Spectroscopic Approach Research Articles

Raman identification of pigments and opacifiers: Interest and limitation of multivariate analysis by comparison with solid state spectroscopical approach—II. Arsenic‐based opacifiers and relation with cobalt ores

AbstractRaman analysis is a noninvasive technique that can be conducted on‐site via a mobile system. However, the presence in variable quantity of different crystalline or amorphous phases (glassy matrix, opacifiers and pigments) in the enamel leads to the partial observation of Raman signatures, signatures often not being characterized in the literature. We study here the phases observed in the white, blue and yellow/green enamels of French and Chinese objects from the 18th century and compare the effectiveness of a solid‐state spectroscopic approach (identification of the parameters determining the vibrational modes in relation to the structures) and the multivariate chemometric approach (PCA and Hierarchical Clustering), carried out on the global or partial spectra, or on the parameters extracted from the first approach. The incorporation of the spectra of neighbouring or similar phases from the literature into the corpus of processed data, in particular those obtained for phases that are not initially structurally characterized, is decisive for the quality of the results. At least four different lead arsenates are identified. The combination of visual observation of the peaks and multivariate analysis shows that the shape, position and area of the band associated with the main As‐O stretching vibration around 820 cm−1 vary according to several criteria related to production techniques specific to certain workshops. The contribution of multivariate analysis based on spectra alone appears to be very limited compared to the examination of spectroscopic parameters.

Evaluation of the reactivity of superoxide radicals with phosphite by direct and indirect kinetic methods

Phosphite (PHI) accounts for a noticeable portion of the total dissolved inorganic phosphorus in diverse aquatic systems. Efficient PHI control in water bodies is challenging due to its high solubility and strong resistance to biotransformation. To verify the role of superoxide radical (O2•−) in PHI transformation to phosphate, we used complementary direct and indirect methods to investigate the kinetic aspects of O2•− induced reactions with PHI. The rate constant (k, M−1 s−1) for the reaction between O2•− and PHI, measured by an in situ long-path absorption spectroscopic approach, was determined to be 420 M−1 s−1. The low k value suggests its minor contribution as compared to hydroxyl radicals commonly used in advanced oxidation processes. We then studied the thermodynamic properties of possible pathways for O2•− oxidation of PHI using density functional theory, and our calculations indicated the reaction is thermodynamically unfeasible. With these fundamental results, we aim for a better understanding on the degradation kinetics and mechanisms for PHI and O2•−, providing useful scientific knowledge for the transformation of phosphorus in sunlit surface waters and engineering wastewater treatment processes.

Host–Guest Interaction Studies of Isoproterenol Hydrochloride with Β-Cyclodextrin in an Aqueous Medium Probed by Volumetric, Acoustic, and Spectroscopic Approach

Host–Guest Interaction Studies of Isoproterenol Hydrochloride with Β-Cyclodextrin in an Aqueous Medium Probed by Volumetric, Acoustic, and Spectroscopic Approach

Signal Amplification for Detection of Nilutamide in Three-Dimensional Electrochemical Sensor Using Copper Metal–Organic Framework Decorated Carbon Nanofibers

The extensive use of antibiotics has rapidly spread antibiotic resistance, which poses significant health risks to humans. Unfortunately, despite this pressing issue, there is still a lack of a reliable on-site detection method for the residues of antibiotics, such as nilutamide (Nlu). Consequently, there is an urgent need to develop and perfect such a detection method to effectively monitor and control antibiotic residues. In this study, the hydrothermal development of copper-metal-organic framework (Cu-MOF) polyhedrons on the functionalized carbon nanofiber (f-CNF) matrix allowed for the detection of Nlu in biological liquids via a sensitive amperometry technique. Further electrochemical detection of Nlu took place with the cyclic voltammetry (CV) technique Cu-MOF/f-CNF. Analytical and spectroscopic approaches were used to confirm the successful synthesis of Cu-MOF/f-CNF. The prepared material was decorated on the surface of GCE and performed as an electrochemical Nlu sensor, with a broad linear range of 0.01 to 141.4 μM and 2 nM as a lower limit of detection. In addition, the composites had a large surface area and many dedicated sites, which improved electrocatalysis. In practical applications, Cu-MOF/f-CNF/GCE provides a novel strategy for improving electrochemical activity by measuring Nlu concentrations in biological samples.

Gd2ZnMnO6/ZnO Ceramic Nanocomposites for the Cycloaddition of Carbon Dioxide, Amines, and Alkenes under Mild Conditions

For the first time, Gd2ZnMnO6/ZnO ceramic nanocomposites (Gd2ZnMnO6/ZnO CNCs) were fabricated by a sol-gel auto-combustion process on the basis of a reaction between Gd, Zn and Mn nitrates and saffron as a green fuel. Gd2ZnMnO6/ZnO ceramic nanocomposites were greenly formed using saffron as a novel fuel and stabilizing agent. The morphology, phase, and anatomical purity of Gd2ZnMnO6/ZnO ceramic nanocomposites could be arranged by quantity and type of fuel, temperature, and reaction period. The specimens were explored by various microscopic and spectroscopic approaches. The uncontrolled release of carbon dioxide (CO2) by industrial processes that acidify the oceans and warm the planet has prompted scientists to try different methods to capture CO2 directly from waste water sources. The fabrication of green nanocatalysts with chemical modifications to create value-added products has many benefits. Considering the morphology of Gd2ZnMnO6/ZnO, an appropriate exteriorlayer for CO2 imbibition was created in all catalystsites. Findings disclosed that Gd2ZnMnO6/ZnO positively affected the fabrication yield of 3-aryl-2-oxazolidinones by carbon dioxide, olefins, and anilines. The product was obtained with an excellent yield of 98%. This high yield was obtained in very mild conditions, such as a pressure of 2.5 atm of carbon dioxide at 80 °C for 3 h. The technique enjoyed profitable performance and forbearance of functional groups. The retrievable catalyst was recycled up to ten times for synthesis of 3-aryl-2-oxazolidinones without significant loss in its activity.

Characterization and Degradation Analysis of Pigments in Paintings by Martiros Sarian: Attenuated Total Reflection Fourier Transform Infrared Spectroscopic Imaging and X-ray Fluorescence Approach

This paper presents a preliminary scientific investigation of pigments used by Martiros Sarian, a prominent Armenian artist known for his vibrant and evocative paintings. The study focuses on five of Sarian’s paintings from different periods of his career, namely, Morning in Stavrino, Arabian Dancer, Caravan, Yerevan Zangu River, and Kirovakan, dated between 1909 and 1948. Non-destructive techniques, including micro-attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic imaging and X-ray fluorescence (XRF), were employed to characterize the pigments in the samples extracted from these paintings. The results reveal the presence of various pigments, including ultramarine blue, cobalt blue, cobalt cerulean blue, viridian, emerald green, cobalt green, celadonite green, cadmium yellow, chrome yellow, Venetian red, yellow ochre, red ochre, lead white, zinc white, and calcium carbonate. Additionally, metal carboxylates and oxalates, degradation products associated with the paint layers, were observed and discussed. The findings contribute to a better understanding of Sarian’s artistic technique and provide valuable insights for the conservation and restoration of his artworks.

Preparation of nanoformulation of 5-fluorouracil to improve anticancer efficacy: integrated spectroscopic, docking, and MD simulation approaches

Nanoformulations (NFs) can be used as a novel drug delivery system to treat all cancer types. One of the major drawbacks of conventional anticancer drugs is that they have poor specificity and higher toxicity towards normal cells. 5-fluorouracil (5-FU) is a well-studied anticancer drug that has a significant role in various cancers, specifically colorectal cancer therapy. This study was performed to determine the functional groups, particle size, surface charge, heterogeneity, and stability of the NF. The NFs of 5-FU were prepared through the ultrasonication technique by increasing the surfactant (Tween-80) concentrations. Among all three NFs, nanoformulated 5-FU (n5-FU) showed the most effective particle size (10.72 nm) with a zeta potential of (-4.57 mV). The cytotoxicity and apoptosis profiles confirmed that n5-FU enhanced the anticancer effect of the pure drug in HCT-116 cells, as evident from MTT assay, fluorescence microscopy, and FACS analysis. In HCT-116 cells, the IC50 values of pure and n5-FU were obtained as 41.3 μM and 18.8 μM, respectively, indicating that n5-FU was more effective against the cancer cell line. The cellular uptake study was performed to check the intake of NF in cancer cells. However, the microtubule-affinity regulating kinase-4 (MARK-4), a cancer-target protein, was purified to study the inhibition and interaction studies. The inhibition assay confirmed the inhibitory potential of 5-FU against MARK-4 protein. the multi-spectroscopic, molecular docking and MD simulation studies were performed to analyse the conformational changes, binding studies, intermolecular interactions, and stability of MARK-4 protein upon binding 5-FU. This demonstrates that NF can enhance the effectiveness of anticancer drugs. Communicated by Ramaswamy H. Sarma

Mechanisms leading to exceptional niobium concentration during lateritic weathering: The key role of secondary oxides

Niobium (Nb) is considered as one of the most immobile elements during supergene weathering due to its low solubility and the expected resistance of the pyrochlore mineral group (A2B2X6Y) in which Nb occupies the B site. Although the resistance of pyrochlore is challenged by direct evidence of alteration in lateritic profiles, the geochemical and mineralogical processes controlling its behavior in the critical zone remains elusive. This study uses a multiscale geochemical, mineralogical and spectroscopic approach to monitor Nb solid speciation in a thick weathering profile. The weathering of the pyrochlore-bearing core carbonatite facies from Morro dos Seis Lagos has resulted in a Fe-enriched laterite with exceptional Nb concentrations (2.91 wt% Nb2O5 on average). The preservation of the successive secondary phases (Ti-, Fe-, Ce-oxides) resulting from weathering processes along the horizons offers the opportunity to track Nb during pyrochlore alteration from the fresh parent rock to the final stages of weathering. Intense lateritization processes have led to an enrichment in Fe and Ti in the pyrochlore B-sites, resulting in the weakening of the structure and its ultimate destabilization due to weaker B-O bonds. After the release of Nb from pyrochlore, the fate of Nb is dependent on the secondary phases formed during weathering. In the lower horizons dominated by Fe oxides, goethite is the main host for Nb (1 wt% Nb2O5) due to its capacity to substitute Fe3+ for Nb5+, in contrast to hematite. In the upper horizons, where Ti oxides have formed during the reworking of the laterite, Nb5+ is preferentially incorporated into brookite and rutile (20 wt% Nb2O5), which may have formed owing to slightly acidic pH and high Nb activity during their growth. The presence of Nb in hollandite and cerianite in a vein from the manganiferous horizon involves the transport of Nb with mobile elements at the scale of the laterite. With this study, we describe a new model accounting for the formation of Nb-enriched laterites. The latter is based on the ability of Nb5+ to substitute for Fe3+, Ti4+, Ce4+ in minerals formed by lateritization processes after its release from pyrochlore. The nature of the secondary Nb-bearing oxides is dependent on the chemistry of the parent rock and the conditions of formation of the laterite. This work, evidencing the mobilization of Nb both at the scale of the mineralogical assemblage and of the entire profile questions the pervasive use of Nb as a geochemical invariant in the critical zone.

Assessing cytotoxic activities, theoretical and in silico molecular docking calculations of phthalocyanines bearing cinnamyloxy-groups

Cancer has been recognized as one of the deadliest diseases in the world in recent years. By chemically tailoring specific properties, anticancer agents can be prepared very effectively for the treatment of various cancer types. In this manner, as anticancer agents, a series of soluble metal-free and metallophthalocyanines carrying cinnamyloxy-groups at peripheral β-positions have been prepared. All synthesized phthalocyanines were characterized by various spectroscopic approaches such as ultraviolet − visible (UV − Vis), Fourier transform infrared (FT-IR), and matrix-assisted laser deionization/ionization time-of-flight mass spectroscopy (MALDI-TOF MS) techniques. These compounds are highly soluble in dimethyl sulfoxide (DMSO) and soluble in common organic solvents. The spectroscopic properties, cytotoxicity, and theoretical calculations of these complexes have been investigated. In cytotoxicity tests, compounds 1, 4, and 7 are the most active against HT-29 cell lines with IC50 values of 36.9 μM, 32.5 μM, and 51.1 μM, respectively. Also, the most and the least cytotoxic compounds against healthy CCD cell line is compounds 5 and 6 with the IC50 value of 13.4 μM and >250 μM, respectively. The PDB ID:4BQG target protein representing the HT-29 cancer cell line and the anti-cancer activities of phthalonitrile and its phthalocyanines were supported by molecular docking studies. Density Functional Theory (DFT) study supported the experimental results, including the spectral data, and implied that the compounds 5-7 are comparable by their characteristics, such as electronic properties, optical properties, electrostatic potentials, reactivity parameters, with the earlier studied compounds 2-4, which were successfully proved to be good candidates for cancer treatment. Communicated by Ramaswamy H. Sarma

Explorations on Solute–Solvent Interactions of Tripotassium Citrate and Sodium Benzoate in Aqueous 1-Ethyl-3-methylimidazolium Ethyl Sulfate Solutions: Physicochemical, Spectroscopic, and Computational Approaches

Explorations on Solute–Solvent Interactions of Tripotassium Citrate and Sodium Benzoate in Aqueous 1-Ethyl-3-methylimidazolium Ethyl Sulfate Solutions: Physicochemical, Spectroscopic, and Computational Approaches

B-374 Early Prediction of Recurrent Non-muscle Invasive Bladder Cancer Using ATR-FTIR in Urine Samples

Abstract Background Non-Muscle Invasive Bladder Cancer (NMIBC) represents approximately 80% of all cases of bladder cancer. It consists primarily of low-grade tumors but has been associated with a high recurrence rate. The high recurrence rate is a significant challenge in its management and treatment plan. Recurrence can occur within months of initial treatment and can lead to more invasive treatment, including surgery combined with additional rounds of chemotherapy. Although the 5-year relative survival rate for patients with NMIBC is around 90%, the risk of recurrence is also high, with up to 70% of patients experiencing a recurrence within 5 years of initial treatment. For this reason, ongoing surveillance and monitoring are critical for people with NMIBC. Invasive cystoscopy, the current standard of care for NMIBC diagnosis and surveillance, can be uncomfortable and painful and carry the risk of complications such as bleeding, infection, and bladder perforation. The development of a fast and non-invasive biopsy-based assay would significantly improve the management of NMIBC. A liquid biopsy-based assay would provide a less invasive alternative that could be used to monitor the disease and detect recurrence while reducing the need for invasive cystoscopy. Methods A fast liquid biopsy-based assay is used with urine samples to enhance the detection of cancer-specific biomarkers. Here, we describe a fast spectroscopic approach for detecting NMIBC recurrence in urine samples. Before the cystoscopy examination, urine samples from 62 previously diagnosed NMIBC patients were collected at their follow-up appointments. Fourier transforms infrared (ATR-FTIR) spectra were acquired from urine samples using the direct application. Utilizing parameter grid searching, spectral processing, and normalization were enhanced. Multivariate and principal component analyses (PCA) were employed to examine the technical variability. Results Cystoscopy outcomes of 62 NMIBC patients (41 cancer-free, 21 recurrences) were documented and used as a reference to our non-invasive approach. We examined the performance of 35 machine learning models using a training set (70%) and a held-out test set (30%). A Regularized Random Forests (RRF) model attained an AUROC of 0.92 with a sensitivity of 86% and a specificity of 77%. The variable importance and predictive ROC spikes around 2912 cm−1 have confirmed the peak of lipid CH2 asymmetrical stretching. An additional spike is also observed around 2980 cm−1, reflecting the stretching vibrations of methyl hydrocarbon chains. Analyzing processed spectra clearly reveals spectral differences between recurrence and NMIBC-free samples. Together, our results suggest an altered lipid profile in urine samples of the recurrent NMIBC patients. Conclusion To the best of our knowledge, this is the first study showing the CH2 lipid asymmetrical fingerprint on the FTIR spectra in the range of 2800 to 3000 cm−1, indicating the recurrence of NMIBC. Because of this explicit fingerprint, this liquid-biopsy spectroscopic technique can offer a promising non-invasive diagnostic tool for the early detection of recurrent NMIBC.

Interaction mechanism of pea proteins with selected pyrazine flavors: Differences in alkyl numbers and flavor concentration

The mechanism of pea protein (PPI) adsorbing flavor components of cooked beef (pyrazine flavor compounds with different concentrations and different numbers of alkyl groups) was researched by spectroscopic and molecular docking approaches. The binding ability results showed that the concentration of pyrazines and the number of alkyl groups in pyrazine strongly influenced the adsorbing ability of PPI. The binding ability of PPI to the pyrazines decreased in the order 2,3,5-trimethyl-pyrazine (TRP) > 2,5-dimethyl pyrazine (DP) > 2-methylpyrazine (MP). The increase in the concentration of pyrazine flavor compounds promoted the enhancement of the adsorption capacity of PPI. Fluorescence and time-resolved fluorescence analysis showed that different molecular structures caused by the amount of alkyl groups on a pyrazine ring showed different quenching types: MP and DP were mainly subjected to static quenching, and TRP with more alkyl groups was mainly subjected to dynamic quenching. During the adsorption of pyrazine flavor compounds, the structure on the peptide bond of pea protein is destroyed. The conformation of pea protein expanded gradually, and the protein changed from ordered structure to disordered structure with lower ΔH. The interactions between pyrazine and pea protein were spontaneous from thermodynamic analysis. Combined with the results of molecular docking, hydrophobic interactions were dominant in the noncovalent interactions between MP and pea protein, whereas hydrogen bonding was dominant between DP/TRP and pea protein. TRP with more alkyl groups could generate new interactions with PPI (π-π stacking interaction) to improve the adsorption capacity of PPI. Pyrazine with more alkyl groups showed a stronger binding force with pea protein to improve the ability of pea protein to adsorb pyrazine flavor compounds, and they displayed different fluorescence quenching mechanisms. This study could provide a theoretical basis for flavor selection and control in the production of pea protein-based meat analogs and thus improve the overall flavor of plant protein-based meat analog products.

Raman identification of pigments and opacifiers: Interest and limitation of multivariate analysis by comparison with solid state spectroscopical approach—I. Lead‐tin and Naples Yellow

AbstractLead‐tin/Naples Yellow provides a bright yellow color often used in combination with a blue‐colored glass to obtain a variety of green hues to decorate enameled glass, metalware, and ceramics. From the analysis of about hundreds of enameled objects from French and Chinese productions of the 18th century, we identify and compare the Raman signatures representative of these yellow pigments. For the first time, we propose several procedures that allow us to compare our data with those obtained from the literature on the spectra of synthesized pigments also characterized by XRD. A first approach is a reasoned analysis of the parameters obtained from the spectral decomposition carried out on spectra visually selected as the most different and the “purest.” A second approach uses multivariate analyses with principal component analysis (PCA) or hierarchical clustering of the spectra and of the band parameters originating from a spectral decomposition. It appears that the precise identification of the phase from simple observation of the sole Raman signature may be unreliable when only main peaks are detected due to the large non‐stoichiometry of the phases and the resulting similarity of the Raman signatures. PCA analysis of the total Raman spectra does not allow relevant classifications due to the strong contributions induced by the bands of the silicate matrix. However, the combination of a reasoned analysis of the Raman spectra with the PCA of spectroscopic parameters extracted from Raman spectral decomposition appears effective in categorizing the different pigments. From the results discussed, at least three types of Raman signatures are identified for each Sn‐ and Sb‐based pigment and correlate with the type, the period, and the location of enamel production.

Hydroxychloroquine-Loaded Chitosan Nanoparticles Induce Anticancer Activity in A549 Lung Cancer Cells: Design, BSA Binding, Molecular Docking, Mechanistic, and Biological Evaluation.

The current study describes the encapsulation of hydroxychloroquine, widely used in traditional medicine due to its diverse pharmacological and medicinal uses, in chitosan nanoparticles (CNPs). This work aims to combine the HCQ drug with CS NPs to generate a novel nanocomposite with improved characteristics and bioavailability. HCQ@CS NPs are roughly shaped like roadways and have a smooth surface with an average size of 159.3 ± 7.1 nm, a PDI of 0.224 ± 0.101, and a zeta potential of +46.6 ± 0.8 mV. To aid in the development of pharmaceutical systems for use in cancer therapy, the binding mechanism and affinity of the interaction between HCQ and HCQ@CS NPs and BSA were examined using stopped-flow and other spectroscopic approaches, supplemented by molecular docking analysis. HCQ and HCQ@CS NPs binding with BSA is driven by a ground-state complex formation that may be accompanied by a non-radiative energy transfer process, and binding constants indicate that HCQ@CS NPs-BSA was more stable than HCQ-BSA. The stopped-flow analysis demonstrated that, in addition to increasing BSA affinity, the nanoformulation HCQ@CS NPS changes the binding process and may open new routes for interaction. Docking experiments verified the development of the HCQ-BSA complex, with HCQ binding to site I on the BSA structure, primarily with the amino acids, Thr 578, Gln 579, Gln 525, Tyr 400, and Asn 404. Furthermore, the nanoformulation HCQ@CS NPS not only increased cytotoxicity against the A549 lung cancer cell line (IC50 = 28.57 ± 1.72 μg/mL) compared to HCQ (102.21 ± 0.67 μg/mL), but also exhibited higher antibacterial activity against both Gram-positive and Gram-negative bacteria when compared to HCQ and chloramphenicol, which is in agreement with the binding constants. The nanoformulation developed in this study may offer a viable therapy option for A549 lung cancer.

Differences and similarities in biophysical and biological characteristics between U87 MG glioblastoma and astrocyte cells.

Current cancer studies focus on molecular-targeting diagnostics and interactions with surroundings; however, there are still gaps in characterization based on topological differences and elemental composition. Glioblastoma (GBM cells; GBMCs) is an astrocytic aggressive brain tumor. At the molecular level, GBMCs and astrocytes may differ, and cell elemental/topological analysis is critical for identifying potential new cancer targets. Here, we used U87 MG cells for GBMCS. U87 MG cell lines, which are frequently used in glioblastoma research, are an important tool for studying the various features and underlying mechanisms of this aggressive brain tumor. For the first time, atomic force microscopy (AFM), scanning electron microscopy (SEM) accompanied by energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) are used to report the topology and chemistry of cancer (U87 MG) and healthy (SVG p12) cells. In addition, F-actin staining and cytoskeleton-based gene expression analyses were performed. The degree of gene expression for genes related to the cytoskeleton was similar; however, the intensity of F-actin, anisotropy values, and invasion-related genes were different. Morphologically, GBMCs were longer and narrower while astrocytes were shorter and more disseminated based on AFM. Furthermore, the roughness values of these cells differed slightly between the two call types. In contrast to the rougher astrocyte surfaces in the lamellipodial area, SEM-EDS analysis showed that elongated GBMCs displayed filopodial protrusions. Our investigation provides considerable further insight into rapid cancer cell characterization in terms of a combinatorial spectroscopic and microscopic approach.

Deciphering conformational changes in human serum albumin induced by bile salts using spectroscopic and molecular modeling approaches

Bile salts are physiologically-important natural amphiphilic biosurfactants synthesized in the liver and play a vital role in the solubilization and digestion of dietary lipids, cholesterol, and other fat-soluble compounds in the body. Bile salts also exhibit pharmacological and biological uses as carriers for transporting scarce water-soluble drugs and other chemicals owing to their unique emulsifying, solubilizing capacities and micelle forming ability. In this context, we present an endeavor towards the possibilities underlying the interaction and binding between the most abundant plasma protein namely, human serum albumin (HSA) and bile salts to demonstrate an intriguing interplay of hydrophobic, electrostatic and hydrogen bonding effects using steady state absorption, fluorescence emission, anisotropy, time-resolved emission, and molecular modelling approaches. The outcome illuminates how amphiphilic interfaces of bile salts under various physico-chemical conditions trigger the conformational changes and binding affinities of native and molten-globule forms of HSA. To elucidate non-covalent interactions during HSA-bile salt supramolecular host–guest complex formation, changes in intrinsic (tryptophan) and extrinsic (ANS) fluorescence have been investigated. The results reveal upon binding of bile salts in subdomain IIA of HSA, the protein undergoes conformational changes mediated primarily by hydrophobic interactions. Furthermore, time-resolved fluorescence measurements provide important structural and dynamical insights into the protein-bile salt supramolecular complexes. Additionally, molecular docking studies on these complexes clearly reveal spontaneous binding of bile salts into subdomain IIA of HSA while suggesting that the binding affinity decreases with the decreasing order of hydrophobicity of the bile salts (NaDC > NaC > NaTC) (ΔGdock = −29.64 kJ mol−1, −26.15 kJ mol−1, −14.35 kJ mol−1), respectively. This study exclusively highlights the molecular mechanism of conformational perturbation in the native (pH 7) and molten-globule (pH 3) forms of HSA, induced by bile salts. We believe that the results reported herein will be helpful in the design and formulation of protein-bile salt-based pharmacological carriers suitable for drug delivery.

Oregano herb adulteration detection through rapid spectroscopic approaches: Fourier transform-near infrared and laser photoacoustic spectroscopy facilities

Oregano is a culinary herb known and used worldwide, whose demand and cost encourage illegal activities in terms of fraud, especially adulteration. The scope of this study is to provide a rapid, cost-effective and easy-to-use approach to detect the adulteration of oregano with a common matrix, the olive leaves. Two analytical solutions were considered, Fourier transform near infrared (FT-NIR), using two different instruments, and laser photoacoustic spectroscopy (LPAS). Different raw data preprocessing procedures were applied, Principal Component Analysis (PCA) was used for preliminary data visualisation, while Partial Least Squares Regression (PLS-R) and Discriminant Analysis (PLS-DA) allowed the authors to classify samples with different adulteration percentages. FT-NIR performed better than LPAS, perhaps also because the photoacoustic system is still an experimental prototype. For example, the coefficient of determination R2 between actual and predicted adulterant concentrations was in the range 0.93–1.00 for FT-NIR and in the range 0.86–0.96 for LPAS. Nevertheless, this allowed the use of a low level data fusion approach to increase the consistency of the statistical model. The fusion between raw data from the LPAS prototype and one of the FT-NIR instruments gave optimal results, confirming the potential of these analytical solutions for the identification of oregano adulterants. The approaches used in the present work could be applied to the identification of other adulterants in herbs and spices by food companies for quality control measurements, possibly for on line and in field analysis.

Experimental and computational study on the spectroscopic approach, chemical reactivity, hyperpolarizabilities and in-silico ligand-protein docking of 5-Chloro-2,4,6-trifluoropyrimidine

The 5-Chloro-2,4,6-trifluoropyrimidine (5CTFP) was chosen for extensive investigation of its theoretical and experimental vibrational assignments, structural discussion, and spectroscopic studies of Fourier-transform infrared (FT-IR), Fourier transform-Raman (FT-Raman), Ultraviolet–visible (UV–vis), and Nuclear magnetic resonance (NMR) by Hartree-Fock (HF) functional with 6-311+G(2d,p) basis set. The spectrum of detailed vibrational interpretation was to be provided by the MOLVIB software. Bonding orbitals participate in all stages of NBO analysis as donors and acceptors, which stabilises molecules through intermolecular charge transfer. Molecular docking research was used to foreseen the binding interactions of 5CTFP derivative with the estrogen receptor 3WZD. Auto-dock software was used to conduct receptor-ligand docking investigation. According to the molecular docking results, the highest mean negative binding affinity (−5.639 kcal/mol) was exhibited by the current chemical. Based on five-point rule of Lipinski, drug similarity was determined, and the ADMET variables were also predicted.

Synthesis, spectral elucidation, thermal study, DFT calculations and biological application of new nano sized coordination compounds of a barbiturate based ligand

Novel titanium (IV), vanadyl (II), nickel (II), copper (II), cobalt (II), mercury (II) and silver (I) coordination compounds were established from a ligand created from a diazotization coupling process between 1-(4-aminophenyl)ethanone and barbituric acid. Analytical, spectroscopic, and thermal approaches were used to detect the best structural geometry of the compounds. The coordination compounds were constructed with (1M:2L) stoichiometry. With the exception of titanium (IV), vanadyl (II), and silver (I), all chelated compounds were non-electrolytes. Except for the vanadyl complex, which possessed square pyramidal geometry, and the silver one with tetrahedral geometry, the chelates of titanium (IV), copper (II), nickel (II), mercury (II) and cobalt (II) possessed an octahedral one. The ligand functioned as an ON-neutral bidentate moiety. The thermal manner of all compounds was studied by thermogravimetric analysis (TGA). According to XRD and TEM analysis, all compounds were nanosized. Theoretical calculations were performed to gain more information about the structure of the ligand and Ag chelate by DFT/B3LYP/LanL2DZ. The ligand and some of its chelates were explored as antibacterial, antifungal, and antitumor agents. According to the findings, the (H2L) activity was enhanced by complexation. The antitumor activity of the Ag(I) chelate was dramatically higher than that of the ligand and other chelates, with an IC50 of 11.5 gmL-1. For antimicrobial, Cu(II) chelate outperformed other complexes and the control drug against A. brasiliensis, B. cereus and P. vulgaris.

Design, synthesis, biological evaluation, and bio-computational modeling of imidazo, thieno, pyrimidopyrimidine, pyrimidodiazepene, and motifs as antimicrobial agents

Abstract In the drug chemistry industry, synthesizing a talented exclusive series of aza-polyheterocyclic compounds was crucial. Aminopyrimidine nucleus reacted with two equivalents of benzaldehyde in the presence of KOH as a starting material to bring about imidazopyrimidine derivative, which experienced intermolecular cyclization using carbon disulfide, Br2/AcOH, and/or HNO2 to produce thiazole, thieno, and/or nitro pyrimidine derivative, respectively. Accordingly, the nucleus of Aminopyrimidine was prepared and used to develop the novel polyheterocyclic systems acylated with two moles of succinic anhydride to furnish the imidazolopyrimidine derivative. Benzylidene ethyl cyanoacetate and aminopyrimidine undergo (3 + 4) intermolecular cycloaddition 1,3 H shift followed by hydrolysis and after CO2 evolution provided diazepine derivative. The diazepine derivative was attained due to the cyclo-condensation of the starting material and acetylacetone. Moreover, the structure of the novel synthesized compound series was exploited and verified via spectroscopic approaches. The synthesized series were tested for antimicrobial activity against gram-positive and gram-negative bacterial strains and antifungal activity. The thienopyrimidine derivatives and diazepine exhibited unusual antimicrobial activity. Furthermore, the molecular docking studies confirmed the biological studies with Molecular Operating Environment and petro orisis molinspiration studies, which proved the activity of compounds 4, 5, 7, 10, 13, and 16.