Synthesis and in vitro properties of trimethylamine- and phosphonate-substituted carboranylporphyrins for application in BNCT
A series of carboranylporphyrins containing either amine or phosphonic acid functionalities and two to six closo-carborane clusters have been synthesized via a [2 + 2] condensation of a dimethylamino- or diethylphosphonate-substituted dipyrromethane with a dicarboranylmethyl-benzaldehyde. The X-ray structures of four key reaction intermediates (1, 2, 3, and 4a) and of two target porphyrins, the diphosphonate ester- and the diamino-tetracarboranylporphyrins 5b and 6a, are presented and discussed. In vitro studies using human carcinoma HEp2 and human glioblastoma T98G cells show that these porphyrins are non-toxic in the dark up to 100 μM concentrations, and that a tetracarboranylporphyrin bearing two quaternary ammonium groups is the most efficiently taken up by cells at short times (up to 8 h), followed by a dicarboranylporphyrin bearing three phosphonic acid substituents. All carboranylporphyrins delivered therapeutic amounts of boron to T98G cells and localized mainly within the cell lysosomes. © 2007 Elsevier Ltd. All rights reserved.
Publication Source (Journal or Book title)
Bioorganic and Medicinal Chemistry
Easson, M., Fronczek, F., Jensen, T., & Vicente, M. (2008). Synthesis and in vitro properties of trimethylamine- and phosphonate-substituted carboranylporphyrins for application in BNCT. Bioorganic and Medicinal Chemistry, 16 (6), 3191-3208. https://doi.org/10.1016/j.bmc.2007.12.020