L-Glutamic acid diethyl ester

Aso, K., Uemura, T., and Shiokawa, Y. (1988) Protease-catalyzed synthesis of oligo-L-glutamic acid from L-glutamic acid diethyl ester. Agric. Biol. Chem., 52... 

Li, G Vaidya, A., Xie, W Gao, W and Gross, R.A. (2008) Enzyme-catalyzed oligopeptide synthesis Rapid regioselective oligomerization of L-glutamic acid diethyl ester catalyzed by papain. ACS Symp. Ser., 999,... 

Enzyme-Catalyzed Oligopeptide Synthesis Rapid Regioselective Oligomerization of L-Glutamic Acid Diethyl Ester Catalyzed by Papain... 

L-glutamic acid diethyl ester hydrochloride (600 mg, 2.5 mmol), papain (100 mg of water-soluble powder containing 40 mg protein), and 5 mL phosphate buffer solution set at a predetermined pH were transferred to a 15 mL Erlenmeyer flask. The flask was gently stirred in a water bath at 40 C for a predetermined reaction time. Then, the reaction mixture was cooled to room temperature and deionized water (20 mL) was added. The insoluble product was separated by centrifugation (6000 rpm), washed once with dilute HCl (2 % v/v)... 

Aso et al and Uyama et al found that crude papain extracts catalyzed oligomerizations of L-glutamic acid diethyl ester (conditions pH 7-8.5, 0.5M, ionic strength 2.0 M phosphate buffer, 25 C and pH 7.0, 40°C, 3 hours) giving oligomers with DP 5 to 9 and DPjvg 9.5 from FAB-Mass spectroscopy and H-... 

Figur e 6. Effect of phosphate buffer concentration on oligo(Y-ethyl-oligoglutamate) yield Reactions were performed with 0,5M L-glutamic acid diethyl ester hydrochloride, 8 mg/mL catalyst, 40 C, pH 7.0 for 20 min with and without external pH control Values reported are the mean from at least duplicate experiments and error bars define the maximum and minimum values obtained. (Reproducedfrom reference 22. Copyright 2006 American Chemical Society.)...

Li G, et al. (2008) Protease-Catalyzed Co-Oligomerizations of L-Leucine Ethyl Ester with L-Glutamic Acid Diethyl Ester. Macromolecules. 41 p. 7003-7012. 

G. Li, A. Vaidya, W. Xie, W. Gao and R. A. Gross, Enzyme-Catalyzed Oligopeptide Synthesis Rapid Regioselective Oligomerization of L-Glutamic Acid Diethyl Ester Catalyzed by Papain , in ACS Symposium Series, ed. H. N. Cheng, American Chemical Society, 2008, vol. 999, Polymer Biocatalysis and Biomaterials II, p. 294. 

Figure 2. MALDI-TOF spectrum of oligo(y-ethyl L-glutamate) synthesized using 0.5ML-glutamic acid diethyl ester hydrochloride, 8 mg/mL catalyst, at 40 for 20 min, pH 7.0 under non-controlledpH conditions.

The chiral complex 54, formed from LiAlFLj, (15,2/f)-(+)- or (l/f,2S)-(—)-iV-methyl-ephedrine (1 equiv.) and 3,5-dimethylphenol (2 equiv.) and originally introduced for the reduction of ketones with 15-80% e.e.s, has also been shown to reduce oximes of a-keto esters with good stereoselectivity. Applied to the reduction of diethyl 2-hydroxyimmo[4- " C]glutarate, it provided [4- " C]glutamic acid diethyl ester in >60% yield and 80% e.e. ". ... 

In more recent work involving a series of alkyl, aralkyl and arylamides of MTX and AMT [316], MeAPA was condensed with a-benzyl L-glutamic acid y-3,4-methylenedioxyanilide by the diethyl phosphorocyanidate coupling procedure to obtain the ester amide (VIII. 195). The benzyl ester group in (VIII.195) was then removed with NaOH to form (VIII.196) in 64% overall yield. Further reaction of (VIII.196) with boron tris(trifluoroacetate) in tri-fluoroacetic acid at 0 °C for 15 min afforded MTX y-(3,4-dihydroxyanilide) ((VIII.197) 79% yield). AMT y-amides (VIII.198)-(VIII.205) were prepared via the blocked intermediates (VIII.206)-(VIII.213), which were generated from FmAPA by the modified mixed anhydride route (four activation cycles ... 

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