Multivalent assembly of a pyrene functionalized thio-N-acetylglucosamine: Synthesis, spectroscopic and WGA binding studies

MONTENEGRO, HUGO O.; DI CHENNA, PABLO H.; SPAGNUOLO, CARLA C.; UHRIG, MARÍA LAURA

CARBOHYDRATE RESEARCH

ELSEVIER SCI LTD

Año: 2019 p. 6 - 12

0008-6215

We introduce here a new fluorescent derivative of thio-N-acetylglucosamine linked to a pyrene system through a triazolylpentyl spacer, designed to self-assemble into a multivalent glycocluster. The synthesis was achieved by efficient CuAAC click reaction between a pyrene functionalized with an azide group and a suitable alkynyl thiomonosaccharide. Spectroscopic studies by fluorometry indicated that the self-assembly in aqueous medium is modulated by concentration and pH changes, the latter due to the presence of the amino group close to the π system. Circular dichroism experiments revealed a moderate positive signal, suggesting that the pyrene-thioGlcNAc conjugate can aggregate into a chiral supramolecular assembly. The sugar moiety showed to specifically and reversibly interact with the wheat germ agglutinin, a fact that was demonstrated by turbidity assay. SEM microscopy of a lyophilized solution at pH 10 revealed a fibrillar morphology compatible with the presence of tubular micelles, whereas crystalline and amorphous solids are formed at lower pHs.