I Aspartic acid

B. J)i.-Aspartic acid. A mixture of 383 g. of the above crude product, 1 1. of concentrated hydrochloric acid, 1 1. of glacial acetic acid, and 1 1. of water is boiled under reflux in a 5-1. round-bottomed flask for 2-3 hours. The reflux condenser is then replaced by a fractionating column, and the mixture is slowly distilled until the temperature at the head of the column has risen to 108°. This requires about 13 hours. The distillate amounts to 1.5 1. (Note 3). 

Owing to the commercialization of Aspartame the demand for i-aspartic acid increased steeply. i-Aspartate can be produced by enantioselective addition of ammonia to fumaric acid catalyzed by aspartase (E.C. 4.3.1.1) (Figure 7.17). 

Scheme 2 Degradation pathways for aspartame APM = aspartame P-APM = P-aspartame PM = phenylalanine methyl ester DKP = 3-benzyl-6-carboxymethyl-2,5-diketopiperazine a-AP = a-L-aspartyl-Z,-phenylalanine PA = L-phenylalanyl-I-aspartic acid)...

S)-2-Aminobutanedioic Acid (i-Aspartic Acid, 5) Single Procedure40 ... 

Figure 33-5 Two-dimensional thin-layer chromatogram (siiica gel) of some amino acids. Solvent A toluene/2-chloroethanol/pyridine. Solvent B chloroform/benzyl alcohol/acetic acid. Amino acids (I) aspartic acid, (2) glutamic acid, (3) serine, (4) /S-alanine, (5) glycine, (6) alanine, (7) methionine, (8) valine, (9) isoleucine,...

Natural moisturizing factor (NMF) this comprises amino acids -I- hexoses -I- urea -I- aspartic acid -I- hexyl-nicotinate... 

ER Andrew, WS Hinshaw, MG Hutchins, ROI Sjoblom. Proton magnetic relaxation and molecular motion in polycrystaUine amino acids. I. Aspartic acid, cystine, glycine, histidine, serine, tryptophan, and tyrosine. Mol Phys 31 1479-1488, 1976. 

The ability of pea chloroplasts to synthesize lysine, threonine and the metabolic intermediate homoserine (which is made in unusually high amounts in peas [8]) from p aspartate is highly dependent on the age of the plants from which th are prepared (Fig. 2). The rates of incorporation of [i ]aspartic acid into lysine, threonine, and homoserine were 2 to 10 times greater in plastids from 7 day old shoots than in those from 13 day old plants (Fig. 2). Moreover, when chloroplasts were isolated from each of four leaf stages of 12 day-old plants (see Fig. 3) those from the youngest leaves (stage 4) were 2 to 5 times more active in amino acid synthesis (Table 1) than those from the oldest leaves (stage 1). 

Gallagher and co-workers used the Amdt-Eistert homo ogation strategy in their synthesis of the potent anthelmintic agent (-)-kainic acid (26). Functionalized pyrrolidine 23 was elaborated from I-aspartic acid. The presence of DMF was crucial to achieve high conversions of the acid 23 to the acid chloride 24, and key intermediate 25 was obtained in good yield. This was subsequently transformed to (-)-kainic acid (26). 

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