N-Methylimidazole-catalyzed acetylation of hydroxy compounds prior to gas chromatographic separation and determination

Wachowiak, Roman; Connors, Kenneth A.

doi:10.1021/ac50037a014

Cited by 45 publications

(13 citation statements)

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“…The AcBPdG was further used as a standard for HPLC separations of 14 C-AcBPdG. Use of THF/Melm as a solvent gave higher postlabeling yields when picomolar amounts of the BPdG adduct were acetylated [25]. Pentakis(Acetyl) BPdG was also the major product under these conditions as verified by LC-MS, but the reaction was faster and more efficient (data not shown).…”

Section: Resultsmentioning

confidence: 93%

Molecular Epidemiology of Breast Cancer: Development and Validation of Acetylation Methods for Carcinogen-DNA Adduct Detection

Shields¹

2002

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and Molecular epidemiology can elucidate new breast cancer risk factors and gene-environment interactions relating to both hormonal and non-hormonal carcinogenic mechanisms. Corroborative epidemiological studies of intermediate biomarkers of carcinogenesis and laboratory studies demonstrating functional importance of the epidemiology findings are needed. The study of carcinogen-DNA adducts can provide corroborative evidence for the importance of genetic susceptibilities in breast cancer risk. We are establishing new assays for the detection of carcinogen-DNA adducts, use it for the first time in humans, and rigorously validate it to prove its utility for human breast tissue analysis in epidemiological studies, and determine adduct levels in relation to metabolizing gene polymorphisms. The assays are novel because one uses a new chemical postlabeling method and quantitates adducts by accelerator mass spectroscopy (an ultrasensitive ,4 C detection unit). The second uses capillary HPLC and laser-induced flourescence. Once validated, we will learn the variability for DNA adduct levels in the population as it relates to age, gender, race, and smoking in breast tissues from 235 donors (200 women, 35 men). We also will develop breast strains from normal donors, determine in vitro adduct formation levels and correlate these levels with p53 induction. Thus, this study will provide new information about genotype-phenotype relationships.14. SUBJECT Currently, many ongoing breast cancer studies are exploring risks related to genetic polymorphisms in these genes. Yet these studies by themselves do not provide absolute proof of etiology or causality. Thus, corroborative epidemiological studies of intermediate biomarkers of carcinogenesis and laboratory studies demonstrating functional importance of the epidemiology findings are needed. We are focusing on carcinogen-DNA adducts because they are promutagenic and lead to alterations in cancer susceptibility genes. They also serve as a marker of the biologically effective dose of a carcinogen, indicating a person's phenotype for metabolism, DNA repair and apoptosis. Several available carcinogen DNA-adduct assays might be useful here, but they are not sufficiently specific and/or sensitive for testing mechanistic hypotheses in humans. We are attempting to establish a new assay for the detection of carcinogen-DNA adducts, use it for the first time in humans, and rigorously validate it to prove it...

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Section: Resultsmentioning

confidence: 93%

Molecular Epidemiology of Breast Cancer: Development and Validation of Acetylation Methods for Carcinogen-DNA Adduct Detection

Shields¹

2002

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“…At lower temperatures it takes from some hours to some days to perform the analysis [35,49,501. 4-Dimethylaminopyridine is an extremely effective catalyst [52]. To accelerate the analysis, more active acidic and basic catalysts are proposed.…”

Section: Introductionmentioning

confidence: 99%

“…To accelerate the analysis, more active acidic and basic catalysts are proposed. Its catalytic activity exceeds pyridine activity by 400 times [52]. 4-Dimethylaminopyridine is an extremely effective catalyst [52].…”

Section: Introductionmentioning

confidence: 99%

Determination of hydroxyl groups in polymers. Review

Boiko¹,

Grischenko²

1985

Acta Polymerica

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The analysis of hydroxyl groups in polymers is reviewed. Recent achievements of chemical, physico-chemical and physical methods for the determination of hydroxyl groups and their differentiation by reactivity have been examined. Particularly, infrared spectroscopy and nuclear magnetic resonance used for this determination are considered. Die Bestimmung yon Hydroxylgruppen in Polymeren. FortschrittsberichtIn dem Bericht werden neuere Entwicklungen chemischer, physikalisch-chemischer und physikalischer Methoden zur Bestimmung von Hydroxylgruppen und ihrer Differenzierung hinsichtlich der Reaktivitat dargestellt. Insbesondere wird die Anwendung der Infrarotspektroskopie und der magnetischen Kernresonanz behandelt. Onpeaenenue zur3powuJabnwx zpynn 8 nom.wepax. O630p 0 6 3 0~ IIOCBfiQeH aHaJIH8y rHAPOKCHnbHhIX rpynn B IIOJIEiMepaX. PaCCMOTpeHbI IlOCJIeAHlle AOCTEiXeHllfi XHMH9eCKHX, @H3HHO-XHMH9eCHHX Ei @H3H4eCKHX MeTOAOB KOJIEi9eCTBeHHOrO OIIpeAeneHElH I' HApOKCHJIbHbIX I'pyIIII H HX AH@-@epeHqEi~EiEinOpeaKqHOHHOltCnOCO6HOCTH. ~C O 6 O~B H l l M~H H~~~~j I~H O H H @~~K~~C H O~C I I~K T~O C MarHHTHOMY pe30HaHCy. Chemical methods of analysisChemical methods a r e simple a n d accessible, t h e y do not require special equipment a n d expensive instruments. At t h e same t i m e t h e y a r e rather time-consuming a n d require considerable amounts of t h e substance t o be analyzed. These methods can mainly give quantitative information. If t h e differentiation of HG is necessary, they become much more time-consuming. Recently t h e effective methods of chemical analysis have appeared which enable HG t o b e determined rapidly a n d exactly enough. Acylation of HG is most widely used, its application for polymers is detailed in t h e handbooks o n polymer analysis. The classical acylation procedure [27, 281 uses acetic (AA) or phthalic anhydride (PA) in pyridine solution, t h e latter being t h e solvent and catalyst of t h e reaction. T h e use of propionic [29], succinic [30--321, nitrobenzoic [33], osulfobenzoic [34], nitrophthalic [35]anhydrides for t h e same purpose is described. As a rule, primary a n d secondary HG a r e fully acylated within 1 t o 2 h a t 100 t o 115°C. Pyromellitic dianhydride (PMDA) [36-381 is more effective. It has as high activity as AA a n d does not interact with aldehyde groups a n d phenolic HG which is characteristic of PA. Dimethylsulfoxide (DMSO) is especially recommended as a solvent [37].T o acylate HG, more active acyl chlorides can b e used. BOIKO and GRISHCHENKO:Deterinination of liydroryl groups in polymers. Review Acta Polymcrica 36 (1985) Nr. 9

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“…Several catalysts more powerful than pyridine are now available, most notably 4-dimethylaminopyridine, which was developed by Steglich and Hofle (1-3) as a catalyst for synthetic acetylations, and has since been applied to analytical acetylations (4)(5)(6)(7). This study introduced N-methylimidazole as an analytical acylation catalyst (8)(9)(10)(11). The relative catalytic effectiveness of pyridine-N-methylimidazole-4-dimethylaminopyridine is about 1:3 X 102:1.7 X lo4, respectively (la), in aprotic solvents.…”

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confidence: 99%

Kinetics and Mechanism of Hydroxy Group Acetylations Catalyzed by N-Methylimidazole

Pandit

Connors

1982

Journal of Pharmaceutical Sciences

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N-Methylimidazole-catalyzed acetylation of hydroxy compounds prior to gas chromatographic separation and determination

Cited by 45 publications

References 14 publications

Molecular Epidemiology of Breast Cancer: Development and Validation of Acetylation Methods for Carcinogen-DNA Adduct Detection

Molecular Epidemiology of Breast Cancer: Development and Validation of Acetylation Methods for Carcinogen-DNA Adduct Detection

Determination of hydroxyl groups in polymers. Review

Kinetics and Mechanism of Hydroxy Group Acetylations Catalyzed by N-Methylimidazole

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