• Title/Summary/Keyword: acetyl DCB

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Non-invasive Biological Monitoring of DNA Adducts Formed at Workers Handling 3,3-Dichlorobenzidine(DCB) by Using GC/MS

  • Lee, Jin-Heon
    • Journal of Environmental Health Sciences
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    • v.29 no.4
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    • pp.21-26
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    • 2003
  • We examine the metabolites(DCB and acetyl DCB) extracted from exfoliated urothelial cells of 33 workers who employed DCB-handling industries. The characteristics of workers submitted urine, whose age, working years and smoking persons were 41.9$\pm$11.1, 8.7$\pm$5.5 and 25(32.0%), respectively. DNA adduct was isolated from the exfoliated urothelial cells by applying $^{32}$ p-postlabeling procedure. Metabolites(DCB and acetyl DCB) were extracted from DNA adducts by hydrolyzing and N-glycosylase. Concentrations of DCB and acetyl DCB were 28.6$\pm$5.25 ng/g DNA, and 17.0$\pm$3.73 ng/g DNA, respectively. The regression between DCB level and exposure years of workers is y = 1.668 + 2.588x(p = 0.005, $r^2$= 0.394). The regression between acetyl DCB level and exposure years of workers is y = 8.071 + 1.325x(p = 0.076, $r^2$= 0.222). Smoking workers are significantly higher than non-smoking workers on DCB and acetyl DCB level(p = 0.065 and 0.021, respectively). DCB level was 33.9$\pm$7.14 ng/g DNA on smokers, and 23.1$\pm$9.97 ng/g DNA on non-smokers. Acetyl DCB was 25.1$\pm$5.27 ng/g DNA on smokers, and 8.92$\pm$7.22 ng/g DNA on non-smokers.

Synthesis and Isolation of Monoacetyl-DCB and Diacetyl-DCB from 3,3대-dichlorobenzidine(DCB) (디클로로벤지딘으로부터 대사물질의 합성과 분리방법에 대한 연구)

  • Lee, Jin-Heon;Lee, Beom-Gyu
    • Journal of Environmental Health Sciences
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    • v.29 no.2
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    • pp.50-55
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    • 2003
  • 3,3-dichlorobenzidine is suspected to be cancinogenic in experimental animal and human. Several studies have investigated excretion of metabolites in urine, hemoglobin adduction and cancer incidence among workers occupationally exposed to 3,3'-dichlorobenzidine. In these researches, metabolites of 3,3'-dichlorobenzidine had a very important role, and were required as highly purity. The purpose of this study was synthesis and isolation of its metabolites from 3,3'-dichlorobenzidine. 3,3'-dichlorobenzidine was partially dissolved in benzene, ether, ethanol and methanol, and completely dissolved in 70% acetic acid on mixtures of citric acid containing less than 1% DCB, pyridine, a mixture of 0.5N NaOH and toluene(1:2), and phenol saturated with 20 mM TRIZA base. DCB, monoacetyl-DCB and diacetyl-DCB were measured by using gas chromatography/mass spectrometry(GC/MS). Detection for checking them was nitrogen phosphorous detection mode(NPD), and for identifying them was selected ion monitoring mode(SIM). The base peaks were 252 m/z in DCB, 252, and 294 m/z in monoacetyl-DCB, and 252, 294 and 336 m/z in diacetyl-DCB, respectively. Diacetyl-DCB was synthesized by titrating DCB solution of pyridine with sufficient acetyl chloride. Precipitation was diacetyl-DCB, which was purity of 98.7%. And its supernatant was composed of DCB, monoacetyl-DCB and diacetyl-DCB. By using acetic acid as controller of acetylation, monoacetyl-DCB was isolated from diacetyl-DCB . And residual pyridine was removed by using acetone. The purity of monoacetyl-DCB was 98.8%.

A Study on 10 Metabolites Separated from DNA Adduce of Blood Lymphocytes in Rats Exposed Orally with 3,3-dichlorobenzidine(DCB) by GC/MS-SIM

  • Shin, Ueon-Sang;Lee, Jin-Heon
    • Journal of Environmental Health Sciences
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    • v.28 no.4
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    • pp.6-11
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    • 2002
  • 3.3'-Dichlorobenzidine(DCB) has be shown carcinogenic in several animals, and the development of non-invasive biomonitoring method in workers exposed with it is a very important subject. DNA adduct is a good biomarker for biomonitoring about carcinogens exposure, and lymphocytes is a good non-invasive samples. So we studied to analyze metabolites in blood lymphocytes of female Sprague-Dawley rats exposed orally with DCB(20, 30, and 40 mg/kg wt.) for 3 weeks. For analysis of them, we isolated DNA adducts from blood lymphocytes by using the enzymes method in /sup 32/P-postlabeling, and measured them by using gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM). 4-aminobiphenyl and phenanthrene-d/sub 10/ were added as internal standard for blank sample. Standard metabolites of DCB were synthesized with using pyridine and acetic acid which were promoter and controller in acetylation of DCB. And they were used for calibration curve. Our results showed two kinds of metabolites in DNA adducts of blood lymphocytes. They were N-acetyl 3,3'-dichlorobenzidine(acDCB) and N,N'-diacetyl 3,3'-dichiorobenzidine(di-acDCB ). They were combined with DNA at the same time as an acetyl of it was removed. So we measured DCB and acDCB for two kinds of metabolites in DNA adducts of blood lymphocytes. Our results showed the levels of DCB were 1.46∼2.26 times more than that of acDCB. And also the levels of metabolites in 20, 30 and 40 mg/kg wt. were gradually increased with going days from 1st to 3rd week. They are 1.66, 1.38 and 0.90 times in total metabolites, 1.76, 1.49 and 1.02 times in DCB, and 1.51, 1.22 and 1.28 times in acDCB. In conclusion, the results of this study showed DCB exposed to rats formed DNA adduct in blood lymphocytes after acetylated to N-acetyl 3.3'-dichloro benzidine(acDCB) and N,N'-diacetyl 3,3'-dichlorobenzidine(di-acDCB), and they could be analyzed by us ing gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM).