Aldehydes scavengers

Scheme 7.129 Efficient amine-scavenging utilizing a polystyrene aldehyde scavenger.

Burcham, P. C. and Pyke, S. M. (2006). Hydralazine inhibits rapid acrolein-induced protein oligomerization Role of aldehyde scavengers and adduct trapping in cross-link blocking and cytoprotection. Mol. Pharm. 69,1056-1065. 

Guiotto, A., Calderan, A., Ruzzo, P., Osier, A., Rubini, C., Jo, D. G., Mattson, M. P., and Borin, G. (2005b). Synthesis and evaluation of neuroprotective a,b-unsaturated aldehyde scavenger histidyl-containing analogues of carnosine. ]. Med. Chem. 48, 6156-6161. Hamano, H., Yoshinaga, K., Eta, R., Emori, Y., Kawasaki, D., lino, Y., Sawada, M., Kuroda, H., and Takei, M. (2006). Effect of polaprezinc on taste disorders in zinc-deficient rats. Biofactors 28, 185-193. 

The aldehyde side product can react with the freshly released amine, thus limiting the chemical yield. To avoid this reaction one can add an aldehyde scavenger, such as semicarbazide hydrochloride, hydrazine or an aldehyde scavenging resin (e.g., supported hydrazines). An alternative is to alter the structure of the photolabile protecting group. 

Alternately, specific stabilizers can also be added into the formulations. The protection against aldehydes, whether present initially in the formulation or released in situ, can be provided by the addition of aldehyde scavengers like, lysine, phenylamine, glutamine, hydroxylamine hydrochloride, p-amino benzoic acid, glycine, etc. " The in situ release of aldehydes as a consequence to degradation of the contents can... 

The main application fields of aldehyde scavengers are PET (more specifically wafer bottles made from PET), and polyacetals such as POM or polymers synthesized from formaldehyde such as urea-formaldehyde resins. 

Research was carried out by our group on the use and regeneration of the Wang aldehyde scavenger 9 to eliminate excess primary amines in libraries of secondary amines prepared by reductive amination. The reaction in this process can be easily followed by gel-phase HR-MAS NMR. The signal of the aldehyde proton disappears at 9.8 ppm a new peak for the imine proton appears at 8.3 ppm in the spectrum as shown in Figure 4.4 and Scheme 4.4. 

HALS may also be combined with amide-containing aldehyde scavengers such as anthranilamide or l,6-bis(2-aminobenzamidoyl) hexane in aromatic polyesters [183]. 

Covalently amlnated silica surface (The aldehyde scavenger)... 

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