Methyl ester groups

Kauss, H. and Hassid, W.Z. (1967) Enzymatic introduction of the methyl ester groups of pectin. J.Biol.Chem. 242 3449-3453. 

Tri-O-acetyl-a-D-xylopyranosyl bromide106 (138) and N-tosyl-L-serine methyl ester107 (139) were condensed in the presence of Drierite and silver oxide, and then the O-acetyl and methyl ester groups were removed by treatment with sodium hydroxide, and the N-tosyl group by means of sodium in liquid ammonia, to give 140. Synthesis of this compound has also been described by other workers108-110 and the a-D an-omer by Brendel and Davidson.108... 

Most of the methyl ester groups are saponified with release of methanol. 

Figure 7.1 The synthesis of a PAMAM-type dendrimer proceeds from a diamine core [e.g., ethylene diamine (EDA)] by initial addition of the amines to the double bonds of methacrylate. Subsequent reaction of the methyl ester groups with EDA produces a G-0 dendrimer with four pendent amine groups. Another round of methacrylate and EDA additions results in a G-l PAMAM dendrimer containing eight primary amines.

Prepare a 1M solution of hydroxylamine in coupling buffer sufficient to again treat the slide. The pH of the coupling buffer should be adjusted to pH 10 after dissolving the hydroxylamine into it. Expose the slide to the hydroxylamine solution in the same manner as the crosslinker treatment. The hydroxylamine will react with the methyl ester groups on the salicylic acids and form hydroxamate functionalities suitable for conjugation with the P(D)BA-modified protein from above. 

Pectin methylesterase (PM) is the enzyme which catalyzes the hydrolysis of the methyl ester groups in pectinic acids. In contrast to PG and protopectinase, a great deal of progress has been made during the past decade in our knowledge of PM. The older term pectase, 8 invented before the chemical action of the enzyme was understood, is now used by a decreasing number of workers while the name pectin-... 

This blend was obtained by polymers mixture extrusion and extraction with the azeotropic mixture of hexane/ethanol, and modifying the obtained polymer surface by coupling of 4-isocyanato butanoic acid methyl ester (as a spacer molecule) to PVA blend, saponification of methyl ester groups and coupling of 4-amino-TEMPO (2,2,6,6-tetramethylpiperidine-l-oxyl) [229],... 

Hooper A, Fisher GL, Konstadinidis K, Jung D, Nguyen H, Opila R, Collins RW, Winograd N, Allara DL (1999) Chemical effects of methyl and methyl ester groups on the nucleation and growth of vapor-deposited aluminum films. J Am Chem Soc 121 8052-8064... 

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