Effect of Ring Substituents on the Transketolase-Catalyzed Conversion of Nitroso Aromatics to Hydroxamic Acids

Details

• Personal Author:
  Corbett BR ; Corbett MD
• Description:
  Transketolase catalyzed the conversion of eight different aromatic C-nitroso compounds into the corresponding N-glycolyl derived hydroxamic acids. Three of the nitroso compounds were also found to be converted in part to the arylhydroxylamines by a reductive process. A correlation was found for the rates of production of these metabolites with the electronegatives of substituent groups that were present on the aromatic ring. The rates of reaction of these substituted nitroso substrates with transketolase and d-fructose-6-phosphate were found to decrease in the order 4-NO2 > 4-CF3 > 3-CF3, unsubstituted > 4-Cl > 4-CH3, 4-phenyl > 4-OC2H5. N,N-Dimethyl-p-nitrosoaniline was not metabolized by transketolase under the conditions employed for the other substrates. Those substrates possessing the strong electron-withdrawing groups 4-NO2, 4-CF3 and 3-CF3 were the only substrates that were found to undergo enzymatic reduction to the hydroxylamines as a competing process. A mechanism was proposed that involves a redox reaction between the nitroso substrate and the enzymatic intermediate "active glycolaldehyde" at the active-site of transketolase. [Description provided by NIOSH]
• Subjects:
  Biochemistry Energy Metabolism Enzymes Hydrocarbons Occupational Health Safety
• Keywords:
  Aromatic Hydrocarbons Enzymatic Effects Enzyme Activity Metabolites Nitroso Compounds
• ISSN:
  0006-2952
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Florida ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  35
• Issue:
  20
• NIOSHTIC Number:
  nn:20060261
• Citation:
  Biochem Pharmacol 1986 Oct; 35(20):3613-3621
• Contact Point Address:
  Michael D. Corbett, Department of Food Science and Human Nutrition, Pesticide Research Laboratory, University of Florida, Gainesville, FL 32611, U.S.A.
• Federal Fiscal Year:
  1987
• Performing Organization:
  University of Florida, Gainesville, Florida
• Peer Reviewed:
  True
• Start Date:
  19840801
• Source Full Name:
  Biochemical Pharmacology
• End Date:
  19870731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:de7846da677ed9f9a6a63ade79d5cca0ca944966713331f9d75c654746d7973786ba3a1c8aa078d54ad3ccbc537cc4b1698a0438220e3ae7e198ce045f26e73a
• Download URL:
  https://stacks.cdc.gov/view/cdc/224218/cdc_224218_DS1.pdf
• File Type:
  [PDF - 831.35 KB ]