Synthesis, and characterization of ruthenium(II) polypyridyl complexes containing α-amino acids and its DNA binding behavior

Reactivity of the ruthenium complexes [Ru(kappa(3)-tptz)(PPh3)Cl-2] (1) and [Ru(kappa(3)-tpy)(PPh3)Cl-2] (2) [tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine; tpy = 2,2':6',2 ''-terpyridine] with several alpha-amino acids [glycine (gly); leucine (leu); isoleucine (isoleu); valine (val); tyrosine (tyr); proline (pro) and phenylalanine (phe)] have been investigated. Cationic complexes with the general formulations [Ru(kappa(3)-L)(kappa(2)-L '')(PPh3)](+) (L = tptz or tpy; L '' = gly, leu, isoleu, val, tyr, pro, and phe] have been isolated as tetrafluoroborate salts. The resulting complexes have been thoroughly characterized by analytical, spectral and electrochemical studies. Molecular structures of the representative complexes [Ru(kappa(3)-tptz)(val)(PPh3)]BF4 (6), [Ru(kappa(3)-tpy)(leu)(PPh3)]BF4 (10) and [Ru(kappa(3)-tpy)(tyr)(PPh3)]BF4 (13) have been determined crystallographically. The complexes [Ru(kappa(3)-tptz)(leu)(PPh3)]BF4 (4), [Ru(kappa(3)-tptz)(val)(PPh3)]BF4 (6), [Ru(kappa(3)-tpy)(leu)(PPh3)]BF4 (10) [Ru(kappa(3)-tpy)(tyr)(PPh3)]BF4 center dot 3H(2)O (13) exhibited DNA binding behavior and acted as mild Topo II inhibitors (10-40%). The complexes also inhibited heme polymerase activity of the malarial parasite Plasmodium yoelii lysate. (C) 2009 Elsevier B. V. All rights reserved.