Sulfo-glycolipids in the class of sulfoquinovosyl diacylglycerol (SQDG) including the stereoisomers are potent inhibitors of DNA polymerase α and β. However, since the α-configuration of SQDG with two stearic acids (α-SQDG-C 1 8 ) can hardly penetrate cells, it has no cytotoxic effect. We tried and succeeded in making a permeable form, sulfoquinovosyl monoacylglycerol with a stearic acid (α-SQMG-C 1 8 ) from α-SQDG-C 1 8 by hydrolysis with a pancreatic lipase. α-SQMG-C 1 8 inhibited DNA polymerase activity and was found to be a potent inhibitor of the growth of NUGC-3 cancer cells. α-SQMG-C 1 8 arrested the cell cycle at the G1 phase, and subsequently induced severe apoptosis. The arrest was correlated with an increased expression of p53 and cyclin E, indicating that α-SQMG-C 1 8 induced cell death through a p53-dependent apoptotic pathway.