Ligand Complexes Research Articles

Nutrient removal in floating and vertical flow constructed wetlands using aluminium dross: An innovative approach to mitigate eutrophication

On global scale, eutrophication is one of the most prevalent environmental threats to water quality, primarily caused by elevated concentration of nutrients in wastewater. This study utilizes aluminum dross (AD), an industrial waste, to create a value-added material by improving its operational feasibility and application for removing phosphate and ammonium from water. The operational challenges of AD such as its powdered nature and effective operation under only extreme pH conditions were addressed by immobilizing in calcium alginate to form calcium alginate aluminium dross (Ca-Alg-Al dross) beads. These Ca-Alg-Al dross beads were further tested for phosphate and ammonium removal from natural wastewater in two different aqueous environment systems: (i) vertical flow constructed wetlands (VF-CWs) followed by Ca-Alg-Al dross beads fixed bed system and (ii) Ca-Alg-Al dross beads mounted floating constructed wetlands (FCW) for remediating polluted lentic ecosystems. Our results show maximum phosphate and ammonium removal of 85 ± 0.41 % and 93.44 %, respectively, in VF-CWs followed by Ca-Alg-Al dross beads fixed bed system. The Ca-Alg-Al dross beads mounted FCW system achieved maximum phosphate removal of 79.18 ± 8.56 % and ammonium removal of 65.45 ± 21.04 %. Furthermore, the treated water from the FCW system was assessed for its potential to inhibit algal growth by artificially inoculating treated water with natural algae to simulate eutrophic conditions. Interestingly, treated water from the FCW system was found capable of arresting the algal growth. Besides, scanning electron microscopy with energy dispersive X-ray (SEM-EDX) and Fourier transform infrared (FTIR) spectroscopy confirmed the functional groups and surface properties and probable participation of multiple mechanisms including ion exchange, electrostatic attraction, and ligand complexation for phosphate and ammonium removal. Overall, these results offer a promising way to utilize AD for high-end applications in wastewater treatment.

Modified nanomagnetite silica core shell with new Cu (II) N,N‐ chelating complex as an efficient and reusable catalyst in the C‐N bond formation

In this article, initially, the TCTCl (DiPrAEA)2 ligand was synthesized and characterized by Fourier transform infrared (FT‐IR), X‐ray crystallography, 1H‐ and 13C‐NMR spectroscopy, and elemental analysis. The crystallographic structure data for the ligand has been deposited at the Cambridge Crystallographic Data Centre (CCDC No. 2282732). Then, using of this novel multidentate ligand, a novel and stable copper (II) nanocatalyst complex was synthesized by anchoring copper (II) acetate onto the core‐shell surface (Fe3O4@SiO2) via the novel multidentate ligand TCTCl (DiPrAEA)2. The successful synthesis of the Fe3O4@SiO2‐NH‐TCT (DiPrAEA)2‐Cu (II) nanocatalyst was confirmed by employing physicochemical techniques such as FT‐IR, X‐ray diffraction, ultraviolet‐visible, thermogravimetric analysis, X‐ray photoelectron spectroscopy, Brunauer–Emmett–Teller, energy‐dispersive X‐ray, dynamic light scattering, inductively coupled plasma, transmission electron microscopy, field emission scanning electron microscopy, and vibrating sample magnetometer. Subsequently, this novel copper (II) nanomagnetic complex was evaluated as an efficient, reusable, and novel catalyst for the formation of C‐N bonds via the Ullmann coupling reaction of aryl halides and nitrogen‐containing compounds. The influence of this novel TCTCl (DiPrAEA)2 ligand on the reactivity and stability of the nanomagnetic copper complex was visible in the Ullmann reaction, which resulted in rapid reaction times and excellent yields, and seven times reusability.

Zn(II) and Cd(II) complexes of dithiocarbamate ligands: synthesis, characterization, anticancer, and theoretical studies

ABSTRACT A potassium 4-(ethoxycarbonyl)phenyldithiocarbamate, (4-etphdtc), and 6-ethoxybenzothiazol)-dithiocarbamate, (6-etbedtc), ligands have been isolated and four metal dithiocarbamate complexes of the type [M(4-etphdtc)2] and [M(6-etbedtc)2] (M = Zn, Cd;) were synthesized and characterized by elemental analysis and spectroscopic techniques (FT-IR,1H and13C{1H}-NMR, HRMS, UV–vis). Thermogravimetric studies of all four complexes were performed and the final product of the thermal decomposition was metal sulfides. The theoretical study with density functional theory (DFT) has been utilized to optimize the structures of the complexes for HOMO–LUMO energy calculation. Non-bonding orbitals (NBO) analysis was performed to determine the numerous hyper-conjugative interactions responsible for the stability of the compound. In addition, Molecular Electrostatic Potential (MEP) analysis was conducted to identify the compounds’ electron-rich, electron-poor, reactive sites, and bonding characteristics. The Electron Localization Function (ELF), and AIM Charges are also calculated. In vitro cytotoxicity, the complexes were examined against cervical cancer cells (HeLa) to assess their reactivity. Molecular docking studies were conducted to confirm the biological activity by simulating the binding orientation and affinity of the ligands and their complexes against VEGFR-2 kinase, The investigated ligands interact with the binding site as; hydrophilic (Lys868, Glu885, His1026, Cys1045, and Asp1046) and hydrophobic (Val889 and Leu889) for 4-etphdtc; hydrophilic (Lys868, Glu885, Cys1045, and Asp1046) and hydrophobic (Val889, Leu889, Leu1035, and Phe1047) for 6-etphdtc. The calculated binding free energy values for Zn(4-etphdtc)2 and Zn(6-etphdtc)2complexes are – 9.700 kcal/mol, – 10.003 kcal/mol, respectively.

A Phenotypic Approach to the Discovery of Potent G-Quadruplex Targeted Drugs.

G-quadruplex (G4) sequences, which can fold into higher-order G4 structures, are abundant in the human genome and are over-represented in the promoter regions of many genes involved in human cancer initiation, progression, and metastasis. They are plausible targets for G4-binding small molecules, which would, in the case of promoter G4s, result in the transcriptional downregulation of these genes. However, structural information is currently available on only a very small number of G4s and their ligand complexes. This limitation, coupled with the currently restricted information on the G4-containing genes involved in most complex human cancers, has led to the development of a phenotypic-led approach to G4 ligand drug discovery. This approach was illustrated by the discovery of several generations of tri- and tetra-substituted naphthalene diimide (ND) ligands that were found to show potent growth inhibition in pancreatic cancer cell lines and are active in in vivo models for this hard-to-treat disease. The cycles of discovery have culminated in a highly potent tetra-substituted ND derivative, QN-302, which is currently being evaluated in a Phase 1 clinical trial. The major genes whose expression has been down-regulated by QN-302 are presented here: all contain G4 propensity and have been found to be up-regulated in human pancreatic cancer. Some of these genes are also upregulated in other human cancers, supporting the hypothesis that QN-302 is a pan-G4 drug of potential utility beyond pancreatic cancer.

Exploring the Enhanced Oxidation Potential through Green Synthesis of Ofloxacin–Silver Complex: Investigating Silver and Ofloxacin Interaction at Varied Concentrations

The purpose for this work is to synthesize ofloxacin–Silver(I) complex with the highest oxidation potential in liquid state with green methodology. Initially, we investigated the complexation of the OFL ligand with silver ions using UV-visible spectrophotometry, differential pulse wave voltammetry, and electrochemical impedance spectroscopy. The UV-visible results indicated the interaction between OFL and Ag+ through a complexation reaction. Notably, the peak corresponding to OFL oxidation at 0.98 V showed a significant increase in the presence of silver, leading to an oxidation potential shift towards positive values attributed to the bond formation between the OFL and Ag+. In terms of structural characterization, various spectroscopic analyses were employed, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, and scanning electron microscopy. The OFL–Ag+ complex formation was confirmed by the appearance of two distinct sharp bands at 547 and 950 cm−1 in the FTIR spectra. The average particle diameter of the OFL–Ag+ complex was determined to be 187.5 nm. This complex, synthesized as a brown solid powder soluble in water, exhibited the highest oxidation potential of 1.32 V. Hence, it holds promise for potential application in antibacterial activity.

Hydrogeochemical and rare earth element properties of geothermal waters and the use of abandoned oil wells in Diyarbakır

Türkiye is one of the most tectonically active regions in the world. Diyarbakır, which was chosen as the study area, is located in the south-eastern Anatolian region of Türkiye and also in the south of the Bitlis-Zagros Suture Zone (BZSZ). Some of the geothermal resources in Diyarbakır are actively exploited. The temperature of Çermik geothermal waters was recorded at 40–51 °C by MTA (General Directorate of Mineral Research and Exploration) between 2010 and 2014. However, subsequent measurements conducted following the Kahramanmaraş earthquake (Mw: 7.7 on 6 February 2023) revealed that the surface temperature of geothermal fluids had increased to between 52 and 56 °C. Previous studies have indicated that there are also many abandoned oil wells in the region where the wellhead temperatures are around 107 °C. As a result of hydrogeochemical analyses, deep circulating geothermal waters such as Çermik have Na-HCO3 composition, while shallow circulating and mixed cold surface waters such as Çınar, Bismil and Sur have Na-Ca-Cl-HCO3 composition. According to the chalcedony geothermometer results, the reservoir temperatures in the study area vary between 90 °C and 173 °C. REY (Rare Earth Elements and Yttrium) results show that geothermal fluids in the study area have negative cerium (Ce), europium (Eu) and yttrium (Y) anomalies. The negative Ce anomaly indicates that the colder aquifers are close to oxygen-rich surface waters and thermal fluids interact with Karacadağ volcanic rocks. Eu anomalies in groundwater are controlled by preferential mobilisation of Eu2+ during water-rock interaction compared to Eu3+, and negative Eu anomalies indicate leakage of geothermal fluids from granites. The Y/Ho values of the thermal fluids in the study area are between 30 and 40. This value is due to the active contribution of fluorine during the mobilisation of REY as a fluoride or fluorocarbonate ligand complex, causing Y to behave as a heavy pseudolanthanide. δ18O and δ2H isotope values show that the geothermal waters in the study area are of meteoric origin. The obtained results reveal that Diyarbakir province has a geothermal potential and usage potential can be increased by using the abandoned oil wells.

Exploration of iron(III) complexes with bidentate N, O-donor Schiff base ligands through synthesis, characterization, DFT, and antibacterial studies

Iron(III) complexes [Fe(SBn)2(H2O)2]NO3 (1, 2) (n=1 or 2) were synthesized via a reaction of Fe(NO3)3.9H2O with N, O-donor Schiff-base ligands (HSBn) in a ratio of 1:2 in terms of moles. Schiff-base ligands (HSBn) were synthesized when a solution of salicylaldehyde in methanol underwent reflux with aniline (HSB1) or 4-chloroaniline (HSB2) in methanol respectively. These aquated iron(III) complexes, 1 & 2 were further reacted with nitrogen-containing molecules as neutral donors (L) (such as pyridine, imidazole, and benzimidazole) in a ratio of 1 part to 2 parts by moles, yielding mixed-ligand complexes [Fe(SBn)2(L)2]NO3(3-8). The synthesized complexes were characterized by elemental analyses, mass spectrometry, and spectroscopic studies (electronic, infrared & NMR spectra), as well as measurements of magnetic susceptibility and conductance. Infrared spectra revealed that Schiff bases coordinated with iron(III) centers in bidentate and chelating mode, primarily through phenolic –O and azomethine–N groups. Electronic spectra confirmed the existence of octahedral iron(III) in a high-spin state within these complexes, consistent with assessments of magnetic susceptibility. DFT-based parameters were determined for ligands HSB1, & HSB2, and complexes 1, 2, & 8 using Gaussian 09 at the B3LYP level. Structural analysis showed slightly distorted octahedral geometry with high spin (d5) and sextet multiplicity in all complexes. The global hardness exhibited an increasing trend: HSB2 < 8 < 2 < 1 < HSB1, while chemical reactivity showed the opposite trend: HSB2 > 8 > 2 > 1 > HSB1. The antibacterial activity of ligands, HSB1 and HSB2, along with complexes 1 and 2, was evaluated against various bacterial strains. Schiff bases, HSB1 and HSB2 inhibited several strains, with complexes 1 and 2 demonstrating improved efficacy, possibly due to altered chemical properties from the complex formation. Despite lower potency than Ciprofloxacin, they offer therapeutic alternatives.

Synthesis, structural, biological applications, DFT, molecular docking studies on Fe(III), Co(II), and Ni(II) complexes incorporating 2‐(pyridin‐2‐yl)phenol and 1H‐benzimidazole‐2‐carboxylic acid

This study provides a detailed investigation into the synthesis, characterization, and biological activities of the coordination compounds FePPHBZC, CoPPHBZC, and NiPPHBZC. These compounds were synthesized with high yields by reacting chloride salts of Iron, Cobalt, or Nickel with 2‐(pyridin‐2‐yl)phenol (PPH) and 1H‐benzimidazole‐2‐carboxylic acid (BZC) in a 1:1:1 ratio. Various techniques including spectroscopic (IR, UV–vis, mass spectra), elemental analysis, conductivity, magnetic, and thermal analyses confirmed the formation and structure of these coordination compounds. Density functional theory (DFT) calculations were used to study their electronic structure, stability, and reactivity. 3D modeling revealed hexacoordinated geometries for Fe and Co complexes and a tetrahedral coordination for the Ni complex. Analysis of the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and other reactivity parameters indicated changes in reactivity upon metal coordination. Molecular Electrostatic Potential (MEP) diagrams identified electron‐rich areas prone to nucleophilic attack, important for protein interactions during docking studies. Biological evaluations demonstrated that metal–ligand complexes exhibit enhanced antimicrobial, antioxidant, and anti‐inflammatory activities compared to individual ligands, with larger inhibition zones and higher inhibitory activity. Molecular docking studies showed strong interactions between metal–ligand complexes and target proteins, suggesting potential therapeutic applications. Among them, FePPHBZC exhibited the strongest interactions, followed by CoPPHBZC and NiPPHBZC, characterized by hydrogen bonding, ionic interactions, and other non‐covalent interactions, contributing to their enhanced stability and binding affinity.

Towards Construction of the “Periodic Table” of 1-Methylbenzotriazole

Metal complexes of benzotriazole-type ligands continue to attract the intense interest of many inorganic chemistry groups around the world for a variety of reasons, including their aesthetically beautiful structures, physical properties and applications. 1-methylbenzotriazole (Mebta) is the N-substituted archetype of the parent 1H-benzotriazole. The first attempt to build a “periodic table” of Mebta, which includes its complexes with several metal ions, is described in this work. This, at first glance, trivial ligand has led to interesting results in terms of the chemistry, structures and properties of its metal complexes. This work reviews the to-date published coordination chemistry of Mebta with Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(I), Cu(II), Zn(II), Pd(II), Au(I) and {UVIO2}2+, with emphasis on their preparations, reactivity, structures and properties. Unpublished results from our group comprising other Co(II), Ni(II), Cu(II) and Zn(II) complexes, as well as Cd(II), Hg(II), Ag(I), In(III) and Sn(IV) ones are briefly reported. Mebta can also provide access to 1D and 3D heterometallic thiocyanato-bridged Co(II)/Hg(II) and Ni(II)/Hg(II) compounds. In almost all cases, Mebta behaves as a monodentate ligand with the nitrogen of position 3 of the azole ring as the donor atom. However, there are two copper complexes in which this molecule adopts a bidentate bridging coordination behavior. Our efforts to complete the “periodic table” of Mebta are continued.

Antituberculosis, antimicrobial, antioxidant, cytotoxicity and anti-inflammatory activity of Schiff base derived from 2,3-diaminophenazine moiety and its metal(II) complexes: structural elucidation, computational aspects, and biological evaluation

Abstract Enticed by the present scenario of infectious diseases, four new Co(II), Ni(II), Cu(II), and Cd(II) complexes of Schiff base ligand were synthesized from 6,6′-((1E-1′E)(phenazine-2,3-dielbis(azanylidene)-bis-(methanylidene)-bis-(3-(diethylamino)phenol)) (H 2 L) to ascertain as effective drug for antituberculosis, anti-inflammatory, antioxidant, cytotoxic and antimicrobial activities. The organic ligand and its metal(II) complexes were characterized by numerous physical and spectroscopic methods, which showed that the complexes have a general formula, [ML], (where M = Co(II) (C1), Ni(II) (C2), Cu(II) (C3) and Cd(II) (C4)), for metal complexes have been proposed and have a square planar geometry, are amorphous in nature, and are thermally stable. Data highlight obtained from activity testing against tuberculosis, inflammation, and oxidants that all compounds are significantly active against these symptoms. Also, was to evaluate the effectiveness of various compounds against bacterial and fungal strains. Specifically, four bacterial strains (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) and two fungal strains (Aspergillus flavus and Candida albicans) were tested and compared to the results of some standard drugs. The results revealed that compound C4 was more effective against bacterial strains than the comparison standard drugs. In addition, C3 was found to be the most effective of the comparison antibiotics against fungi, while the other compounds showed moderate antifungal activity. Moreover, to support the vitro results, certain computational studies as molecular docking studies, DFT, MESP, and AMEDT were also conducted to confirm the effectiveness of an organic ligand and its complexes against tuberculosis. These studies revealed that C4 is the most effective against tuberculosis and has desirable effects such as absorption, no degradation and no hepatotoxicity, etc.

Bidentate bromhexine drug coordination modes with various transition metal ions: Synthesis, characterization, and in vitro antibacterial and anti-breast cancer activity tests

BackgroundBromhexine (BHX) is a mucolytic drug used in treatment the respiratory disorders which are associated with excessive or viscid mucus. Transition metal complexes have made tremendous progress in the treatment of a variety of human ailments, according to reported articles. Transition metal complexes are being developed as medications with a lot of effort. Metal complexes can form a variety of coordination geometries, giving them distinct forms. So, binary metal complexes of bromhexine drug have been prepared to enhance the biological activity and stability of the free drug. MethodsA new series of binary complexes with bromhexine drug (BHX) has been prepared with some transition metal ions namely Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II). Elemental analyses, FT-IR, mass spectrometry, thermal studies and UV-Vis spectra have been used to characterize and structurally elucidate the produced metal complexes. Antibacterial activity has been tested for the ligand and metal complexes against a variety of pathogenic bacterial species (Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus). In addition, the ligand has been tested for anticancer efficacy against the MCF-7 breast cancer cell line, as opposed to binary metal complexes. The binding orientation or conformation of the free BHX ligand and Co(II) complex in the active region of the protein of crystal structure of Escherichia coli (PDB ID: 3T88) and Pseudomonas aeruginosa (PDB ID: 6NE0) has been performed using molecular docking studies. ResultsThe BHX ligand coupled in neutral bidentate mode to the metal ions, according to FT-IR and 1H-NMR spectral results. The molar conductivity measurements of the complexes in DMF proved the electrolytic nature of all binary complexes. Co(II) complex showed the highest inhibition zone diameter against S. aureus, E. coli and P. aeruginosa. Zn(II) complex had the greatest inhibitory effect against P. aeruginosa and B. subtilis. Also, Cd(II) chelate appeared high efficacy as antibacterial agent against Pseudomonas aeruginosa and Staphylococcus aureus. ConclusionAll the output data conjugated to confirm the octahedral geometry of the metal complexes. The biological findings revealed that metal complexes can be more active than the free BHX ligand. Against MCF-7 cell line, Cd(II)-L complex is highly active complex (4.95 µg/mL) but BHX free drug is the most active compound (3.96 µg/mL).

Synthesis, spectral analysis, XRD, molecular docking simulation of dithranol and glycine mixed ligand complexes and their potential role in suppressing breast cancer cells via down‐regulating the expression of protein metalloproteinase‐9

Five novel complexes of nickel (II)(1), zinc (II)(2), zirconium (IV)(3), lanthanum (III)(4), thorium (IV)(5), with the dithranol (Dithr) ligand and glycine (Gly) were synthesized and characterized. Their structures were investigated using elemental analysis, molar conductance (Λ), magnetic studies (μeff), spectroscopic methods (FT‐IR, UV–Vis., 1H NMR, XRD), mass spectrometry, TG/DTG and DTA. Findings revealed that Dithr was chelated via two hydroxyl oxygen atoms and carbonyl group while, Gly chelated through carboxylic oxygen and nitrogen atom. All complexes appeared with molar ratio 1:1:1 (M:Dithr:Gly) and were electrolytes with 1:1 for (1), (2) and (3) complexes, 1:2 for (4) complex, and 1:3 for (5) complex according to elemental analysis and molar conductivity data. All metal‐chelates, except Th (IV)‐complex, were confirmed to have lattice water molecules based on their thermal behavior. Average crystalline size of all compounds was calculated using XRD analysis and found in the range 35.50–55.57 nm, indicating the compounds existed as nanocrystalline structure, except zirconium (IV) complex. Then, we studied cytotoxic effects of our synthetic drugs on the survival of an aggressive‐breast‐cancer‐histotype“66cl‐4.” Given its involvement in cancer‐metastasis, matrix‐metalloproteinase‐(MMP)‐9 protein expression was evaluated using western‐blotting‐assays. Th(IV)‐complex emerged as the most effective option in inhibiting cancer‐cells‐proliferation (IC50: 9.39 μM), and suppressed expression MMP‐9 levels by 86%, at 25 μM dose, and drug‐binding‐affinity was interpreted via molecular modeling.

Molecular docking, MD simulation, and MMGBSA-binding free energy estimation study identify antibiotic analogs as potential antimalarials targeting housekeeping proteins of Plasmodium falciparum apicoplast

ABSTRACT Plasmodium falciparum exclusively harbours a non-photosynthetic plastid-like organelle called ‘apicoplast,’ crucial for survival. The apicoplast genome resembles chloroplasts, albeit much reduced at 35 kb. The housekeeping functions of the apicoplast are similar to prokaryotes, and several antibiotics have been reported to kill the malaria parasite by targeting its housekeeping functions. However, a significant structural difference between bacterial and apicoplast housekeeping proteins promotes the discovery of antibiotic analogs specifically targeting apicoplast proteins. In this study, we used a high-throughput virtual screening approach to analyze 80% of structurally similar antibiotic analog libraries against five protein targets, including histone-like protein (PfHU), gyrase A subunit (PfGyrA), RNA polymerase β subunit (PfRpoβ), elongation factor G (PfEF-G), and elongation factor Tu (PfEF-Tu) involved in different housekeeping functions of the apicoplast. This computational screening identified molecules with better binding affinities than those antibiotics shown to have antimalarial activities, suggesting they may be more potent antimalarial compounds. The molecular dynamics simulations study revealed stable conformational changes with strong hydrogen bonds between the protein–ligand complexes. The top-hit antibiotic analogs exhibit favourable drug-like characteristics, making them promising candidates for future clinical studies. We propose further biochemical and phenotypic testing of these antibiotic analogs to develop more effective apicoplast-targeting antimalarials.

In silico exploration of potential PRKG1 Inhibitors: A comprehensive study using MTIOPEN Screening, molecular Docking, and MD simulation

The enzyme protein kinase G1 (PRKG1) plays a crucial role in cellular signaling pathways such as smooth muscle relaxation, neuronal signaling, and platelet aggregation. The dysregulation of PRKG1 leads to different diseases, making it a promising drug target. In this study, we employed a comprehensive in silico strategy to explore potential inhibitors of PRKG1 by using the crystal structure of the PRKG1 protein. The active site of PRKG1 protein was parameterized within a three-dimensional grid box. The 100 hit compounds identified during virtual screening were docked to the prepared PRKG1 receptor to predict binding affinities. The top ten compounds were chosen, and their binding affinities ranged from −10.734 to −10.398 kcal/mol. Finally, a 200 ns long simulation was run to confirm the stability of the protein–ligand complexes at the binding sites of the two top compounds against the PRKG1 receptor. All these findings suggest that the selected compounds can serve as potential compounds to inhibit the PRKG1 function in biological assays.

In-silico study unveils potential phytocompounds in Andrographis paniculata against E6 protein of the high-risk HPV-16 subtype for cervical cancer therapy

Despite therapeutic advancements, cervical cancer caused by high-risk subtypes of the human papillomavirus (HPV) remains a leading cause of cancer-related deaths among women worldwide. This study aimed to discover potential drug candidates from the Asian medicinal plant Andrographis paniculata, demonstrating efficacy against the E6 protein of high-risk HPV-16 subtype through an in-silico computational approach. The 3D structures of 32 compounds (selected from 42) derived from A. paniculata, exhibiting higher binding affinity, were obtained from the PubChem database. These structures underwent subsequent analysis and screening based on criteria including binding energy, molecular docking, drug likeness and toxicity prediction using computational techniques. Considering the spectrometry, pharmacokinetic properties, docking results, drug likeliness, and toxicological effects, five compounds—stigmasterol, 1H-Indole-3-carboxylic acid, 5-methoxy-, methyl ester (AP7), andrographolide, apigenin and wogonin—were selected as the potential inhibitors against the E6 protein of HPV-16. We also performed 200 ns molecular dynamics simulations of the compounds to analyze their stability and interactions as protein–ligand complexes using imiquimod (CID-57469) as a control. Screened compounds showed favorable characteristics, including stable root mean square deviation values, minimal root mean square fluctuations and consistent radius of gyration values. Intermolecular interactions, such as hydrogen bonds and hydrophobic contacts, were sustained throughout the simulations. The compounds displayed potential affinity, as indicated by negative binding free energy values. Overall, findings of this study suggest that the selected compounds have the potential to act as inhibitors against the E6 protein of HPV-16, offering promising prospects for the treatment and management of CC.

Phosphorescent Pt(II) complexes of C^N^N type tridentate ligands augmented for liquid crystallinity

ABSTRACT Using the cyclometallation reaction, Pt(II) complexes of diarylbipyridynic ligands bearing alkoxy-groups were prepared and then modified with phenylаcetylene derivatives. The target compounds were characterised by absorption and emission spectroscopy, differential scanning calorimetry, small angle X-ray scattering, polarisation microscopy, and DTF calculations. The mesomorphic properties of the obtained compounds were investigated and their liquid crystallinity was confirmed.

Evolution of bioactive 3, 4-dihydropyrimidin-2(1H)-ones by an efficient heterogeneous Ni-phen MCM-41 mixed ligand complex under green path

Evolution of bioactive 3, 4-dihydropyrimidin-2(1H)-ones by an efficient heterogeneous Ni-phen MCM-41 mixed ligand complex under green path

Sporadic binding of perchlorate and dicyanamide ions in trinuclear CuII2NiII complexes with a reduced di-Schiff base ligand: Synthesis, structures and spectral properties

Two new unusual trinuclear linear heterometallic complexes, [(CuLR)2Ni(ClO4)2{CO(CH3)2}2]·0.17H2O (1) and [(CuLR)2Ni(N3C2)2(0.5CH3OH)2] (2) have been synthesized by using [CuLR] as a “metalloligand” (where H2LR=N,N′-bis(2-hydroxybenzyl)-1,3-propanediamine) in presence of anions perchlorate and dicyanamide, respectively. Both the complexes have been diagnosed by elemental analysis, spectroscopic investigations, and single crystal XRD study. In these complexes, the terminal “ligand complex” [CuLR] coordinates to the central nickel atom via double phenoxido oxygen atoms bridge, resulted in a linear trinuclear structures. In both structures, the anions (perchlorate for 1 and dicyanamide for 2) coordinate to the terminal Cu(II) centers of the trinuclear unit (Cu(II)-Ni(II)-Cu(II)) to complete the distorted octahedral geometry around Cu(II); whereas the central Ni(II) metal ion remains in square planar geometry. The binding of perchlorate or dicyanamide to the terminal Cu(II) instead of central Ni(II) ion is rather unusual compared to the complexes of analogous unreduced species.

Catalytic Investigation of ε-caprolactone Polymerization through Schiff BaseTitanium (IV) Complexes

Background: The ring-opening polymerization (ROP) reaction has provided an efficient and convenient route to prepare polyesters of high molecular weight, low polydispersity index, and high optical purity. The poly(ε-caprolactone) (PCL) and poly(lactide) (PLA) were prepared through ROP reaction of ε-caprolactone and D, L-lactide, respectively. These compounds have a huge industrial demand and become an interest among the scientific community to develop more economically and eco-friendly catalysts for ROP reactions. Methods: Three Schiff base ligands, 2-((benzo[d]thiazole-2-ylimino)methyl)phenol, L1; 2-(1-benzo[d]thiazole-2-ylimino)ethyl)phenol, L2; and 2- ((benzo[d]thiazole-2-ylimino)methyl)-5-methoxyphenol, L3; were prepared by the reaction of 2-aminobenzothiazole with 2-hydroxybenzaldehyde, 2-hydroxyacetophenone and 2-hydroxy-4-methoxybenzaldehyde in 1:1 molar ratio. In anticipation of interesting stereochemistry, reactivity, and catalytic potential against ε-caprolactone polymerization, three Titanium(IV) complexes (1 – 3) of these Schiff base ligands were synthesized. All the prepared compounds were characterized by elemental analysis, molar conductance, FT-IR, UV-Vis, 1H-NMR, 13C{1H}-NMR and FAB-Mass spectroscopic technique. Geometry was optimized with the help of DFT. Results: Complex 3 gives a much higher yield (87.7%) in comparison to 1 and 2. The order of catalytic efficiency for complexes is 3&gt;1&gt;2. With the increase in temperature, the % yield was found to decrease, and results are in support of moderate to good potency of synthesized catalysts. Conclusion: Complexes were screened for catalytic potency against ε-Caprolactone polymerization reaction. A most plausible mechanism for the polymerization was also proposed.

New nano-complexes targeting protein 3S7S in breast cancer and protein 4OO6 in liver cancer investigated in cell line

Cancer, a lethal ailment, possesses a multitude of therapeutic alternatives to combat its presence, metal complexes have emerged as significant classes of medicinal compounds, exhibiting considerable biological efficacy, especially as anticancer agents. The utilization of cis-platin in the treatment of various cancer types, including breast cancer, has served as inspiration to devise novel nanostructured metal complexes for breast cancer therapy. Notably, homo- and hetero-octahedral bimetallic complexes of an innovative multifunctional ether ligand (comprising Mn(II), Ni(II), Cu(II), Zn(II), Hg(II), and Ag(I) ions) have been synthesized. To ascertain their structural characteristics, elemental and spectral analyses, encompassing IR, UV–Vis, 1H-NMR, mass and electron spin resonance (ESR) spectra, magnetic moments, molar conductance, thermal analysis, and electron microscopy, were employed. The molar conductance of these complexes in DMF demonstrated a non-electrolytic nature. Nanostructured forms of the complexes were identified through electron microscopic data. At ambient temperature, the ESR spectra of the solid complexes exhibited anisotropic and isotropic variants, indicative of covalent bonding. The ligand and several of its metal complexes were subjected to cytotoxicity testing against breast cancer protein 3S7S and liver cancer protein 4OO6, with the Ag(I) complex (7) evincing the most potent effect, followed by the Cu(II) with ligand (complex (2)), Cis-platin, the ligand itself, and the Cu(II)/Zn(II) complex (8). Molecular docking data unveiled the inhibitory order of several complexes.