Sugar modified

The natural moisture of the cocoa bean combined with the heat of roasting cause many chemical reactions other than flavor changes. Some of these reactions remove unpleasant volatile acids and astringent compounds, partially break down sugars, modify tannins and other nonvolatile compounds with a reduction in bitterness, and convert proteins to amino acids that react with sugars to form flavor compounds, particularly pyrazines (4). To date, over 300 different compounds, many of them formed during roasting, have been identified in the chocolate flavor (5). 

Brook, M.A., Chen, Y., Guo, K., Zhang, Z. and Brennan, J.D. (2004) Sugar-modified silanes precursors for silica monoliths. Journal of Materials Science, 14, 1469-1479. 

C.H. Liang, S. Yao, Y.H. Chiu, P.Y. Leung, N. Robert, J. Seddon, P. Sears, C.K. Hwang, Y. Ichikawa, A. Romero, Synthesis and biological activity of new 5-0-sugar modified ketolide and 2-fluoro-ketolide antibiotics, Bioorg. Med. Chem. Lett. 15 (2005) 1307-1310. 

Kamo et al. [Biochim. Biophys. Acta, 367, 1 and 11 (1974)] have shown that nonionic sugars modify the zeta potential of slime mold cells. Aggregation of colloids is related to their surface charge and their surface potential. This fact shows evidence of long-range electrostatic interactions controlled by metabolic reactions taking place at the membrane and able to modify the composition of the membrane medium interface. In this process the diffusion is not relevant, as indicated by Mrs. Babloyantz. 

Branched-chain sugars constitute a widely represented subclass of carbohydrates which have long attracted the attention of synthetic organic chemists due to their possible incorporation into sugar-modified... 

Dufner G, Schworer R, Muller B, Schmidt RR. Base- and sugar-modified cytidine monophosphate iV-acetylneuraminic acid (CMP-Neu5Ac) analogues - synthesis and smdies with (2-6)-sialyltransferase from rat Uver. Eur. J. Org. Chem. 2000 1467—... 

The fragmentation of base-modified nucleosides related to cytokinin and sugar-modified nucleosides, mainly cyclo- and T- and 3 -chloro derivatives,has been reported. However, all of the El-induced reactions discussed in these reports have already been presented above. Although they do not introduce any new fragmentation pathways, both reports present a... 

Herdewijn, P, Balzarini, J., Baba, M., et al. (1988) Synthesis and anti-HIV activity of different sugar-modified pyrimidine and purine nucleosides. J. Med. Chem., 31, 2040-2048. 

Introduction of a fluoride at the 3-position of neuraminic acid yielded a compound (57) that was a competitive inhibitor of the a-(2,6)-sialyl-trans-ferase. Base and sugar-modified analogues of CMP-Neu5Ac have also been prepared to investigate the tolerance of oc-(2,6)-sialyl-transferase to base exchange (58) and modification of the 5-, 8- or 9-position of neuraminic acid (59), (60). While base-exchange was not tolerated, modifications of the acid moiety yielded compounds that were substrates for the enzyme. 

The materials to be spray dried, e.g. flavouring concentrates or fmit, have to be prepared into a solution or an emulsion. Flavour concentrates, e.g. essential oils, extracts and/or mixtures of these with other flavouring substances, are emulsified in water with gum arabic and then homogenised with a solution of the dry carrier. Useful carriers are modified starch products, maltodextrin, sugar, modified whey proteins. 

In order to preserve optimal stability in the hybridization of RNA by sugar-modified oligonucleotides, nucleosides substituted at the 2 -position must retain a C3 -endo puckered conformation. To this end, the 2 -0- 2-[iV,N-(dimethylamino)oxy]ethyl and the 2 -0- 2-[Ar,lV-(diethylamino)oxy]-ethyl 3 -phosphoramidite derivatives of thymidine (38a, 38b) have been synthesised. The nucleoside precursors were prepared from a phthalimido-derivative obtained from 2,2 -anhydro-5-methyluridine which had been treated, after appropriate protection, with a borate ester generated in situ and then reacted with PPha, DEAD and AT-hydroxyphthalimide. The incorporation of (38a) and (38b) in oligonucleotides and oligodeoxynucleotides resulted in high binding affinity for... 

Table 11.3-8. Nucleoside phosphorylase-catalyzed synthesis with various heterocycles as acceptors or sugar-modified nucleosides as donors.

Advances in synthesis of sugar-modified nucleosides in past 10 years 01YGK331. 

With the aim of studying the structure-biological activity relationship, many permutations of tiazofurin that comprised variations in both the sugar and thiazole subunits were prepared. Among the sugar-modified tiazofurins. 

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