Water cyclodienes

Cyclodienes. These are polychlorinated cycHc hydrocarbons with endomethylene-bridged stmctures, prepared by the Diels-Alder diene reaction. The development of these insecticides resulted from the discovery in 1945 of chlordane, the chlorinated adduct of hexachlorocyclopentadiene and cyclopentadiene (qv). The addition of two Cl atoms across the double bond of the ftve-membered ring forms the two isomers of chlordane [12789-03-6] or l,2,4,5,6,7,8,8-octachloro-2,3,3t ,4,7,7t -hexahydro-4,7-methano-lJT-indene, QL-trans (mp 106.5°C) and pt-tis (32) (mp 104.5°C). The p-isomerhas signiftcantiy greater insecticidal activity. Technical chlordane is an amber Hquid (bp 175°C/267 Pa, vp 1.3 mPa at 25°C) which is soluble in water to about 9 fig/L. It has rat LD qS of 335, 430 (oral) and 840, 690 (dermal) mg/kg. Technical chlordane contains about 60% of the isomers and 10—20% of heptachlor. It has been used extensively as a soil insecticide for termite control and as a household insecticide. 

TR. Dombrowski, E.M. Thurman, and G.B. Mohrman, A first application of enzyme-linked immunosorbent assay for screening cyclodiene insecticides in ground water, in Environmental Immunochemical Methods, ed. J.M. Van Emon, C.L. Ger-lach, and J.C. Johnson, American Chemical Society, Washington, DC, pp. 148-154 (1996). 

Figure 2. Absorption of cyclodienes by fish and Xenopus in a static system (A), goldfish treated with photo-cis-chlordane (B), goldfish with cis-chlordane (C), blue gills with photodieldrin (D), blue gills with photo-cis-chlordane (E), bluegills with cis-chlorane and (F), Xenopus with ds-chlordane. All exposures were made at 5 ppb. (see Table 1 for biomass and volume of water).

Transfer of the aquatic animals, after absorption of the cyclodiene, to insecticide-free water showed variations in elimination pattern related with the chemical as well as its concentration in the body. It follows a somewhat biphasic response, there is initial rapid elimination of high concentration followed by a slow elimination at lower body concentrations (Fig. 3)(21,22, 23). Xenopus, even at low body levels of cis-chlordane, eliminate it at slightly faster rate than fish. Photo-cis-chlordane seems to be eliminated at a faster rate than cis-chlordane by both goldfish and bluegill (Table 2). The elimination of photo-cis-chlordane by goldfish and bluegill and of photodieldrin by blue-gill shows a biphasic response (Fig. 3). 

Since elimination of these apolar cyclodienes does take place in fish, we examined the nature of radioactivity in both fish and water. 

Table 2. Elimination of cyclodienes by aquatic vertebrates following their transfer, after maximum absorption in a static system, to insecticide-free water. 

Epoxide rings of alkene and arene compounds are hydrated to form trans-diols. The enzymes that catalyze the addition of a molecule of water to an epoxide ring to yield diols are called epoxide hydrolases (also known as epoxide hydrases). Epoxide hydrolase activity has been detected in numerous species of insects. Enzymatic epoxide hydration of certain cyclodiene insecticides and their analogs has been demonstrated in the housefly, blowfly (Calliphora erythrocephala), yellow mealworm (Tenebrio molitor), Madagascar cockroach (Gromphadorhina portentosa), southern army worm (Spodoptera eridania), and red flour beetle (Tribolium castaneum). Epoxide hydrolase is also important in the metabolism of juvenile... 

See a/so Carbon Monoxide Charcoal Chlorine Chlorine Dioxide Cyclodienes Diazepam Organochlorine Insecticides Phosgene Pollution, Soil Pollution, Water. 

Competition Enzvme-Linked Immunosorbent Assay. A competition enzyme-linked immunosorbent assay (cELISA) was developed to quantify the amount of heptachlor in solution and to evaluate the ability of the antibodies to distinguish among various cyclodiene insecticides and related chemicals. Microtiter plates were coated with 0.25 ng/well hept-BSA (100 p.l/well of a 2.5 ng/mL solution of hept-BSA in distilled water was allowed to evaporate onto the bottoms of the wells at 37° C). The plates were then blocked with DB as described above. Competitors (analytical standards dissolved in methanol) were added to the DB such that the resulting solution was 50% methanol. An aliquot (200 pL) of this competitor-dilution buffer solution was added to an antigen-coated well. Then, the amount of competitor was serially diluted down the microtiter plate, so each well contained 100 iL of competitor in a 50% methanol-dilution buffer solution. Next an equal volume of dilution DB 100 ng of anti-heptachlor monoclonal antibody was added to each well. Thus, each well contained 200 )xl of a 25% methanol solution in DB, antibody and competitor. Plates were incubated for 1 h at 37° C and then processed as described above. 

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