Biomaterial Database

Free radicals trapped in methyl alpha-D-mannopyranoside X-irradiated at 77 K: an ESR/ENDOR study. 1987

W A Bernhard, and J Huttermann, and D M Close, and K R Mercer

Department of Biophysics, University of Rochester, New York 14642.

Four free radicals are trapped in methyl alpha-D-mannopyranoside X-irradiated and maintained at 77 K. All four have been identified, with high confidence levels, using ESR and ENDOR spectroscopy. One, an alkoxy radical located at O4, is characterized by a gmax of 2.059, an isotropic beta hydrogen hyperfine coupling (hfc) of 98 MHz, and small interactions due to gamma or delta hydrogens. The second, a secondary dioxyalkyl radical due to loss of hydrogen from C1 is characterized by one beta hfc with an isotropic component of 19.03 MHz. The third, a secondary hydroxyalkyl radical due to loss of hydrogen from C2 is characterized by two nonexchangeable hydrogens with isotropic beta interactions of 22.45 and 6.44 MHz and one exchangeable hydrogen with an isotropic beta interaction of 9.88 MHz. The fourth is a .CH2OR radical that is formed by the net loss of hydrogen from the methyl group.

UI	MeSH Term	Description	Entries
D008759	Methylglycosides
D008766	Methylmannosides	Mannosides formed by the reaction of the hydroxyl group on the anomeric carbon atom of mannose with methyl alcohol. They include both alpha- and beta-methylmannosides.	Methylmannopyranosides
D009686	Nuclear Physics	The study of the characteristics, behavior, and internal structures of the atomic nucleus and its interactions with other nuclei. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Nuclear Physic,Physic, Nuclear,Physics, Nuclear
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D005615	Freezing	Liquids transforming into solids by the removal of heat.	Melting