Mono- and oligosaccharide sensing by phenylboronic acid-appended 5,15-bis(diarylethynyl)porphyrin complexes

Porphyrin derivatives bearing a pair of boronic acid groups (1, 1 (.) Zn, and 1 Cu) were designed and synthesized from 2 to construct a saccharide sensing system. Compounds 1, 1 (.) Zn, and 1 (.) Cu have a diethynyl porphyrin rotational axis, which is expected to act as a saccharide-binding modulator. Saccharide binding studies were conducted by UV-vis, fluorescence, and circular dichroism (CD) spectroscopies. In a water-methanol 1: 1 (v/v) mixed solvent, we have found that 1 (.) Zn can bind mono- and oligosaccharides including Lewis oligosaccharides to produce 1:1 host-saccharide complexes with the association constants of 10(2) - 10(3) M-1 range. This paper thus demonstrates a new principle to design a boronic acid-based saccharide receptor. (C) 2004 Elsevier Ltd. All rights reserved.