Synthesis and Characteristics of Fluorescent BODIPY-Labeled Gangliosides

A series of new fluorescent-labeled gangliosides bearing the residues of acids labeled by 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene(BODIPY) in the polar or/and apolar moiety were synthesized. These are ganglioside GM1 labeled with the residue of 4,4-difluoro-4-bora-3a,4a-diaza-5,7-dimethyl-s-indacenyl-3-propanoic (BODIPY-FL-propanoic) and -indacenyl-5-pentanoic (BODIPY-FL-pentanoic) acid in the oligosaccharide moiety of the molecule, and ganglioside GD1a labeled with two residues of BODIPY-FL-pentanoic acid in the oligosaccharide moiety and also with the residue of BODIPY-FL-pentanoic acid and the residue of 4,4-difluoro-4-bora-3a,4a-diaza-5-octyl-s-indacenyl-5-pentanoic acid in the ceramide part of the molecule. Some spectral characteristics and the behavior in the model membrane systems of the synthesized probes were studied. In their emission spectra, the BODIPY-labeled gangliosides included into phosphatidylcholine liposomes at high concentrations (>1 mol %) exhibit a long-wavelength maximum (at 630 nm) in addition to the usual maximum (at 510–515 nm).