Biomaterial Database

A comparison of scavenging abilities of antioxidants against hydroxyl radicals. 1996

J Ueda, and N Saito, and Y Shimazu, and T Ozawa

National Institute of Radiological Sciences, Chiba-shi, Japan.

The reactivities of various antioxidative compounds including catechol derivatives and endogenous radical scavengers toward hydroxyl radical (.OH) were investigated by an electron spin resonance-spin trapping method, thiobarbituric acid method, and DNA strand scission assay. Hydroxyl radical was generated by both the reaction of Cu(II) complex with hydrogen peroxide (H2O2) and ultraviolet (uv) photolysis of H2O2. At physiological pH, catechol derivatives such as protocatechuic acid and catechin greatly suppressed the DNA strand scission by .OH produced from the reaction of Cu(en)2 with H2O2, whereas ascorbic acid and acetylcysteine accelerated DNA strand scission. The former case is due to the chelation of catechol derivatives to Cu(II) ion, forming of Cu(II) complexes being unable to react with H2O2, and the latter case is due to the acceleration of the reduction rate of Cu(II) to Cu(I). On the other hand, all compounds used here suppressed the DNA strand scission by .OH produced from uv photolysis of H2O2. The differences of the reactivities between the reaction system of Cu(en)2-H2O2 and the uv photolysis of H2O2 have been discussed.

UI	MeSH Term	Description	Entries
D010782	Photolysis	Chemical bond cleavage reactions resulting from absorption of radiant energy.	Photodegradation
D003300	Copper	A heavy metal trace element with the atomic symbol Cu, atomic number 29, and atomic weight 63.55.	Copper-63,Copper 63
D003497	Cyclic N-Oxides	Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.	Heterocyclic N-Oxides,Cyclic N Oxides,Heterocyclic N Oxides,N Oxides, Cyclic,N-Oxides, Cyclic,N-Oxides, Heterocyclic,Oxides, Cyclic N
D004249	DNA Damage	Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.	DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D004278	DNA, Superhelical	Circular duplex DNA isolated from viruses, bacteria and mitochondria in supercoiled or supertwisted form. This superhelical DNA is endowed with free energy. During transcription, the magnitude of RNA initiation is proportional to the DNA superhelicity.	DNA, Supercoiled,DNA, Supertwisted,Supercoiled DNA,Superhelical DNA,Supertwisted DNA
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
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D000975	Antioxidants	Naturally occurring or synthetic substances that inhibit or retard oxidation reactions. They counteract the damaging effects of oxidation in animal tissues.	Anti-Oxidant,Antioxidant,Antioxidant Activity,Endogenous Antioxidant,Endogenous Antioxidants,Anti-Oxidant Effect,Anti-Oxidant Effects,Anti-Oxidants,Antioxidant Effect,Antioxidant Effects,Activity, Antioxidant,Anti Oxidant,Anti Oxidant Effect,Anti Oxidant Effects,Anti Oxidants,Antioxidant, Endogenous,Antioxidants, Endogenous
D013113	Spin Labels	Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)	Spin Label,Label, Spin,Labels, Spin
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships