The ability of newly synthesized genistein benzyl and glycosylated derivatives to permeabilize the liposome membrane was studied by calcein-leakage method. All studied derivatives appeared to be more effective than their parent compound--genistein. Comparing the experimental results with theoretical calculations we found that in the case of benzyl derivatives the dipole moment of added benzene ring (with its substitutions) might be important for the strength of flavonoids-lipid interactions. This conclusion may have some implications for QSAR studies in which mostly the dipole moments of entire molecules are considered.