Anti-proliferative Activities towards Human Brain Glioma U251 Cells and Human Carcinoma Cells (KB3-1) of Some Twin-Drug Type Bivalent C 2 -Symmetrical Phenylboronic Acid Derivatives

: Derivatives of C2-symmetrical bivalent phenylboronic acid exhibit several remarkable biological activities such as anti-herpes simplex virus (HSV)-1 and cytotoxic activities against Vero cells and they can reverse the effect of anticancer drugs. Novel symmetrical bivalent molecules were synthesized and their biological activities were evaluated in vitro using a human brain glioma cell line (U251) and a human carcinoma cell line (KB3-1). Among the tested compounds (1a-i), bivalent C2-symmetrical phenylboronic acid derivative 1g showed the highest anti-proliferative activity towards both U251 and KB3-1 cells. The values of 50% anti-proliferative activity (IC50) of this compound against the two cell lines (U251 and KB3-1) were 19.0 and 3.78 µM, respectively. The anti-proliferative activity of compound 1g towards KB3-1 cells was higher than that of cisplatin. The bivalent C2-symmetrical compound 1g had a linear methylene linker in the molecule.