Cancer Cell Cytotoxicity of Cyclometalated Compounds Obtained with Osmium(II) Complexes

Abstract

A library of 29 organoosmium compounds has been built up with known and novel cyclometalated compounds obtained with C-N, N(∧)C(∧)N, and C(∧)N(∧)N ligands. All compounds have been tested for their in vitro cytotoxic properties against A172, a tumor cell line derived from a human glioblastoma, this affording a contrasted picture of the activities of the compounds gathered in this study. Some compounds displayed good to excellent activities, some of them showing IC50 in the nanomolar range. The level of activity was tentatively correlated to several physicochemical properties of the compounds such as their E(0)1/2(Os(III/II)) redox potential and their lipophilicity (log Po/w). A parallel with related ruthenium derivatives was tentatively proposed.

Iron(III) Pincer Complexes as a Strategy for Anticancer Studies

“…As for RDCs, the activity of ODCs is related both to their lipophilicity, which favors cell entry, and to their reduction potentials. [16] The development of iron-based drugs is highly relevant owing to the lower intrinsic toxicity of iron. However, examples of iron complexes with anticancer properties are scarce relative to the number of examples available for ruthenium and osmium complexes, even if a steadily growing number of publications has been observed in recent years.…”

Applications of five-membered ring products of cyclometalation reactions as anticancer agents

“…The cyclometalated five-membered osmium derivatives of 2-Phenylpyridine, 2-phenylpyrazoline, 2-phenyloxazine and 2,6-bis(2-pyridyl)benzene, 2.44a -2.57b (Fig. 8) [28], were tested for their in vitro cytotoxic properties with respect to A172, a tumor cell line derived from a human glioblastoma, as shown in Table 15. A majority of these compounds exhibit good to excellent in vitro cytotoxicity toward the A172 tumor cell line.…”

“…8. Five-membered ring osmium cyclometalation reaction compounds as anticancer agents [28]. In the 2,6-diphenylpyridine cyclometalated phenylphosphine or N-heterocyclic carbene gold derivatives 2.58 -2.63 ( Fig.…”

“…The cytotoxicity IC 50 values (μ-M, 72 h) of the cyclometalation reaction five-membered ring osmium compounds 2.44a-2.57b with respect to A172 derived from a human glioblastoma[28].…”

Development of anticancer agents: wizardry with osmium

“…Pfeffer and coworkers obtained analogous cycloosmated compounds via an intramolecular CH activation reaction of various Ndonor ligands. This versatile synthetic route yielded a large library of ligands that acted as C, N-, C,N,N-or C,N,C-chelators towards the osmium center [29]. All complexes displayed good to excellent cytotoxicity towards the human glioblastoma cell line A172 and the most active complex 10 ( Figure 1) showed IC50 values in the high nM range.…”