The Important Role of the Nuclearity, Rigidity, and Solubility of Phosphane Ligands in the Biological Activity of Gold(I) Complexes

Abstract

A series of 4-ethynylaniline gold(I) complexes containing monophosphane (1,3,5-triaza-7-phosphaadamantane (pta; 2), 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane (3), and PR , with R=naphthyl (4), phenyl (5), and ethyl (6)) and diphosphane (bis(diphenylphosphino)acetylene (dppa; 7), trans-1,2-bis(diphenylphosphino)ethene (dppet; 8), 1,2-bis(diphenylphosphino)ethane (dppe; 9), and 1,3-bis(diphenylphosphino)propane (dppp; 10)) ligands have been synthesized and their efficiency against tumor cells evaluated. The cytotoxicity of complexes 2-10 was evaluated in human colorectal (HCT116) and ovarian (A2780) carcinoma as well as in normal human fibroblasts. All the complexes showed a higher antiproliferative effect in A2780 cells, with the cytotoxicity decreasing in the following order 5>6=9=10>8>2>4>7>3. Complex 4 stands out for its very high selectivity towards ovarian carcinoma cells (IC =2.3 μm) compared with colorectal carcinoma and normal human fibroblasts (IC >100 μm), which makes this complex very attractive for ovarian cancer therapy. Its cytotoxicity in these cells correlates with the induction of the apoptotic process and an increase of intracellular reactive oxygen species (ROS). The effects of the nuclearity, rigidity, and solubility of these complexes on their biological activity were also analyzed. X-ray crystal structure determination allowed the identification of short N-H⋅⋅⋅π contacts as the main driving forces for the three-dimensional packing in these molecules.

Effect of Gold(I) on the Room‐Temperature Phosphorescence of Ethynylphenanthrene

“…Hydrogen atoms at positions 1, 2, and 4 (see position numbering in Scheme 2) are more affected by the coordination of the metal atom with a 0.1 ppm downfield shift. The 31 P{ 1 H} NMR spectra show in all cases one signal, as a direct indication of the formation of only one product, that is approximately 50–60 ppm downfield shifted with respect to the free phosphane, as previously observed in other similar reactions (Figures S3–S22 in the Supporting Information) [24, 26–31] …”

“…The Au−C and C≡C distances and P‐Au‐C and Au‐C≡C angles (Table 1) are in the usual ranges for Au I alkynyl complexes [28, 31–41] . Linear coordination of the phenanthrene ligands at the Au I centers is observed, with P‐Au‐C angles of 172.6–179.0°.…”

“…An additional absorption band centered at 300 nm appears for 1 c / 2 c , containing the trinaphthylphosphane (PNaph 3 ) ligand, which is ascribed to the π–π*(Naph 3 ) transition [31] . In the case of 1 d / 2 d , a lower energy absorption band is observed as a tail, which has been assigned to the absorption of aggregates and arises from σ*(Au Au)–π* transitions, as an indication of the possible aurophilic contacts in solution for these complexes [51] …”

Supramolecular tripodal Au(i) assemblies in water. Interactions with a pyrene fluorescent probe

“…Previous work reported by 4 us has been mainly based on linear mononuclear compounds containing aromatic chromophores that can improve the self-assembly process by the presence of    interactions. 3,5,11,12,29 In this work, we can demonstrate that the absence of this type of interactions, based on the presence of aromatic chromophores, does not prevent intermolecular contacts and aggregation leading to the formation of very long fibers. The simplicity of the present molecules are particularly important since it can be demonstrated that only Au(I) and probably some hydrogen bonds coming from phosphine units are necessary in these supramolecular assemblies.…”

Theoretical Investigation of Structural and Optoelectronic Properties of Ternary Acetylides A2MC2 (A = Li, Na, K) and (M = Te, Pb, Pt)

“…They obtained these compounds after synthetizing Li2C2 (Na2C2) by reacting the elemental Li (Na) with acetylene gas. New materials with distinct structures and different properties have been updated by Głodek et al [14], Chan et al [15], Svahn et al [16], Marmol et al [17], and Sanchez-de-Diego et al [18], using multiple diagnostic techniques. On the other hand, there are many fields of use of these structures in several areas, as shown by Lankelma et al [19], Tian et al [20], Kuroda et al [21], Hau et al [22], and Zhou et al [23].…”