UV Spectroscopy Research Articles

Formation mechanism of nanopores in dense films of anodic alumina

Constant-current anodization of pure aluminum was carried out in non-corrosive capacitor working electrolytes to study the formation mechanism of nanopores in the anodic oxide films. Through comparative experiments, nanopores are found in the anodic films formed in the electrolytes after high-temperature storage (HTS) at 130 °C for 240 h. A comparison of the voltage−time curves suggests that the formation of nanopores results from the decrease in formation efficiency of anodic oxide films rather than the corrosion of the electrolytes. FT-IR and UV spectra analysis shows that carboxylate and ethylene glycol in electrolytes can easily react by esterification at high temperatures. Combining the electronic current theory and oxygen bubble mold effect, the change in electrolyte composition could increase the electronic current in the anodizing process. The electronic current decreases the formation efficiency of anodic oxide films, and oxygen bubbles accompanying electronic current lead to the formation of nanopores in the dense films. The continuous electronic current and oxygen bubbles are the prerequisites for the formation of porous anodic oxides rather than the traditional field-assisted dissolution model.

Comprehensive analysis of organic dye doped metal-coordinated single crystals: A study of structural, optical, thermal, dielectric, piezoelectric and mechanical characteristics

Organic dye can induce positive changes in optical, mechanical and electrical properties of semi-organic single crystals. Single crystals of pure and 0.01 mol% SSY dye doped ZTS are grown from a slow evaporation solution technique. The structural properties of pure and SSY-dyed ZTS crystals are characterized using SCXRD and PXRD, confirming the maintenance of crystallinity and incorporation of dye molecules within the host lattice of ZTS crystal. Both ZTS crystals belong to orthorhombic crystal system with space group Pca21. The refined lattice parameters and cell volume of present pure ZTS crystal are a = 11.1723 Å, b = 7.7989 Å, c = 15.5357 Å, α = β = γ = 90°, V = 1353.6762 Å3. The intensity of all Raman peaks in ZTS is enhanced by the incorporation of dye. Optical spectroscopic UV–visible and photoluminescence techniques highlight the comparative studies of light absorption, energy bandgap, optical constants and fluorescence emission. An increment of 0.05 eV in optical bandgap is observed in dyed ZTS. The dielectric properties with variation in frequency range (23 Hz–10 MHz) at different temperature range (30–100 °C) are evaluated through impedance spectroscopy, showing an increase in dielectric constant around 15 % and reduction in dielectric loss, indicating potential for improved performance in electronic applications. A significant enhancement is observed in the piezoelectric coefficient (d33) in dyed ZTS single crystals. The d33 value of ZTS is increased from 2.75 to 2.95 pC/N by the doping of organic dye. Vickers micro-hardness tester is used to know the mechanical strength through micro-indentation, which illustrated an increase in the hardness nature of dyed ZTS single crystals. These findings provide a foundation for the future development of ZTS-based materials for technological applications, offering a promising route for the advancement of functional materials in the domain of piezoelectric and optoelectronic technologies.

An investigation of the structure property relation of Na2MnWO6 for device application

This communication delves into the structural, microstructural, dielectric, impedance, modulus, and optical properties of the double-perovskite ceramic Na2MnWO6. Our X-ray diffraction study revealed a multiphase crystal structure in this ceramic, a result of high-temperature mixed-oxide synthesis. Morphological studies indicated a nearly uniform grain scattering and distribution with minimal spaces. The Maxwell-Wagner model, by addressing alternative polarisation mechanisms, studied the frequency-dependent dielectric properties. Our study of temperature-dependent dielectric permittivity identified a ferroelectric to paraelectric phase transition dielectric aberration. The material’s NTCR characteristic was determined using impedance analysis. Jonscher’s power law showed that the conduction mechanism follows the overlapping of large polaron tunnelling and correlated barrier hopping models, establishing the link between conductivity and frequency. Relaxation and conduction activation energies support electron hopping. UV spectroscopy revealed a band gap of 4.01 eV, and temperature-dependent resistance studies suggest a potential use in thermistors with due parameters. These findings significantly enhance our understanding of NMWO, paving the way for its potential uses in electronics and optics, owing to its unique structural, electrical, and optical features.

Metronidazole Analysis: Method Development and Validation by using UV Spectroscopy

Metronidazole Analysis: Method Development and Validation by using UV Spectroscopy

Green synthesis of palladium nanoparticles using Asterarcys sp. and their applications

Asterarcys-mediated algal extract, which is non-toxic and renewable, was used to synthesize palladium nanoparticles (PdNPs) efficiently and ecologically friendly. The palladium nanoparticle's fabrication was seen within two hours. UV spectroscopy, FTIR, XRD, SEM, EDX and TEM with SAED pattern were used to confirm the properties of the synthesized nanoparticles. Palladium nanoparticles have been developed, indicated by their deep brown color and broad UV-visible absorption spectra. The SAED and XRD patterns of the manufactured nanoparticles provided evidence of their face-centred cubic crystal structure. Because of reflections from the (1 1 1), (2 0 0), (2 2 0), (3 1 1), and (2 2 2) planes, the XRD pattern is broad, indicating that the FCC nanoparticles are crystalline in nature. The biomolecule responsible for Pd2+ reduction and PdNPs capping has been found by analyzing the FTIR spectra of dried PdNPs and dry algal powder. The average particle size, according to a TEM image, is 13 nm, whereas it ranges from 4 to 24 nm. In moderate reaction conditions, the catalytic activity of PdNPs was investigated in C-C cross-coupling processes including Mizoroki-Heck and Suzuki-Miyaura reactions. 1H NMR and 13C NMR were used to characterize the isolated product. The PdNPs exhibited strong catalytic activity and produced excellent conversion of the corresponding products.

Biological Effects of Green Synthesized Al-ZnO Nanoparticles Using Leaf Extract from Anisomeles indica (L.) Kuntze on Living Organisms.

The synthesis of Al-ZnO nanoparticles (NPs) was achieved using a green synthesis approach, utilizing leaf extract from Anisomeles indica (L.) in a straightforward co-precipitation method. The goal of this study was to investigate the production of Al-ZnO nanoparticles through the reduction and capping method utilizing Anisomeles indica (L.) leaf extract. The powder X-ray diffraction, UV spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy with EDAX analysis were used to analyze the nanoparticles. X-ray diffraction analysis confirmed the presence of spherical structures with an average grain size of 40 nm in diameter, while UV-visible spectroscopy revealed a prominent absorption peak at 360 nm. FTIR spectra demonstrated the presence of stretching vibrations associated with O-H, N-H, C=C, C-N, and C=O as well as C-Cl groups indicating their involvement in the reduction and stabilization of nanoparticles. SEM image revealed the presence of spongy, spherical, porous agglomerated nanoparticles, confirming the chemical composition of Al-ZnO nanoparticles through the use of the EDAX technique. Al-ZnO nanoparticles showed increased bactericidal activity against both Gram-positive and Gram-negative bacteria. The antioxidant property of the green synthesized Al-ZnO nanoparticles was confirmed by DPPH radical scavenging with an IC50 value of 23.52 indicating excellent antioxidant capability. Green synthesized Al-ZnO nanoparticles were shown in in vivo studies on HeLa cell lines to be effective for cancer treatment. Additionally, α-amylase inhibition assay and α-glucosidase inhibition assay demonstrated their potent anti-diabetic activities. Moving forward, the current methodology suggests that the presence of phenolic groups, flavonoids, and amines in Al-ZnO nanoparticles synthesized with Anisomeles indica (L.) extract exhibit significant promise for eliciting biological responses, including antioxidant and anti-diabetic effects, in the realms of biomedical and pharmaceutical applications.

Synthesis ADMET molecular docking, MD simulation and MM-PBSA investigations of a novel hetero-steroid with Anti-proliferative and Anti-inflammatory properties

Two novel steroidal derivatives 2 and 3were synthesized, one by aldol condensation and the other by further reaction of the adduct formed, with ethyl cyanoacetate. The synthesized compounds have been characterized using ¹H, ¹³C NMR, UV and FT-IR Spectroscopy. The in-silico identification of potential anticancer and anti-inflammatory activity with regard to the synthesized compounds was performed. ADMET analysis of the synthesized compounds were performed to check their pharmacokinetic behaviour as well as potential ability to act as major drug candidates. Docking and molecular dynamics simulations provided insights into synthesized compounds that binds in the active sites of all the proteins selected strongly indicating that both of them can act as versatile anti-cancer and anti-inflammatory drug while ADMET analysis showed compound 2 to be least toxic and depicts good absorption pattern which can further contribute as major bioactive compound with therapeutic potential.

Decrease in radiocesium adsorption of illite induced by soil organic matter: Quantity or quality?

Organic matter blocks highly selective frayed edge sites on clay minerals and reduces radiocaesium adsorption. The effects of different soil organic matter on Cs adsorption on illite have been investigated. The quantity and quality of soil organic matter was varied by extracting from three contrasting soils and varying extraction conditions. Extracted organic matter was quantified, and analysed using UV and fluorescent spectroscopy. Cs adsorption was markedly lower in soil aqueous extracts, than in simple electrolyte solution at the same ionic strength (IS). Part of the decrease was attributed to soluble soil potassium. After correction for ionic strength and potassium, the relative distribution coefficient of Cs, KdIS,K, decreased with increasing dissolved organic carbon (DOC) concentration. The correlation between KdIS,K and DOC was largely unchanged by taking into account any of the measured spectral parameters. We find no evidence that molecular size and composition of organic coatings determine their effect on the Cs adsorption properties of illite.

Exploring environmental sustainability through dimension reduction algorithms: A cost-effective UV spectroscopic method for simultaneous determination of veterinary binary mixtures of doxycycline hydrochloride and tylosin tartrate

This study presents a cost-effective and environmentally friendly approach for the simultaneous determination of a veterinary binary mixture comprising doxycycline hydrochloride (DOX) and tylosin tartrate (TYZ) utilizing UV spectroscopy alongside dimension reduction algorithms (DRAs). Seventeen DRAs were evaluated, and their performances were compared based on four metrics: mean squared error (MSE), mean absolute error (MAE), median absolute error (MedAE), and coefficient of determination (R2). Based on the performance indices, Isomap algorithm demonstrated the highest predictive capacity among all DRAs. MSE, MAE, MedAE and R2 values of (0.38, 0.28, 0.19 and 0.999) and (0.08, 0.26, 0.22 and 0.998) were obtained for calibration and test datasets, respectively across a concentration range 4.67–30 μg mL−1 for DOX. MSE, MAE, MedAE and R2 values of (0.54, 0.34, 0.19 and 0.994) and (0.07, 0.19, 0.07 and 0.998) were obtained for calibration and test datasets, respectively across a concentration range 3.51–24 μg mL−1 for TYZ. The developed method underwent validation utilizing the accuracy profile approach. An ecological impact assessment was carried out employing six greenness evaluation tools: The Green Solvent Selection Tool (GSST), National Environmental Methods Index (NEMI), the Assessment of Green Profile (AGP), carbon footprint analysis, Analytical Greenness Calculator (AGREE), and Complementary Green Analytical Procedure Index (Complex GAPI). Additionally, we applied blueness and whiteness assessments using Blue Applicability Grade Index (BAGI) and Red-Green-Blue 12 (RGB 12) algorithms, respectively. The proposed method demonstrated higher GSST scores, a more "green" profile in NEMI, a superior AGP profile, and better environmental sustainability in Complex GAPI. The calculated carbon footprint value was 0.0002 kg CO2 equivalent per sample, The AGREE score was 0.87, BAGI was assessed at 72.5, and the whiteness assessment by the RGB12 algorithm was 89.6. Statistical comparison of the proposed method with a previously reported HPLC method for dosage form analysis revealed no significant differences at a 95% confidence level. This study highlights the novelty of combining UV spectroscopy with dimension reduction algorithms, offering significant advancements over traditional UV and chemometric methods for the analysis of these drugs. This approach not only enhances the efficiency and accuracy of determining active ingredients in pharmaceutical dosage forms but also contributes to environmental sustainability.

Are nano-colloids controlling rare earth elements mobility or is it the opposite? Insight from A4F-UV-QQQ-ICP-MS

Rare earth element (REE) mobility in the environment is expected to be controlled by colloids. Recent research has detailed the structure of iron-organic colloids (Fe-OM colloids), which include both large colloids and smaller nano-colloids. To assess how these nano-colloids affect REE mobility, their interactions with REE and calcium (Ca) were investigated at pH 4 and 6. Using Asymmetric Flow Field Flow Fractionation (A4F) combined with UV and Triple Quadrupole Inductively Coupled Plasma Mass Spectrometry (QQQ-ICP-MS), Fe-OM nano-colloids were separated from bulk Fe-OM colloids and their REE and Ca content were analyzed. Without REE and Ca, nano-colloids had an average diameter of approximately 25 nm. Their structure is pH-dependent, with aggregation increasing as pH decreases. At high REE loadings (REE/Fe ≥ 0.05), REE induced a size increase of nano-colloids, regardless of pH. Heavy REE (HREE), with their high affinity for organic matter, formed strong complexes with Fe-OM colloids, resulting in large aggregates. In contrast, light REE (LREE), which bind less strongly to organic molecules, were associated with the smallest nano-colloids. Low REE loading did not cause noticeable fractionation. Calcium further enhanced the aggregation process at both pH levels by neutralizing the charges on nano-colloids. These findings indicate that REE can act as aggregating agent controlling their own mobility, and regulating colloid transfer.

Isolation, physico-chemical characteristics and acute toxicity determination of water-soluble polysaccharide from basidial raw material Ganoderma lucidum

As a result of the study, branched polysaccharides were isolated from the basidiomycete raw materials of Ganoderma lucidum. It has been established that the isolated fractions contain branched polysaccharides in the form of complexes with melanin. After purification of polysaccharides by ion-exchange chromatography, two fractions were obtained from basidial raw materials: neutral polysaccharides GW-1 with a yield of 25.71% and anionic polysaccharides GW-2, the yield of which was 5.26%, respectively. The physicochemical properties of the obtained samples were studied by IR and UV spectroscopy. The degree of purity of the obtained fractions of branched polysaccharides was established. Using gas chromatography, one-dimensional (13C NMR, 1H NMR) and two-dimensional (COSY, TOCSY, HSQC, HMBC, NOESY) NMR spectroscopy, the composition and molecular structure of the obtained polysaccharide samples were determined. The results showed that the isolated and purified polysaccharides are branched glucans with 1,4,6- and 1,3,6-bonds between glucopyranose units. Pharmacotoxicological studies were carried out on white outbred mice and it was found that the resulting polysaccharides belong to class V, practically non-toxic compounds (LD50 ≥ 2000 mg/kg). Isolated polysaccharides (GW) are promising biologically active components, on the basis of which it is possible to create drugs with hepatoprotective and antitumor activity.

Thermogravimetric and petrocollecting and petrodispersing study of the surfactants synthesized from the reaction of N1-(2-Aminoethyl)ethane- 1,2-diamine with fatty acids having different carbon chain length

In this scientific-research work, surfactants were synthesized from three different fatty acids, dodecanoic, tetradecanoic and hexadecanoic acid, with the participation of N1-(2-Aminoethyl)ethane-1,2-diamine and many of their properties were comparatively analyzed. The structure and composition of the obtained compounds were identified by IR and UV spectroscopy. In addition, the thermal characteristics of the complexes and the mass changes during the processes caused by the influence of temperature were studied by TG, DTA analysis. The thermal properties were studied in the “STA 449 F3” Jupiter (Germany, “NETZSCH”) synchronous thermoanalyzer, in the thermoprogrammed dynamic mode in an inert (nitrogen) environment in the range of 20–600 oC, starting from room temperature and increasing the temperature at a rate of 10 oC/min. Finally, in order to investigate the use of surfactants in the removal of oil spills from a water basin, petrocollecting and petrodispersing properties were studied in three different water samples with different salinity and mineralization. From the moment surfactant is issued, observations are made, the surface area of the oil slick is measured at certain time intervals and the value of K is calculated. When the crude oil layer is dispersed, the water surface cleaning coefficient (Kd) is measured as a percentage at certain time intervals.

Synthesized Bis-Triphenyl Phosphonium-Based Nano Vesicles Have Potent and Selective Antibacterial Effects on Several Clinically Relevant Superbugs.

The increasing emergence of multidrug-resistant (MDR) pathogens due to antibiotic misuse translates into obstinate infections with high morbidity and high-cost hospitalizations. To oppose these MDR superbugs, new antimicrobial options are necessary. Although both quaternary ammonium salts (QASs) and phosphonium salts (QPSs) possess antimicrobial effects, QPSs have been studied to a lesser extent. Recently, we successfully reported the bacteriostatic and cytotoxic effects of a triphenyl phosphonium salt against MDR isolates of the Enterococcus and Staphylococcus genera. Here, aiming at finding new antibacterial devices possibly active toward a broader spectrum of clinically relevant bacteria responsible for severe human infections, we synthesized a water-soluble, sterically hindered quaternary phosphonium salt (BPPB). It encompasses two triphenyl phosphonium groups linked by a C12 alkyl chain, thus embodying the characteristics of molecules known as bola-amphiphiles. BPPB was characterized by ATR-FTIR, NMR, and UV spectroscopy, FIA-MS (ESI), elemental analysis, and potentiometric titrations. Optical and DLS analyses evidenced BPPB tendency to self-forming spherical vesicles of 45 nm (DLS) in dilute solution, tending to form larger aggregates in concentrate solution (DLS and optical microscope), having a positive zeta potential (+18 mV). The antibacterial effects of BPPB were, for the first time, assessed against fifty clinical isolates of both Gram-positive and Gram-negative species. Excellent antibacterial effects were observed for all strains tested, involving all the most concerning species included in ESKAPE bacteria. The lowest MICs were 0.250 µg/mL, while the highest ones (32 µg/mL) were observed for MDR Gram-negative metallo-β-lactamase-producing bacteria and/or species resistant also to colistin, carbapenems, cefiderocol, and therefore intractable with currently available antibiotics. Moreover, when administered to HepG2 human hepatic and Cos-7 monkey kidney cell lines, BPPB showed selectivity indices > 10 for all Gram-positive isolates and for clinically relevant Gram-negative superbugs such as those of E. coli species, thus being very promising for clinical development.

Innovative Formulation and Evaluation of Phytosomal Nanoparticles from Ixora Coccinea Linn and its Pharmacological Screening

The use of herbal extracts in pharmaceutical formulations has gained significant attention due to their therapeutic potential and minimum side effects and shows pharmacological profiles as anti-inflammatory, anticancer, and antimicrobial. Thus, the intent of the current study was to develop a potential drug carrier system phytosomal nanoparticle using an extract of the plant “Ixora coccinea”. The extract of Ixora coccinea was prepared by using the maceration method and it is incorporated into Phytosome nanoparticles by using the solvent evaporation method. The impact of various process parameters and material attributes on the average particle size and drug entrapment efficacy. Extract loaded Phytosomal nanoparticles were characterized by particle size determination, Zeta potential, FTIR, and UV spectroscopy. The pharmacological screening consolidated antimicrobial activity was carried out by the well diffusion method, wherein it was performed against Gram Positive (B. Cerus, NCIM-2703) and Gram Negative (E. coli, NCIM 2832) bacteria strains. Which resulted in showing phytosomal nanoparticles show good activity than the extract. The anti-inflammatory activity was carried out by the protein denaturation method, which concluded that Ixora Coccinea phytosomal nanoparticles show better activity. Therefore, it results in moderate anti-inflammatory activity as compared to standard Diclofenac sodium. Keywords: Phytosome nanoparticles, Solvent evaporation method, Invitro anti-inflammatory activity.

Photophysical Response of Propranolol in Biomimetic Micellar Media of Alkyltrimethylammonium Bromide Surfactants: Effect of pH and Alkyl Chain Length.

The photophysical behavior of a β-blocker drug propranolol (PPL) in micellar environments, formed by alkyltrimethylammonium bromide surfactants viz.; Cetyltrimethylammonium bromide (CTAB), Tetradecyltrimethylammonium bromide (TTAB), and Dodecyltrimethylammonium bromide (DTAB), has been investigated through fluorescence and UV-visible spectroscopic techniques at pH levels of 3.5, 7.4, and 10.4. The impact of pH on the critical micelle concentration (cmc) and micropolarity of micelles were assessed using pyrene as a photophysical probe. The cmc values were found to be lower at pH 10.4 compared to pH 7.4 and pH 3.5. Fluorescence emission intensities of PPL at 323nm, 338nm, and 352nm were significantly influenced by pH, hydrophobic alkyl chain length of surfactants, and their concentrations. Quenching experiments with Cetylpyridinium chloride (CpCl) indicated the localization of charged and uncharged forms of PPL within micelles, with quenching constant (Ksv) values dependent on alkyl chain length and pH. At pH < pKa, PPL is positioned near the Stern layer, whereas at pH 10.4, its naphthalene moiety resides near the hydrophobic micellar core. UV spectroscopy showed that the charged form of PPL interacted with micelles only above cmc, while the neutral form interacted even below the cmc. Density Functional Theory (DFT) reveals the HOMO of the surfactants to be localized on the hydrocarbon chains, and the LUMO localized around the quaternary ammonium unit. Upon complexation with PPL, both HOMO and LUMO shifted to the drug, thereby decreasing energy levels. The findings are explained based on weak noncovalent interactions, further supported and analyzed through Reduced Density Gradient (RDG) and Noncovalent Interaction (NCI) methods, confirming synergistic non-covalent interactions in surfactant-PPL complexes.

A novel chemical probe based on the salamo-Co(II) complex for the highly selective fluorescence detection of tyrosine

A new and rare Salamo-Co(II) complex probe L-Co2+ was designed and synthesised. The structure of the [Co3(L)2(μ-OAc)2(MeOH)2]⋅2H2O complex was obtained by X-ray diffraction experiments. Three Co(II) atoms are in a line in the complex, and all Co(II) atoms form a 6-coordinated octahedral configuration. The probe L-Co2+ selectively recognises tyrosine in DMF/H2O (8:2, v/v). Upon addition of tyrosine, the fluorescence intensity of L-Co2+ was enhanced in a short time. The probe showed high selectivity and sensitivity for tyrosine, detection limit is 4.27 × 10−8 M. The recognition mechanism of probe L-Co2+ for Tyr was inferred by FT-IR spectra, UV spectroscopy, ESI mass spectra and DFT calculations. Finally, due to the simplicity and specificity of the identification process, the probe was also subjected to a test paper experiment and a milk assay.

Screening of sweet potatoes varieties, physicochemical and biological activity studies of glycoproteins of selected varieties

In order to meet the nutritional and health needs of different consumers, the main nutrients of eight new sweet potatoes (SPs) varieties were to characterize by principal component analysis. The watermelon red (WR) variety is proving to be the preferred SPs variety because of its high nutritional value and unique sensory features. Three homogeneous fractions SPFG-1, SPFG -2 and SPFG-3 with yield of 53.02% ± 3.20%, 10.50% ± 0.61% and 5.20% ± 0.35% were obtained from the WR by multifrequency ultrasonic extraction (MUE), isolated and purified with DEAE Sepharose CL-6B and Sephadex G-100 gel chromatography. Physiochemical and structural characteristics of three fractions were studied with chemical components analysis, HPLC, HPGPC, and β-elimination, UV, FT-IR and CD spectrum analysis. SPFG-1, SPFG-2 and SPFG-3 were all conjugates with O-glycosylation with the molecular weight of 30.42 ± 2.12, 391.15 ± 25.12 and 6.85 ± 0.78 kDa, including seven monosaccharides and 17 amino acids with quite different mole percentages, that they were predominantly α-helix, β-folding and irregularly curled with a relatively small β-turning content. Meanwhile, the three conjugates exhibited excellent antioxidant and hypoglycemic activities by radical scavenging, α-glycosidase and α-amylase inhibition assays. These findings are helpful to promote the breeding, cultivation and promotion of new SPs varieties with higher nutritional value, as well as the development and application of glycoproteins.

Atranorin is a novel potential candidate drug for treating myelodysplastic syndrome

This work is devoted to the study of biocompatibility, cyto- and genotoxicity, mechanism of action and prospects for the use of atranorin, which is an AKT kinase inhibitor, for the treatment of myelodysplastic syndrome. Atranorin was isolated by preparative flash chromatography; identification was carried out by UV, IR, and NMR spectroscopy, mass spectrometry, and elemental analysis. Biocompatibility studies included studies of haemocompatibility, genotoxicity, antioxidant activity, cytotoxicity against ECV340 and HEK293 cell lines. Computer modelling of the interaction of atranorin with AKT kinase was carried out using docking followed by molecular dynamics of the resulting complexes; the ADMET properties of atranorin were also calculated. Flow cytometry included analysis of the expression level of PD-L1 and TIM-3 in the presence of atranorin on THP-1, Mono-Mac-1 and KG-1 cell lines, as well as human bone marrow cells.

Experimental and theoretical investigations for novel 6-nitroquinoxaline-2,3‑dione derivatives: Synthesis, characterization, DFT calculations, ADME analysis, hirshfeld surface calculations, molecular docking studies, and antiproliferation evaluation

This work describes the synthesis of eight different 6-nitro-1,4-disubstituted-quinoxaline-2,3‑dione derivatives (4a-h). The starting material, 6-nitroquinoxaline-2,3‑dione 3 was prepared by reacting 4-nitro-o-phenylenediamine 1 with oxalic acid 2 at reflux in hydrochloric acid. Compound 3 was alkylated with various alkyl halides under solid-liquid phase transfer catalysis (PTC) to give the dialkyl quinoxalines (4a-h). The structures of all compounds obtained were elucidated based on spectroscopic measurements: 1H, 13C NMR, MS and UV spectroscopy and confirmed by single-crystal X-ray diffraction studies in the case of 4a, 4b, 4f, and 4h. The geometrical parameters and spectral data were also compared with those of a DFT geometry optimization and molecular orbital calculation at the B3LYP/6–311++G (d, p) level of theory. The closest contacts between the molecules of the four structures were investigated by analyzing their Hirshfeld surfaces and docking investigations in the protein EGFR (pdbid: 4HJO). Moreover, the experimental results are correlated to the calculated ones and showed great compatibility. Cell proliferation was used to measure the immunomodulatory activity of 4a-h compared to a control consisting only of normal cells cultured alone to determine their antiproliferative screening which concluded that the quinoxaline derivatives 4c, 4d, 4f and 4g showed immunomodulatory potential.

Traffic lights inspired colorimetric sensing platform for cadmium/lead ions: PO43- induced structural change of porphyrin metal-organic framework

Developing rapid and user-friendly visual techniques for distinguishing and identifying heavy metal ions is a critical pursuit in food and environmental analysis. In this work, a zirconium-based metal organic framework (MOF) known as PCN-222 has been synthesized, serving as a colorimetric nanoplatform for the differentiation and detection of Cd2+ and Pb2+ in the presence of PO43-. The remarkable characteristic of PCN-222 stems from its reaction with PO43-, where the robust bonding between PO43- and Zr nodes triggers the collapses of PCN-222, leading to the release of ligands (TCPP) with visible alteration in solution color to light red. When exposure to Cd2+ and Pb2+, shifts to green and yellow, respectively, are discernible. These changes can be ascribed to differences in the size, atomic configuration, and electronegativity of the two metal ions, which impact their interaction with TCPP. The innovative concept of a nanomaterial traffic light is introduced based on these color transitions. Accurate quantification of Cd2+ and Pb2+ can be efficiently accomplished both individually and concurrently using UV spectroscopy and a mobile phone APP, providing adaptability in method selection depending on on-site conditions. Moreover, the platform effectively tackles selectivity challenges associated with ligand-based detection methods, showcasing high sensitivity, distinct visual indications, and simplicity in instrumentation requirements.