10.1016/S0022-328X(01)00783-5
The research focuses on the synthesis and biological evaluation of silicon- and germanium-containing β-amino acids and their incorporation into decapeptides to study C/Si/Ge bioisosterism. The purpose is to develop efficient methods for synthesizing these amino acids and to assess their potential as GnRH antagonists. Key chemicals include 3,6-diethoxy-2,5-dihydropyrazine as the starting material, and (chloromethyl)trimethylsilane and (chloromethyl)trimethylgermane for introducing silicon and germanium groups, respectively. The β-amino acids were synthesized using two methods (A and B), with Method B yielding better overall results. The enantiomers of the amino acids were resolved using preparative liquid chromatography with CHIROBIOTIC T as the stationary phase. The resolved amino acids were then incorporated into decapeptides via solid-phase synthesis, and their antagonistic potencies at the human GnRH receptor were evaluated. The decapeptides exhibited medium potency as GnRH antagonists, with similar potencies for the carbon, silicon, and germanium analogs, indicating significant bioisosterism. The study concludes that silicon and germanium can effectively replace carbon in these peptides, maintaining biological activity, which is crucial for developing new peptide analogs for hormone-dependent cancer therapy and assisted reproduction.
