title: Enantioselective degradation and enantiomerization of indoxacarb in soil.
abstract: In this study, the enantioselective degradation and enantiomerizaton of indoxacarb were investigated in two soils under nonsterilized and sterilized conditions using a chiral OD-RH column on a reversed-phase HPLC. Under nonsterilized conditions, the degradation of indoxacarb in two soils was enantioselective. In acidic soil, the half-lives of R-(-)- and S-(+)-indoxacarb were 10.43 and 14.00 days, respectively. Acidic soil was preferential to the degradation of R-(-)-indoxacarb. In alkaline soil, the half-lives of R-(-)- and S-(+)-indoxacarb were 12.14 and 4.88 days, respectively. S-(+)-Indoxacarb was preferentially degraded. Under sterilized conditions, approximately 5-10% of the initial concentration degraded after 75 days of incubation in acidic soil, whereas in alkaline soil, approximately half of the initial concentration degraded due to chemical hydrolysis under alkaline conditions. Enantiomerization was also discovered in acidic and alkaline soils. The results showed that mutual transformation existed between two enantiomers and that S-(+)-indoxacarb had a significantly higher inversion rate to R-(-)-indoxacarb than its antipode.
authors.affiliation: Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, Laboratory of Insect Toxicology, South China Agricultural University , Guangzhou 510642, China.
authors.forename: Dali
authors.initials: D
authors.lastname: Sun
authors.forename: Junxiao
authors.initials: J
authors.lastname: Pang
authors.forename: Jing
authors.initials: J
authors.lastname: Qiu
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Chenglan
authors.initials: C
authors.lastname: Liu
authors.forename: Bining
authors.initials: B
authors.lastname: Jiao
mesh_terms: D001673:Biodegradation, Environmental; D006207:Half-Life; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism; D010078:Oxazines / Q000737:chemistry* / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: D007306:Insecticides; D010078:Oxazines; D012987:Soil; D012989:Soil Pollutants; C401104:indoxacarb