Anticancer Activity of Iridium(III) Complexes Based on a Pyrazole-Appended Quinoline-Based BODIPY

Abstract

A pyrazole-appended quinoline-based 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (L1, BODIPY) has been synthesized and used as a ligand for the preparation of iridium(III) complexes [Ir(phpy)(L1)]PF (1; phpy = 2-phenylpyridine) and [(η-CMe)Ir(L1)Cl]PF (2). The ligand L1 and complexes 1 and 2 have been meticulously characterized by elemental analyses and spectral studies (IR, electrospray ionization mass spectrometry, H andC NMR, UV/vis, fluorescence) and their structures explicitly authenticated by single-crystal X-ray analyses. UV/vis, fluorescence, and circular dichroism studies showed that complexes strongly bind with calf-thymus DNA and bovine serum albumin. Molecular docking studies clearly illustrated binding through DNA minor grooves via van der Waals forces and their electrostatic interaction and occurrence in the hydrophobic cavity of protein (subdomain IIA). Cytotoxicity, morphological changes, and apoptosis have been explored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Hoechst 33342 staining. IC values for complexes (1, 30 μM; 2, 50 μM) at 24 h toward the human cervical cancer cell line (HeLa) are as good as that of cisplatin (21.6 μM) under analogous conditions, and their ability to kill cancer cells lies in the order 1 > 2. Because of the inherent emissive nature of the BODIPY moiety, these are apt for intracellular visualization at low concentration and may find potential applications in cellular imaging and behave as a theranostic agent.

Visible-Light Driven Photoelectrochemical Platform Based on the Cyclometalated Iridium(III) Complex with Coumarin 6 for Detection of MicroRNA

“…The electronic absorption spectrum for [(C6) 2 Ir­(dppz)] + PF 6 – was measured in DMF solution at room temperature, as depicted in Figure . Like other C6-based iridium complexes reported previously, − the complex exhibits notably intense absorption in the visible region, with ε = 9.8 × 10 4 M –1 cm –1 at λ = 485 nm and discernible absorption out to λ ∼ 540 nm, which is assigned to the C6-centered intraligand charge transfer (ILCT) along with weaker MLCT-based transitions. It is heartening that the ε value is 5 times more than that of a frequently used photoactive species, Ru­(bpy) 3 2+ , at 450 nm (ε = 1.8 × 10 4 M –1 cm –1 ), indicating viable candidates for the photoactive material.…”

Cyclometalated Ir(III) Complexes Involving Functionalized Terpyridine-Based Ligands Exhibiting Aggregation-Induced Emission and Their Potential Applications in CO2 Detection

“…Selected geometrical parameters are given in Table S2, while pertinent views along with atom numbering scheme are depicted in Figure . From the structure it is evident that in these complexes N5 and N6 from 2-phenylpyridine are trans -disposed − (Figure ). Crystal structure further revealed that [(ppy) 2 Ir] unit in theses complexes is coordinated with N^N-chelating site of the terpyridine moiety creating a slightly distorted octahedral environment about Ir­(III) center.…”

Synthesis and Antiproliferative Activity of 2,4,6,7-Tetrasubstituted-2H-pyrazolo[4,3-c]pyridines

“…In current medicinal chemistry, the incorporation of a pyrazole nucleus is a common practice to develop new drug-like molecules with anti-cancer, anti-diabetic, anti-viral, anti-inflammatory, anti-bacterial, anti-fungal, antineurodegenerative, anti-tubercular, anthelmintic, antimalarial, and photosensitizing properties [2][3][4][5][6][7][8][9][10], among others, thus giving rise to a great number of approved therapeutics [11]. Besides numerous biological activities, pyrazoles have also been documented to possess dyeing and fluorescence properties [12][13][14][15][16], and some of them can be used as colorimetric or fluorescent probes for sensing small molecules, ions, or pH [17][18][19][20][21][22][23][24][25][26][27][28], which may have applications in in vivo imaging [29][30][31]. Pyrazolopyridines are among the most studied condensed pyrazole systems in organic and pharmaceutical chemistry (Figure 1).…”