Oxidative activation and degradation of organophosphorus pesticides mediated by iron porphyrins

• Published in: Journal of Pesticide Science Vol. 30; no. 2; pp. 103 - 110
• Main Authors: Fujisawa, T.(Sumitomo Chemical Co. Ltd., Takarazuka, Hyogo (Japan)), Katagi, T
• Format: Journal Article
• Language: English
• Published: Tokyo Pesticide Science Society of Japan 01.01.2005; Japan Science and Technology Agency
• Subjects: Biological and medical sciences; Biomimetics; CITOCROMO P450; COMPOSE ORGANOPHOSPHORE; COMPUESTO ORGANICO DEL FOSFORO; CYTOCHROME P450; DEGRADACION; DEGRADATION; FER; Fundamental and applied biological sciences. Psychology; HIERRO; IRON; MNDO-PM3 calculations; ORGANOPHOSPHORUS COMPOUNDS; Organophosphorus pesticides; OXIDACION; OXIDATION; oxidation mediated by iron porphyrin; OXYDATION; PESTICIDAL PROPERTIES; PESTICIDE; PESTICIDES; Phenols; Phytopathology. Animal pests. Plant and forest protection; PLAGUICIDAS; PORFIRINAS; PORPHYRINE; PORPHYRINS; PROPIEDADES PLAGUICIDAS; PROPRIETE DES PESTICIDES; RELACION ESTRUCTURA ACTIVIDAD; RELATION STRUCTURE ACTIVITE; STRUCTURE ACTIVITY RELATIONSHIPS; Sulfur; Degradation; Porphyrin; Pesticides; organophosphorus pesticides; oxidation mediated by iron porphyrin; Activation; Iron; Organophosphorus compounds; Oxidation; MNDO-PM3 calculations
• ISSN: 1348-589X; 0385-1559; 1349-0923
• DOI: 10.1584/jpestics.30.103

Biomimetic oxidation mediated by three types of iron porphyrins was examined for five organophosphrus pesticides, fenitrothion (I), cyanophos (II), tolclofos-methyl (III), butamifos (IV) and fenthion (V). The major products from 1-IV were the corresponding phenols and each oxon formed via a phosphoxathiirane intermediate by oxidation at the P=S moiety similarly as reported for their mammalian metabolism by cytochrome P450 enzymes. Stepwise oxidation of the methylthio sulfur via sulfoxide to sulfone, and ester cleavage and oxidative desulfuration primarily proceeded for V. Both the electron distribution of the highest occupied molecular orbital and its energy level of the pesticides calculated by MNDO-PM3 were shown to control the reaction site and rate of oxidation at sulfur atoms.