Simple synthesis of ruthenium pi complexes of aromatic amino acids and small peptides.

The interaction of [Ru(eta(6)-C(10)H(8))(Cp)](+) (Cp=C(5)H(5)) with aromatic amino acids (L-phenylalanine, L-tyrosine, L-tryptophane, D-phenylglycine, and L-threo-3-phenylserine) under visible-light irradiation gives the corresponding [Ru(eta(6)-amino acid)(Cp)](+) complexes in near-quantitative yield. The reaction proceeds in air at room temperature in water and tolerates the presence of non-aromatic amino acids (except those which are sulfur containing), monosaccharides, and nucleotides. The complex [Ru(eta(6)-C(10)H(8))(Cp)](+) was also used for selective labeling of Tyr and Phe residues of small peptides, namely, angiotensin I and II derivatives.

Synthesis of monosubstituted functional derivatives of carboranes from 1-mercapto-ortho-carborane: 1-HOOC(CH(2))(n)S-1,2-C(2)B(10)H(11) and [7-HOOC(CH(2))(n)S-7,8-C(2)B(9)H(11)](-) (n = 1-4).

A general approach to synthesis of monosubstituted functional derivatives of 1,2-dicarba-closo-dodecaborane (ortho-carborane) is proposed. Reactions of the triethylammonium salt of 1-mercapto-ortho-carborane (Et(3)NH)[1-S-1,2-C(2)B(10)H(11)] with ethyl omega-bromoalkyl carboxylates and omega-bromoalkylnitriles in ethanol result in the corresponding carboranyl esters and nitriles that in turn can be converted to carborane-based carboxylic acids 1-HOOC(CH(2))(n)S-closo-1,2-C(2)B(10)H(11) (n = 1-4). Mild deboronation of the closo-carborane cage with CsF in ethanol gives caesium salts of the corresponding nido-carboranes Cs[7-HOOC(CH(2))(n)S-nido-7,8-C(2)B(9)H(11)]. This approach is suitable for synthesis of compounds to be used in boron neutron capture therapy and radionuclide diagnostics of cancer.

Novel boronated derivatives of 5,10,15,20-tetraphenylporphyrin: synthesis and toxicity for drug-resistant tumor cells.

We have developed the synthesis of boronated porphyrins for potential application in cancer treatment, based on the functional derivatives of 5,10,15,20-tetraphenylporphyrin. Boronated amide derivatives starting from 5,10,15,20-tetra(p-aminophenyl)porphyrin and 9-o- and 9-m-carborane carboxylic acid chlorides were prepared. Also, the reaction of 2-formyl-5,10,15,20-tetraphenylporphyrin with closo-C-lithium-o- and m-carboranes, as well as with closo-C-lithium monocarbon carborane, yielded neutral and anionic boronated hydroxy derivatives of 5,10,15,20-tetraphenylporphyrin, respectively. Water-soluble forms of neutral compounds were prepared by deboronation of closo-polyhedra with Bu4NF into nido-7,8- and nido-7,9-dicarbaundecaborate anions. Monocarbon carborane conjugated with copper (II) complex of 5,10,15,20-tetraphenylporphyrin was active for a variety of tumor cell lines (IC50 approximately 5 microM after 48-72 h of exposure) but was inert for non-malignant fibroblasts at up to 100 microM. At low micromolar concentrations, this compound caused the death of cells that express P-glycoprotein and other mechanisms of resistance to conventional anticancer drugs.