Identification of Feldin, an Antifungal Polyyne from the Beefsteak Fungus Fistulina hepatica

Abstract

Fruiting body-forming members of the Basidiomycota maintain their ecological fitness against various antagonists like ascomycetous mycoparasites. To achieve that, they produce myriads of bioactive compounds, some of which are now being used as agrochemicals or pharmaceutical lead structures. Here, we screened ethyl acetate crude extracts from cultures of thirty-five mushroom species for antifungal bioactivity, for their effect on the ascomycete Saccharomyces cerevisiae and the basidiomycete Ustilago maydis. One extract that inhibited the growth of S. cerevisiae much stronger than that of U. maydis was further analyzed. For bioactive compound identification, we performed bioactivity-guided HPLC/MS fractionation. Fractions showing inhibition against S. cerevisiae but reduced activity against U. maydis were further analyzed. NMR-based structure elucidation from one such fraction revealed the polyyne we named feldin, which displays prominent antifungal bioactivity. Future studies with additional mushroom-derived eukaryotic toxic compounds or antifungals will show whether U. maydis could be used as a suitable host to shortcut an otherwise laborious production of such mushroom compounds, as could recently be shown for heterologous sesquiterpene production in U. maydis.

Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity

“…Given the remarkable technological breakthroughs offered by these carbon allotropes and the more recently nanomedicine research attention on natural polyynes isolated by fungi, bacteria, plants, the interest in synthetic linear carbon chains (i.e., polyynes/carbyne, the one-dimensional allotrope of carbon composed of sp-hybridized carbon atoms), and their unusual potential properties is heavily increased [ 17 , 18 , 19 ]. Natural polyynes are characterized by a great variety of structural features (oxygen-containing functional groups, ring chain, aromatic rings, etc.)…”

A polyyne toxin produced by an antagonistic bacterium blinds and lyses a Chlamydomonad alga

“…They have been isolated from different organisms, including a variety of land plants, fungi, and insects. However, few bacterial polyynes are known to be of ecological relevance ( 31 , 41 – 43 ). The first identified bacterial gene cluster coding for the biosynthesis of a polyyne was caryoynencin from Burkholderia spp ( 31 ).…”

A polyyne toxin produced by an antagonistic bacterium blinds and lyses a green microalga

“…They have been isolated from different organisms, including a variety of land plants, fungi, and insects. However, only few bacterial polyynes are known of ecological relevance (31,(39)(40)(41). The first identified bacterial gene cluster coding for the biosynthesis of a polyyne was caryoynencin from Burkholderia spp.…”