N6-furfuryladenine (kinetin) is a cytokinin growth factor with several biological effects observed in human cells and fruit flies. Kinetin exists naturally in the DNA of almost all organisms tested so far, including human cells and various plants. The cytotoxicity effect of kinetin on MCF-7 breast cancer cell lines was measured by the sulforhodamine B (SRB) assay and the results showed that kinetin could inhibit cell growth in a dose-dependent manner with an IC50 value of 52 μmol/L at 96 h after the drug was added into the culture. The interaction of bovine serum albumin (BSA) with kinetin was studied in aqueous solution at physiological conditions, using constant protein concentration and various drug contents. UV-vis spectroscopic method was used to determine kinetin binding mode, the binding constant and the effects of kinetin complexation on protein structure. The spectroscopic results showed that kinetin is located along the polypeptide chains with overall affinity constant of KKinetin-BSA = 6.8 x 104 M-1.Key words: N6-furfuryladenine (kinetin), MCF-7, cytotoxicity, sulforhodamine B (SRB), bovine serum albumin (BSA)
