title: Oocydin A, a chlorinated macrocyclic lactone with potent anti-oomycete activity from Serratia marcescens.
abstract: A unique chlorinated macrocyclic lactone, termed oocydin A, was isolated from a strain of Serratia marcescens growing as an epiphyte on Rhyncholacis pedicillata, an aquatic plant native to the Carrao river of the Venezuelan-Guyanan region of South America. The lactone has a molecular mass of 470 Da, and contains one atom of chlorine, a carboxyl group and a tetrahydrofuran ring internal to a larger macrocyclic ring. MICs of approximately 0.03 microg ml(-1) were noted for oocydin A against such phytopathogenic oomycetes as Pythium ultimum, Phytophthora parasitica, Phytophthora cinnamomi and Phytophthora citrophora. With regard to the true fungi, oocydin A had either minimal or no effect against certain Fungi Imperfecti (including several pathogens of humans), two ascomycetes and a basidiomycete. Oocydin A may have potential as an antimycotic in agricultural applications and especially for crop protection.
authors.affiliation: Department of Plant Sciences, Montana State University, Bozeman, MT 59717, USA1.
authors.forename: Gary
authors.initials: G
authors.lastname: Strobel
authors.affiliation: Department of Plant Sciences, Montana State University, Bozeman, MT 59717, USA1.
authors.forename: Jia-Yao
authors.initials: JY
authors.lastname: Li
authors.affiliation: Department of Applied Biological Science, Science University of Tokyo, Noda, Chiba 278-8510, Japan2.
authors.forename: Fumio
authors.initials: F
authors.lastname: Sugawara
authors.affiliation: The Institute of Physical and Chemical Research, Wako, Saitama 351- 0198, Tokyo, Japan3.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Koshino
authors.affiliation: Department of Chemistry, University of Utah, Salt Lake City, UT 84112, USA4.
authors.forename: James
authors.initials: J
authors.lastname: Harper
authors.affiliation: Department of Botany and Range Science, Brigham Young University, Provo, UT 84602, USA5.
authors.forename: W M
authors.initials: WM
authors.lastname: Hess
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D017753:Ecosystem; D005618:Fresh Water; D007783:Lactones / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D013058:Mass Spectrometry / Q000379:methods; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D009868:Oomycetes / Q000187:drug effects* / Q000254:growth & development; D010838:Phytophthora / Q000187:drug effects / Q000254:growth & development; D010944:Plants / Q000382:microbiology; D012706:Serratia marcescens / Q000254:growth & development / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D003470:Culture Media; D007783:Lactones; C403892:oocydin A