Recent progress in glycobiology reveals that sugar-chains play a crucial role in cell-cell recognition among immunity, inflammation, and malignant tumor in the living body. To study the mechanism of action requires a sample of sufficient quantity. However, isolating a sugar chain and a glycoside in pure form, difficulty follows sugar chain composition again, and studies have been limited to a few sugar chains. Glycosides are a group of compounds known to be the active principle of a natural drug. We have isolated triterpene glycosides from a Leguminosae plant, which improved liver disorder, and steroid glycosides from a plant of the Solanaceous with cytotoxic activity against human cancer cell lines. A biological activity test suggested an important role of the aglycone part and the sugar chain part of those glycosides. Although many studies of sugar chains of glycoprotein and glycolipid are known, there are few examples of studies of the sugar chain function of a glycoside of a natural drug, and the role of a sugar chain of a glycoside for its pharmacologic action expression is unknown. Therefore, as a biological tool investigating the function of a sugar chain of a natural glycoside, we have begun to synthesize a useful "glycoside" which can be utilized as a lead compound having activity.