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1. The major metabolites of 3,5-di-tert.-butyl-4-hydroxytoluene (BHT) in the rat are 3,5-di-tert.-butyl-4-hydroxybenzoic acid (BHT-acid), both free (9% of the dose) and as a glucuronide (15%), and S-(3,5-di-tert.-butyl-4-hydroxybenzyl)-N-acetylcysteine. 2. The mercapturic acid does not appear to derive from the usually accepted enzyme mechanism, and may involve a non-enzymic reaction between BHT free radical and cysteine. 3. The ester glucuronide and mercapturic acid found in rat urine are also the major metabolites in rat bile and must be responsible for the enterohepatic circulation. 4. Free BHT-acid is the main component in rat faeces. 5. In man, BHT-acid, free and conjugated, is a minor component in urine, and the mercapturic acid is virtually absent. The bulk of the radioactivity is excreted as the ether-insoluble glucuronide of a metabolite in which the ring methyl group and one tert.-butyl methyl group are oxidized to carboxyl groups, and a methyl group on the other tert.-butyl group is also oxidized, probably to an aldehyde group. 6. These differences in metabolism by the rat and by man are sufficient to account for the difference in excretion by the two species.

1. A large proportion of a single oral dose of [(14)C]Ionox 220 to rats is eliminated in 24 days: 89.3-97.4% of the label is excreted in the faeces (much of this is eliminated in the first 4 days after dosage), 1% in the urine and less than 0.1% in the expired gases; 4.06% of (14)C is present in the carcass and viscera after removal of the gut, and most of this is in the fatty tissues. 2. About 87% of (14)C in the faeces is due to unchanged antioxidant, 5% to the quinone methide, 5% to the free acid and 3% to an unidentified polar constituent. Three-fifths of (14)C in the urine is due to 3,5-di-tert.-butyl-4-hydroxybenzoic acid and the remainder to the ester glucuronide. In three individual animals, one-half of (14)C in the bile is due to the free acid, one-quarter to the ester glucuronide and the remainder to unchanged antioxidant, whereas in another all of (14)C in the bile is due to Ionox 220. About 97% of (14)C in the body fat is due to unchanged antioxidant and the remainder to the free acid. 3. Up to 20% of a single oral dose of Ionox 220 is absorbed in rats: 13-14% is metabolized. 3,5-Di-tert.-butyl-4-hydroxybenzoic acid accounts for just over 5% of a dose of Ionox 220, 3,5-di-tert.-butyl-4-hydroxybenzoyl-beta-d-glucopyranosiduronic acid for less than 0.4%, the quinone methide for just over 5% and an unidentified compound for less than 3%. 4. The physiological and biochemical implications of ingesting Ionox 220 are discussed.

The article focuses on a paper showing results of patch testing with rubber antioxidants and accelerators. The author uses a routine series of patch tests with monobenzyl ether of hydroquinone, phenyl beta naphthylamine, mercaptobenzothiazole, tetramethylthiuram monosulphide and diphenylguanldine.

1. General considerations on oxygen toxicity suggest an important role for antioxidants as protectants for the more labile cellular components, including proteins and DNA. 2. Low effective levels of protectants against experimental oxygen poisoning suggest radical chain-breaking (model: NO) or self-regenerating (model: Co2+-Co3+) properties for these compounds. 3. Consideration of the elements of common biological occurrence suggests N (and possibly S) compounds as potentially important antioxidants. It is suggested that the unshared electron pair of N(III) is of importance in the activity of organic N-compounds against oxidants or oxidizing radicals. 4. Several chemical oxidations and a variety of conditions have been used in demonstrating the antioxidant activity of IAA and a variety of indoles, hydrazines and other N-compounds. Test systems include pyrogallol - O2, S= - H2O2 and I- - H2O2, especially the last. Reaction media range from acidic to alkaline and include both aqueous and ethanolic systems. 5. Among the indoles, antioxidant activity can be related to structure. Their ability to decrease the initial rate of I- oxidation is reduced by: (a) substitution at the 3-position; (b) introduction of an electron-withdrawing group at the 2- or 3-position and (c) replacement of N with another atom or heteroatom. This kind of activity may be increased however by: (a) introduction of OH into the benzene ring and (b) by introduction of an electron-releasing agent at the 2-position. Activity is not affected by (a) substitution on N, or (b) 3-substitution with an ethylamine group. 6. Activity among other chemical groups has not yet been related to structure, but several biologically active compounds including thyroxin and isoniazid are powerful antioxidants. Even simple aliphatic amines, including a tertiary amine, exhibit weak inhibiting properties. 7. A number of the active compounds are known to have some kind of biological activity at comparatively low concentrations, including serotonin, 5-hydroxy-IAA, indole and EDTA. 8. Experiments carried out on germination and early seedling growth with turnip, rice and lettuce show isoniazid, hydrazine, indole-3-ethylamine, and skatole, all powerful antioxidants, to be growth promoters as well. 9. It is concluded that although definite "cause-effect" relationships between antioxidative and biological activities have not yet been proven, the wide-spread occurrence of antioxidants together with our current information on oxygen toxicity calls for serious consideration when mechanism of hormone and regulator actions are under consideration. [ABSTRACT FROM AUTHOR]

The vinyl-ether linkage of plasmalogen was cleaved by rat brain homogenates; practically all activity was localized in the soluble fraction of the homogenate. The cleavage of the vinyl-ether linkage was tightly coupled to the reduction of molecular oxygen; about 3.5—4 mol oxygen were reduced for each mol vinyl-ether cleaved. Both the reduction of oxygen and the cleavage of vinyl-ether ceased if the reaction was run in an atmosphere of nitrogen or if antioxidants such as N,N-diphenyl-p-phenylenediamine, butylated hydroxytoluene or Quercetin were used, in the presence of oxygen. Either reaction was also inhibited by the addition of the following chelators: EDTA, citrate, dipyridyl, desferal and o-phenanthroline. A detergent such as sodium deoxycholate was required for optimal activity. The reaction (i.e., vinyl-ether cleavage or oxygen uptake) was directly proportional to protein concentration and time and had an optimal pH at about 7.3. When reaction rates were plotted against substrate concentration, hyperbolic curves of the Michaelis-Menten type were obtained. The active component of rat brain supernatant was dialyzable, was not inactivated when heated for 10 min at 100 °C and did not precipitate in a saturated ammonium sulfate solution. This suggests that cleavage of the vinyl-ether linkage of plasmalogen is catalyzed by a thermostable, low-molecular-weight, non-protein component of rat brain supernatant. [ABSTRACT FROM AUTHOR]

The necessity and difficulty of developing an ideal formulation of a chemical coating for optimum man-made fiber processing on textile equipment under varying conditions is stressed. In the absence of such a coating, the fiber has little economic value. The phrase "spin-finish" is defined. The various compounds chiefly used are listed by chemical classes under luhricants without surface activity, external antistatic agents for surface of fiters, and emulsifiers having lubricating function. The necessary properties of components and blends are discussed. Patents covering spin-finishes are reviewed for the years following the introduction of the first man-made fiber nylon in 1938. Reference is made to concepts found in new patents for internal antistatic agents and for new fibers. Suggestions for synthesis of new compounds with enhanced properties are made. The bibliography covers 80 patent and literature references. [ABSTRACT FROM PUBLISHER]

The article presents a study which examined the effects of various organic substances on the incidence of dental caries in cotton rats. Organic substances discussed include amino acids, phenolic acids, polyphenols, and antioxidants. Polyphenols such as hesperidin and hesperetin methyl chalcone were found to reduce the incidence of dental caries significantly.