ISSN:
1438-2199
Schlagwort(e):
Amino acids
;
Schiff bases
;
Kinetics
;
Pyridoxal 5′-phosphate
;
Vitamin B-6 group
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary Stability of Schiff bases from Pyridoxal-5′-phosphate andα- and nonα-amino acids and amines have been studied in a wide range of pH. Furthermore the transamination process for the PLP-serine Schiff base and the cyclization reaction of PLP-histidine Schiff base have also been studied. Results show that theα-position on carboxyl group of amino acids plays an important role on the mechanism of hydrolysis of imine bond. Absence of ionic groups in the surroundings of that bond seems to be an important fact of stability. In the transamination reaction, the rate-determining step is the isomerization of the Schiff base to ketoimine, since the rate constants for disappearance of Schiff base coincide with the rate constants for PMP formation. This process is catalyzed by the OH−/H2O system and the monoprotonated amino acid.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00806010
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