Methylation-glucosylation

Class 2. Transferases transfer chemical groups from one molecule to another, or within a single molecule. They include amino, acyl, methyl, glucosyl, and phosphoryl transferases, kinases, phosphomutases, transaldolase, and transketolase. 

In the literature, there are a large number of different flavanols found in many different plants worldwide. Their structures differ from each other in the stereochemistry of the asymmetric carbons, the hydroxylation pattern of the aromatic rings, type and number of ester-linked substituents (e.g., methyl, glucosyl derivatives) or ester-linked substituents (e.g., phenolic acid derivatives), degree of polymerization, etc. 

Fig. 2. Time profiles of Tc content in T. chinensis suspension cultures elicited with methyl jasmonate (MJA), 2-Hydroxyethoxyethyl jasmonate (HEEJA), 2-hydroxyethyl jasmonate (HEJA), D-Glucosyl jasmonate (GJA) and 2,3-dihydroxypropyl jasmonate (DHPJA). One hundred pAf of each elicitor was added to the cultures in IpL of ethanol per ImL of culture medium on day 7 of cultivation. Data are the means of three flasks and vertical bars show standard deviations.

Addition of an aqueous solution of PEG to a saturated aqueous solution of a-CD at room temperature did not lead to complex formation unless the average molecular weight of PEG exceeded 200 [46]. Moreover, carbohydrate polymers such as dextran and pullulan failed to precipitate complexes with PEG, and the same was true for amylose, glucose, methyl glucose, maltose, maltotriose, cyclodextrin derivatives, such as glucosyl-a-CD and maltosyl-a-CD, and water-soluble polymers of a-CD crosslinked by epichlorohydrin. These facts suggested to Harada et al. the direction for further research. 

Direct C-glucosylation can also be effected by boiling methyl a-D-glucopyranoside in benzene in the presence of aluminum chloride and boron trichloride. In this way, 2,3,4,6-tetra-0-acetyl-/3-D-glucopyranosylbenzene was prepared in 32% yield.143 C-Glycosyla-... 

Sucrose Maltose Lactose Methyl a-glucoside0 Glucosyl resorcinol ... 

The polymer bound thioethyl 2-amido glucosyl 51a is a competent 2-amidoglucosyl donor toward glycal acceptors when activated with methyl triflate in the standard manner.21 The formation of P-2-aminoglucosyl C1 —>4 53) and p-2-aminoglucosyl (1—>3 54)-linked disaccharides proceeded in over 70% yield (Scheme 2.16). The P-2-aminoglucosyl (1 —>6)-linked disaccharide 52 was formed in lower yields. 

Saccharomyces cerevisiae) C-8 (S) Hydroxylation Streptomyces rimosus) 2,4-0-methylation and 2-0-methylation,4-0-glucosylation [126,127]... 

The results just discussed suggest that it is only alpha cyclodextrin that shows a conformational change on complex-formation, due to the rotation of one of its D-glucosyl units. Whether this conformational change contributes to the stability of the complex, as proposed by Saenger, is, however, debatable. Bergeron and Meeley " showed that methylation of the... 

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