Glycosyl activated derivatives

Occurrence, chemistry, synthesis and cytokinin activity of l -methyl-rran.s-zeatin and its analogs (glycosylated adenine derivatives) 97H(46)659. 

Synthesis of glycosyl phosphates by exposure of hemiacetals to 81 activated derivatives of phosphoric acid... 

Nucleoside 5 -phosphates are employed as starting materials to prepare the activated derivatives (56). Their synthesis has been discussed in a Chapter in this Series.266 The methods used most frequently for preparing glycosyl phosphates involve the interaction of protected glycosyl bromides with diphenyl phosphate and subsequent removal of the protective groups,267 or by fusion of the peracetylated monosaccharides with anhydrous phosphoric acid.268... 

In all of the foregoing examples, an activated derivative of the nucleotide has been employed for generating the pyrophosphate link. An attempt to use an activated glycosyl phosphate failed 311 the only product identified from the reaction between /3-D-glucopyranosyl phosphoramidate (68) and uridine 5 -phosphate was the cyclic phosphate 69. The ease of participation of the sterically accessible, C-2 hydroxyl group probably accounts for this result. The usual procedure... 

The most significant adverse effect of glycosylated mammalian-derived rhM-CSF is a transient, dose- and schedule-related severe thrombocytopenia, which correlates with monocytosis and tjrpicaUy occurs after 7-10 days of treatment (7). Thrombocytopenia sometimes resolves despite continued administration of rhM-CSF and has usually not been sufficiently severe to cause bleeding. In other cases, a 50% reduction in the dose of rhM-CSF should be considered to allow treatment to be continued. The mechanism of rhM-CSF-induced thrombocytopenia does not involve suppression of hemopoiesis, but rather increased activity of the monocjTe/macrophage system in the liver and spleen (8). 

Dietrich, H., Espinosa, J. F., Chiara, J.L, Jimenez-Barbero, J., Leon, Y, Varela-Nieto, L, Mato, J.M., Cano, F.H., Foces-Foces, C., and Martin-Lomas, M. Glycosyl inositol derivatives related to inositolphosphoglycan mediators synthesis, structure and biological activity. Chem. Eur. J., 1999, 5, 320-336. 

Dietrich H, Espinosa JF, Chiara JL, Jimenez-Barbero J, Le6n Y, Varela- Nieto I, Mato H-M, Cano FH, Foces-Foces C, Martin-Lomas M (1999) Glycosyl inositol derivatives related to inositolphosphoglycans mediators synthesis, structure, and biological activity. Chem Eur J 5 320-336... 

For the purposes of this chapter, an arbitrary distinction is made between protonic and thermal activation, wherein protonic activation is caused by the action of acid at room temperature or lower, and thermal activation refers to the use of elevated temperatures with or without the addition of acid. In fact, in both cases, the initial steps in the postulated mechanisms are protonation of the C-2 oxygen atom followed by elimination of the aglycone to yield a ketohexofuranosyl or pyranosyl cation, which is the reactive intermediate in certain circumstances, this might be in equilibrium with the derived glycosyl fluoride. 

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