Research of evaluate conditions for the safe and effective use of current pesticide chemicals and to develop better pesticides with improved selectivity continues to focus on their metabolism, photodecomposition and mode of action. The major emphasis is on synthetic pyrethroid insecticides, which have recently entered major use in agricultural pest control. Chemical studies involve photodecomposition, synthesis of metabolites and photoproducts, and spectroscopy and analysis of the pyrethroids and their degradation products. Toxicological investigations on pyrethroids concern their metabolism in various organisms and enzyme systems, their synergistic interactions with other pesticides, and their neurophysiological effects. Studies on phosphorylating and carbamoylating agents consider those actions consider those actions of organophosphorus and methylcarbamate pesticides and related compounds which are not attributable to acetylcholinesterase inhibition, e.g. the biochemical lesions leading to teratogenic and/or delayed neurotoxic effects in vertebrates and the mode of action of monocyclic and bicyclic toxicants. The metabolism of S-alkyl phosphorothiolate pesticides is also investigated. Studies on novel or poorly understood target sites examine the mode of action of antidotes for herbicide injury to crops, herbicides and their metabolites that inhibit various photosynthetic processes, and inhibitors of chitin synthesis and/or chitin synthetase. Structure-activity considerations are important in these investigations. Studies on reactions of mutagenic and possibly carcinogenic pesticides and their degradation products attempt to identify that actual mutagenic components of pesticides and their metabolites and photoproducts with current emphasis on S-chloroallyl thio- and dithiocarbamate herbicides and pyrethroid insecticides. It may be possible to avoid the serious implications of mutagenic and carinogenic lesions by changes in manufacturing methods and purification procedures or by slight structural modifications on the pesticides.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Program Projects (P01)
Project #
5P01ES000049-23
Application #
3095765
Study Section
(SSS)
Project Start
1977-12-01
Project End
1987-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
23
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of California Berkeley
Department
Type
DUNS #
094878337
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Casida, John E; Quistad, Gary B (2004) Organophosphate toxicology: safety aspects of nonacetylcholinesterase secondary targets. Chem Res Toxicol 17:983-98
Sparks, S E; Quistad, G B; Li, W et al. (2000) Chloropicrin dechlorination in relation to toxic action. J Biochem Mol Toxicol 14:26-32
Tomizawa, M; Casida, J E (1999) Minor structural changes in nicotinoid insecticides confer differential subtype selectivity for mammalian nicotinic acetylcholine receptors. Br J Pharmacol 127:115-22
Fang, N; Casida, J E (1999) New bioactive flavonoids and stilbenes in cube resin insecticide. J Nat Prod 62:205-10
Sparks, S E; Quistad, G B; Casida, J E (1999) Organophosphorus pesticide-induced butyrylcholinesterase inhibition and potentiation of succinylcholine toxicity in mice. J Biochem Mol Toxicol 13:113-8
Fang, N; Casida, J E (1999) Cube resin insecticide: identification and biological activity of 29 rotenoid constituents. J Agric Food Chem 47:2130-6
Latli, B; D'Amour, K; Casida, J E (1999) Novel and potent 6-chloro-3-pyridinyl ligands for the alpha4beta2 neuronal nicotinic acetylcholine receptor. J Med Chem 42:2227-34
Schneider, M; Quistad, G B; Casida, J E (1999) Glutathione activation of chloropicrin in the Salmonella mutagenicity test. Mutat Res 439:233-8
Staub, R E; Quistad, G B; Casida, J E (1999) S-methyl N-butylthiocarbamate sulfoxide: selective carbamoylating agent for mouse mitochondrial aldehyde dehydrogenase. Biochem Pharmacol 58:1467-73
Schuler, F; Yano, T; Di Bernardo, S et al. (1999) NADH-quinone oxidoreductase: PSST subunit couples electron transfer from iron-sulfur cluster N2 to quinone. Proc Natl Acad Sci U S A 96:4149-53

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