Novel Polyketide-Terpenoid Hybrid Metabolites from a Potent Nematicidal <i>Arthrobotrys oligospora</i> Mutant Δ<i>AOL_s00215g278</i>

Abstract

Here, we reported that detailed investigation on trace targeted metabolites from nematode-trapping fungus <i>Arthrobotrys oligospora</i> mutant with deletion of P450 gene <i>AOL_s00215g278</i> led to isolation of 9 new polyketide-terpenoid hybrid derivatives, including four new glycosides of the key precursor farnesyl hydrotoluquinol (<b>1</b>) and, surprisingly, four new sesquiterpenyl epoxy-cyclohexenoids (SECs) analogues. Among them, two major target metabolites <b>1</b> and <b>14</b> displayed moderate nematode inhibitory ability. Moreover, the mutant lacking <i>AOL_s00215g278</i> could form far more nematode-capturing traps within 6 h in contact with nematodes and show rapid potent nematicidal activity with killing 93.7% preys, though deletion of the P450 gene resulted in dramatic decrease in fungal colony growth and failure to produce fungal conidia. The results unequivocally revealed that gene <i>AOL_s00215g278</i> should be involved in not only the SEC biosynthetic pathway in the nematode-trapping fungus <i>A. oligospora</i> but also fungal conidiation and nematicidal activity.