Synthesis and Characterization of Novel Cu(II), Pd(II) and Pt(II) Complexes with 8-Ethyl-2-hydroxytricyclo(7.3.1.0(2,7))tridecan-13-one-thiosemicarbazone: Antimicrobial and in Vitro Antiproliferative Activity

New Cu(II), Pd(II) and Pt(II) complexes, (Cu(L)(H(2)O)(2)(OAc)) (1), (Cu(HL)(H(2)O)(2)(SO(4))) (2), (Cu(L)(H(2)O)(2)(NO(3))) (3), (Cu(L)(H(2)O)(2)(ClO(4))) (4), (Cu(L)(2)(H(2)O)(2)) (5), (Pd(L)(OAc))H(2)O (6), and (Pt(L)(2)) (7) were synthesized from 8-ethyl-2-hydroxytricyclo(7.3.1.0(2,7))tridecan-13-one thiosemicarbazone (HL). The ligand and its metal complexes were characterized by IR, (1)H-NMR, (13)C-NMR, UV-Vis, FAB, EPR, mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The free ligand and the metal complexes have been tested for their antimicrobial activity against E. coli, S. enteritidis, S. aureus, E. faecalis, C. albicans and cytotoxicity against the NCI-H1573 lung adenocarcinoma, SKBR-3 human breast, MCF-7 human breast, A375 human melanoma and HL-60 human promyelocytic leukemia cell lines. Copper complex 2 exhibited the best antiproliferative activities against MCF-7 human breast cancer cells. A significant inhibition of malignant HL-60 cell growth was observed for copper complex 2, palladium complex 6 and platinum complex 7, with IC(50) values of 1.6 µM, 6.5 µM and 6.4 µM, respectively.