Triazine-cored dendritic molecules containing multiple o-carborane clusters

A series of C-3-symmetricaltriazine-cored small dendritic molecules containing three to nine peripheral o-carborane clusters were synthesized through Cu(I)-catalyzedazide-alkyne cycloaddition reactions. The newly synthesized molecules containing multiple o-carborane moieties were characterized using nuclear magnetic resonance and matrix-assisted laser desorption/ionization-time of flight mass spectral analysis. The biological evaluation of these three to nine cage dendrimers was performed using breast cancer cells (Michigan Cancer Foundation 7). All these dendritic compounds showed cytotoxicity toward breast cancer cells, and the toxicity increased as the number of peripheral o-carboranes increased. The 9-cage molecule showed the highest cytotoxicity, and the half maximal inhibitory concentration (IC50) value was found to be 80.67 ng/ml. Its cytotoxicity was significantly higher than the common chemotherapy agent cisplatin. As expected, the boron-richo-carborane-appended molecules showed high thermal stability. The thermal stability increased as the number of peripheral o-carborane moieties increased.