Synthesis and cardiac activity evaluation of the proposed structures of fuzinoside

In order to revise the structure of fuzinoside and investigate its cardiac activity, four proposed structures (2-5) with different forms and linkage positions of the disaccharide were synthesized through 10∼14 chemical steps from the commercially available d-galactose. None of the synthetic glycosides were consistent with the natural one by comparison of their NMR data, indicating that the true structure of fuzinoside remains to be confirmed. Nevertheless, cardiac activity evaluation in the isolated bullfrog heart assay has shown that glycerol β-d-galctofuranosyl-(1→2)-β-d-galactofuranoside (2) is a potential cardiotonic agent.