title: Sphaeropsidones, phytotoxic dimedone methyl ethers produced by Diplodia cupressi: a structure-activity relationship study.
abstract: Sphaeropsidone and episphaeropsidone are two phytotoxic dimedone methyl ethers produced by Diplodia cupressi, the causal agent of a canker disease of cypress in the Mediterranean area. In this study, eight derivatives obtained by chemical modifications and two natural analogues were assayed for phytotoxic and antifungal activities, and a structure-activity relationship was examined. Each compound was tested on nonhost plants and on five fungal pathogenic species belonging to the genus Phytophthora. The results provide insights into structure-activity relationships within these compounds. It was found that the hydroxy group at C-5, the absolute C-5 configuration, the epoxy group, and the C-2 carbonyl group appear to be structural features important in conferring biological activity. The conversion of sphaeropsidone into the corresponding 1,4-dione derivative led to a compound showing greater antifungal activity than its precursor. This finding could be useful in devising new natural fungicides for practical application in agriculture.
authors.affiliation: Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy. evidente@unina.it
authors.forename: Antonio
authors.initials: A
authors.lastname: Evidente
authors.forename: Lucia
authors.initials: L
authors.lastname: Maddau
authors.forename: Bruno
authors.initials: B
authors.lastname: Scanu
authors.forename: Anna
authors.initials: A
authors.lastname: Andolfi
authors.forename: Marco
authors.initials: M
authors.lastname: Masi
authors.forename: Andrea
authors.initials: A
authors.lastname: Motta
authors.forename: Angela
authors.initials: A
authors.lastname: Tuzi
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D029781:Cupressus / Q000382:microbiology; D003512:Cyclohexanones / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019083:Mediterranean Region; D008738:Methyl Ethers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D003904:Mitosporic Fungi / Q000737:chemistry*; D015394:Molecular Structure; D018515:Plant Leaves / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000935:Antifungal Agents; D003512:Cyclohexanones; D004224:Diterpenes; D008738:Methyl Ethers; C523395:sphaeropsidone; C004774:dimedone