Synthesis and conformational investigation of tetrapeptide analogues of the fragment B23-B26 of insulin
摘要:
Tetrapeptides containing one of a set of four different alpha,alpha-dialkyl glycines at the C-terminus were synthesized by conventional methods in solution and their conformational. behavior investigated by H-1 NMR spectroscopy in connection with molecular mechanics calculations. The results were consistent with conformations stabilized by a gamma-turn in the case of compounds with alkyl groups larger than methyl, while the corresponding Aib derivative did not exhibit intramolecular hydrogen bonding. (C) 2004 Elsevier Ltd. All rights reserved.