Biomaterial Database

Electron spin resonance study of free radicals generated from retinyl- and ionyl-derivatives. 1990

R C Mordi, and J C Walton

Department of Chemistry, University of St Andrews, Fife, U.K.

Free radicals generated from alpha- and beta-ionyl bromides gave well resolved ESR spectra, but retinyl bromide and chloride gave only broad signals. Delocalised radicals were also spectroscopically observed on hydrogen abstraction from alpha-ionane, alpha-ionyltrimethylsilylether and buten-3-ynyl-2,6,6-trimethyl-2-cyclohexene. Retinyl and beta-ionyl radicals, derived from the corresponding xanthates, were successfully spin trapped with nitrosodurene. The results suggested that the secondary sites C(7) and C(9) were the most reactive in the beta-ionyl radical and that the secondary sites C(7) and C(11) and probably the primary site C(15) were the most reactive in the retinyl radical.

UI	MeSH Term	Description	Entries
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D002084	Butylated Hydroxytoluene	A di-tert-butyl PHENOL with antioxidant properties.	Butylhydroxytoluene,2,6-Bis(1,1-dimethylethyl)-4-methylphenol,2,6-Di-t-butyl-4-methylphenol,2,6-Di-tert-butyl-4-methylphenol,2,6-Di-tert-butyl-p-cresol,4-Methyl-2,6-ditertbutylphenol,BHT,Di-tert-butyl-methylphenol,Dibunol,Ionol,Ionol (BHT),2,6 Di t butyl 4 methylphenol,2,6 Di tert butyl 4 methylphenol,2,6 Di tert butyl p cresol,4 Methyl 2,6 ditertbutylphenol,Di tert butyl methylphenol,Hydroxytoluene, Butylated
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
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
D012172	Retinaldehyde	A diterpene derived from the carotenoid VITAMIN A which functions as the active component of the visual cycle. It is the prosthetic group of RHODOPSIN (i.e., covalently bonded to ROD OPSIN as 11-cis-retinal). When stimulated by visible light, rhodopsin transforms this cis-isomer of retinal to the trans-isomer (11-trans-retinal). This transformation straightens-out the bend of the retinal molecule and causes a change in the shape of rhodopsin triggering the visual process. A series of energy-requiring enzyme-catalyzed reactions convert the 11-trans-retinal back to the cis-isomer.	11-trans-Retinal,3,7-dimethyl-9-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4,6,8-Nonatetraenal,Axerophthal,Retinal,Retinene,Retinyl Aldehydde,Vitamin A Aldehyde,all-trans-Retinal,11-cis-Retinal,11 cis Retinal,11 trans Retinal,Aldehydde, Retinyl,Aldehyde, Vitamin A,all trans Retinal
D012176	Retinoids	A group of tetraterpenes, with four terpene units joined head-to-tail. Biologically active members of this class are used clinically in the treatment of severe cystic ACNE; PSORIASIS; and other disorders of keratinization.	Retinoid
D013859	Thiocarbamates	Carbamates in which the -CO- group has been replaced by a -CS- group.	Thiocarbamate
D055598	Chemical Phenomena	The composition, structure, conformation, and properties of atoms and molecules, and their reaction and interaction processes.	Chemical Concepts,Chemical Processes,Physical Chemistry Concepts,Physical Chemistry Processes,Physicochemical Concepts,Physicochemical Phenomena,Physicochemical Processes,Chemical Phenomenon,Chemical Process,Physical Chemistry Phenomena,Physical Chemistry Process,Physicochemical Phenomenon,Physicochemical Process,Chemical Concept,Chemistry Process, Physical,Chemistry Processes, Physical,Concept, Chemical,Concept, Physical Chemistry,Concept, Physicochemical,Concepts, Chemical,Concepts, Physical Chemistry,Concepts, Physicochemical,Phenomena, Chemical,Phenomena, Physical Chemistry,Phenomena, Physicochemical,Phenomenon, Chemical,Phenomenon, Physicochemical,Physical Chemistry Concept,Physicochemical Concept,Process, Chemical,Process, Physical Chemistry,Process, Physicochemical,Processes, Chemical,Processes, Physical Chemistry,Processes, Physicochemical