Metal complexes of natural melophlins and their cytotoxic and antibiotic activities

Complexes of the natural melophlins A and C with Mg. Zn, Ga, La and Ru were prepared, characterized and tested for antimicrobial and cytotoxic effects. The lanthanum complex La(melophlinato C)3 and the ruthenium complex chlorido(eta(6)-p-cymene)(melophlinato C)ruthenium(II) inhibited cells of human A-498 kidney cancer at IC50=0.54 mu M and 1.0 mu M, respectively, and so distinctly better than free melophlin C. Another synergistic effect of coordinating melophlins to bioactive metals was found in the growth inhibition of the melophlin C-resistant bacterium Micrococcus luteus by Ga, La and Ru complexes of melophlin C. (c) 2008 Elsevier Inc. All rights reserved.