title: Bioactivity, toxicity and dissipation of hexaconazole enantiomers.
abstract: In this study, the bioactivity, acute toxicity and dissipation in vegetables of the individual enantiomers of the fungicide hexaconazole had been investigated. The optical pure single enantiomers were prepared and the bioactivity of (+)-, (-)- and rac-hexaconazole was tested using four target fungi including Colletotrichum gloeosporioides Penz, Alternaria solani, Alternaria mali Roberts and Monilinia fructicola. The results showed (-)-hexaconazole was always more active than (+)-hexaconazole with the fungicidal activity 11–13-fold higher to A. solani, A. mali Roberts and Monilinia fructicola, and 1.26-fold higher to C. gloeosporioides Penz. (-)-Hexaconazole also showed 1.3-fold higher acute toxicity to aquatic species Daphnia magna based on the 48 h EC50 values. There was obvious enantioselectivity in the dissipation in tomato with (-)-hexaconazole degraded faster resulting an enrichment of (+)-form, and the half-lives of (-)-hexaconazole and (+)-hexaconazole in tomato were 2.96 d and 3.38 d respectively, while it was not enantioselective in green pepper, in which the both enantiomers had the half-lives about 4.36 d. The findings are helpful for better environmental and ecological risk assessment of hexaconazole on an enantiomeric level.
authors.forename: Jiajun
authors.initials: J
authors.lastname: Han
authors.forename: Jiazhen
authors.initials: J
authors.lastname: Jiang
authors.forename: Hang
authors.initials: H
authors.lastname: Su
authors.forename: Mingjing
authors.initials: M
authors.lastname: Sun
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Donghui
authors.initials: D
authors.lastname: Liu
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000818:Animals; D003621:Daphnia / Q000187:drug effects / Q000502:physiology; D005658:Fungi / Q000187:drug effects / Q000502:physiology; D005659:Fungicides, Industrial / Q000378:metabolism / Q000633:toxicity*; D007700:Kinetics; D018551:Solanum lycopersicum / Q000187:drug effects / Q000502:physiology; D013237:Stereoisomerism; D023382:Toxicity Tests, Acute; D014230:Triazoles / Q000378:metabolism / Q000633:toxicity*
chemical_list: D005659:Fungicides, Industrial; D014230:Triazoles; C409722:hexaconazole