Luminescent Palladacycles Containing a Pyrene Chromophor; Synthesis, Biological and Computational Studies of the Interaction with DNA and BSA

Abstract

One of the most active areas within the field of bioorganometallic chemistry, complexes of N-heterocyclic carbenes (NHCs), have recently gained interest. Herein, we report two luminescent palladium N-heterocyclic carbene complexes; namely [Pd {(C,N)-C 6 H 4 CH 2 NH(CH 2 CH 3 )}(1)] (2) and [Pd{(C,N)-C 6 H 4 CH 2 NH 2 }(1)] (3) (1 = 1-methyl-3-(2-oxo-2-(pyren-1-yl)ethyl)-2,3-dihydroimidazol-2-ylidene) which were synthesized from the reaction of luminescent imidazolium salt (1(H)Br) and binuclear Palladacycles. The interactions of them with CT-DNA evaluated via absorption, emission and CD spectral techniques as well as measurements of viscosity and thermal denaturation and the results have been shown that they bounded to CT-DNA by intercalation and groove binding modes. The in vitro cytotox-icity of compounds 2-3 and 1(H)Br on human breast (MCF-7) and cervical epithelial carcinoma (HeLa) cancer cells lines, indicated the wide range of anticancer activities of them with low IC 50 values. Moreover, based on the protein binding ability studies, the intrinsic fluorescence of BSA could be strongly quenched by compounds via a static quenching mechanism. Competitive binding study using Eosin, Digoxin and Ibuprofen as site markers, indicated that the compounds could bind to sites I and II on BSA structure. Finally, all data obtained from biophysical studies were validated by molecular modeling study. Computational results showed that palladium complexes have the potential for detection of mismatch DNA.

Water-Soluble Pyrene-Adorned Imidazolium Salts with Multicolor Solid-State Fluorescence: Synthesis, Structure, Photophysical Properties, and Application on the Detection of Latent Fingerprints

“…Ltd. 1- N -methyl-3-(2-oxo-2-(pyren-1-yl)ethyl)-imidazolium bromide ( 1 ) was prepared as reported. 44 [1- N -isopropyl-3-(2-oxo-2-(pyren-1-yl)ethyl)-imidazolium bromide ( 2 ), 1- N -allyl-3-(2-oxo-2-(pyren-1-yl)ethyl)-imidazolium bromide ( 3 ) and 1- N -isopropyl-3-(2-oxo-2-(pyren-1-yl)ethyl)-imidazolium hexafluorophosphate ( 4 ) were newly synthesized by modified procedures. Thin-layer chromatography (TLC) was performed on Merck 1.05554 aluminum sheets precoated with silica gel 60 F254, and the spots were visualized with UV light at 254 nm or under iodine.…”

Luminescent Imidazolium Salts as Bright Multi‐Faceted Tools for Biology

“…The delicate structural adjustment of IMs toxicity to obtain anticancer activities has led to numerous recent developments, including the conception of N‐ heterocyclic carbenes (NHC), [53–55] whose σ‐donor character highly stabilizes them when complexing transition metals, with no risk of degradation in physiological media. The inclusion of polyaromatic ligands in complexes to obtain biological properties only led to a few studies, [56,57] and the use of these compounds fluorescence to study their interaction with DNA has barely been reported [58,59] …”

“…Kazeminasab et al [59] . recently produced a rather complete study about a new luminescent NHC ligand ( 4 ) bearing a pyrene fragment, and two complexes ( 5 ) and ( 6 ) based on palladium, binding 4 (Figure 11).…”

“…[49] studies, [56,57] and the use of these compounds fluorescence to study their interaction with DNA has barely been reported. [58,59] Kazeminasab et al [59] recently produced a rather complete study about a new luminescent NHC ligand (4) bearing a pyrene fragment, and two complexes ( 5) and ( 6) based on palladium, binding 4 (Figure 11). These three compounds interact via groove-binding with calf-thymus DNA, i. e., CT-DNA, and selectively bind to the I and II sites of bovine serum albumin, i. e., BSA.…”

“…Figure11. Luminescent ligand (4) and complexes (5-6) exhibiting anticancer properties, which can be used to study their interaction with CT-DNA and BSA [59]. Reviews doi.org/10.1002/ejoc.202100459…”