Enzyme-catalyzed syntheses of amino acid derivatives
Küçük Resim Yok
Tarih
1990
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
48 SUMMARY Our study has been planned in two sections, synthesis of N-acyl amino acid derivatives and N-Benzoylamino acid alkyl esters using enzyme-catalyzed reactions. As enzyme, papain was used but in some experiments were also repeated with pepsin. At first, L-Phenyl alanine, L-Tyrosine and L-Alanine as amino acid and as acylating reactant DL-Lactic acid, L-B- Phenyl lactic acid and DL-Mandelic acid were chosen. The reactions were proceed containing homogen system, such as, SO'/, ethanol, 35'/t DMF, acetoni tr i le, Glycerine, and ethyl- glycole and buffer, biphasic systems, such as, buffer-di- choloromethane-ethanol and buf fer-ni tromethane, at 37°C for 24 hours. As buffer 1M (pH 4.2) citrate-phosphate buffer was used. Reactions were traced with t.l.c. analysis periodi cally. The solvent system, used for t.l.c, chloroform- methanol-water ( 5/4/1 ) and n-butanol-acetic acid-water (4/1/1). In used reaction system, the different Rf values were obtained other than the starting material but these were not expected amino acid derivatives. Consequently, these spots could be di-,tri-, etc. peptides. In section two, papain catalyzed synthesis of N-Benzoyl amino acid alkyl esters were carried out at various volumes of buffer-CH2Cİ2 - alcohol systems. As buffer, 1M (pH 4.2) citrate-phosphate buf fer, as DL-amino acids, DL-Alanine, DL- Phenylalanine, DL-Valine and DL-Glutamic acid, as alcohol,49 methanol, ethanol, n-propanol and n-butanol were used. The reactions were performed at 37 'C for 72 hours. EXcept N- Benzoyl-DL-Glutamic acid, with other amino acids, the ester synthesis were achieved. The best product yield obtained with N-Benzoyl-DL-Alanine esters. When the immobilized was used, the product yield N-Benzoyl-DL-Alanine ethyl esters were investigated. But reaction yield could not be increased in this systems. The basic factor effected on reactions were resulted from solubility of substrates and products in aqueous and organic phases.
Açıklama
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Anahtar Kelimeler
Biyokimya, Biochemistry, Amino asitler, Amino acids, Enzimler, Enzymes
