Magnetic Resonance Studies of the Red-Photochemistry of C-Nitroso Derivatives, and of the Action of NO and NO2 on Biologically Important Substances

Boucenna, Mohamed-Cherif (1991) Magnetic Resonance Studies of the Red-Photochemistry of C-Nitroso Derivatives, and of the Action of NO and NO2 on Biologically Important Substances. PhD thesis, University of Glasgow.

Abstract

This thesis begins, chapter one, with a general introduction to the photochemistry of C-nitroso compounds, nitroxide radicals, and photochemical reactions of some optically active geminal chloronitroso derivatives of terpenes. The remaining chapters of the thesis then describe the author's work on two important aspects of C-nitroso systems. 1) Photochemical reactions in solid 2-chloro-2-nitrosonorbomane Chapter two examines analyses of a sample of solid 2-chloro-2-nitrosonorbomane by means of infra red, mass spectroscopy and modem high resolution nuclear magnetic resonance spectroscopy. This work shows that the solid is racemic and dimeric, and contains mixtures of dd-, ll-, dl- and ld-isomers. It also enables the configuration at the >C(2)ClNO residue to be established. Detailed high resolution nuclear magnetic resonance spectroscopic studies show that in solutions, 2-chloro-2-nitrosonorbomane exists mainly in the monomeric form, in equilibrium with a small amount of the corresponding dimeric forms. Irradiation of the solid with red visible light causes some white crystals and a brown viscous oil to be formed. The components of these two phases have been identified. In order to account for the observed photolysis products, a reaction mechanism is postulated. This invokes a Beckmann-like rearrangement reaction which may be of general synthetic use for converting geminal chloronitroso derivatives into lactams which may be of pharmacological interest. In chapter three, information from the work described in chapter two is combined with work carried out by earlier investigators to show how circular dichroism studies can be combined with high resolution nuclear magnetic resonance spectroscopy to enable the configurations at optically active >CCINO centres of other geminal chloronitroso terpene derivatives to be determined. 2) Action of NO and NO2 on some biologically important substances In chapter four, it is pointed out that the work described in chapters 1-3 of this thesis may have significance for the agricultural and medical toxicology, including carcinogenesis, of compounds containing nitrogen. This chapter describes the results obtained from detailed spectroscopic studies of reactions that take place when some steroids, fatty acids, pyrimidine bases and purine bases of biological interest are brought into contact with acidified solutions of sodium nitrite. These studies show that acidified sodium nitrite affects steroids and almost certainly carbohydrates. It isomerises unsaturated fatty acids, and therefore almost certainly affects the permeability of cell membranes. It affects pyrimidine bases and purine bases, and almost certainly nucleosides, nucleotides and nucleic acids. It also affects amino acids and proteins. Acidified sodium nitrite must interfere with the genetic code. MO and NO2 must be implicated in some areas of carcinogenesis and in bacterial toxic shock.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry, Physical chemistry
• Date of Award: 1991
• Depositing User: Enlighten Team
• Unique ID: glathesis:1991-78327
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:33
• Last Modified: 30 Jan 2020 15:33
• URI: https://theses.gla.ac.uk/id/eprint/78327