- Elimination kinetics and toxicity of 2,3,7,8-tetrachlorothianthren, a thio analogue of 2,3,7,8-TCDD
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In comparison to the polychlorinated dibenzo-p-dioxins (PCDD) informations on their thio analogues the polychlorinated thianthrens (PCTA) are very limited. In this study we investigated the kinetics and toxicity of 2,3,7,8-tetrachlorothianthren (TCTA), the analogue of the most toxic PCDD congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). It was found that TCTA is rapidly eliminated in mouse liver homogenate fortified with an NADPH-regenerating system suggesting rapid metabolic degradation by liver monooxygenases. Furthermore, TCTA was rapidly eliminated from mouse liver and whole body. In accordance with this rapid elimination, a weekly dosage of 1 mg TCTA per kg body weight (i.p.) over six weeks did not result in weight loss or other signs of overt toxicity in male mice. In rat hepatocytes in primary culture, TCTA was active as inducer of dioxin receptor-regulated cytochrome P4501A1 activity measured as 7-ethoxyresorufin O-deethylase (EROD). The relative inducing potency was about 0.0001 in comparison to TCDD. In spite of this molecular effects, the rapid elimination both in vitro and in vivo argues against a consideration of a TCDD equivalency factor for TCTA.
- Weber, R.,Hagenmaier, H.,Schrenk, D.
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- Sulfuryl chloride in the synthesis of derivatives of dibenzothiophene, phenoxathiin, and thianthrene
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Reactions of sulfuryl chloride with dibenzothiophene and related heterocyclic systems have been studied. It is shown that under different conditions, C- or S-halogenation of the heterocycle takes place. A series of new chlorine derivatives of dibenzothiophene, phenoxathiin and thianthrene have been synthesized and characterized. 1997 Plenum Publishing Corporation.
- Savin,Nedel'kin,Zverev
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p. 333 - 337
(2007/10/03)
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- The study on UV-degradation dynamics of 2,3,7,8-tetrachlorodibenzo-p-dioxin and its analogues
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A study on UV-degradation dynamics of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and its analogues 2,3,7,8-tetrachlorophenoxthin (2,3,7,8-TCPT) and 2,3,7,8-tetrachlorothianthrene (2,3,7,8-TCTR) in solvents CHCl3 and CCl4 was completed. The results indicated that they were degradated by UV in different way in different solvent. The degradation of 2,3,7,8-TCDD and 2,3,7,8-TCPT are pseudo-first-order reactions in CHCl3, but complex reactions in CCl4; the degradation of 2,3,7,8-TCTR is a zero-order reaction in CHCl3, but a pseudo-first-order reaction in CCl4. All of the three compounds disappeared in CCl4 much faster than in CHCl3 under 254 nm UV-irradiation.
- Qin, Zhaohai
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- Sulfur analogues of polychlorinated dibenzo-p-dioxins, dibenzofurans and diphenyl ethers as inducers of CYP1A1 in mouse hepatoma cell culture and structure-activity relationships
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Three sulfur-containing compounds, 2,3,7,8-tetrachlorothianthrene (TCTA), 2,3,7,8-tetrachlorodibenzothiophene (TCDT), and 3,3',4,4'- tetrachlorodiphenyl sulfide (TCDPS), were analyzed for their CYP1A1-inducing potencies - measured as aryl hydrocarbon hydroxylase (AHH) and 7- ethoxyresorufin O-deethylase (EROD) activities - in mouse hepatoma cell culture Hepa-1. Marked differences in the induction potencies were observed among the three compounds studied and between 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD) and its sulfur analogue. The estimated EC50 values for TCDD, TCTA, and TCDT were about 8 pM, 700 pM, and 7.5 nM, respectively. TCDPS did not elicit any AHH/EROD induction. Comparative molecular field analysis (CoMFA) was not able to predict correctly the biological potency of TCTA and TCDT. The most important reason for the poor performance of the model may be the positive point charge of sulfur in TCTA and TCDT.
- Kopponen,Sinkkonen,Poso,Gynther,Karenlampi
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p. 1543 - 1548
(2007/10/03)
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