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EDC·HCl and Potassium Salts of Oxyma and Oxyma‐B as Superior Coupling Cocktails for Peptide Synthesis
Author(s) -
Jad Yahya E.,
Khattab Sherine N.,
de la Torre Beatriz G.,
Govender Thavendran,
Kruger Hendrik G.,
ElFaham Ayman,
Albericio Fernando
Publication year - 2015
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201500142
Subject(s) - chemistry , racemization , peptide synthesis , pentapeptide repeat , peptide , potassium , reagent , solvent , carbodiimide , amino acid , combinatorial chemistry , organic chemistry , medicinal chemistry , stereochemistry , biochemistry
Nowadays, DIC is the most widely used carbodiimide for solid‐phase peptide synthesis, while EDC · HCl is mostly used only for solution‐phase synthesis. In this paper, we report new coupling cocktails containing EDC · HCl in combination with potassium salts of OxymaPure and Oxyma‐B (i.e., K‐Oxyma and K‐Oxyma‐B, respectively). These reagent cocktails gave spectacular purity compared to DIC/classical N ‐hydroxylamine derivatives in the solid‐phase peptide synthesis of the Aib‐enkephaline (Aib = 2‐aminoisobutyric acid) pentapeptide (H‐Tyr‐Aib‐Aib‐Phe‐Leu‐NH 2 ), a hindered peptide. Furthermore, we found that the EDC · HCl/K‐Oxyma combination can be used with DMF, THF, or MeCN as the solvent. The optimized cocktail gave less racemization than benzotriazole derivatives, but slightly more than OxymaPure and Oxyma‐B during stepwise solution‐phase peptide synthesis.