyrimidinone bearing non-polar substituents.…”