Chlordene epoxide

Only 6% of the radioactivity from radiolabeled ( "C) heptachlor was found in the urine while 60% was found in the feces of male rats 10 days after a single oral dose indicating that most of the radioactive material was not absorbed and was excreted in the feces (Tashiro and Matsumura 1978). These data strongly suggest that a large percentage of heptachlor is absorbed from the gastrointestinal tract and eliminated via the bile into the feces. More than 72% of the radioactivity eliminated in the feces was present as metabolites of heptachlor (heptachlor epoxide, 13.1% H-2, < 0.1% 1-OH-chlordene, 19.5% 1-OH-chlordene epoxide, 17.5% 1,2-OH-chlordene, 3.5% H-6, 19.0%). 

Incubations of heptachlor with a mixed culture of soil microorganisms for 12 weeks showed conversion of heptachlor to chlordene, 1-exohydroxychlordene, heptachlor epoxide, and chlordene epoxide. A mixed culture of soil microorganisms, obtained from a sandy loamy soil, degraded heptachlor epoxide to the less toxic 1-exohydroxychlordene. Conversion was about 1% per week during the 12-week test period (Miles et al. 1971). 

Heptachlor rapidly degraded when incubated with acclimated, mixed microbial cultures under aerobic conditions. After 4 wk, 95.3% of the applied dosage was removed (Leigh, 1969). In a mixed bacterial culture under aerobic conditions, heptachlor was transformed to chlordene, 1-hydroxychlordene, heptachlor epoxide, and chlordene epoxide in low yields (Miles et al, 1971). Heptachlor rapidly degraded when incubated with acclimated, mixed microbial cultures under aerobic conditions. After 4 wk, 95.3% of the applied dosage was removed (Leigh, 1969). 

Chlordene chlorohydrin, see Chlordane Chlordene epoxide, see Heptachlor Chlorinated dibenzo-p-dioxin, see Pentachlorophenol Chlorinated dibenzo-p-dioxins, see PCB-1242, PCB-1254... 

Substrates heptachlor epoxide, chlordene epoxide, dieldrin and endrin. 

Table 4.3 The enaatioselective toxicities of the enantiomers of chlordene, chlordene epoxide and heptachlor exo-epoxide insecticides on German cockroach (Blattella german-ica) [25]...

Figure 13.1 Chemical structure of chlordane-related compounds 1, chlordene (4,5,6,7,8,8-hexachloro-3a,4,7,7a-tetrahydro-4, 7-methanoindene) 2, c/ s-chlordane, also known as alpha-chlordane (1-exo, 2-exo, 4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene) 3, trans-chlordane, also known as gamma-chlordane (1-exo, 2-endo, 4,5,6,7,8,8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene) 4, heptachlor (1,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahydro-4,7-methanoindene) — technical heptachlor contains about 15% c/s-chlordane and 2.5% trans-chlordane 5, heptachlor epoxide (1,4,5,6,7,8,8-heptachloro-2,3-epoxy-3a,4,7,7a-tetrahydro-4,7-methanoindene) and 6, oxychlordane, also known as octachlor epoxide (1-exo, 2-endo, 4,5,6,7,8,8-octachloro,2,3-exo-epoxy-2,3,3a,4,7,7a-hexahydro-4,7-methanoindene). 

Microorganisms such as Nocardiopsis sp., an actinomycete, can metabolize cis- and trans-chlo-rdane to at least eight solvent-soluble substances, including dichlorochlordene, oxychlordane, hep-tachlor, heptachlor endo-epoxide, chlordene chlorohydrin, and 3-hydroxy-trans-chlordane (Beeman and Matsumura 1981). Based on studies of chlordane metabolism in animals, four metabolic pathways are proposed (Feroz and Khan 1979a WHO 1984 Nomeir and Hajjar 1987 USEPA 1988) ... 

Lu PY, Metcalf RL, Hirwe AS, et al. 1975. Evaluation of environmental distribution and fate of hexachlorocyclopentadiene, chlordene, heptachlor, and heptachlor epoxide in a laboratory model ecosystem. J Agric Food Chem 23(5) 967-973. 

Soil The actinomycete Nocardiopsis sp. isolated from soil extensively degraded pure cis- and /ra/3s-chlordane to dichlorochlordene, oxychlordane, heptachlor, heptachlor e/ c/o-epoxide, chlordene chlorohydrin, and 3-hydroxy-traas-chlordane. Oxychlordane slowly degraded to 1-hydroxy-2-chlorochlordene (Beeman and Matsumura, 1981). In Hudson River, NY sediments, the presence of adsorbed chlordane suggests it is very persistent in this environment (Bopp et al., 1982). The reported half-life in soil is approximately 1 yr (Hartley and Kidd, 1987). 

The primary metabolism of heptachlor is in the liver where microsomal enzymes convert the parent compound to the more toxic heptachlor epoxide as well as to the less toxic metabolites l-chloro-3-hydroxychlor-dene, 1-hydroxychlordene, and 1-hydroxy-2,3-epoxy-chlordene. These latter metabolites are also more easily excreted. Both heptachlor and heptachlor epoxide are stored in adipose tissue and in the liver, kidney, and muscle tissues. The epoxide is the primary storage form. Heptachlor is able to cross the placenta and has been found in human milk. Metabolites of heptachlor are excreted in urine and feces. 

Lu, P.-Y, R.L. Metcalf, A.S. Hirwe, and J.W. Williams. Evaluation of Environ-mental Distribution and Fate of Hexachlorocyclopentadiene, Chlordene, Heptachlor, andHep-tachlor Epoxide in a Model Ecosystem, J. Agric. Food Chem., 23(5) 967-973 (1975). 

---