Synthesis of sugar-substituted poly(phenylenevinylene)s

Sugar-containing PPVs, poly{2-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)]-5-methoxy-p-phenylenevinylene-alt-p-phenylenevinylene} (PPV-GlcNAc) and poly{2,5-bis-O-(beta-d-glucopyranosyl)]-p-phenylenevinylene-alt-p-phenylenevinylene} (PPV-Glc(2)), were synthesized via Heck reaction of p-divinylbenzene (DVB) with O-glycosylated hydroquinones, 2,5-dibromo-4-methoxyphenyl 2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-beta-D-glucopyranoside (3) and 1,4-bis(O-2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-2,5-dibromobenzene (6), respectively. Acetyl protecting groups of the PPVs are completely removable under mild conditions (yield 69-87%). The structures were confirmed using (1)H NMR and IR spectra. Size exclusion chromatography (SEC) (eluent: DMF, polystyrene standards) measurements indicated that respective M(n) and M(w)/M(n) values of the obtained polymers are 4.49 x 10(3) and 2.3(5) (PPV-GlcNAc) and 3.86 x 10(3) and 1.3(9) (PPV-Glc(2)). These sugar-containing PPVs are soluble in water/DMF (8/2, v/v) and are recognized by Concanavalin A (Con A), D-glucose-binding protein. Blue shift of lambda(max) of the conjugated polymer backbone was confirmed when the glucose-substituted PPV interacts with Con A. Based on those binding properties, these results revealed that the obtained PPVs with pendant sugars have capabilities for detection of biological stimuli.