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Cryochemistry: freezing effect on peptide coupling in different organic solutions
Author(s) -
Vajda Tamás,
Szókán Gyula,
Hollósi Miklós
Publication year - 1998
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/(sici)1099-1387(199806)4:4<300::aid-psc148>3.0.co;2-i
Subject(s) - formamide , chemistry , acetonitrile , tripeptide , solvent , epimer , dimethylformamide , peptide , high performance liquid chromatography , coupling reaction , organic chemistry , solvent effects , medicinal chemistry , chromatography , catalysis , biochemistry
The freezing effect on peptide coupling in organic solutions of different polarity has been investigated and compared with the results obtained in liquid phase. The model reaction of DCC‐activated coupling of Boc‐Ala‐Phe‐OH with H‐Ala‐OBu t has been carried out in dioxane, dimethylsulfoxide and formamide, as well as in mixtures (90%/10%, v/v) of dioxane with acetonitrile, dimethylformamide, dimethylsulfoxide and formamide. The reactions have been traced and evaluated by RP‐HPLC analysis. Freezing the reaction mixture resulted in all cases in a significant suppression of the N ‐dipeptidylurea side‐product formation together with a slight decrease of tripeptide epimerization. The coupling yields and the side effects depended on the solvent, with the dioxane and dioxane/acetonitrile mixture produced the best results. The role of freezing and solvent in the improved results is discussed. © 1998 European Peptide Society and John Wiley & Sons, Ltd.