The invention is intended to provide an excellent antitumor agent. An antitumor agent contains a glycolipid glycoside compound represented by Formula (1) or a pharmacologically acceptable salt thereof as an active ingredient:
in the formula, R
1
to R
4
are the same as or different from each other and represent an alkanoyl group or a hydrogen atom, and A represents a sugar alcohol residue or a polyol residue.
Stereoselective total synthesis of acremomannolipin A and its anomer, the potent calcium signal modulators with a novel glycolipid structure: role of the stereochemistry at the anomeric center on the activity
Acremonium strictum, by employing the stereoselective β-mannosylation of 4,6-O-benzylidene-protected mannosyl sulfoxide with d-mannitol as the key reaction is described. The α-anomer (epi-1) of 1 was also synthesized selectively. The calcium modulating activity was reduced upon inversion of the configuration at the anomeric center, indicating that the β-configuration of the mannose moiety is preferable for the