Alanine glycine synthesis

Unlike fractions of pig-kidney protein, Neurospora crassa extracts can use L-glutamine, but not ammonium salts nor ammonium salts plus adeno-sine-5-triphosphoric acid. No synthesis of D-glucosamine is stimulated in Neurospora extracts by L-glutamic acid, L-aspartic acid, L-asparagine, L-alanine, glycine, L-valine, L-leucine, L-lysine, L-arginine, L-serine, L-cys-teine, L-citrulline, L-ornithine, butyramide, putrescine, or urea. Recently, a protein fraction has been discovered, in rat liver, that converts D-glucose... 

The amino acids derived from pyruvate or 3-phosphogIycerate include alanine, serine, and glycine. Synthesis of these amino acids can be achieved by multiple pathways involving several different subcellular compartments. Although enzymes that could contribute to their biosynthesis are easily demonstrable in plants (Miflin and Lea, 1982), the relative contribution of each potential pathway may vary from species to species, and within a single organism in different tissues or under different physiological conditions. 

Simple esters cannot be allylated with allyl acetates, but the Schiff base 109 derived from o -amino acid esters such as glycine or alanine is allylated with allyl acetate. In this way. the o-allyl-a-amino acid 110 can be prepared after hydrolysis[34]. The Q-allyl-o-aminophosphonate 112 is prepared by allylation of the Schiff base 111 of diethyl aminomethylphosphonates. [35,36]. Asymmetric synthesis in this reaction using the (+ )-A, jV-dicyclohex-ylsulfamoylisobornyl alcohol ester of glycine and DIOP as a chiral ligand achieved 99% ec[72]. 

The sequence of each different peptide or protein is important for understanding the activity of peptides and proteins and for enabling their independent synthesis, since the natural ones may be difficult to obtain in small quantities. To obtain the sequence, the numbers of each type of amino acid are determined by breaking down the protein into its individual amino acids using concentrated acid (hydrolysis). For example, hydrolysis of the tetrapeptide shown in Figure 45.3 would give one unit of glycine, two units of alanine, and one unit of phenylalanine. Of course, information as to which amino acid was linked to which others is lost. 

The imines of ( )-(l/ ,2/ ,5/ )-2-hydroxy-3-pinanone and glycine, alanine and norvaline methyl esters were highly successful as Michael donors in the asymmetric synthesis of 2,3-di-substituted glutamates. The chiral azaallyl anions derived from these imines by deprotonation with lithium diisopropylamide in THF at — 80 "C undergo addition to various ,/ -unsaturated esters with modest to high diastereoselectivities210,394. 

Abelian T., Chinchilla R., Galindo N., Guillena G., Najera C., Sansano J. M. Glycine and Alanine Imines As Templates for Asymmetric Synthesis of a-Amino Acids Eur. J. Org. Chem. 2000 2689-2697... 

Although useful, this synthesis of reduced quinoxalines has not been fully developed yet. 7-Azabicyclo[4.1.0]heptane (423, R = H) and glycine (424, Q = H) in refluxing aqueous ammonium chloride for 90 min gave octahydro-2(l//)-quinoxalinone (425, Q = R = H) in 40% yield." Similar treatment of 7-methyl-7-azabicyclo[4.1.0]heptane (423, R = Me) gave l-methyloctahydro-2(l//)-quinox-alinone (425, Q = H, R = Me) in 62% yield and 7-methyl-7-azabicyclo[4.1.0] heptane (423, R = Me) with L-alanine (424, R = Me) in refluxing aqueous ammonium chloride for 16 h gave two separable diastereoisomers of 1,3-dimethylocta-hydro-2(l//)-quinoxalinone (425, Q = R = Me), isolated as hydrochlorides in 26%... 

Interaction of Ni11 ions with amino acids is also important for asymmetric synthesis of amino acids. A convenient large-scale asymmetric synthesis of enantiometrically pure trans-cinnamyl-glycine and -o-alanine via reaction of cinnamyl halides with Ni11 complexes of a chiral Schiff base of glycine and alanine has been elaborated.1711 Similar procedures have been applied to other amino acids as well.1712... 

Sidney Fox and Kaoru Harada, in particular, used simulation experiments to show how volcanism may have been involved in the synthesis of prebiotic molecules. They heated a stream of gas (CH4, NH3 and H2O) to about 1,123 K (using a silicate contact) after cooling, they could detect glycine, alanine, p-alanine and aspartic acid (among others). This experiment was intended to simulate exhalation from the earth s crust, as in volcanoes (Fox and Harada, 1961 Harada and Fox, 1964). 

Fig. 5.6 The formation of alanine and glycine in the salt-induced peptide synthesis reaction (Suwannachot and Rode, 1998)...

The process was also applicable to microwave-assisted reactions. Thus, 140a, 140b, and 140 (R1 = z-Pr, R4 = indol-3-ylmethyl) were prepared in a two-step, one-pot synthesis in yields of 55%, 39%, 20%, and with 70%, 73%, 50% ee, respectively. In the first step anthranilic acid was reacted with the appropriate A-BOC-protected amino acid (glycine, L-alanine, and L-valine, respectively) in the presence of P(OPh)3 and dry pyridine under irradiation at 150 °C for 140a or conventional heating at 55 °C for 140b and 140 (R1 = z-Pr, R4 = indol-3-ylmethyl). In the second step the resulting... 

The extension to amino acid synthesis on surfaces has also been observed with platinised Ti()2 surfaces, with CH4, NH3 and H20 solutions producing glycine, alanine, glutamine, aspartic acid and serine, all photosynthesised and trapped in the resulting layers near to the surface by their charge. 

Glycine plays an important inhibitory role in the lower brain stem and spinal cord. Little is known about the synthesis of glycine. It activates a Cl- channel, which is antagonized by strychnine. Other endogenous amino acids may activate the glycine channel, such as taurine and j8-alanine. Neuropeptides... 

The non-essential amino acids are alanine, arginine, aspartate, asparagine, cysteine, glutamate, glutamine, glycine, proline, serine and tyrosine. A summary of the reactions involved in their synthesis is given in Figure 8.3 and full details of these pathways are provided in Appendix 8.2. 

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