Gas-Phase Deprotonation of the Peptide Backbone for Tripeptides and Their Methyl Esters with Hydrogen and Methyl Side Chains
作者:Samantha S. Bokatzian-Johnson、Michele L. Stover、David A. Dixon、Carolyn J. Cassady
DOI:10.1021/jp3113528
日期:2012.12.27
deprotonate experimentally by electrospray ionization. Experimental GAs for these esters are in the range of 336.7–338.1 kcal/mol, in excellent agreement with the calculated G3(MP2) values. Experimental GAs could not be obtained for the other three methylesters (AlaGlyAla-OMe, AibAibAib-OMe, and SarSarSar-OMe) because they did not produce sufficient deprotonated molecular ions. Trisarcosine methyl ester
Compounds of the formula 1 or 1a ##STR1## wherein R.sup.1 is H--, H--Gly or H--Leu and R.sup.2 is H or COOH and pharmaceutically acceptable salts thereof, are disclosed. The compounds of formulae 1 and 1a are useful for the management of diabetes and the treatment of acromegaly. Methods for their use are also disclosed.