Recognition properties of receptors consisting of imidazole and indole recognition units towards carbohydrates

• Monika Mazik and
• André Hartmann

Beilstein J. Org. Chem. 2010, 6, No. 9, doi:10.3762/bjoc.6.9

• carbohydrates were investigated by 1H NMR spectroscopic titrations in CDCl3 and DMSO-d6/CDCl3 mixtures. The stoichiometry of the receptor–sugar complexes was determined by mole ratio plots [51][52] and by the curve-fitting analysis of the titration data [53]. The 1H NMR titration experiments [54] with octyl β

Synthesis and binding studies of two new macrocyclic receptors for the stereoselective recognition of dipeptides

• Ana Maria Castilla,
• M. Morgan Conn and
• Pablo Ballester

Beilstein J. Org. Chem. 2010, 6, No. 5, doi:10.3762/bjoc.6.5

• themselves can be regarded as strands 1 and 3 of a three-stranded β-sheet, with cross-linking between the chains through the 4-position of adjacent phenylalanine residues. We also report on the conformational equilibria of these receptors in solution as well as on their tendency to dimerize. 1H NMR titration

• study of the molecular recognition properties of the receptors toward the different guests. All binding constants were determined using 1H NMR titration experiments. As an example, Figure 10a shows a series of spectra acquired during the titration of receptor 2 with n-C6H13-D-Ala-D-Ala-NH2. We monitored

• temperature show that the variation in chemical shift fits a simple theoretical dimerization model, although higher order aggregation cannot be ruled out. Using 1H NMR titration experiments we have determined the association constant values of the 1:1 complexes formed between receptors 1, 2, 15, and 17 and a