Synthesis and binding studies of 9,10-disubstituted anthracene and dibenzobarrelene-based receptors for recognition of carbohydrates in water

Abstract: Artificial, amfiphilic, and biomimetic receptors soluble in water were synthesized via attaching polar amino acids to hydrophobic back-bones possessing a surface suitable for hydrophobic interactions. The hydrophobic back-bones chosen in this thesis were anthracene and dibenzobarrelene structures. A route to an efficient synthesis of a dibenzobarrelene backbone with two sets of orthogonal reactivities was developed. Several different types of receptors were synthesized; • based on 9,10-bis-aminomethyl-anthracene where polar amino acids were coupled in C->N and N->C direction • based on 9,10-bis-aminomethyl-dibenzobarrelene with the amino acids in the C->N direction. Within the project, a new method of cleaving the thio-protecting group 2-(trimethylsilyl)ethyl sulfide with an acyl chloride and silver tetrafluoroborate was developed and evaluated. Binding studies of the receptors were performed with p-nitrophenyl glycosides and uronides in water and the show a moderate binding. However, calculated dissociation constants, Kd 10-30 mM, were in the same range as other published receptors for carbohydrates in water and for natural proteins binding monosaccharides. A small diastereoselectivity between GalA and GlcA was detected, where GalA was bound slightly stronger by a dibenzobarrelene-based receptor with arginine as side chain