Six novel donor–π–acceptor organic dyes bearing a pyrimidine as the anchoring group have been obtained in good yields by combination of the microwave-assisted Suzuki cross-coupling and nucleophilic ...aromatic substitution of hydrogen reactions. Their absorption, photoluminescence and electrochemical properties were fully investigated in detail. The infrared spectra of dyes adsorbed on TiO2 indicate the formation of coordinate bonds between the pyrimidine ring of dyes and the Lewis acid sites (exposed Tin+ cations) of the TiO2 surface. This work demonstrates that the pyrimidine rings of dye sensitizers that form a coordinate bond with the Lewis acid site of a TiO2 surface are promising candidates as the electron-withdrawing anchoring group. The data from quantum calculations show that all of the dyes are potentially good photosensitizers for dye-sensitized solar cells.
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•The new carbazole and triphenylamine-containing dyes for DSSCs are synthesized.•The using of pyrimidine fragment as the anchoring group for DSSCs is described.•Redox and photophysical properties of dyes have been studied.•Quantum chemical calculations were performed to characterize the DSSCs.
In the realm of food industry, the choice of non-consumable materials used plays a crucial role in ensuring consumer safety and product quality. Aluminum is widely used in food packaging and food ...processing applications, including dairy products. However, the interaction between aluminum and milk content requires further investigation to understand its implications. In this work, we present the results of multiscale modelling of the interaction between various surfaces, that is (100), (110), and (111), of fcc aluminum with the most abundant milk proteins and lactose. Our approach combines atomistic molecular dynamics, a coarse-grained model of protein adsorption, and kinetic Monte Carlo simulations to predict the protein corona composition in the deposited milk layer on aluminum surfaces. We consider a simplified model of milk, which is composed of the six most abundant milk proteins found in natural cow milk and lactose, which is the most abundant sugar found in dairy. Through our study, we ranked selected proteins and lactose adsorption affinities based on their corresponding interaction strength with aluminum surfaces and predicted the content of the naturally forming biomolecular corona. Our comprehensive investigation sheds light on the implications of aluminum in food processing and packaging, particularly concerning its interaction with the most abundant milk proteins and lactose. By employing a multiscale modelling approach, we simulated the interaction between metallic aluminum surfaces and the proteins and lactose, considering different crystallographic orientations. The results of our study provide valuable insights into the mechanisms of lactose and protein deposition on aluminum surfaces, which can aid in the general understanding of protein corona formation.
Milk Protein Adsorption on Metallic Iron Surfaces Mosaddeghi Amini, Parinaz; Subbotina, Julia; Lobaskin, Vladimir
Nanomaterials (Basel, Switzerland),
06/2023, Letnik:
13, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Food processing and consumption involves multiple contacts between biological fluids and solid materials of processing devices, of which steel is one of the most common. Due to the complexity of ...these interactions, it is difficult to identify the main control factors in the formation of undesirable deposits on the device surfaces that may affect safety and efficiency of the processes. Mechanistic understanding of biomolecule-metal interactions involving food proteins could improve management of these pertinent industrial processes and consumer safety in the food industry and beyond. In this work, we perform a multiscale study of the formation of protein corona on iron surfaces and nanoparticles in contact with cow milk proteins. By calculating the binding energies of proteins with the substrate, we quantify the adsorption strength and rank proteins by the adsorption affinity. We use a multiscale method involving all-atom and coarse-grained simulations based on generated ab initio three-dimensional structures of milk proteins for this purpose. Finally, using the adsorption energy results, we predict the composition of protein corona on iron curved and flat surfaces via a competitive adsorption model.
Understanding the specifics of interaction between the protein and nanomaterial is crucial for designing efficient, safe, and selective nanoplatforms, such as biosensor or nanocarrier systems. ...Routing experimental screening for the most suitable complementary pair of biomolecule and nanomaterial used in such nanoplatforms might be a resource-intensive task. While a range of computational tools are available for prescreening libraries of proteins for their interactions with small molecular ligands, choices for high-throughput screening of protein libraries for binding affinities to new and existing nanomaterials are very limited. In the current work, we present the results of the systematic computational study of interaction of various biomolecules with pristine zero-valent noble metal nanoparticles, namely, AgNPs, by using the UnitedAtom multiscale approach. A set of blood plasma and dietary proteins for which the interaction with AgNPs was described experimentally were examined computationally to evaluate the performance of the UnitedAtom method. A set of interfacial descriptors (log P NM, adsorption affinities, and adsorption affinity ranking), which can characterize the relative hydrophobicity/hydrophilicity/lipophilicity of the nanosized silver and its ability to form bio(eco)corona, was evaluated for future use in nano-QSAR/QSPR studies.
•Quantum chemical calculations were carried out for PCBs congeners.•Calculated descriptors were used to explain the PCBs reactivity in SN and SE substitutions.•Obtained data were used to estimate the ...PCBs reactivity in the SN reactions.•Calculated descriptors were insufficient to explain the PCBs reactivity in the SE reactions.•New neutralization methods of the large-capacity PCBs were discussed.
To explain the chemical reactivity of polychlorinated biphenyls in nucleophilic (SN) and electrophilic (SE) substitutions, quantum chemical calculations were carried out at the B3LYP/6-31G(d) level of the Density Functional Theory in gas phase. Carbon atomic charges in biphenyl structure were calculated by the Atoms-in-Molecules method. Chemical hardness and global electrophilicity index parameters were determined for congeners. A comparison of calculated descriptors and experimental data for congener reactivity in the SN and SE reactions was made. It is shown that interactions in the SN mechanism are reactions of the hard acid–hard base type, these are the most effective in case of highly chlorinated substrates. To explain the congener reactivity in the SE reactions, correct descriptors were not established. The obtained results can be used to carry out chemical transformations of the polychlorinated biphenyls in order to prepare them for microbiological destruction or preservation.
A one‐pot approach for the synthesis of 2‐aryl‐5‐amino‐1,2,3‐triazoles is reported. This approach involves a tandem nucleophilic addition of alkylamines to hydrazonoyl cyanides and in situ oxidative ...cyclization of the resulting 2‐(arylazo)ethene‐1,1‐diamines in the presence of copper(II) acetate and air. The described one‐pot procedure is characterized by good yields, excellent selectivity, methodical simplicity, and uses readily available chemicals. This method was applied to the gram‐scale synthesis of 2‐aryl‐1,2,3‐triazoles.
A new one‐pot synthesis of functionalized 2‐aryl‐1,2,3‐triazoles has been developed. The developed procedure is efficient, safe and applicable to a broad scope of substrates. In addition, tethis approach has a higher atom economy factor and allows for the synthesis of new 2‐aryl‐1,2,3‐triazoles that were not previously accessible using reported methods.
Ion-coupled transport of neurotransmitter molecules by neurotransmitter:sodium symporters (NSS) play an important role in the regulation of neuronal signaling. One of the major events in the ...transport cycle is ion-substrate coupling and formation of the high-affinity occluded state with bound ions and substrate. Molecular mechanisms of ion-substrate coupling and the corresponding ion-substrate stoichiometry in NSS transporters has yet to be understood. The recent determination of a high-resolution structure for a bacterial homolog of Na
+/Cl
−-dependent neurotransmitter transporters, LeuT, offers a unique opportunity to analyze the functional roles of the multi-ion binding sites within the binding pocket. The binding pocket of LeuT contains two metal binding sites. The first ion in site NA1 is directly coupled to the bound substrate (Leu) with the second ion in the neighboring site (NA2) only ∼7
Å away. Extensive, fully atomistic, molecular dynamics, and free energy simulations of LeuT in an explicit lipid bilayer are performed to evaluate substrate-binding affinity as a function of the ion load (single versus double occupancy) and occupancy by specific monovalent cations. It was shown that double ion occupancy of the binding pocket is required to ensure substrate coupling to Na
+ and not to Li
+ or K
+ cations. Furthermore, it was found that presence of the ion in site NA2 is required for structural stability of the binding pocket as well as amplified selectivity for Na
+ in the case of double ion occupancy.
Determining the accurate chemical structures of synthesized compounds is essential for biomedical studies and computer-assisted drug design. The unequivocal determination of N-adamantylation or ...N-arylation site(s) in nitrogen-rich heterocycles, characterized by a low density of hydrogen atoms, using NMR methods at natural isotopic abundance is difficult. In these compounds, the heterocyclic moiety is covalently attached to the carbon atom of the substituent group that has no bound hydrogen atoms, and the connection between the two moieties of the compound cannot always be established via conventional 1H-1H and 1H-13C NMR correlation experiments (COSY and HMBC, respectively) or nuclear Overhauser effect spectroscopy (NOESY or ROESY). The selective incorporation of 15N-labelled atoms in different positions of the heterocyclic core allowed for the use of 1H-15N (J HN) and 13C-15N (J CN) coupling constants for the structure determinations of N-alkylated nitrogen-containing heterocycles in solution. This method was tested on the N-adamantylated products in a series of azolo-1,2,4-triazines and 1,2,4-triazolo1,5-apyrimidine. The syntheses of adamantylated azolo-azines were based on the interactions of azolo-azines and 1-adamatanol in TFA solution. For azolo-1,2,4-triazinones, the formation of mixtures of N-adamantyl derivatives was observed. The J HN and J CN values were measured using amplitude-modulated 1D 1H spin-echo experiments with the selective inversion of the 15N nuclei and line-shape analysis in the 1D 13С spectra acquired with selective 15N decoupling, respectively. Additional spin–spin interactions were detected in the 15N-HMBC spectra. NMR data and DFT (density functional theory) calculations permitted to suggest a possible mechanism of isomerization for the adamantylated products of the azolo-1,2,4-triazines. The combined analysis of the J HN and J CN couplings in 15N-labelled compounds provides an efficient method for the structure determination of N-alkylated azolo-azines even in the case of isomer formation. The isomerization of adamantylated tetrazolo1,5-b1,2,4triazin-7-ones in acidic conditions occurs through the formation of the adamantyl cation.
Polymer-coated nanoparticles (NP) are commonly used as drug carriers or theranostic agents. Their uptake rates are modulated by the interactions with essential serum proteins such as transferrin and ...albumin. Understanding the control parameters of these interactions is crucial for improving the efficiency of these nanoscale devices. In this work, we perform a multiscale computational study of protein adsorption onto polyethylene glycol (PEG) coated gold and silver NPs, producing protein-NP adsorption rankings as a function of PEG grafting density, which are validated against previously reported experimental protein-NP binding constants. Furthermore, the applied nano-docking method provides information on the preferred orientation of proteins immobilised on the surface of NPs. We propose a method of construction of model core-shell NPs
. The presented protocol can provide molecular level insights for the experimental development of biosensors, nanocarriers, or other nanoplatforms where information on the preferred orientation of protein at the bio-nano interface is crucial, and enables fast
prescreening of assays of various nanocarriers,
, combinations of proteins, NPs, and coatings.
Polymer-coated nanoparticles (NP) are commonly used as drug carriers or theranostic agents. Their uptake rates are modulated by the interactions with essential serum proteins such as transferrin and ...albumin. Understanding the control parameters of these interactions is crucial for improving the efficiency of these nanoscale devices. In this work, we perform a multiscale computational study of protein adsorption onto polyethylene glycol (PEG) coated gold and silver NPs, producing protein-NP adsorption rankings as a function of PEG grafting density, which are validated against previously reported experimental protein-NP binding constants. Furthermore, the applied nano-docking method provides information on the preferred orientation of proteins immobilised on the surface of NPs. We propose a method of construction of model core-shell NPs
in silico
. The presented protocol can provide molecular level insights for the experimental development of biosensors, nanocarriers, or other nanoplatforms where information on the preferred orientation of protein at the bio-nano interface is crucial, and enables fast
in silico
prescreening of assays of various nanocarriers,
i.e.
, combinations of proteins, NPs, and coatings.
Polymer-coated nanoparticles (NP) are commonly used as drug carriers or theranostic agents.
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