Felix A M, Wang C T, Liebman A A, Delaney C M, Mowles T, Burghardt B A, Charnecki A M, Meienhofer J
Int J Pept Protein Res. 1977 Oct;10(4):299-310. doi: 10.1111/j.1399-3011.1977.tb02801.x.
A series of analogs of thyroliberin (TRH) ([L-delta3Pro3]-TRH, [D-delta3Pro3]-TRH, [L-3-MeHis2, L-delta3Pro3]-TRH) in which proline was replaced by L- or D-3, 4-dehydroproline was synthesized. The analogs exhibited approximately the same biological activity as the corresponding proline-containing peptides. These analogs and others in which 3, 4-dehydroproline is present at the NH2-terminal, COOH-terminal or internal positions in the peptide were successfully reduced with deuterium or tritium to provide the 3, 4-2H2-proline or 3,4-3H2-proline analogs, respectively, with near theoretical values of substitution. A novel procedure for the chemical resolution of DL-3, 4-dehydroproline is also described.
