Synthesis of Guanidinium-Derived Receptor Libraries and Screening for Selective Peptide Receptors in Water

Abstract

A library of “tweezer” receptors, incorporating a guanidinium “head group” and two peptide derived side arms has been prepared on the solid‐phase using an orthogonally protected guanidinium scaffold 12. The library was screened with various tripeptide derivatives in an aqueous solvent system. A tweezer receptor 25 for the side chain protected tripeptide 19 was identified from the screening experiments. Receptor 25 was resynthesised and solution binding studies were carried out, which revealed that 25 binds to tripeptide 19 with Ka=8.2×104±2.5×104 (15 % DMSO/H2O, pH 8.75) and with appreciable selectivity over the tripeptide enantiomer 22 and the side chain deprotected tripeptide 20.

Synthesis and in Vitro and in Vivo Characterization of Highly β1-Selective β-Adrenoceptor Partial Agonists

“…To avoid this complication with the remaining analogues, tert -butyl-2-aminoethylcarbamate ( 31 ) was employed instead of 11 . Selective mono-Boc protection of ethylenediamine ( 11 ) was accomplished in excellent yield using a literature method 39 to give amine 31 (Scheme 3). The stoichiometric condensation of 31 with corresponding substituted phenylisocyanates permitted preparation of the Boc-protected intermediates 32a and 32c – r in moderate to good yield, with the pure products being easily isolated by filtration following precipitation with hexanes.…”

Synthesis of Unsymmetrical Tweezer Receptor Libraries and Identification of Receptors for Lys‐D‐Ala‐D‐Ala in Aqueous Solution

“…4 The incorporation of a specific recognition site for the carboxylate functionality into the general receptor structure has facilitated the identification of receptors for peptides with a free carboxylate terminus. In this context, we have used bis(aminoalkyl)guanindiniums as a scaffold to prepare libraries of two‐armed “tweezer” receptor structures 1 (Scheme ) and hence identified receptors for a side‐chain‐protected tripeptide in aqueous media 2e…”

Relationship Between the Ligand Structure and the Luminescent Properties of Water‐Soluble Lanthanide Complexes Containing Bis(bipyridine) Anionic Arms

“…[35] IR spectra were recorded by using a Nicolet 210 spectrometer as KBr pellets. Compounds 1, [16] 3, [20] 4 [21] and 7 [22] were obtained according to literature procedures and full experimental procedures for the synthesis of intermediate compounds 5, 6, 8, 9, 10, 13, 14, 16, 17, and 20 are reported in the Supporting Information.…”