- Enzymatic syntheses of N-protected Leu-enkephalin and some oligopeptides in organic solvents
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Enzymatic syntheses of bioacitive pentapeptide, N-protected Leu- enkephalin and some other oligopeptides in organic solvents were studied. The stereoselectivity of the enzymatic reaction was examined by using racemic substrates. Different enzymes, solvent systems and protecting groups were compared. The importance of the essential water was addressed. The side chain of tyrosine was not protected during all the enzymatic reactions, P-DL-AlaOY (P=Z or Boc, Y=H or Me) and P-DL-TyrOEt were coupled with GlyNHNHPh by papain and α-chymotrypsin in mixed solvent or organic solvent to obtain the expected optically pure products P-L-AlaGlyNHNHPh and P-L-TyrGlyNHNHPh respectively in good yield. Two sweetener precursors, ZAspXaaOR (XaaOR=PheOMe or AlaOcHex) were synthesized by thermolysin in tert-amyl alcohol and some reaction conditions were optimized to get the best yield. Full enzymatic synthesis of N-protected Leu-enkephalin ZTyrGlyGlyPheLeuOH was investigated using α-chymotrypsin and thermolysin as catalysts in dichloromethane and tert-amyl alcohol.
- Ye, Yun-Hua,Tian, Gui-Ling,Xing, Guo-Wen,Dai, Dong-Cheng,Chen, Gang,Li, Chong-Xi
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p. 12585 - 12596
(2007/10/03)
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- Polypeptide and its production and use
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Novel polypeptide of the formula: H-Tyr-Gly-Gly-Phe-Met-Lys-Pro-Tyr-Thr-Lys-Gln-Ser-His-Lys-Pro-Leu-Ile-Thr-Leu-Leu-Lys-His-Ile-Thr-Leu-Lys-Asn-Glu-Gln-OH is useful as an analgesic agent. Methods of its preparation are also disclosed.
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- PEPTIDE SYNTHESIS BY USING PHENYLPHOSPHONIC ESTER AS A COUPLING REAGENT
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Synthesis of peptides containing various functions was efficiently accomplished by treatment of the tetrabutylammonium salts of N-protected amino acids (or peptides) with amino acid esters in the presence of bis(o- or p-nitrophenyl) phenylphosphonate.Synthesis of leucine-enkephalin was successfully achieved by the above method employing a (3+2) or (4+1) fragment coupling approach.
- Watanabe, Yutaka,Morito, Naoya,Kamekawa, Ken-ichi,Mukaiyama, Teruaki
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