A tricatecholic receptor for carbohydrate recognition: synthesis and binding studies.
A new tripodal receptor bearing three catechol subunits on a benzene platform has been synthesized in four steps from 1,3,5-triethylbenzene and pyrogallol. The binding ability of the tricatecholic receptor was investigated toward several monosaccharides in CDCl3, where multiple equilibria were detected, and compared to that of a previously reported trisureidic receptor of analogous structure. Association constants were measured by 1H NMR titrations, and the corresponding affinities were assessed through the BC50 parameter, a binding descriptor univocally defining the affinity of a host for a guest in multi-equilibrium systems. Results show that the tripodal catecholic receptor binds the octyl glycosides with affinities ranging from 0.87 to 5.2 mM and with a 6-fold selectivity factor for the alpha-mannoside over the beta-glucoside. Although the affinity for glycosides was not appreciably improved with respect to the ureidic receptor, a significant change in selectivity was obtained by the H-bonding group replacement.
Cacciarini
Martina
M
Dipartimento di Chimica Organica and Laboratorio di Progettazione Sintesi e Studio di Eterocicli Biologicamente Attivi (HeteroBioLab), Università di Firenze, Italy.
Cordiano
Elisa
E
Nativi
Cristina
C
Roelens
Stefano
S
D002241:Carbohydrates / Q000737:chemistry*; D002396:Catechols / Q000737:chemistry*; D015394:Molecular Structure
D002241:Carbohydrates; D002396:Catechols; C034221:catechol