Trisaccharide moiety

In contrast to the former Plantago CHX [55], the gel-forming CHX from psyllium (Plantago ovata) husks [54] was found to be a neutral, highly branched arabinoxylan with the (1 4)-j8-D-xylopyranose backbone substituted at position 2 with single Xylp units and at position 3 with the trisaccharide moiety (7). 

K. Matsuoka, M. Terabatake, Y. Esumi, D. Terunuma, and H. Kuzuhara, Synthetic assembly of trisaccharide moieties of globotriaosyl ceramide using carbosilane dendrimers as cores. A new type of functional glyco-material, Tetrahedron Lett., 40 (1999) 7839-7842. 

Similar instances, in which analytical data were of prime importance and where no products were isolated, are the oxidations of various di-D-fructose dianhydrides,80 inositols,81 the trisaccharide moiety of the alkaloid solamargine,82 2-O-a-L-fucopyranosyl-L-fucitol derived from fucoidin83 (a polysaccharide sulfate ester), trehalose and neotrehalose,84 maltotetraose,85 D-galactopyranosyl-glyceritol,86 and a 3-pentulose.87... 

Two new diterpene dilactone glycosides with a trisaccharide moiety from Podocarpus nagi. Xu, Y.M. Xuan, L.J. Stud. Plant. Sci. 1999, 6, 399-402. 

The fact that methyl 2,3- and 2,6-di-O-benzyl galactopyranosides give the same 2,3,6-trisubstituted compound has been utilized in the synthesis of the trisaccharide moiety of gangliotriosyl-ceramide. The intermediate methyl lactoside having only the axial OH-4 of the galactose unit free resulted from a mixture of both penta-O-benzyl lactosides, thus avoiding the separation of the 4,6- and 3,4-O-isopropyIidene precursors [164],... 

A related strategy was used for synthesis of a more complex carbohydrate, the trisaccharide moiety of globotriaosyl ceramide (Gb3) [10b] (Scheme 3.19). In this reaction an acyl-based fluorous protecting group was used to facilitate the intermediate purification steps in a similar way as can be achieved by solid phase carbohydrate chemistry [12]. 

L. H. Briggs and L. C. Vining, Solanum alkaloids. X. Mode of linkage in trisaccharide moiety of solanine and solasonine, J. Chem. Soc., (1953) 2809-2815. 

A peculiar sugar modification occurs in the biosynthesis of the aclacino-mycins. These anthracyclines contain a trisaccharide moiety attached to the aklavinone scaffold at the C-7 position (Scheme 1). The first two carbohydrates in the aclacinomycins are rhodosamine and 2-deoxyfucose, but they differ structurally in their third sugar component, which is rhodinose in AclN, cinerulose A in AclA, L-aculose in AclY and cinerulose B in AclB [157]. The conversion of rhodinose to L-aculose is catalysed in a two-step process by the FAD-dependent enzyme aclacinomycin oxidoreductase [71] (Scheme 5, step 31). The three-dimensional structure of this oxidase revealed that the cofactor FAD is bound via two covalent bonds to the enzyme. Crystal structure and functional data further established a mechanism where the two different reactions are catalysed in the same active site of the enzyme but by different active site residues [71]. 

TWO NEW DITERPENE DILACTONE GLYCOSIDES WITH A TRISACCHARIDE MOIETY FROM PODOCARPUSNAGI... 

Complete assignment of and C-NMR spectra and conformational studies have been reported for six Lewis D-related trisaccharides/ nine protected a-(l ->3)-linked digitoxoside trisaccharides,the two trisaccharide moieties of the anthracycline antibiotic ditrisarubicin the tetrasaccharide ganglioside... 

C-N.m.r. lines have been assigned to the terminal, central and directly attached monosaccharide residues in a triterpenoid saponin with a trisaccharide moiety, on the basis of decreasing spin-lattice relaxation times, the so-called "partially relaxed Fourier transform" method. The solution conformation of acarbose (16) has been determined by H and n.O.e. n.m.r. techniques and compared with that predicted by hard-sphere exo-anomerlc effect calculations. 

Ciclamycin 0 has been synthesized by methods involving preparation of the trisaccharide moiety by coupling glycal monomers... 

The sequence of the trisaccharide moiety of the plant glycoside colubrinoside has been determined by m.s. of the methylated and the methylated and reduced trisaccharide or the a< tylated or trimethylsilylated trisaccharide. A g.l.c.-m.s. 

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