Acid, acetic aspartic

Figure 4.12 Effect of counter-ions and copper on the retention of amino acids. Column, octadecyl-bonded silica gel, 25 cm x 4.6 mm i.d. eluent, 0.01 M sodium acetate buffer (pH 5.6) containing 1.2 mM sodium octanesulfonate (Oc) andj or 0.1 mM copper acetate (Cu) flow rate, 1ml min-1 detection, UV 220 nm. Compounds Glu, glutamic acid, Asp, aspartic acid.

Assumptions Synthesis of phenylpyruvic acid Batch synthesis process for precursors overal yield of 95+% of theoretical to pheny Ihydantoin overall yield of 90+% of theoretical from phenylhydantoin to phenylpyruvic acid recovery and recycle of acetic acid no byproduct crec taken for acetic acid formed from acetic anhydride addition. Conversion of phenylpyruvic acid and aspartic acid. Bioreactor productivity of-18 g PHE/L/h (four columns in parallel) 98% overall conversion no byproduct credit taken for pymvic acid (recovery cost assumed to be of by revenue from sale) 80% recovery of L-PHE downstream of bioreactor. 

Buchanan, Bachofen, and Arnon (29) found that extracts from Chromatium catalyzed a synthesis of pyruvate from acetyl-CoA, CO2, and reduced ferredoxin. Pyruvate did not accumulate in the absence of a trap, but was converted mainly to the amino acids, alanine, aspartate, and glutamate. Synthesis of these amino acids from acetate and CO2, by way of pyruvate, was in agreement with the earlier labeling data of Tomlinson (102) with anaerobic bacteria and of Cutinelli et al. (34) with another photosynthetic bacterium, Rhodospirillum rubrum. 

Acetic acid Acetaldehyde Acetone L-Alanine l-Alanine ion L-Alaninate ion L-Arginine dl-Aspartic acid L-Aspartic acid L-Aspartic acid ion L-Aspartate ion Benzene Butyric acid Butyrate ion Carbon dioxide Citric acid Citrate ion Creatine L-Cysteine L-Cystine Ethanol Ethyl acetate Formic acid Formate ion Fumaric acid Fumarate ion a-D-Glucose p-D-Glucose Glycerol L-Glutamic acid L-Glutamate ion... 

Aspartic acid was separated by chromatography on a calibrated colunn of BioRad AG1-X8, 100-200 mesh, anion exchange resin. Hie resin was regenerated with 4 colunn volumes of 1 M sodium Half of the sanple was applied to the colunn elution was carried out with 1 M acetic acid. The aspartic acid fraction was evaporated in a rotatory evaporator. Hie L-leucyl-DL-aspartic acid dipeptides were synthesized by the procedure of Manning and Moore (14). Hie D/L aspartic acid ratio was determined with a Beckman Model 118 Automatic Amino Acid Analyzer. 

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,...

Fig. 11.2.11. Isocratic separation of PTH-amino adds. Chromatographic conditions column, Ultrasphere ODS (250 X 4.6 mm I.D.) mobile phase, 0.01 M sodium acetate (pH 4.9)-acetonitrile (62.2 37.8) flow rate, 1 ml/min temperature, ambient. Peak identity corresponding to the single letter code for amino acids D, aspartic acid E, glutamic acid N, asparagine Q, glutamine T, threonine G, glycine A, alanine Y, tyrosine M, methionine V, valine P, proline W, tryptophan F, phenylalanine K, lysine I, isoleucine L, leucine S, serine. Reproduced from Noyes (1983), with...

Fig. 59. Finger print of a casein hydrolysate on cellulose MN 300 plate size 20 X 20cm layer thickness 0.25 mm. 1 dimension electrophoresis with buffer of 25 ml formic acid and 78 ml acetic acid per litre 400 V and 75 min run. 2 dimension TLC with chloroform-methanol-17.5% ammonium hydroxide (41+41+18). 1 leucine + isoleucine 2 phenylalanine 3 valine 4 methionine 5 proline 6 tyrosine 7 hydroxy-proline 3 alanine 9 serine + threonine id glycine ii histidine i2 arginine + lysine 13 glutamic acid 14 aspartic acid 8 Thin-Layer Chromatography, 2nd Edition...

By refluxing neopeptin with dilute acetic acid free aspartic acid, a tetrapeptide and N-acyl-Ser-Ser were obtained. The structure of the N-acyl-dipeptide was established by El mass spectrometry of its methyl... 

IS placed at the center of a sheet of cellulose acetate The sheet is soaked with an aqueous solution buffered at a pH of 6 0 At this pH aspartic acid C ) exists as its — 1 ion alanine as its zwittenon and lysine as its +1 ion... 

A solution of 88.5 parts of L-phenylalanine methyl ester hydrochloride in 100 parts of water is neutralized by the addition of dilute aqueous potassium bicarbonate, then is extracted with approximately 900 parts of ethyl acetate. The resulting organic solution is washed with water and dried over anhydrous magnesium sulfate. To that solution is then added 200 parts of N-benzyloxycarbonyl-L-aspartic acid-a-p-nitrophenyl, -benzyl diester, and that reaction mixture is kept at room temperature for about 24 hours, then at approximately 65°C for about 24 hours. The reaction mixture is cooled to room temperature, diluted with approximately 390 parts of cyclohexane, then cooled to approximately -18°C in order to complete crystallization. The resulting crystalline product is isolated by filtration and dried to afford -benzyl N-benzyloxycarbonvI-L-aspartyl-L-phenylalanine methyl ester, melting at about 118.5°-119.5°C. 

Figure 9 A synthetic mixture of water-soluble carboxylic acids separated by anion-exchange chromatography. Column 0.3 cm x 300 cm Diaoion CA 08, 16-20 p (Mitsubishi Kasei Kogyo). Eluant 200 mM HC1. Detection reaction with Fe3-benzohy-droxamic acid-dicyclohexy carbodiimide-hydroxylamine perchlorate-triethyl amine with absorbance at 536 nm. Analytes (1) aspartate, (2) gluconate, (3) glucuronate, (4) pyroglutamate, (5) lactate, (6) acetate, (7) tartrate, (8) malate, (9) citrate, (10) succinate, (11) isocitrate, (12) w-butyrate, (13) a-ketoglutarate. (Reprinted with permission from Kasai, Y., Tanimura, T., and Tamura, Z., Anal. Chem., 49, 655, 1977. 1977 Analytical Chemistry).

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