Bovine Serum Albumin Binding Research Articles

Exploration of the intermolecular isoproturon–bovine serum albumin combination: Biophysical and computational prospects

Isoproturon (IPU), a selective systemic herbicide that is frequently applied to eradicate large-leaved weeds and annual grasses in agricultural fields. However, the accumulation of IPU residues during food production might negatively affect on human and animal health. To comprehend the impact of IPU on the mankind and environment, the interaction analysis of IPU with plasma protein is crucial. This work used a variety of techniques, including fluorescence, UV–vis absorption, computational docking and dynamics simulation to extensively examine the combination of IPU with bovine serum albumin (BSA) under typical physiological settings. IPU quenched the BSA fluorescence and form the IPU–BSA complex through a static process. A weak binding affinity was anticipated (binding constant = 4.68–2.48 × 103 M−1) for IPU–BSA interaction. Thermodynamic results revealed that the IPU–BSA binding reaction was a spontaneous process, predominantly governed by hydrogen bonds, van der Waals and hydrophobic forces, which was well supported by molecular docking analysis. Synchronous and three-dimensional fluorescence spectral results exhibited microenvironmental fluctuations near the protein’s Trp and Tyr residues with added IPU, but inclusion of IPU to BSA was observed to enhance the protein’s thermal constancy. Site marker displacement results demonstrated that IPU desirably binds to BSA at site II. An in silico findings also unveiled the primary binding arrangement of IPU was placed at site II of BSA and surrounded by hydrophobic and polar residues. Molecular dynamics simulation results suggested the IPU–BSA complex persisted compact and stable.

Schiff base ligand: A colorimetric approach for tungsten and carbonate detection with insights into BSA binding studies

A Schiff base ligand, 2,2′-((1E,1′E)-(naphthalene-1,5-diylbis(azanylylidene))- bis(methanylylidene))bis(4-bromophenol) named DB-1, was synthesized using 1,5-diaminonaphthalene and 5-bromo-salicylaldehyde. Several analytical techniques were utilized to confirm the synthesized ligand's structural and chemical purity, e.g., FTIR, NMR, SCXRD, PXRD, TGA, HRMS, and elemental analysis. Subsequently, DB-1 was employed as a susceptible and specific colourimetric sensor to recognize W6+ and CO32– ions. The sensitivity of DB-1 was estimated with limit of detection (LOD) values, i.e. 0.11 µM and 0.08 µM for W6+ and CO32– ions, respectively. Furthermore, the luminescence studies and molecular docking simulations confirmed strong interactions of DB-1 with Bovine Serum Albumin (BSA). Molecular docking studies were implemented to gain insight into the molecular-level interactions that underscore the binding of DB-1 with BSA. This facet of the present research suggests that DB-1 holds promise not only as a susceptible colourimetric sensor for W6+ and CO32– ions but also for its potential applications in BSA-related studies.

A pH-sensitive supermolecular fluorescent probe for albumin-mediated cell imaging

A supermolecular fluorescent probe with favorable pH-sensitive serum albumin responsiveness was successfully fabricated based on the assembly of a binary host-guest complex of water-soluble pillar [5]arene (WP5) and ICT probe DPI. DPI possessed a favorable fluorescence "turn-on" property towards bovine serum albumin (BSA). This property was retained after the binary amphipathic complex formation between WP5 and DPI. Moreover, due to the excellent pH responsiveness of WP5, WP5⊃DPI complex exhibited favorable pH-sensitive BSA responsiveness. The WP5⊃DPI complex also possessed strong BSA binding ability. Common commercial drugs had a negligible adverse effect on the BSA responsiveness of WP5⊃DPI complex. Furthermore, the amphiphilic WP5⊃DPI complex assembled into stable spherical nanoparticles in solution. Such a pH-sensitive supramolecular fluorescent probe had negligible cytotoxicity but exhibited excellent cell permeability and favorable cell imaging properties, demonstrating potential for albumin-mediated precise tumor imaging.

Biomass-derived potential nano-biomaterials: Protein binding, anti-biofilm activity and bio-imaging

Deriving carbon dots (CDs) from renewable sources is gaining popularity due to their prevalence, cost effectiveness, improved aqueous solubility, and increased biocompatibility. CDs, which are made up of crystalline graphitized carbon cores and multiple surface groups, are now spawning a lot of attention in the biological domains. Herein, the CDs were derived from dried rose petals using hydrothermal route and were completely characterized utilizing pivotal techniques. The prepared CDs are spherical particles that are approximately 5–6nm in size and have exceptional stability when exposed to pH and light irradiation. The derived CDs are excitation dependent fluorescent in nature with the quantum yield of 6%. Bovine serum albumin (BSA) binding interaction has been studied with CDs and evaluated through Stern−Volmer equation. The fluorescence quenching mechanism of BSA by CDs followed static type, is further confirmed by the lifetime studies. The binding mode of the CDs with BSA has been studied by molecular docking and the computed binding free energy for CDs is calculated to be −9.62 kcal/mol. Antibiofilm activity revealed that CDs were efficient in reducing the biofilm formations in both gram-positive and gram-negative bacterium. Predominantly, CDs used in this study were significant in reducing the biofilms of gram-negative bacterium. Furthermore, the CDs are effectively used as an efficient biological probe for bioimaging studies.

Induced Circular Dichroism Analysis of Thermally Induced Conformational Changes on Protein Binding Sites Under a Crowding Environment.

Protein-ligand interactions in crowded cellular environments play a crucial role in biological functions. The crowded environment can perturb the overall protein structure and local conformation, thereby influencing the binding pathway of protein-ligand reactions within the cellular milieu. Therefore, a detailed understanding of the local conformation is crucial for elucidating the intricacies of protein-ligand interactions in crowded cellular environments. In this study, we investigated the feasibility of induced circular dichroism (ICD) using 8-anilinonaphthalene-1-sulfonic acid (ANS) for local conformational analysis at the binding site in a crowding environment. Bovine serum albumin (BSA) concentration-dependent measurements were performed to assess the feasibility of ANS-ICD for analyzing protein interior binding sites. The results showed distinct changes in the ANS-ICD spectra of BSA solutions, indicating their potential for analyzing the internal conformation of proteins. Moreover, temperature-dependent measurements were performed in dilute and crowding environments, revealing distinct denaturation pathways of BSA binding sites. Principal component analysis of ANS-ICD spectral changes revealed lower temperature pre-denaturation in the crowded solution than that in the diluted solution, suggesting destabilization of binding sites owing to self-crowding repulsive interactions. The established ANS-ICD method can provide valuable conformational insights into protein-ligand interactions in crowded cellular environments.

Syntheses, structures, Hirshfeld surface analyses, BSA interactions and molecular docking studies of two leucine Schiff base complexes of oxovanadium(IV)

Two mixed-ligand oxovanadium(IV) complexes with a Schiff base derived from o-vanillin and leucine and 1,10-phenanthroline or 2,2´-bipyridine as a co-ligand, [VO(o-van-Leu)phen] (1) and [VO(o-van-Leu)bipy]·H2O (2), were prepared and structurally characterized by IR spectra, elemental analyses and single-crystal X-ray diffraction. The crystal structures reveal that each oxovanadium(IV) atom in complexes 1 and 2 is surrounded by a N3O3 coordination sphere to form a distorted octahedron with a Schiff base and neutral bidentate ligand phen or bipy. Hirshfeld surface analyses and 2D fingerprint plots indicated that the molecular packings in crystals were dominated by H···H, O···H/H···O, C···H/H···C and π-π interactions. The interactions of both complexes with bovine serum albumin (BSA) were studied by using various spectroscopic and molecular docking methods. BSA binding constants (K), estimated by UV–Vis spectroscopy, were 2.53 × 104M−1 for 1 and 3.18 × 104M−1 for 2, respectively. Together with results of fluorescence and CD spectral studies, it showed that complex 2 has a better affinity for BSA than complex 1. Molecular docking investigation indicated that the two complexes had the similar mode of binding and located within subdomain IIA of BSA. Complex 2 had greater binding activity with the binding free energy (∆Gbinding) of –6.5 kcal/mol than Complex 1 with ∆Gbinding of–5.42 kcal/mol, consisting with the analyses of spectroscopic experimental results.

Ga(III) pyridinecarboxylate complexes: potential analogues of the second generation of therapeutic Ga(III) complexes?

A series of novel Ga(III)—pyridine carboxylates ([Ga(Pic)3]·H2O (GaPic; HPic = picolinic acid), H3O[Ga(Dpic)2]·H2O (GaDpic; H2Dpic = dipicolinic acid), [Ga(Chel)(H2O)(OH)]2·4H2O (GaChel; H2Chel = chelidamic acid) and [Ga(Cldpic)(H2O)(OH)]2 (GaCldpic; H2Cldpic = 4-chlorodipicolinic acid)) have been synthesized by simple one-step procedure. Vibrational spectroscopy (mid-IR), elemental analysis, thermogravimetric analysis and X-ray diffraction confirmed complexes molecular structure, inter and intramolecular interactions and their influence to spectral and thermal properties. Moreover, complex species speciation was described in Ga(III)-HPic and Ga(III)-H2Dpic systems by potentiometry and 1H NMR spectroscopy and mononuclear complex species were determined; [Ga(Pic)2]+ (logβ021 = 16.23(6)), [Ga(Pic)3] (logβ031 = 20.86(2)), [Ga(Dpic)2]− (logβ021 = 15.42(9)) and [Ga(Dpic)2(OH)]2− (logβ-121 = 11.08(4)). To confirm the complexes stability in 1% DMSO (primary solvent for biological testing), timescale 1H NMR spectra were measured (immediately after dissolution up to 96 h). Antimicrobial activity evaluated by IC50 (0.05 mM) is significant for GaDpic and GaCldpic against difficult to treat and multi-resistant P. aeruginosa. On the other hand, the GaPic complex is most effective against Jurkat, MDA-MB-231 and A2058 cancer cell lines and significantly also decreases the HepG2 cancer cells viability at 75 and 100 μM concentrations in a relatively short time (up to 48 h). In addition, fluorescence measurements have been used to elucidate bovine serum albumin binding activity between ligands, Ga(III) complexes and bovine serum albumin.Graphical abstract

Multi-spectroscopies and molecular simulation insights into the binding of bovine serum albumin and sodium tripolyphosphate

Sodium tripolyphosphate (STPP) is an odorless and water-soluble anionic mineral compound. STPP is used as a separator, texturizer, emulsifier and buffer in the food and detergent industries. Considering the importance of the topic and the interaction of food additives with biological molecules including blood serum albumin, we investigated the binding properties of STPP food additive to blood serum albumin through UV–Vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and molecular docking analysis. According to the results, after forming a complex with BSA, STPP reduced the fluorescence intensity of BSA through static quenching mechanisms, and the UV–Vis absorption results were also confirmatory. Synchronous fluorescence and FT-IR results showed that the microenvironment and secondary structure of BSA changed in the presence of STPP. The synchronous fluorescence study has shown that the quenching toward Trp residue is higher than Tyr residue. The thermodynamic results showed that van der Waals force and hydrogen bonding play the main roles in the formation of the STPP-BSA complex. The binding constant decreases from 2.23 × 106 to 4.25 × 101 (M−1) with increasing temperature, indicating a decrease in complex formation due to the interaction of STPP with BSA. Furthermore, molecular docking studies showed that STPP binds to the cavity between domains IIIA and IIIB by van der Waals forces and hydrogen bonds through residues Ser 418, Thr 419, Tyr 496, Lys 499, and Lys 533.

Unravelling the role of lipid composition on liposome-protein interactions

Upon in vivo administration of nanoparticles, a protein corona forms on their surface and affects their half-life in circulation, biodistribution properties, and stability; in turn, the composition of the protein corona depends on the physico-chemical properties of the nanoparticles. We have previously observed lipid composition-dependent in vitro and in vivo microRNA delivery from lipid nanoparticles. Here, we carried out an extensive physico-chemical characterisation to understand the role of the lipid composition on the in vivo fate of lipid-based nanoparticles. We used a combination of differential scanning calorimetry (DSC), membrane deformability measurements, isothermal titration calorimetry (ITC), and dynamic light scattering (DLS) to probe the interactions between the nanoparticle surface and bovine serum albumin (BSA) as a model protein. The lipid composition influenced membrane deformability, improved lipid intermixing, and affected the formation of lipid domains while BSA binding to the liposome surface was affected by the PEGylated lipid content and the presence of cholesterol. These findings highlight the importance of the lipid composition on the protein-liposome interaction and provide important insights for the design of lipid-based nanoparticles for drug delivery applications.

Synthesis, characterization, DNA binding, protein binding, antioxidant and anti microbial activity of tetrazole ring based complexes

Novel Cu(II) and Co(II) complexes of 2-(1H-Tetrazol-5-yl) acetohydrazide were synthesized by microwave assisted green synthesis. These compounds were characterized by electronic, FT-IR, 1H NMR, Mass, thermogravimetric, PXRD, ESR, SEM and EDAX techniques. The analytical data show that for Cu(II) complex, metal to ligand ratio is 1:1 and for Co(II) complex, metal to ligand ratio is 1:2. Electronic spectra predicts the tetrahedral geometry for the Cu(II) complex and octahedral geometry for the Co(II) complex. ESR showed superhyperfine spectrum suggesting covalent character in Cu complex. gII = 2.4097 is consistent with dxy ground state supporting its tetrahedral geometry. The interaction of the ligand and complexes with Calf Thymus DNA (CT-DNA) was explored by using absorption, fluorescence spectroscopic, viscometry methods and molecular docking. Interaction of the ligand and complexes with Bovine Serum Albumin (BSA) protein was investigated by absorption and fluorescence techniques. Co (II) complex exhibited highest DNA & BSA binding propensity. Investigation of the antioxidative properties showed that the metal complexes have mild radical scavenging potency against DPPH radical. Ligand and its two complexes were tested for antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa. Both complexes showed good bactericidal activity against Staphylococcus aureus, the Co(II) complex was found to be more potent than Streptomycin.

Mechanistic and kinetic aspects of Natamycin interaction with serum albumin using spectroscopic and molecular docking methods

Natamycin (NT) is a polyene natural antimycotic, which has an antimicrobial effect against yeasts and molds and is used as a preservative in the food industry. In the present study, we evaluated NT interaction with bovine serum albumin (BSA) through surface plasmon resonance (SPR) and several spectroscopic techniques, which are accompanied by a molecular docking study. According to the results, the intensity of BSA fluorescence decreased by adding different concentrations of NT. The fluorescence quenching results showed that NT reduces the intensity of BSA fluorescence by forming a complex with BSA through a hybrid quenching. Binding constant decreases from 18.73 to 2.13 (102 M−1) with increasing temperature, which indicates a decrease in complex formation owing to the interaction of NT with BSA. Negative values of ΔH° and ΔS° confirmed that van der Waals forces and hydrogen bonds are the basic forces in the interaction of NT with BSA. Moreover, increasing the equilibrium constants values with increasing temperature indicated that BSA binding to NT decreased. Finally, BSA interaction occurring with NT through Ser 109, Asp 111, Lys 114, Leu 115, Glu 424, and Arg 458 have been verified via molecular docking analysis. Attained results via SPR and fluorimetry showed that the binding constant between BSA and NT decreased when the temperature was raised.

Histamine derived Schiff bases and corresponding spinaceamines - synthesis, characterization and biological evaluation

The synthesis of eight new histamine-based Schiff bases and cyclic derivatives spinaceamines was accomplished by the reaction of corresponding aldehydes and histamine as amine-counterpart in absolute ethanol. Bearing in mind that the presence of the imino group/or spinaceamine core in the organic molecular scaffold could bring prominent pharmaceutical properties, all synthesised compounds have been screened for their antimicrobial activities against a range of different bacterial and fungal strains and antioxidant activity, as well as for interactions with bovine serum albumin (BSA) and DNA molecules. According to the observed MIC values, the best activity for both, fungal and bacterial species, was displayed by the compound 3c bearing histamine and quinoline moieties in the structure, especially for Staphylococcus aureus. Results obtained in the fluorescence quenching experiments have confirmed ability of tested compounds for DNA and BSA binding, while docking simulations revealed the site I of sub-domain IIA of BSA as a location of binding sites of tested compounds, as well as the minor grove and intercalation interactions with quite similar possibilities to be considered as compounds DNA-binding modes. Further, the molecular docking studies also gave insight into binding modes to the targeted enzymes (CYP51, cytochrome P450 and TyRS) related to the antifungal and antibacterial potential of tested compounds. Two compounds were selected, Schiff base 3c and spinaceamine 4d, to assess the stability of compounds under the physiological conditions (UV-vis spectroscopic study) and in silico ADME properties (SwissADME software), where both compounds have shown the stability after 72 hours in selected medium, and a potential as a drug based on their ADME properties.

Probing the interaction of tert-butylhydroquinone and its β-cyclodextrin inclusion complex with bovine serum albumin

Tert-butylhydroquinone (TBHQ) is a synthetic antioxidant found widely in foods such as cooking oil, fried baked goods and meat products, however, if consumed in excessive quantities, it may cause nutritional problems and chronic diseases. The binding of TBHQ to transport protein before and after β-cyclodextrin (β-CD) encapsulation was investigated by multiple spectroscopies and molecular docking technology. At 298 K, the binding constant, enthalpy, and entropy of bovine serum albumin (BSA) with TBHQ were (1.18 ± 1.50) × 104 M−1, (−110.11 ± 15.29) kJ mol−1 and (−293.36 ± 50.87) J mol−1 K−1 at 298 K, respectively. By forming a stable complex with BSA through van der Waals forces and hydrogen bonds, TBHQ altered BSA's secondary structure and microenvironmental polarity. However, the binding affinity of TBHQ with BSA decreased after encapsulation by β-CD, but the binding distance increased. Because of the encapsulation of β-CD, the interference of TBHQ with the BSA conformation was also inhibited. Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscope study confirmed the formation of an inclusion complex between CD and TBHQ. According to UV spectroscopy, TBHQ and β-CD have a binding constant of (1.21 ± 0.03) × 103 M−1. The formation of TBHQ–β-CD inclusion complex inhibited the binding of TBHQ and BSA, possibly because the inclusion of β-CD prevented TBHQ from entering the hydrophobic cavity of BSA, which prevented TBHQ from binding to BSA, alleviating the negative effects of TBHQ on BSA conformation. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging results showed that the antioxidant activity of TBHQ was not affected by β-CD encapsulation.

Imatinib cation based MOIFs with [Fe(CN)5NO]2−, [Fe(CN)6]3− [Fe(CN)6]4− as adsorbent of organic pollutants, and their protein interaction study

Inorganic-organic hybrid (IOH) compounds are being widely used in the design of multifunctional materials owing to their rich properties and flexible assembly. Here, we report three metal organic ionic frameworks (MOIFs)/ IOH, for the adsorption of toxic organic pollutants and Bovine Serum Albumin (BSA) interaction, synthesized via simple ion-exchange mechanism in water using Na2[Fe(CN)5NO], K3[Fe(CN)6], K4[Fe(CN)6] and 4-[(4-methylpiperazin-1-yl)methyl]-N-(4-methyl-3-{[4-(pyridin-3-yl)pyrimidin-2yl]amino}phenyl) mesylate (ImM). These were characterized through powder XRD, NMR, UV/ Vis and FTIR techniques for their structural elucidation. The thermal gravimetric analysis (TGA) revealed their two transitions due to loss of water and organic compound. Additionally, the band gap was found in the range of 3.2 to 3.3 eV, inferred their applicability in the field of semiconductors. MOIFs have shown the adsorption of toxic pollutants (Organic dyes) investigated through thermal kinetics and activation parameters which inferred about the interaction between organic dyes and MOIFs as characteristics for the adsorption system. Adsorption has also been analyzed through conductivity data where according to Ostwald's dilution law for weak electrolytes was applied. For knowing medicinal aspects, MOIFs have also been tested for BSA binding activity analyzed with UV–Vis, fluorescence and docking studies, which showed good quenching efficacy as well as interaction ability.

Electronic and ring size effects of N-heterocyclic carbenes on the kinetics of ligand substitution reactions and DNA/protein interactions of their palladium(II) complexes

The synthesis, substitution kinetics and DNA/BSA interactions of four cationic Pd(II) complexes [Pd(1)Cl]BF4 (Pd1), [Pd(2)Cl]BF4 (Pd2), [Pd(3)Cl]BF4 (Pd3) and [Pd(4)Cl]BF4 (Pd4), derived from the reaction of [PdCl2(NCCH3)2] with ligands 2,6-bis(3-methylimidazolium-1-yl)pyridine dibromide (1), 2,6-bis(3-ethylimidazolium-1-yl)pyridine dibromide (2), 2,6-bis(1-methylimidazole-2-thione)pyridine (3), and 2,6-bis(1-ethylimidazole-2-thione)pyridine (4), respectively are reported. The complexes were characterised by various spectroscopic techniques and single crystal X-ray diffraction for compound Pd2. Kinetic reactivity of the complexes with the biologically relevant nucleophiles thiourea (Tu), L-methionine (L-Met) and guanosine 5′-monophosphate sodium salt (5’-GMP) was in the order: Pd1 > Pd2 > Pd3 > Pd4, which was largely dependent on the electronic and ring size of the chelate ligands, consistent with Density functional theory (DFT) simulations. The interactions of the complexes with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) binding titrations showed strong binding. Both the experimental and in silico data reveal CT-DNA intercalative binding mode.Graphical abstract

A good and bad aggregation: Effect of imidazolium- and cholinium-based ionic liquids on the thermal stability of bovine serum albumin

The present work describes the effect of imidazolium- and cholinium-based ionic liquids (ILs) on the thermal stability, binding and aggregation of bovine serum albumin (BSA). The studied ILs include choline chloride [Ch][Cl], choline dihydrogenphosphate [Ch][DHP], choline acetate [Ch][OAc], 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4], 1-octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF4] 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][TfO], 1-butyl-3-methylimidazolium acetate [BMIM][OAc], and 1-butyl-3-methylimidazolium methanesulfonate [BMIM][CH3SO3]. The state of BSA in presence of ILs was assessed by circular dichroism (CD), temperature dependent circular dichroism, fluorescence spectroscopy, and dynamic light scattering (DLS). The thermal stability of BSA in presence of ILs increased (above 85 °C) in all studied ILs except [OMIM][BF4]. Differences of binding ILs with BSA depending on alkyl chain length were estimated, the probable binding modes were identified using molecular docking. The influence of ILs on the aggregation of BSA at different temperatures was established. It was found that the ILs with short alkyl chain length (up to butyl) promote aggregation of the native form of BSA increasing its thermal stability.

Insights on the in-vitro binding interaction between donepezil and bovine serum albumin

In this work, the binding mechanism between donepezil (DNP) and bovine serum albumin (BSA) was established using several techniques, including fluorimetry, UV- spectrophotometry, synchronous fluorimetry (SF), fourier transform infrared (FTIR), fluorescence resonance energy transfer (FRET) besides molecular docking study. The fluorescence quenching mechanism of DNP-BSA binding was a combined dynamic and static quenching. The thermodynamic parameters, binding forces, binding constant, and the number of binding sites were determined using a different range of temperature settings. Van't Hoff's equation was used to calculate the reaction parameters, including enthalpy change (ΔHο) and entropy change (ΔSο). The results pointed out that the DNP-BSA binding was endothermic. It was shown that the stability of the drug-protein system was predominantly due to the intermolecular hydrophobic forces. Additionally, the site probing method revealed that subdomain IIA (Site I) is where DNP and BSA's binding occurs. This was validated using a molecular docking study with the most stable DNP configuration. This study might help to understand DNP's pharmacokinetics profile and toxicity as well as provides crucial information for its safe use and avoiding its toxicity.

A novel binuclear Lanthanum complex containing 1,10-phenanthroline; from crystal structure to biological and antitumor activity

UV–Vis and IR spectroscopy, elemental analysis, and X-ray crystallography are used to characterize a novel dimeric Lanthanum(III) complex with 1,10-phenanthroline (phen), [LaCl2(Phen)2-µ-Cl2- LaCl2(Phen)2]. It is also being examined for its antibacterial, anticancer, and DNA (Fish Salmon DNA) and protein (Bovine Serum Albumin) binding properties. The title compound's crystals are triclinic, P1¯; with a (Å) = 9.914(3), b (Å) = 10.927(3), c (Å) = 12.047(3), V (Å3) = 1151.7(5), α (°) = 84.797(5), β (°) = 77.224(4), γ (°) = 64.814(5), Z = 1 and Dcalc = 1.747 (g/cm3). It has a centrosymmetric binuclear [LaCl2(Phen)2 (µ-Cl)]2 unit (the two bridging chlorine atoms lie on an inversion center). The molecular modeling method was used to study the binding qualities both empirically and conceptually. Absorption and fluorescence spectroscopy methods were used to determine thermodynamic parameters, the binding constant (Kb), and the possible binding process. With a binding constant (Kb) of 1.78 × 105, the volume of binding to FS DNA supports groove binding, which is consistent with docking estimates. With a static technique, the as-synthesized complex efficiently suppressed BSA emission and was bound by Kb = 1.17 × 105 at 298 K, demonstrating its high tendency for BSA contact via van der Waals force and hydrogen bond. Antimicrobial testing on a variety of bacteria revealed that it has good antibacterial action. The MTT method was used to test the in vitro cytotoxicity of the La2(III) complex in A-549 cell lines, which exhibited considerable activity.

Interaction between oxidised state of quercetin and bovine serum albumin in presence of surfactant aggregates with different charges

The present investigation focuses on the role of surfactant and its charge on the interaction of flavonoid Quercetin (QCT) and Bovine serum albumin (BSA). QCT is known to undergo autoxidation in many chemical environments which has different characteristics compared to its non-oxidised structure. In this experiment, two ionic surfactants used. They are anionic surfactant, Sodium dodecyl sulfate (SDS) and Cationic surfactants Cetyl pyridinium bromide (CPB). The characterizations employed are conductivity, FT-IR, UV–visible spectroscopy, Dynamic light scattering (DLS) and Zeta potential measurements. The critical micellar concentration (CMC) as well as the counter-ion binding constant (β) have been calculated by making use of specific conductance values, in aqueous medium at 300 K. Various thermodynamic parameters, ΔG0 m, standard free energy of micellization, ΔH0 m, standard enthalpy of micellization and ΔS0 m, standard entropy of micellization are calculated. The negative value of ΔG0 m in all systems is indicative of spontaneous binding occurring in both QCT + BSA + SDS (−23.35 kJ mol−1) and QCT + BSA + CPB (−27.18 kJ mol−1). The higher negative value infers the latter is a more stable system with greater spontaneity. The UV-visible spectroscopy study points at stronger binding of QCT and BSA in presence of surfactants and also there is stronger binding of CPB in ternary mixture with higher binding constant compared to SDS ternary mixture. Which is evident from the binding constant calculated from Benesi-Hildebrand plot (QCT + BSA + SDS, 244.46 M−1; QCT + BSA + CPB, 336.53 M−1). Further, the structural alterations occurring in the above systems has been observed by FT-IR spectroscopy. The DLS and Zeta potential measurements also support the above finding. Communicated by Ramaswamy H. Sarma

Synthesis and biological evaluation of benzamide-chalcone hybrids as potential c-Metkinase and COX-2 inhibitors.

c-Met kinase and cyclooxygenase 2 (COX-2) enzymes are two significant targets in tumor progression. Chalcone and benzamide moieties were combined using molecular hybridization to assess their potential as c-Met kinase and COX-2 inhibitors. 4-Methylbenzamide and 4-chlorobenzamide chalcone analogs were synthesized, characterized, and evaluated for antiproliferative activity on Michigan Cancer Foundation-7 (MCF-7), HT-29, MDA-MB-231, COLO-205, and A549 cell lines by sulforhodamine-B stain (SRB) assay. Following the SRB assay, compounds were evaluated for their c-Met kinase and COX-2 inhibitory potential. All compounds inhibited COX-2 with half-maximal inhibitory concentration (IC50 ) <10 µM. Compounds 7h, 7i, 7j, 8f, and 8j inhibited c-Met with IC50 <10 µM. Compound 7h was evaluated for its long-term antiproliferative and anti-migratory effects by colony formation and wound healing assay. It exerted these effects in a concentration-dependent manner. Compounds 7j and 8j were further evaluated for in vitro antiangiogenic effects. Compound 7j exhibited moderate antiangiogenic effect while compound 8j exhibited strong effect. Compounds 7h, 7i, 7j, 8f, and 8j were evaluated for the serum protein binding, using the in vitro bovine serum albumin binding assay. The results indicated that the tested compounds bind to bovine serum albumin (BSA) and can be further explored by other studies.