Direct unimolar stearoylation of methyl α-D-glucopyranoside (1) at room temperature showed selectivity at C-6 primary position and furnished 6-O-stearoyl-α-D-glucopyranoside 2 in 46% yield. The lower yield was due to the formation of several inseparable mixtures although 2,3,6-tri-O-stearoyl-α-D-glucopyranoside 3 was isolated in 28% yield. In search of novel biologically active glucopyranosides, both the stearates 2 and 3 were further modified into several acyl esters utilizing their free hydroxyls. Prediction of activity spectra for substances (PASS) and in vitro antimicrobial assay indicated that these stearoyl esters have better antifungal potentiality. In this respect, the structure-activity relationship (SAR) is discussed for insight understanding of the necessity of acyl group(s) in the glucopyranoside unit.