Synthesis, characterization and DNA interaction studies of new complexes containing 2-mercaptobenzothiazole and different dinitrogen or phosphorous aromatic donors

Abstract The synthesis of new complexes of 2-mercaptobenzothiazole (Hmbt), [Zn(L)(mbt)(H 2 O) 2 ]Cl, [M(mbt)(L)]Cl (M(II) = Pd, Pt; L = bpy, phen), [M(mbt)(PPh 3 )Cl] (M(II) = Pd, Pt), [Zn(PPh 3 ) 2 (Hmbt) 2 Cl 2 ], [Ru(mbt) 2 (H 2 O) 2 ], [Ru(PPh 3 ) 2 (mbt) 2 ], [Ir(mbt) 3 ]Cl, [OsO 2 (mbt) 2 ], [Rh(mbt) 3 (H 2 O) 3 ], [Ag(Hmbt)(mbt)] and [Au(mbt) 2 Cl], are reported. Their structures are discussed on the bases of spectroscopic [(IR, Raman, UV–Vis, NMR ( 1 H, 13 C and 31 P) and mass)], elemental analysis, molar conductivity and thermal degradation measurements. The in vitro anticancer activity of Hmbt and its complexes, [Zn(L)(mbt)(H 2 O) 2 ]Cl, [M(L)(Hmbt)]Cl (M(II) = Pd, Pt; L = bpy, phen) and [Ag(Hmbt)(mbt)], were evaluated against human breast cancer (MDA-MB231) and human ovarian cancer (OVCAR-8) cell lines. The CT-DNA-binding properties of [Zn(mbt)(phen)(H 2 O) 2 ]Cl, [Pd(Hmbt)(phen)]Cl, [Pt(L)(Hmbt)]Cl (L = bpy, phen) and [Au(mbt) 2 Cl], were studied using circular dichroism (CD) spectroscopy. The CD spectral data are further supported by UV–Vis titrations of [Pt(phen)(mbt)]Cl, [Pd(phen)(mbt)]Cl and [Zn(mbt)(phen)(H 2 O) 2 ]Cl with CT-DNA. The results indicate that the complexes may have intercalative CT-DNA binding capabilities.