Through a simple chemoenzymatic approach 6'- and 3-esters of 2-O-beta-D-glucosylglycerol 1, with short-medium length fatty acid acyl chains, were prepared. The study of their in vitro antitumor promoting effect on Epstein-Barr virus early antigen (EBV-EA) activation, in comparison with that of the 1-esters previously described, confirms the significant activity of such monoacylated glycoglycerolipid analogues and establishes for the glucose series that the 1-substitution and the hexanoyl chain are the proper structural features for the maximum activity.