Y-Ethyl glutamate

The possibility that products may be hydrolyzed by extended time exposure to protease was studied. Products obtained at 20 min and 3 h were both analyzed by MALDI-TOF and NMR. However, no observable difference in %-hydrolysis of ester side chains was found for these products. This is explained by precipitation from solution of oligo(y-ethyl glutamate) limiting its accessibility to protease. 

Ring-opening copolymerization was simultaneously investigated with homopolymerization of N-carboxy-a-amino acid anhydrides, NCAs, by Bamford at al Polymerization of a mixture of NCAs of y-ethyl-L-glutamate and sarcosine ... 

Fig. 7. Conversion-time curves for polymerization of NCA s (0.224 mole l l) with amines (0.015 mole l-1) at 25 C in iV.iV-dimethylformamide. O y-Ethyl-L-glutamate NCA-di-isopropylamme A y-Ethyl-L-glutamate NCA-n-hexyl-amine Q Sarcosine NCA-di-isopropylaraine Sarcosine NCA-n-hexylamine. (Reprinted from paper by C, H. Bamford, and H. Block Polyamino Acids, Polypeptides and Proteins, p, 65, Wisconsin University Press 1962 (Fig. 7)3...

As shown in Fig. 7, sarcosine NCA, the N-substituted anhydride, polymerises faster than y-ethyl-L-glutamate NCA if the polymerisation... 

An even more convincing argument is provided by the studies (46), results of which are also shown in Fig. 14. Tri-n-butyl amine in dimethyl formamide induces only a slow polymerisation of L-proline NCA whereas the polymerisation of y-ethyl-L-glutamate NCA is very fast under these conditions even if the concentration of the base is reduced by a factor of ten (78, 46). This is a striking observation since proline NCA is an extremely reactive monomer and polymerises very fast on addition of a primary amine. However, addition of 3-methyl hydantoin,... 

Poly-y-ethyl-L-glutamate CDCI3, CD2C12 Chiral 98,99... 

Several polymers were found to fit all or most of the above criteria and were used to prepare the carrier films. Many polymers have been used for this purpose, viz., ethyl cellulose, poly(y-benzyl glutamate), poly(vinyl acetate), cellulose acetate phthalate, and the copolymer of methyl vinyl ether with maleic anhydride. In addition to the base polymers, plasticizers were often needed to impart a suitable degree of flexibility. Plasticizers, which are found to be compatible with polymeric materials include, acetylated monoglycerides, esters of phthalic acid such as dibutyl tartarate, etc. An excipient was usually incorporated into the matrix of the carrier films. The excipients used were water-soluble materials, which are capable of creating channels in the polymer matrix and facilitate diffusion of the drug. PEGs of different molecular weights were used for this purpose. 

General procedure for papain-catalyzed oligo( y-ethyl-L-glutamate) synthesis... 

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.

Figure 3. Time course of oligo(y-ethyTL-glutamate) synthesis and change in pH during oligo(y-ethyl L-glutamate) synthesis for the control (0.9M) and reactions in 0.5, 0.9 and 1.3Mphosphate buffer. Synthesis was performed at 40 °C in 0.9M phosphate buffer at pH 7 under non-controlled pH conditions. Values reported are the mean from at least duplicate experiments and error bars define the maximum and minimum values obtained. (Reproduced from reference 22. Copyright 2006 American Chemical Society.)...

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