Synthesis, Physicochemical and Photophysical Characterization of 4-(1-Pyrenyl)-butyl-α-D-mannopyranoside

Glycolipids are biomolecules composed of a lipid chain (lipophilic) and a monosaccharide or oligosaccharide as hydrophilic group. Their chemical structure and biological role make them undoubtedly good candidates for a large and continuously growing number of biotechnological applications. Mannose is a carbohydrate present on membrane glycolipids of a wide number of pathogenic microorganisms (bacteria, fungi, protozoa, and viruses) and specifically recognized by several lectins. We synthesized a mannose derivative linked through a short methylene chain to a pyrene moiety which behaves as a surfactant, able to aggregate, and retains the photophysical properties of pyrene: showing comparable absorption and emission spectra, having lower fluorescence quantum yield and the ability to form excimer, and finally the ability to produce O2(1Δg) with high quantum yields. Thus, this novel molecule would open future applications for detection (fluorescence) or inactivation (singlet oxygen) of bacterial pathogens, viruses, tumor cells, or particular cells.