Glutamine derivatives

The IBX oxidation of protected glutamine derivatives such as Z-Leu-Phe-Gln(Trt)[CH2OH] afford linear Z-Leu-Phe-Gln(Trt)-H in 93% yield. It should be noted that oxidation of nonprotected glutamine derivatives such as Z-Leu-Phe-Gln[CH2OH] typically result in equilibration between Z-Leu-Phe-Gln-H and the predominate cyclic hemiaminal form. The oxidation of protected glutamine derivatives such as Z-Leu-Phe-Gln(Trt)[CH2OH] afford only linear Z-Leu-Phe-Gln(Trt)-H 38]... 

The result suggested that the activation of the carboxyl group of glutamine derivatives increases the acidity of the C - H bond of the adjacent asymmetric carbon and thereby enhances the tendency to racemize. They thus came up with a new idea to use isoglutamine (35) instead of glutamine (11) as a starter. In this case, the carboxyl group to be activated for ring closure is removed from the vicinity of the asymmetric carbon atom (Fig. 4). 

Glutamine synthetase catalyzes the incorporation of ammonia into glutamine, deriving energy from the hydrolysis of ATP (Fig. 3b). This enzyme is named a synthetase, rather than a synthase, because the reaction couples bond formation with the hydrolysis of ATP. In contrast, a synthase does not require ATP. 

It is accepted that the cells in tumors in vivo undergo high rates of aerobic glycolysis to produce lactate. A major substrate appears to be glutamine derived from the degradation of muscle proteins (Newsholme et al., 1985 McKeehan,... 

The utilization of NPAAs in medical research, e.g. the use of various glutamine derivatives for investigation of kainate-receptor-mediated cell death (Brauner-Osborne et al, 1997), and their increasing use in studies of oligopeptide chemistry and in the development of new pharmaceutical applications (Kreuzfeld et al, 1996) underscore the requirement for detailed and comprehensive information about their biology and biochemistry. 

The carboxamide groups of asparagine and glutamine derivatives 26 are susceptible to dehydration during carbodiimide-mediated esterification at the a-carboxy groups (Scheme 4).[64] reaction probably involves formation of aspartyl- or glutamylisoimide 28 by attack... 

Mizuno, M, Muramoto, I, Kobayashi, K, Yaginuma, H, Inazu, T, A simple method for the s3mthesis of N -glycosylated asparagine and -glutamine derivatives. Synthesis, 162-165, 1999. 

IR spectra of the La(III) and Ce(III) complexes of Schiff bases from the condensation of 2-hydroxy-1-naphthaldehyde with a-aminoacids show ONO-tridentate coordination (except for the L-glutamine derivative, which is OONO-tetradentate.479 The IR spectra of Pr(III), Eu(III), Gd(III), Dy(III) and Yb(III) complexes of furohydroxamic acid show that the ligands are N.O-bidentate.480 Raman and IR spectra of [Er(pic)4]", where Hpic = picolinic acid, reveal that the complex is 8-coordinate, with each ligand coordinated through a (unidentate) carboxylate O and a ring N atom.481... 

Glutamine derived from the diet and from muscle during fasting can be converted to alanine in the intestine. Which enzymes are involved in the conversion ... 

All the above-mentioned glutamine-derived metabolites were found to be intermediates in the biosynthesis of the 490 quinone 438), which entails oxidation catalyzed by tyrosinase purified from extracts of A. bisporus 433). It was observed 437), however, that enzymatic oxidation of the catechol GDHB carried out at pH 6.5 produced GBQ, whereas the latter could be converted to the 490 quinone when the pH was raised to 7.8, with or without tyrosinase being present (Scheme 101). This indicated that the intramolecular transformation which provided 490 quinone in the last step was nonenzymatic. 

Acivicin is a fermentation product with antitumour activity isolated at Upjohn in 1973. The herbicidal activity was claimed by Rohm and Haas in 1985. We found it has interesting oomycete activity, and prepared analogs varying at positions 3, 5, 2 , NH2 and COOH. Acivicin inhibits glutaminases, so we tested known glutaminase-inhibitors, and glutamine derivatives with cysteine protease pharmacophores, some of which also showed interesting oomycete activity. 

Fig. 218. Formation of substituted L-glutamine derivatives 1 Glutamine synthetase, which has a relatively low substrate specificity...

Joullie and coworkers utilized camphorsultam in the synthesis of glutamine derivatives (eq 29). The camphorsultam auxiliary could be cleaved with lithium hydroxide. 

Bush MF, Oomens J, Saykally RJ, Williams ER. Alkali metal ion binding to glutamine and glutamine derivatives investigated by infrared action speetroseopy and theory. J Phys Chem A. 2008 112 8578-84. 

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