title: Cyclopaldic acid, seiridin, and sphaeropsidin A as fungal phytotoxins, and larvicidal and biting deterrents against Aedes aegypti (Diptera: Culicidae): structure-activity relationships.
abstract: Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. From a preliminary screening of fungal phytotoxins, cyclopaldic acid (1), seiridin (2), sphaeropsidin A (4), and papyracillic acid (5) were evaluated for their biting deterrent and larvicidal activities against Ae. aegypti L. Because compounds 1, 2, 4, and 5 exhibited mosquito biting deterrent activities and 1 and 4 demonstrated larvicidal activities, further structureactivity relationship studies were initiated on these toxins. In biting-deterrence bioassays, 1, 2, 4, and 5, 3,8-didansylhydrazone of cyclopaldic acid, 1F, 5-azidopentanoate of cyclopaldic acid A, 1G, the reduced derivative of cyclopaldic acid, 1 H, isoseiridin (3), 2'-O-acetylseiridin (2A), 2'-oxoseiridin (2C), 6-O-acetylsphaeropsidin A (4A), 8,14-methylensphaeropsidin A methyl ester (4B), and sphaeropsidin B (4C) showed activities higher than the solvent control. Sphaeropsidin B (4C) was the most active compound followed by 2A, while the other compounds were less active. Biting-deterrence activity of compound 4C was statistically similar to DEET. In the larvicidal screening bioassays, only compounds 1 and 4 demonstrated larvicidal activities. Based on LD50 values, compound 4 (LD50 36.8 ppm) was significantly more active than compound 1 (LD50 58.2 ppm). However, the activity of these compounds was significantly lower than permethrin.
authors.affiliation: Dipartimento di Science Chimiche, Università di Napoli Federico II, Complesso Universitario Monte Sant'Angelo, Via Cintia 4, IT-80126 Napoli.
authors.forename: Alessio
authors.initials: A
authors.lastname: Cimmino
authors.forename: Anna
authors.initials: A
authors.lastname: Andolfi
authors.forename: Fabiana
authors.initials: F
authors.lastname: Avolio
authors.forename: Abbas
authors.initials: A
authors.lastname: Ali
authors.forename: Nurhayat
authors.initials: N
authors.lastname: Tabanca
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
authors.forename: Antonio
authors.initials: A
authors.lastname: Evidente
mesh_terms: D000330:Aedes / Q000187:drug effects / Q000254:growth & development; D000818:Animals; D001572:Benzofurans / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity; D004224:Diterpenes / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D005663:Furans / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D007302:Insect Repellents / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D007306:Insecticides / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D007814:Larva / Q000187:drug effects; D004718:Saccharomycetales / Q000737:chemistry / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D001572:Benzofurans; D004224:Diterpenes; D005663:Furans; D007302:Insect Repellents; D007306:Insecticides; C106059:seiridin; C016326:cyclopaldic acid; C570422:sphaeropsidin A
keywords: Biting deterrence; Dengue fever; Fungi; Larvicidal activity; Phytotoxins; Structureactivity relationship (SAR)