Isolation and identification of antifungal fatty acids from the basidiomycete Gomphus floccosus.
Bioautography of extracts of the fruiting bodies of the basidiomycete Gomphus floccosus (Schw.) Singer indicated the presence of fungitoxic compounds in the ethyl acetate fraction against the plant pathogens Colletotrichum fragariae, Colletotrichum gloeosporioides, and Colletotrichum acutatum. Bioassay-guided fractionation of this fraction resulted in the isolation of the bioactive fatty acids (9 S,10 E,12 Z)-9-hydroxy-10,12-octadecadienoic acid (1), (9 E,11 Z)-13-oxo-9,11-octadecadienoic acid (2), and (10 E,12 E)-9-oxo-10,12-octadecadienoic acid (3). These three oxylipins were further evaluated for activity against a greater range of fungal plant pathogens (C. fragariae, C. gloeosporioides, C. acutatum, Botrytis cinerea, Fusarium oxysporum, Phomopsis obscurans, and Phomopsis viticola) in in vitro dose-response studies. Phomopis species were the most sensitive fungi to these compounds. At 120 h of treatment, the IC50 values for compounds 1, 2, and 3 for P. obscurans were 1.0, 4.5, and 23 microM, respectively, as compared to 1.1 microM for the captan positive control.
Cantrell
Charles L
CL
Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture, University, Mississippi 38677, USA. charles.cantrell@ars.usda.gov
Case
Bethany P
BP
Mena
E Edward
EE
Kniffin
Toby M
TM
Duke
Stephen O
SO
Wedge
David E
DE
D000935:Antifungal Agents / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D001487:Basidiomycota / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D048690:Fruiting Bodies, Fungal / Q000737:chemistry / Q000378:metabolism; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development
D000935:Antifungal Agents; D005227:Fatty Acids