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15. 'Mass spectrometry of vitamin B6: Different forms of the vitamin, its metabolites, antimetabolites, and analogs'.

Author

Dejongh, D. C., Perricone, S. C., Gay, M. L., and Korytnyk, W.

Abstract

The mass spectra of the different forms of vitamin B6, some metabolites and antimetabolites, and some analogs are reported. The free bases are suitable for study, but the 5-phosphates are not sufficiently volatile. The hydrochloride salts dissociate thermally in the inlet system into the free base and HCl and give the spectrum of the free base with the spectrum of HCL superimposed on it. The compounds studied are: pyridoxol, pyridoxamine and pyridoxal, which are different forms of vitamin B6; 4-pyridoxic acid and its lactone, 5-pyridoxic acid lactone, isopyridoxal, 5-formyl-3-hydroxy-2-methylpyridine-4-carboxylic acid, and 3-hydroxy-2-methylpyridine-4,5-dicarboxylic acid, which are vitamin B6 metabolites; α4-and α5-deoxypyridoxol, 3-deoxypyridoxol, and 4- and 5- norpyridoxol, which are antimetabolites and analogs of vitamin B6. [ABSTRACT FROM AUTHOR]

Published
1968
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17. Notes.

Author

Khalique, A., Tilney-Bassett, J. F., Coutts, R. T., Wibberley, D. G., Hammond, P. R., Coates, G. E., Golightly, D. S., Baker, E. H., Mitchell, W. J., Topsom, R. D., Vaughan, J., Eméleus, H. J., Packer, K. J., Welcman, N., Korytnyk, W., Wiedeman, W., Lewis, J. R., Barltrop, J. A., Giles, D., and Hanson, J. R.

Published
1962
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22. Alanine Derivatives with Reactive Groups

Author

Paul, B. and Korytnyk, W.

Abstract

The synthesis of diazoketone analogs of amino acids and associated problems were investigated with N-phthaloyl-DL-alanine serving as a model. The carboxyl was activated by conversion to the acid chloride or, under mild conditions, to the mixed anhydride obtained with ethyl chloroformate or dicyclohexylcarbodiimide; the product was reacted with diazomethane. Deblocking the phthaloyl group with hydrazine gave 3-amino-1-diazo-2-butanone as a well-characterized solid salt and ES a less stable oil. Further reactions of the blocked diazoketone of DLdanine, such as conversion to a-haloketones, Wolff rearrangement, and deuterium exchange on C-1 were investigated. 3-Amino-1-diazo-2-butanone had moderate inhibitory activity against mouse mammary adenocarcinoma in cell culture.

Published
1978
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24. Selective esterifications and acyl rearrangements in vitamin B6

Author

Paul, B. and Korytnyk, W.

Abstract

After our work involving the acyl migration and selective esterification of pyridoxol, we investigated similar phenomena in pyridoxal and pyridoxamine. Esterification of pyridoxal under various conditions gave esters with the hemiacetal structure. In pyridoxal, acyl migration could not be detected, possibly because of inability to form the ortho acid intermediate, hence permitting selective esterification of the phenolic hydroxyl. In pyridoxamine, O → N acyl migration takes place very readily from both the 3-O and α5-O positions, but the reverse migration could not be observed. 3-O, α4-N and α4-N, α5-O diesters of pyridoxamine have been prepared. Thus it is now possible to obtain selectively esterified derivatives of pyridoxal and pyridoxamine by taking advantage of either the absence or the presence of acyl migration. 5-Thiol esters of pyridoxol have been obtained, but no acyl migration in the direction 5-S → 4-O could be detected. Factors that determine acyl migration are discussed.

Published
1969
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