Factors influencing the nutritional value of fish flour. V. Chlorocholine chloride, a toxic material in samples extracted with 1,2-dichloroethane

Extraction of lyophilized cod fillets with 1,2-dichloroethane resulted in the formation of chlorocholine chloride (CCC) ((2-chloroethyl)trimethylammonium chloride), a toxic choline derivative. CCC isolated chromatographically from 1,2-dichloroethane-extracted fish was identical with CCC prepared by reacting 1,2-dichloroethane with trimethylamine. The infrared spectrum of the reineckate salt of CCC isolated from 1,2-dichloroethane-extracted fish also was found to be identical with synthetic chlorocholine reineckate. A method for the determination of CCC in 1,2-dichloroethane-extracted fish is described.

Amino acid and metal composition of the alpha- and beta-lytic proteases of Sorangium sp

Amino acid compositions of two enzymes, α- and β-lytic proteases of Sorangium sp., are reported. The calculated molecular weights and nitrogen contents are in good agreement with experimental values reported previously. A method is described for computing a "best estimate" of the multiplier which converts composition per unit weight of enzyme preparation to composition per mole of enzyme. According to analyses of the performate-oxidized enzymes and of the carboxymethylated enzymes, the α-enzyme has six and the β-enzyme has four half-cystine residues. Titratable sulfhydryl groups could not be detected in either enzyme. The β-enzyme contains one atom of zinc; removal of zinc with o-phenanthroline did not release a titratable sulfhydryl group.

Thyroglobulin: evidence for crystallization and association

Crystals of thyroglobulin have been obtained from ammonium sulfate solutions and have been examined by electron microscopy as shadowed carbon replicas. Unit size in the crystal is 228 +/- 9 angstroms, which corresponds to a molecular weight of 5,300,000. Data are in accord with the possibility that this unit represents a polymer of thyroglobulin.

The formation of 2-hydroxypropylmercapturic acid from 1-halogenopropanes in the rat

1. 2-Hydroxypropylmercapturic acid, i.e. N-acetyl-S-(2-hydroxypropyl)-l-cysteine, has been isolated, as the dicyclohexylammonium salt, from the urine of rats dosed with 1-bromopropane. 2. The formation of the same metabolite from 1-chloropropane, 1-iodopropane, 1,2-epoxypropane and 1-chloropropan-2-ol has been demonstrated by chromatographic examination of the urine excreted by rats after they had been dosed with these compounds. 3. (+)- and (-)-Dicyclohexylammonium 2-hydroxypropylmercapturate have been prepared by fractional crystallization of the mixture of isomers obtained by two methods: the reaction of 1,2-epoxypropane with l-cysteine followed by acetylation, and the reduction of 2-oxopropylmercapturic acid. 4. The following compounds have also been prepared: S-(3-hydroxypropyl)-l-cysteine, (+)- and (-)-S-(2-hydroxypropyl)-l-cysteine, dicyclohexylammonium 3-hydroxypropylmercapturate, (+)- and (-)-dicyclohexylammonium 2-hydroxy-1-methylethylmercapturate, and (+)- and (-)-dicyclohexylammonium 1-(ethoxycarbonyl)ethylmercapturate.

The photometric determination of quaternary ammonium salts and of certain amines by compound formation with indicators. I. Quaternary ammonium salts

Published methods for the determination of quaternary ammonium compounds by (a) titration with anionic surface-active agents, and (b) measuring the change in colour intensity produced in an indicator in aqueous solution, have been found inapplicable to compounds of molecular weight lower than that of cetrimide. The indicator extraction method has been studied in some detail and the results of variations of conditions and the effects produced by interfering substances described and discussed. A general indicator extraction method is proposed which is applicable to all quaternary compounds except those of very low molecular weight.