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Katagi T.,Sumitomo Chemical
Topics in Current Chemistry | Year: 2012

New experimental approaches together with recent progress in spectroscopic technologies have given useful information to understand better the environmental fate of synthetic pyrethroids. The successive transformation of intermediate free radicals by using spin-trapping reagents and fluorophores enables their easier detection in aqueous photolysis. Chiral chromatographic analyses have shown stereo-selective metabolism of pyrethroids in soil. The knowledge on relevant enzymes in soil and plant being involved in hydrolysis, oxidation, and glucose conjugation of pyrethroids has been accumulated. Utilization of either iron-porphyrin with an oxidant or isolated leaf cells as model systems can give more information on metabolism of pyrethroids. © 2011 Springer-Verlag Berlin Heidelberg.


Okamoto M.,Sumitomo Chemical
Journal of Pharmaceutical and Biomedical Analysis | Year: 2014

In the industry of fine chemicals, including pharmaceutical and agricultural chemicals, analytical tests are performed by production departments or contract research organizations at some stage in the research and development of products. These external organizations are required to maintain the capabilities to perform analytical tests using methods that are equivalent to or better than those specified by analytical method validation. For this reason, transfer of analytical procedures to an alternative site becomes necessary.In this review, the relationship between transfer of analytical procedures and assay validation is introduced, focusing on analytical procedures that include HPLC. © 2013 Elsevier B.V.


Kaneko H.,Sumitomo Chemical
Journal of Agricultural and Food Chemistry | Year: 2011

Synthetic pyrethroids, a major insecticide group, are used worldwide to control agricultural and household pests. Mammalian metabolism of pyrethroids was substantially launched in the 1960s and 1970s by the research groups of Professor Casida and Sumitomo Chemical Co., which made great contributions to the elucidation of their metabolic fates. They showed that ester hydrolysis and oxidation play predominant roles in mammalian metabolism of pyrethroids and that rapid metabolism leads to low mammalian toxicity. These metabolic reactions are mediated by carboxylesterases and CYP isoforms, the resultant metabolites then undergoing various conjugation reactions. In general, there are substantially neither significant species differences in metabolic reactions of pyrethoids nor metabolic differences among their chiral isomers except with fenvalerate, one isomer of which yields a lipophilic conjugate causing toxicity. © 2010 American Chemical Society.


Uneme H.,Sumitomo Chemical
Journal of Agricultural and Food Chemistry | Year: 2011

Clothianidin, a neonicotinoid insecticide, has been found by former Agro Division, Takeda Chemical Industries, Ltd. (Sumitomo Chemical Co., Ltd., at present) and codeveloped with Bayer CropScience. During the studies on neonicotinoid insecticides, nitenpyram (an open-chain nitromethylene derivative) was prepared first, showing a potent activity against Hemiptera and Thysanoptera pests, and its modification led to clothianidin (a nitroguanidine derivative). Clothianidin exhibits excellent control efficacies in small amounts for a wide variety of insect pests such as Hemiptera, Thysanoptera, Coleoptera, Lepidoptera, and Diptera for the long term, with excellent systemic action and by a variety of application methods. The structural features of clothianidin are a thiazole ring and an open-chain guanidine skeleton. The structure-activity relationships of guanidine derivatives and the synthetic studies of clothianidin are also discussed. © 2010 American Chemical Society.


Katagi T.,Sumitomo Chemical
Reviews of Environmental Contamination and Toxicology | Year: 2010

From the viewpoint of protecting the natural environment, aquatic ecotoxicological assessment of new pesticides and many existing ones has increasingly become more important. To assess the impact of pesticides on aquatic organisms, international authorities (utilizing OECD and USEPA testing guidelines) require completion of many acute and chronic ecotoxicological studies. Among such studies is testing to measure the potential for bioconcentration. In addition, the authorities in these agencies insist that physico-chemical properties and environmental fate be determined for each registered pesticide. The rationale for such testing is based on the concept that, even if used in conformance with good agricultural practices, pesticides may enter surface waters by several routes such as spray drift, surface runoff, and field drainage, and they may be partitioned to bottom sediments (Katagi 2006). The endpoints of such ecotoxicological testing include mortality and effects on hatching, development, and reproduction. Such endpoints are usually expressed as median-lethal or median-effect concentrations (LC50 and EC50) and no-observed-effect-concentrations (NOEC); such values can be compared with predicted environmental concentrations in exposure media for purposes of risk assessment (Miyamoto et al. 2008). Because aquatic organisms interact with each other in the food web, knowledge of their tendency to bioconcentrate residues in water and from dietary exposure is important when evaluating real environmental pesticide effects. In general, bioconcentration is the most popular term for describing the process by which pesticides enter organisms directly from water through the gills or through epithelial tissues. In contrast, bioaccumulation includes the effect of dietary uptake through food consumption or intake of bottom sediments (Miyamoto et al. 1990). When the levels of a pesticide, accumulated by organisms, are concentrated through two or more trophic levels in a food web, the process is referred to as biomagnification (Connell 1988). © 2010 Springer Science+Business Media, LLC.

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