Synthesis of taurine analogues from alkenes: preparation of 2-aminocycloalkanesulfonic acids.

(+/-)trans 2-Aminocyclohexanesulfonic acid and (+/-)trans 2-aminocyclopentanesulfonic acid were prepared from cyclohexene and cyclopentene respectively by sulfur monochloride addition, followed by oxidation to 2-chlorosulfonic acid and substitution of chlorine.

2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethoxydiphenyl, a new metabolite of 2-t-butyl-4-methoxyphenol in the rat.

A method has been developed for the determination of 2-t-butyl-4-methoxyphenol (BHA) and its metabolite di-BHA in rat plasma and tissues using gas chromatography-mass spectrometry with selected ion detection. Deuterium labeled BHA-d3 and di-BHA-d6 were synthesized and added to the tissue specimens as internal standards before methylene chloride extraction. The extracted compounds were derivatized with trifluoroacetic anhydride and analyzed by selected ion monitoring. Rat plasma and intestine concentrations of BHA and di-BHA at different times (0.15-24 hr) following the oral administration of a single dose of BHA (2 g X kg-1 body weight) were determined. Both BHA and di-BHA were present in all the analyzed samples, their concentration peaking within 1 hr after treatment. While in the intestine BHA levels were about 10 times higher than those of di-BHA, in the plasma they were between 100 and 15 times higher. These findings indicate that rat intestine is capable of transforming in vivo BHA into di-BHA and suggest that this organ is the major site where this transformation occurs.

Oxidation of 2-t-butyl-4-methoxyphenol (BHA) by horseradish and mammalian peroxidase systems.

Di-BHA, 2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethoxy-diphenyl, was isolated as the product of the reaction of either commercial horseradish peroxidase or partially purified rat intestine peroxidase (Donor-H(2)O(2) oxidoreductase, EC 1.11.1.7.) and hydrogen peroxide with 2-t-butyl-4-methoxyphenol (BHA). BHA, Di-BHA and other cyclic compounds possessing a hydroxyl group in the ring were found to be competitive inhibitors with respect to guaiacol, and non-competitive inhibitors with respect to hydrogen peroxide in a system containing guaiacol, hydrogen peroxide and peroxidase. A free radical intermediate generated during peroxidatic oxidation of BHA was detected and identified by means of EPR spectroscopy. It was estimated that during one hour incubation the peroxidase activity present in the rat ileum mucosa is able to oxidise 12mumoles BHA at a saturating concentration. It is suggested that peroxidative oxidation at the intestinal wall may represent a contribution to the inactivation of some phenol derivatives potentially toxic to mammals.