Antifungal activity of thiophenes from Echinops ritro.
Extracts from 30 plants of the Greek flora were evaluated for their antifungal activity using direct bioautography assays with three Colletotrichum species. Among the bioactive extracts, the dichloromethane extract of the radix of Echinops ritro (Asteraceae) was the most potent. Bioassay-guided fractionation of this extract led to the isolation of eight thiophenes. Antifungal activities of isolated compounds together with a previously isolated thiophene from Echinops transiliensis were first evaluated by bioautography and subsequently evaluated in greater detail using a broth microdilution assay against plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, Colletotrichum gloeosporioides, Botrytis cinerea, Fusarium oxysporum, Phomopsis viticola, and Phomopsis obscurans. 5'-(3-Buten-1-ynyl)-2,2'-bithiophen (1), alpha-terthienyl (2), and 2-[pent-1,3-diynyl]-5-[4-hydroxybut-1-ynyl]thiophene (5) at 3 and 30 microM were active against all three Colletotrichum species, F. oxysporum, P. viticola, and P. obscurans.
Fokialakis
Nikolas
N
Natural Products Utilization Research Unit, Agricultural Research Service, U.S. Department of Agriculture, P.O.Box 8048, University of Mississippi, University, Mississippi 38677, USA.
Cantrell
Charles L
CL
Duke
Stephen O
SO
Skaltsounis
Alexios L
AL
Wedge
David E
DE
D001203:Ascomycota / Q000187:drug effects; D020171:Botrytis / Q000187:drug effects; D020231:Colletotrichum / Q000187:drug effects*; D031182:Echinops Plant / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000302:isolation & purification / Q000494:pharmacology*; D005670:Fusarium / Q000187:drug effects; D008752:Methylene Chloride; D010936:Plant Extracts / Q000494:pharmacology; D010944:Plants / Q000382:microbiology; D013876:Thiophenes / Q000302:isolation & purification / Q000494:pharmacology*
D005659:Fungicides, Industrial; D010936:Plant Extracts; D013876:Thiophenes; C019101:alpha-terthienyl; D008752:Methylene Chloride