title: Secondary metabolites of the grapevine pathogen Eutypa lata inhibit mitochondrial respiration, based on a model bioassay using the yeast Saccharomyces cerevisiae.
abstract: Acetylenic phenols and a chromene isolated from the grapevine fungal pathogen Eutypa lata were examined for mode of toxicity. The compounds included eutypine (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl aldehyde), eutypinol (4-hydroxy-3-[3-methyl-3-butene-1-ynyl] benzyl alcohol), eulatachromene, 2- isoprenyl-5-formyl-benzofuran, siccayne, and eulatinol. A bioassay using the yeast Saccharomyces cerevisiae showed that all compounds were either lethal or inhibited growth. A respiratory assay using 2,3,5-triphenyltetrazolium (TTC) indicated that eutypinol and eulatachromene inhibited mitochondrial respiration in wild-type yeast. Bioassays also showed that 2- isoprenyl-5-formyl-benzofuran and siccayne inhibited mitochondrial respiration in the S. cerevisiae deletion mutant vph2Delta, lacking a vacuolar type H (+) ATPase (V-ATPase) assembly protein. Cell growth of tsa1Delta, a deletion mutant of S. cerevisiae lacking a thioredoxin peroxidase (cTPx I), was greatly reduced when grown on media containing eutypinol or eulatachromene and exposed to hydrogen peroxide (H(2)O(2)) as an oxidative stress. This reduction in growth establishes the toxic mode of action of these compounds through inhibition of mitochondrial respiration.
authors.affiliation: Plant Mycotoxin Research Unit, Western Regional Research Center, USDA-ARS, 800 Buchanan Street, Albany, CA 94710, USA.
authors.forename: Jong H
authors.initials: JH
authors.lastname: Kim
authors.forename: Noreen
authors.initials: N
authors.lastname: Mahoney
authors.forename: Kathleen L
authors.initials: KL
authors.lastname: Chan
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Molyneux
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Campbell
mesh_terms: D000480:Alkynes / Q000378:metabolism; D001203:Ascomycota / Q000378:metabolism* / Q000472:pathogenicity; D001547:Benzaldehydes / Q000378:metabolism; D001681:Biological Assay; D008928:Mitochondria / Q000502:physiology; D009183:Mycotoxins / Q000378:metabolism* / Q000494:pharmacology*; D018384:Oxidative Stress; D010101:Oxygen Consumption; D010935:Plant Diseases / Q000382:microbiology; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D027843:Vitis / Q000382:microbiology*
chemical_list: D000480:Alkynes; D001547:Benzaldehydes; D009183:Mycotoxins; C102200:eutypine; C031784:siccayne