Polymers glycopeptides

Polymers containing covalently bound monosaccharide and amino-acid residues are termed glycoproteins, glycopeptides or peptidogiycans. It is not possible to give... 

Soluble polyethylene glycol (PEG) as polymer support was also successfully investigated. Precipitation after each reaction step in order to remove excesses of reagents and soluble byproducts seemed to work well. Another topic of great interest is direct glycosylation of solid support connected peptides in order to arrive finally at glycopeptides. (9-Glycosyl trichloroacetimidates also proved successful in this endeavor. 

Convergent glycopeptide synthesis with polymer-bound carbohydrates... 

CONVERGENT GLYCOPEPTIDE SYNTHESIS WITH POLYMER-BOUND CARBOHYDRATES... 

The third and final stage of synthesis of cell walls occurs outside the cytoplasmic membrane. Thus, the transpepfidation reaction results in transformation of the linear glycopeptide polymer into the CTOss-Unked form. The enzyme transpeptidase, a membrane-bound enzyme, binds pentapepfide side chains by replacing terminal o-alanines. 

The main function of the ester 34 in bacterial cells seems to be its participation in the biosynthesis of the glycopeptide cell-wall polymer. If this process is blocked, there results the accumulation of a high concentration of sugar nucleotide precursors in the cell. A number of these compounds have been isolated the simplest one is the ester of uridine 5 -pyrophosphate with N-acetylmuramic acid [2-acetamido-3-0-(D-l-carboxyethyl)-2-deoxy-D-glucose] (37), first obtained from Staphylococcus aureus cells that had been treated with penicillin7,151 or Gentian Violet.144 An intermediate in the biosynthesis of 37 was isolated and shown to be the 3 -enolpyruvate ether152,153 (38). 

W. Kosch, J. Marz, and H. Kunz, Synthesis of glycopeptide derivatives of peptide T on a solid-phase using an allylic linkage. React. Polym. 22 181 (1994). 

The most popular and commonly used chiral stationary phases (CSPs) are polysaccharides, cyclodextrins, macrocyclic glycopeptide antibiotics, Pirkle types, proteins, ligand exchangers, and crown ether based. The art of the chiral resolution on these CSPs has been discussed in detail in Chapters 2-8, respectively. Apart from these CSPs, the chiral resolutions of some racemic compounds have also been reported on other CSPs containing different chiral molecules and polymers. These other types of CSP are based on the use of chiral molecules such as alkaloids, amides, amines, acids, and synthetic polymers. These CSPs have proved to be very useful for the chiral resolutions due to some specific requirements. Moreover, the chiral resolution can be predicted on the CSPs obtained by the molecular imprinted techniques. The chiral resolution on these miscellaneous CSPs using liquid chromatography is discussed in this chapter. 

From the carbohydrate analyses of peak II, it was determined that 780 pg of polysaccharide (i.e., polymers of neutral monosaccharides with polymer mol. wt. of 1,000-5,000) were reversibly complexed with the estimated 19.5 pg of glycopeptide contained in this peak. Hence, the calculated carbohydrate glyco-peptide weight ratio is approximately 40 1. 

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