Glutamic acid reduction

The 20 ammo acids listed m Table 27 1 are biosynthesized by a number of different path ways and we will touch on only a few of them m an introductory way We will exam me the biosynthesis of glutamic acid first because it illustrates a biochemical process analogous to a reaction we discussed earlier m the context of amine synthesis reductive ammatwn (Section 22 10)... 

Arninobenzoyl-L-glutarnic acid (12) is obtained by condensation of -nitrobenzoyl chloride [122-04-3] (18) with L-glutamic acid [56-86-0] (19) under Schotten-Baumann conditions. This is followed by reduction of the nitro group with either sodium hydrogen sulfide (29) or by electrochemical methods (30). 

Another viable method for the synthesis of L-foUc acid (1) starts from 6-formylpterin (23). The diester of L-glutamic acid (24) is condensed with 6-formylpterin (23). Reduction of the Schiff base with sodium borohydride is followed by hydrolysis to yield L-foUc acid (37). 

Crystallization remains the primary means of controlling the polymorphic or solva-tomorphic state of a compound, and various groups have examined the influences of processing parameters on the identity and quality of the isolated form. Seeding was used to reduce the size of the metastable zone of eflucimibe, and thereby control the identity of the desired polymorphic identity of the product through a reduction in concomitant crystallization [16], Process improvements have been developed that were found to improve the filterability and enhance the bulk density of ranitidine Form-1 [17], while the variation of process parameters used in an oscillatory baffled crystallizer enabled better selection to be made between the metastable a- and /i-forms of (z.)-glutamic acid [18]. 

The relationship of the dicarboxylic amino acids, aspartic and glutamic acids to this process has also been studied (106). This investigation has been facilitated by a quantitative method for the codetermination (23) of the dehydrogenation indicator, resazurin, and its reduction product, resorufin. The wood destroying molds used were Trameles cinnabarina and Lentinus lepideus. 

Chemical methods for folic acid detection are not useful for unfractionated biologic materials (H16). Reduction of folic acid in acid yields a methylpteridine and N-(p-aminobenzoyl) glutamic acid. The latter is estimated by a method for aromatic amines (B33). Another assay method of historical interest is the growth of chicks as a measure of the folic acid content of crude biological mixtures. 

By the route shown in Scheme 7, 5-amino-5,6-dideoxy-DL-gulonic acid (dl-69) was prepared.113 When D-glucuronic acid reacted with l-glutamic acid under reductive conditions, 6-deoxy-6-[l,3-di(carboxy-propyl)amino]-L-gulonic acid was formed.114... 

This is converted into furazanpropionic acid by sulphuric acid and then into cyanonitrosobutyric acid by caustic soda. Saponification changes the cyanonitrosobutyric acid into a-nitrosoglutaric acid from which glutamic acid is obtained by reduction ... 

Examples of photoreduction processes, brought about by hydrogen abstraction from solvents are the reduction of azobenzene to hydrazo-benzene,81 of 2,3-diphenyl-5,8-quinoxalinedione (CXXXIII) to its hexahydro derivative,148 of pteroxyl-L-glutamic acid to dihydro-2-amino-4-hydroxypteridine-6-aldehyde,80 and of the blue gem-chloro-nitroso compounds CXXXIV-CXXXVI to the corresponding ketox-imes.189... 

The (R)-enantiomer of (242) has also been prepared and used as a chiral auxiliary in an enantioselective aldol synthesis of (+)-(S )-gingerol (79CB3703). (R )-Glutamic acid (246) was thus converted into (i )-pyroglutamic acid by simply heating in water. Conversion of (247) to its methyl ester and LAH reduction delivered alcohol (248). Ethyl nitrite treatment of (248) gave nitrosoamine (249), which was methylated to furnish (250). Exposure of (250) to LAH completed the synthesis of the required chiral auxiliary RAMP [(R)- l-amino-2-(methoxymethyl)pyrrolidine]. The hydrazone (252), derived from RAMP and acetone, was... 

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