By the newly developed assay method, a novel glycolipid Acremomannolipin A (1), isolated from the fungi Acrernonium strictum, was identified as a potent calcium signal modulator. The structure of 1 elucidated on the basis of intensive spectroscopic analyses as well as its degradative studies was quite unique, the D-mannopyranose being connected with D-mannitol through a β-glycoside linkage. All the hydroxyls in the mannose were highly masked as peresters with aliphatic acids, and the moiety being made hydrophobic, whereas the mannitol part exerting the highly hydrophilic property. The first total synthesis of acremomannolipin A (1) was also achieved in this study by employing the characteristic stereoselective β-mannosylation of 4,6-O-benzylidene-protected mannosyl sulfoxide with a D-mannitol derivative in the presence of trifluoromethanesulfonic anhydride as the key reaction. The physical and spectroscopic properties were completely in accord with those of the natural Acremomannolipin A. [chemical formula]
