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1.
Dalton Trans ; 50(6): 2253-2267, 2021 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-33506238

RESUMO

Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)2]n, (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 Å. Primarily, in vitro DNA interaction studies revealed a metallopolymer which possesses high DNA binding propensity and cleaves DNA via the oxidative pathway. We further analysed its potential on cancerous cells MCF-7, HeLa, A549, and two non-tumorigenic cells HEK293 and HBE. The selective cytotoxicity potential of PCU1 against A549 cells driven us to examine the mechanistic pathways comprehensively by carrying out various assays viz, cell cycle arrest, Annexin V-FTIC/PI assay, autophagy, intercellular localization, mitochondrial membrane potential 'MMP', antiproliferative assay, and gene expression of TGF-ß and MMP-2.

2.
Nanomaterials (Basel) ; 10(12)2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-33266260

RESUMO

In the present study, mesoporous silica nanoparticles (MSNs) synthesized through sol-gel process and calcined at 600 °C were further surface functionalized by a copolymer chain of L-ascorbic acid (AS) and polyaniline (PAni) by in situ free radical oxidative polymerization reaction. The surface modification of MSNs by AS-g-PAni was confirmed by using various analytical techniques, namely FTIR, XRD, SEM-EDX, TEM and AFM. The composition of AS-g-PAni@MS was found to be composed of C (52.53%), N (20.30%), O (25.69%) and Si (1.49%), with 26.42 nm as the particle size. Further, it was applied for the adsorption of crystal violet (CV) dye under batch, as well as fixed bed method. RSM-BBD was taken into consideration, to optimize the various operational parameters effecting the adsorption through batch method. To explore maximum efficiency of the material, it was further subjected to adsorption of CV under fixed bed method, using the variable bed heights of 3.7, 5.4 and 8.1 cm. Based on high value of regression coefficient (R2) and low value of RMSE given as (0.99, 0.02) for 3.7 cm, (0.99, 0.03), the breakthrough data were very well defined by the Thomas model, with optimum concurrence of stoichiometric adsorption capacity values. The external mass transfer equilibrium data were well fitted by the Langmuir model, with maximum monolayer adsorption capacity of 88.42 mg g-1 at 303K, 92.51 mg g-1 at 313 K, 107.41 mg g-1 at 313 K and 113.25 mg g-1 at 333 K. The uptake of CV by AS-g-PAni@MS was well defined by pseudo second order model with rate constant K2 = 0.003 L mg-1 min-1 for 50 and 0.003 L mg-1 min-1 for 60 mg L-1 CV. The adsorption reaction was endothermic with enthalpy (ΔH) value of 3.62 KJ mol-1 and highly efficient for treatment of CV-contaminated water for more the five consecutive cycles.

3.
Molecules ; 25(24)2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339423

RESUMO

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2-sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV-Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric-derivative thermogravimetric analysis, indicating its stability up to 95 °C.

4.
Molecules ; 25(24)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348597

RESUMO

Epoxy resins (EP) have been used as a thermos-setting material in the field of coating, casting, bonding agent, and laminating. However, a major drawback associated with its use is the lack of good flaming properties, and it is responsible for heavy smoke along with hazardous gases considerably limiting its uses in various fields. In this study, N-ethanolamine triazine-piperizine, a melamine polymer (ETPMP), was established as a new charring-foaming agent and was successfully synthesized with ethanolamine, piperizine, cyanuric chloride, and melamine as precursor molecules via the nucleophilic substitution reaction method. Elemental analysis and Fourier transform infrared (FTIR) spectroscopy analysis were applied to approve the synthesis of ETPMP and confirmation of its structure and characterization. The epoxy coating of intumescent flame retardant (IFR) was equipped by introducing ETPMP, ammonium polyphosphate (APP), and copper oxide (CuO) in multiple composition ratios. CuO was loaded at various amounts into the IFR-coating system as a synergistic agent. The synergistic action of CuO on IFR coatings was scientifically examined by using different analytical tests such as vertical burning test (UL-94V), limited oxygen index (LOI), thermal gravimetric analysis (TGA), cone calorimeter, and scanning electron microscope (SEM). The results showed that small changes in the amount of CuO expressively amplified the LOI results and enhanced the V-0 ratings in the UL-94V test. The TGA data clearly demonstrate that the inclusion of CuO can transform the thermal deprivation behavior of coatings with a growing char slag proportion with elevated temperatures. Information from cone calorimeter data affirmed that CuO can decrease the burning factors by total heat release (THR) together with peak heat release rate (PHRR). The SEM images indicated that CuO can enrich the power and compression of the intumescent char that restricts the movement of heat and oxygen. Our results demonstrate a positive influence of CuO on the epoxy-headed intumescent flame retardant coatings.

5.
Antibiotics (Basel) ; 9(11)2020 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-33227950

RESUMO

Antibiotic resistance is one of the major current global health crises. Because of increasing contamination with antimicrobials, pesticides, and heavy metals, the aquatic environment has become a hotspot for emergence, maintenance, and dissemination of antibiotic and heavy metal resistance genes among bacteria. The aim of the present study was to determine the co-resistance to quinolones, ampicillin, and heavy metals among the bacterial isolates harboring extended-spectrum ß-lactamases (ESBLs) genes. Among 73 bacterial strains isolated from a highly polluted stretch of the Yamuna River in Delhi, those carrying blaCTX-M, blaTEM, or blaSHV genes were analyzed to detect the genetic determinants of resistance to quinolones, ampicillin, mercury, and arsenic. The plasmid-mediated quinolone resistance (PMQR) gene qnrS was found in 22 isolates; however, the qnrA, B, C, and qnrD genes could not be detected in any of the bacteria. Two variants of CMY, blaCMY-2 and blaCMY-42, were identified among eight and seven strains, respectively. Furthermore, merB, merP, merT, and arsC genes were detected in 40, 40, 44, and 24 bacterial strains, respectively. Co-transfer of different resistance genes was also investigated in a transconjugation experiment. Successful transconjugants had antibiotic and heavy metal resistance genes with similar tolerance toward antibiotics and heavy metals as did their donors. This study indicates that the aquatic environment is a major reservoir of bacteria harboring resistance genes to antibiotics and heavy metals and emphasizes the need to study the genetic basis of resistant microorganisms and their public health implications.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 247: 119156, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33189980

RESUMO

A diaminobenzophenone Schiff base derived probe 1, was synthesized and structure elucidation was carried out by spectroscopic studies viz., FT-IR, UV-vis, 1H, and 13C NMR and mass spectrometry. The sensing phenomenon with different metal ions (Cr3+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+) was investigated by employing absorption and fluorescence titrations, which demonstrated that probe 1 exhibited selective fluorescent sensing behavior towards Fe2+ ion among various other metal ions. The porobes selceteclivity towards Fe2+ was also examined by colorimetric assay which revealed a change in the color from light yellow to brown upon addition of Fe2+ ion. A remarkable increase in the fluorescence intensity of probe 1 was observed towards Fe2+ ion, which was found to be associated with the inhibition of photoinduced electron-transfer (PET) and CN isomerization processes, respectively. The chemosensor exhibited an association constant value of 6.173 × 107 M-2 as determined by using non-linear least square fit data. Job's plot calculated the binding stoichiometry, and the sensing phenomenon of Fe2+ towards the probe was further supported by Density Functional Theory (DFT) calculations and 1H NMR studies. The detection limit of probe 1 was found to be 0.0363 µM, which is below the permissible limits according to the WHO guideline (5 µM) for Fe2+ ions in the drinking water. Furthermore, the practical application of probe 1 was studied by analyzing the content of Fe2+ in different water samples.

7.
Nanomaterials (Basel) ; 10(11)2020 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-33171741

RESUMO

Water pollution caused by metal contamination is of serious concern. Direct determination of trace metal ions in real water samples remains challenging. A sample preparation technique is a prerequisite before analysis. Herein, we report the facile water-based hydrothermal synthesis of cadmium sulfide nanoparticles on a cellulose nanofiber surface to prepare a new adsorbent material. Field emission scanning electron microscopy, high-resolution tunneling electron microscopy, elemental mapping and X-ray photoelectron microscopy were used to characterize the surface morphology, structural determination, elemental composition and nature of bonding. The nanoadsorbent (cadmium-sulfide-decorated cellulose nanofibrils (CNFs@CdS)) was employed for the solid-phase extraction and determination of trace Hg(II) from aqueous media. The experimental conditions were optimized systematically and the data show a good Hg(II) adsorption capacity of 126.0 mg g-1. The CNFs@CdS adsorbent shows the selective removal of Hg(II) accordingly to the hard and soft acid-base theory of metal-ligand interaction. A high preconcentration limit of 0.36 µg L-1 was obtained with a preconcentration factor of 580. The lowest level of trace Hg(II) concentration, which was quantitatively analyzed by the proposed method, was found to be 0.06 µg L-1. No significant interferences from the sample matrix were observed in the extraction of Hg(II). Analysis of the standard reference material (SRM 1641d) was carried out to validate the proposed methodology. Good agreement between the certified and observed values indicates the applicability of the developed methodology for the analysis of Hg(II) in tap water, river water and industrial wastewater samples.

8.
J Mol Model ; 26(12): 341, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33200284

RESUMO

HER-2 type breast cancer is one of the most aggressive malignancies found in women. Tucatinib is recently developed and approved as a potential medicine to fight this disease. In this manuscript, we present the gross structural features of this compound and its reactivity and wave function properties using computational simulations. Density functional theory was used to optimise the ground state geometry of the molecule and molecular docking was used to predict biological activity. As the electrons interact with electromagnetic radiations, electronic excitations between different energy levels are analysed in detail using time-dependent density functional theory. Various intermolecular and intermolecular interactions are analysed and reaction sites for attacking electrophiles and nucleophiles identified. Information entropy calculations show that the compound is inherently stable. Docking with COVID-19 proteins show docking score of - 9.42, - 8.93, - 8.45 and - 8.32 kcal/mol respectively indicating high interaction between the drug and proteins. Hence, this is an ideal candidate to study repurposing of existing drugs to combat the pandemic.


Assuntos
Antineoplásicos/química , Antivirais/química , Betacoronavirus/química , Elétrons , Oxazóis/química , Inibidores de Proteases/química , Piridinas/química , Quinazolinas/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Antineoplásicos/metabolismo , Antivirais/metabolismo , Betacoronavirus/enzimologia , Sítios de Ligação , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Reposicionamento de Medicamentos , Humanos , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Oxazóis/metabolismo , Inibidores de Proteases/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estrutura Secundária de Proteína , Piridinas/metabolismo , Teoria Quântica , Quinazolinas/metabolismo , Termodinâmica , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/metabolismo
9.
Polymers (Basel) ; 12(11)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33212915

RESUMO

Ethylenediamine modified Ammonium polyphosphate (EDA-MAPP), and Charring-Foaming Agents (CFA) was prepared via a simple chemical approach and further utilizes for the preparation of Epoxy resin based intumescent flame retardation coatings. The ratio belongs to MAPP and CFA was fixed at 2:1 ratio. Comparative thermo gravimetric analysis TGA study of Modified Ammonium polyphosphate (MAPP) and Ammonium polyphosphate (APP) investigated. Sb2O3 was introduced into flame retardation coating formulation at various amounts to evaluate the synergistic action of Sb2O3 along with flame retardant coating system. The synergistic action of Sb2O3 on flame retardation coating formulation was studied by vertical burning test (UL-94V), thermo gravimetric analysis (TGA), Limited Oxygen Index (LOI), and Fourier Transform Infra-Red spectroscopy (FTIR). The UL-94V results indicated that adding Sb2O3 effectively increased flame retardancy and meets V-0 ratings at each concentration. The TGA results revealed that the amalgamation of Sb2O3 at each concentration effectively increased the thermal stability of the flame retardant coating system. Cone-calorimeter study results that Sb2O3 successfully minimized the combustion parameters like, Peak Heat Release Rate (PHRR), and Total Heat Release (THR). The FTIR result shows that Sb2O3 can react with MAPP and generates the dense-charred layer which prevents the transfer of heat and oxygen.

10.
Polymers (Basel) ; 12(11)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33213104

RESUMO

We report the facile hydrothermal synthesis of polyaniline (PANI)-modified molybdenum disulfide (MoS2) nanosheets to fabricate a novel organic-inorganic hybrid material. The prepared 3D nanomaterial was characterized by field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction studies. The results indicate the successful synthesis of PANI-MoS2 hybrid material. The PANI-MoS2 was used to study the extraction and preconcentration of trace mercury ions. The experimental conditions were optimized systematically, and the data shows a good Hg(II) adsorption capacity of 240.0 mg g-1 of material. The adsorption of Hg(II) on PANI-MoS2 hybrid material may be attributed to the selective complexation between the-S ion of PANI-MoS2 with Hg(II). The proposed method shows a high preconcentration limit of 0.31 µg L-1 with a preconcentration factor of 640. The lowest trace Hg(II) concentration, which was quantitatively analyzed by the proposed method, was 0.03 µg L-1. The standard reference material was analyzed to determine the concentration of Hg(II) to validate the proposed methodology. Good agreement between the certified and observed values indicates the applicability of the developed method for Hg(II) analysis in real samples. The study suggests that the PANI-MoS2 hybrid material can be used for trace Hg(II) analyses for environmental water monitoring.

11.
Int J Mol Sci ; 21(22)2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33233673

RESUMO

A new double-open-cubane core Cd(II)-O-Cu(II) bimetallic ligand mixed cluster of type [Cl2Cu4Cd2(NNO)6(NN)2(NO3)2].CH3CN was made available in EtOH/CH3CN solution. The 1-hydroxymethyl-3,5-dimethylpyrazole (NNOH) and 3,5-dimethylpyrazole (NNH) act as N,O-polydentate anion ligands in coordinating the Cu(II) and Cd(II) centers. The structure of the cluster in the solid state was proved by XRD study and confirmed in the liquid state by UV-vis analysis. The XRD result supported the construction of two octahedral and one square pyramid geometries types around the four Cu(II) centers and only octahedral geometry around Cd(II) two centers. Interestingly, NNOH ligand acts as a tetra-µ3-oxo and tri-µ2-oxo ligand; meanwhile, the N-N in NNH acts as classical bidentate anion/neutral ligands. The interactions in the lattice were detected experimentally by the XRD-packing result and computed via Hirschfeld surface analysis (HSA). The UV-vis., FT-IR and Energy Dispersive X-ray (EDX), supported the desired double-open cubane cluster composition. The oxidation potential of the desired cluster was evaluated using a 3,5-DTB-catechol 3,5-DTB-quinone as a catecholase model reaction.

12.
Polymers (Basel) ; 12(10)2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33076461

RESUMO

Cellulose nanofibers were covalently functionalized using diethylenetriamine penta (methylene phosphonic acid) and studied for the extraction of heavy metal ions. The surface-functionalized nanofibers showed a high adsorption capacity towards heavy metal ions as compared to bare nanofibers. The elemental composition and surface morphology of the prepared bio-adsorbent was characterized by X-ray photoelectron spectroscopy, attenuated total reflectance infrared spectroscopy, field emission scanning electron microscopy, and energy dispersive spectroscopy. The prepared material was studied to develop a column-based solid phase extraction method for the preconcentration of trace metal ions and their determination by inductively coupled plasma optical emission spectroscopy. The batch experimental data was well fitted to Langmuir adsorption isotherms (R2 > 0.99) and follows pseudo-second-order kinetics. The experimental variables such as sample pH, equilibrium time, column breakthrough, sorption flow rate, the effect of coexisting ions, and eluent type were systematically studied and optimized accordingly. The detection limit of the proposed method was found to be 0.03, 0.05, and 0.04 µg L-1 for Cu(II), Pb(II), and Cd(II), respectively. Certified Reference Materials were analyzed to validate the proposed method against systematic and constant errors. At a 95% confidence level, the Student's t-test values were less than the critical Student's t value (4.302). The developed method was successfully employed for the preconcentration and determination of trace metal ions from real water samples such as river water and industrial effluent.

13.
Curr Drug Deliv ; 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33023446

RESUMO

AIM: - The synthesis of seven new antioxidant agents based on the combination of thiazole, pyridine, triazole and pyrazole moieties. - The studies of their antioxidant activity using DPPH reduction method. - The DFT analysis of the 7 ligands. - The docking study was also investigated. - The better binding affinity with α-cyclodextrin as best drug delivery system. BACKGROUND: - The screening of new antioxidant compounds and find the good mechanism for binding sites, with correlating between experience and computer theory. OBJECTIVES: - The synthesis of seven new antioxidant agents (nitrogen compounds) based on the combination of thiazole, pyridine, triazole and pyrazole moieties. - The studies of their antioxidant activity using DPPH reduction method. - The DFT analysis of the 7 synthesized ligands. - The docking study was also investigated by using the amino acids Ala167 and Arg172. - The better binding affinity with α-cyclodextrin as best drug delivery system. METHODS: - Chemistry: synthesis of ligands by condensation reaction - Application: Antioxidant activities using DPPH - Computational studies: using DFT and Docking - Correlation between all these properties. RESULT: - Chemistry: synthesis of 7 ligands by condensation reaction with 89% yield - Application: Antioxidant activities using DPPH reduction with a good value IC50=13.05 ± 3.73 µg/ml - Computational studies: using DFT (EHOMO and ELUMO) and Docking APX with the amino acids Ala167 and Arg172 compared to the ascorbic acid - Correlation between all these properties : α-cyclodextrin as best drug delivery system (better binding affinity than caffeic acid). CONCLUSION: For the drug delivery study, The ACD is best system for all the compounds due to the smallest cavity size which makes the binding affinities favorable and possible to prepare prospective nano-antioxidants.

14.
J Mol Liq ; 318: 114082, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32863490

RESUMO

Melatonin is a natural hormone from the pineal gland that regulates the sleep-wake cycle. We examined the structure and physico-chemical properties of melatonin using electronic structure methods and molecular-mechanics tools. Density functional theory (DFT) was used to optimise the ground-state geometry of the molecule from frontier molecular orbitals, which were analysed using the B3LYP functional. As its electrons interacted with electromagnetic radiation, electronic excitations between different energy levels were analysed in detail using time-dependent DFT with CAM-B3LYP orbitals. The results provide a wealth of information about melatonin's electronic properties, which will enable the prediction of its bioactivity. Molecular docking studies predict the biological activity of the molecules against the coronavirus2 protein. Excellent docking scores of -7.28, -7.20, and -7.06 kcal/mol indicate that melatonin can help to defend against the viral load in vulnerable populations. Hence it can be investigated as a candidate drug for the management of COVID.

15.
Saudi J Biol Sci ; 27(8): 2164-2173, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32714043

RESUMO

The development of preferentially selective cancer chemotherapeutics is a new trend in drug research. Thus, we designed and synthesized novel ternary complexes, [Cu(tryp)(Hnor)2(DMSO)]NO3 (1) and [Zn(tryp)(Hnor)2(DMSO)]NO3 (2) (tryp = DL-Tryptophane; Hnor = Norharmane, ß-carboline; DMSO = Dimethyl sulfoxide), characterized with elemental analysis, FTIR, UV-vis, FL, NMR, ESI-MS, and molar conductivity. Furthermore, the TD-DFT studies with UV-vis and FTIR validated the proposed structures of 1 and 2. Moreover, we evaluated the HOMO-LUMO energy gap and found that 1 has a smaller energy gap than 2. Then, 1 and 2 were assessed for anticancer chemotherapeutic potential against cancer cell lines MCF7 (human breast cancer) and HepG2 (human liver hepatocellular carcinoma) as well as the non-tumorigenic HEK293 (human embryonic kidney) cells. The MTT assay illustrated the preferentially cytotoxic behavior of 1 when compared with that of 2 and cisplatin (standard drug) against MCF7 cells. Moreover, 1 was exposed to MCF7 cells, and the results indicated the arrest of the G2/M phases, which followed the apoptotic pathway predominantly. Generation of ROS, GSH depletion, and elevation in LPO validated the redox changes prompted by 1. These studies establish the great potential of 1 as a candidate for anticancer therapeutics.

16.
Molecules ; 25(9)2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32403218

RESUMO

Three new tetradentate NNNS Schiff bases (L1-L3) derived from 2-(piperidin-4-yl)ethanamine were prepared in high yields. UV-Visible and FTIR spectroscopy were used to monitor the dehydration reaction between 2-(piperidin-4-yl)ethanamine and the corresponding aldehydes. Structures of the derived Schiff bases were deduced by 1H and 13C NMR, FTIR, UV-Vis, MS, EA, EDS, and TG-derived physical measurements. DFT/B3LYP theoretical calculations for optimization, TD-DFT, frequency, Molecular Electrostatic Potential (MEP), and highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) / were performed for L2. The in vitro antimicrobial activities of the three Schiff bases were evaluated against several types of bacteria by disk diffusion test using Gentamicin as the standard antibiotic. Schiff bases revealed good antioxidant activity by the DPPH method, and the IC50 values were compared to the Trolox standard. Pancreatic porcine lipase inhibition assay of the synthesized compounds revealed promising activity as compared to the Orlistat reference.

17.
Acta Crystallogr E Crystallogr Commun ; 76(Pt 3): 344-348, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32148873

RESUMO

The asymmetric unit of the title compound, C23H28O4, comprises two half-mol-ecules, with the other half of each mol-ecule being completed by the application of twofold rotation symmetry. The two completed mol-ecules both have a V-shaped appearance but differ in their conformations. In the crystal, each independent mol-ecule forms chains extending parallel to the b axis with its symmetry-related counterparts through C-H⋯π(ring) inter-actions. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (65.4%), H⋯C/C⋯H (21.8%) and H⋯O/O⋯H (12.3%) inter-actions. Optimized structures using density functional theory (DFT) at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structures in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 225: 117457, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31450223

RESUMO

Drug-binding and interactions with plasma proteins strongly affect their efficiency of delivery, hence considered as a key factor in determining the overall pharmacological action. Alpha-1-acid glycoprotein (AGP), a second most abundant plasma protein in blood circulation, has unique drug binding ability and involved in the transportation of various compounds. Here, we have investigated the mechanism of interaction between AGP and potential Cu/Zn metallo-drugs of benzimidazole derived organic motifs (CuL2 and ZnL2, where L is Schiff base ligand) by applying integrated spectroscopic, biophysical techniques and computational molecular docking analyses. We found that both the metallo-drugs (CuL2 and ZnL2) were bound at the central cavity of AGP interacting with the residues of lobe I, lobe II as well as lobe III. The binding of metallo-drugs to AGP occurs in 1:1 M ratios. Hydrogen bonding, electrostatic and hydrophobic interactions played a significant role in stabilizing the AGP-metallo-drug complexes. Binding affinities of both the metallo-drugs towards AGP at 298 K were of the order of 104-105 M-1, corresponding to Gibbs free energy of stabilization of approximately -5.50 to -6.62 kcal mol-1. Furthermore, the spectroscopic investigation by circular dichroism and synchronous fluorescence analyses suggest conformational changes in AGP upon the binding of metallic compounds.


Assuntos
Benzimidazóis/química , Compostos Organometálicos/química , Orosomucoide/química , Animais , Benzimidazóis/metabolismo , Benzimidazóis/farmacologia , Sítios de Ligação , Bovinos , Dicroísmo Circular , Cobre/química , Transferência Ressonante de Energia de Fluorescência , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Técnicas In Vitro , Ligantes , Simulação de Acoplamento Molecular , Compostos Organometálicos/metabolismo , Compostos Organometálicos/farmacologia , Orosomucoide/efeitos dos fármacos , Orosomucoide/metabolismo , Ligação Proteica , Conformação Proteica , Bases de Schiff/química , Bases de Schiff/metabolismo , Bases de Schiff/farmacologia , Espectrometria de Fluorescência , Eletricidade Estática , Zinco/química
19.
Int J Biol Macromol ; 150: 941-947, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31765758

RESUMO

Cactus pear peel as agricultural waste containing arabinogalactan and pectin was thermally treated at 300 °C for 4 h and the resultant carbonized material was applied as adsorbent for the removal of methylene blue dye as a model cationic dye. The prepared adsorbent was characterized by means FTIR for structural characterization, N2 physisoprtion measurements for texture properties, SEM and EDAX for morphological and elemental analysis. The characterization results clearly show that the prepared material is porous with several -OH and CO terminals. The point of zero charge was found to be 7 as detected by batch equilibrium method. The adsorption process was optimized in terms of pH values, contact time, initial dye concentration and temperature. The kinetic study indicated that the pseudo-second-order model can perfectly describe the investigated adsorption process; moreover, the equilibrium results were best fitted by Freundlich model. Furthermore, at pH 8.0, the adsorption capacity was achieved to the maximum value of methylene blue as 102 mg/g. Thermodynamic investigation showed that the adsorption process is spontaneous, endothermic in nature with higher entropy, while the activation energy calculations indicated a physisorption process. The obtained results showed the high potential of the bio-based adsorbent for removal of methylene blue from wastewater.

20.
Dalton Trans ; 49(12): 3658-3661, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-31267121

RESUMO

We reported a microporous MOF FJU-101 with open naphthalene diimide functional groups for room temperature (RT) high methane storage. At RT and 65 bar, the total volumetric CH4 storage capacity of 212 cm3 (STP) cm-3 of FJU-101a is significantly higher than those of the isoreticular MFM-130a and UTSA-40a. The enhanced methane uptake in FJU-101a is attributed to the polar carbonyl sites, which can generate strong electrostatic interactions with CH4 molecules.

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