Chemistry and biology of some low molecular weight boron compounds for boron neutron capture therapy.

Boronated DNA targeting agents are especially attractive candidates for BNCT because they may deliver boron-10 to the nuclei of tumor cells. Numerous boron-containing analogs have been synthesized and some have shown promising results in initial biological tests. One of the most challenging tasks in this special field of research remains the finding of suitable targeting strategies for the selective delivery of boron rich DNA-intercalator/alkylator to tumor cells. Synthetic and biological studies of boron compounds suitable for DNA-binding are reviewed. The amino acid p-boronophenylalanine (BPA) is presently of considerable clinical interest. Other boronated amino acids might also be candidates for BNCT either per se, as part of part of tumor-seeking peptides or conjugated to targeting macromolecules. A large number of boronated L- and D-amino acids with varying liphophicility and sterical requirements are now available for evaluation. Recent synthetic and biological studies of aromatic boronoamino acids, carboranylamino acids and carboranyl amines are also reviewed.