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

Porphyrin derivatives bearing a pair of boronic acid groups (, , and ) were designed and synthesized from to construct a saccharide sensing system. Compounds , , and 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 can bind mono- and oligosaccharides including Lewis oligosaccharides to produce 1:1 host–saccharide complexes with the association constants of 102−103 M−1 range. This paper thus demonstrates a new principle to design a boronic acid-based saccharide receptor.