| Summary: | 碩士 === 國立中興大學 === 環境工程學系 === 90 === The objective of this research is to develop a biochemical assay using protein adducts as biomarker of exposure to assess the cumulative body burden of estrogen quinones in target organs. The alkaline permethyla-tion procedure which used methyl iodine and sodium hydroxide as cata-lysts to cleave cysteinyl adducts of estrogen quinones. The cleaved ad-ducts are recovered by organic solvent extractions and analyzed by gas chromatography/electron-impacted mass spectrometer (GC-EIMS). Cysteinyl adducts of estrogen-2,3- quinone and estrogen-3,4-quinone on cyteines (Cys), glutathiones (GSH) and bovine serum albumins (BSA) are characterized by the alkaline permethylation procedure. Results from the optimization of the alkaline permethylation procedure reveal that the optimal condition for adduct cleavage is when modified cysteines react with 6N NaOH and 1 mL of CH3I at 100℃ for 6 hours. The limit of detection is estimated to be between 250 pmole and 1 nmole on column. Additionally, the synthetic cysteinyl adduct of estrogen-3,4-quinone was further purified by HPLC-UV and was used to quantify modified proteins. Regression analysis of the concentration-adduct levels of indicates that the production of E1-3,4-quinone-modified BSA adducts was estimated to be 2.92 nmole/g protein/nM.
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