Article

Mechanism of osazone formation.

Nature (Impact Factor: 38.6). 02/1955; 175(4448):220. DOI: 10.1038/175220a0
Source: PubMed

ABSTRACT A FACT which seems to have escaped attention in formulating a mechanism for osazone formation is that beta-alkayl substituted phenylhydrazines are oxidized very readily in air to form phenylhydrazones1:

17 Bookmarks
 · 
789 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A systematic comparison of six sugar indicators for their sensitivity, specificity, cross-reactivity, and suitability in the context of crude lysates revealed para-hydroxybenzoic acid hydrazide (pHBH) to be best suited for application in a plate-based phosphatase-assisted universal sugar-1-phosphate nucleotidyltransferase assay. The addition of a general phosphatase to nucleotidyltransferase reaction aliquots enabled the conversion of remaining sugar-1-phosphate to free sugar, the concentration of which could be rapidly assessed via the pHBH assay. The assay was validated using the model glucose-1-phosphate thymidylyltransferase from Salmonella enterica (RmlA) and compared favorably with a previously reported HPLC assay. This coupled discontinuous assay is quantitative, high throughput, and robust; relies only on commercially available enzymes and reagents; does not require chromatography, specialized detectors (e.g., mass or evaporative light scattering detectors), or radioisotopes; and is capable of detecting less than 5 nmol of sugar-1-phosphate. It is anticipated that this high-throughput assay system will greatly facilitate nucleotidyltransferase mechanistic and directed evolution/engineering studies.
    Analytical Biochemistry 07/2008; 377(2):251-8. · 2.58 Impact Factor
  • Journal of Heterocyclic Chemistry 03/2009; 35(5):1161 - 1170. · 1.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mit Hilfe von 14C-Phenylhydrazin wird gezeigt, daβ die Dehydrierung von 1-Desoxy-1-phenylamino-4.6-benzal-D-fructose-phenylhydrazon (V) nicht über eine intramolekulare Oxydoreduktion verläuft2). Das Phenylhydrazon des Amadori-Produktes (V) wird durch chemisch nicht gebundenes Phenylhydrazin dehydriert. Unter geeigneten Bedingungen findet Osazonbildung statt, bevor vollständiger Austausch zwischen radioaktiv markiertem und nicht-markiertem Phenylhydrazin eingetreten ist. Der Arylhydrazin-Austausch erfolgt bevorzugt dann, wenn die Ausbildung einer En-diamin-Struktur möglich ist.
    Annalen der Chemie und Pharmacie 01/2006; 684(1):216 - 223. · 3.10 Impact Factor