Tri-saccharides

Similarly, anhydro derivatives of monosaccharides and disaccharides readily react with 359 to give the respective carba-di- and -tri-saccharide. 

The rather complicated enzymic hydrolyses of three of the tri-saccharides receive a clear interpretation through the relationships that are shown in Table IV. 

Scheme 20. Tetra- and tri-saccharides 90 and 91, contained in the antitumor agent Julibroside J28.

B. E. Davison, R. J. Ferrier, A. C. Richardson, and N. R. Williams, Mono-, di- and tri-saccharides and their derivatives, Specialist Periodical Reports Carbohydrate Chemistry, Vol. 13, (1982) Royal Society of Chemistry, London, Part 1. 

Fig. 23. Methyl a-septanoside mono-, di-, and tri-saccharides 243-245 assayed against jack-bean a-mannosidase.

Although the isolation and identification of new disaccharides, tri-saccharides and tetrasaccharides and their derivatives, either by acid hydrolysis or by controlled oxidative degradation, " would be of great help in these studies it would appear to be worth while to develop other indirect methods of approach involving the use of enzymes capable of effecting scission at specific points in the molecular complex. Better methods for the quantitative separation of sugars and their derivatives are in the process of development and it is not unlikely that in the near future it will be possible to derive formulas not only for plant gums but for the many related complex polysaccharides. 

Functionalization of the dihydropyran ring to a hexose system allowed the preparation of a remarkable variety of di- and tri-saccharides for example, hexopyranosyl-(1 3)-D-glucoses of the a-D-... 

G. O. Aspinall, D. Chatterjee, and L, Khondo, The hex-5-enose degradation Zinc dust cleavage of 6-deoxy-6-iodo-a-D-galactopyranosidic linkages in methylated di- and tri-saccharides, Can. J. Chem. 62 2728 (1984). 

Transesterification of sugars and derivatives with such active esters as the acetate, butanoate, decanoate, or dodecanoate of 2,2,2-trichlorethanol allowed selective acylation. In this first way, D-glucose, D-galactose, and D-mannose, in multigram quantities, gave the primary acylate in fair yield,110 in pyridine solution, in the presence of PPL (70,000 U). This type of reaction was also selective with di- and tri-saccharides thus, in... 

In this study they condensed the a-glycosyl bromide (243) with the disaccharide (245) in the presence of silver carbonate — silver perchlorate to give the a-linked tri-saccharide (241) in 58% yield or the bromide (244) with the disaccharide (246) in the presence of the mixed silver catalysts to give the a-linked trisaccharide (242) in 63 % yield. In the earlier approach, the preparation of the P-chloride (237) required a previous treatment of the a-bromide with tetraethylammonium chloride under carefully controlled conditions. 

Table 3. Calculated dihedral

F. J. Plou, M. A. Cruces, M. Ferrer, G. Fuentes, E. Pastor, M. Bernabe, M. Christensen, F. Comelles, J. L. Parra, and A. Ballesteros, Enzymatic acylation of di- and tri-saccharides with fatty acids Choosing the appropriate enzyme, support and solvent, J. Biotechnol., 96 (2002) 55-66. 

Part I Mono-. Di-. and Tri-saccharides and their Derivatives Part II Macromolecules "The Senior Reporter and six other reporters have again accomplished the difficult task of providing a comprehensive coverage of literature in the field. Over 3. 00 articles are Cited, and the reporters have done a superb job of abstracting their important points". 

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