FTIR Spectra Research Articles

Desulfurising Fuels Using Alcohol-Based Deep Eutectic Solvents Using Extractive Catalytic Oxidative Desulfurisation Method

Removal of sulfur compounds from transportation fuels is a requirement in the worldwide effort to reduce emissions from transportation fuels. Refineries use the hydrodesulfurisation (HDS) process to reduce sulfur compounds in fuels. However, the HDS process requires high hydrogen pressure and temperature, making it costly. An alternative to the HDS process is oxidative desulfurisation via solvent extraction, which requires low-temperature operating conditions. In this regard, deep eutectic solvents (DESs) are attractive for researchers to desulfurise transportation fuels via solvent extraction due to their low-cost. In our study, DESs were synthesised using phenylacetic acid (PAA) and salicylic acid (SAA) as hydrogen bond acceptors (HBAs) and tetraethylene glycol (TTEG) as hydrogen bond donor (HBD) in the mole ratio of 1:2. DESs were characterised by using Fourier transform infrared (FTIR) spectroscopy. Physicochemical properties of DESs, such as density, viscosity and refractive index, were also measured. The synthesised DESs were used to extract organosulfur compounds from model fuel and actual diesel. An oxidation study was carried out for model fuel and diesel, followed by solvent extraction using these synthesised DESs. The extraction efficiency for PAA/TTEG(1:2) and SAA/TTEG(1:2) was achieved as 50.16% and 38.89% for model fuel at a temperature of 30°C using a solvent to feed ratio of 1.0 while for diesel, it was 38% and 37%. However, it increased to 77%, 68% and 54%, 73%, respectively, for PAA/TTEG(1:2) and SAA/TTEG(1:2) when the feedstocks were oxidised. These results showed better extraction performance of DES PAA/TTEG(1:2) than that of SAA/TTEG(1:2) at low temperature 30°C using combined extractive catalytic oxidative desulfurisation. Hence, the DES synthesised using SAA and TTEG in the molar ratio of 1:2 works better as an extraction solvent for removing organic sulfur compounds from fuels at low temperatures.

Evaluation of characterization and adsorption kinetics of natural organic matter onto nitric acid modified activated carbon

Natural organic substances (NOM) found in drinking water are a major contributor to disinfectant by-product formation and are potentially toxic to humans. Traditional water treatment techniques may not always effectively treat NOMs. Therefore, an advanced treatment method such as adsorption can be inexpensive, simple and efficient. The selected adsorbent's and the NOMs properties both affect the removal effectiveness of the adsorption method. Activated carbon (AC), which is widely used in real-scale water treatment plants, has been modified and used in recent years In order to oxidize the porous carbon surface, raise its acidic qualities, eliminate mineral components, and enhance the surface's hydrophilic qualities. In this research, AC was modified with nitric acid (M-PAC) and NOM removal was investigated. In addition, it is discussed how the modification with nitric acid changes the adsorbent structure and chemistry. A morphology with smooth and irregular voids was observed as a result of nitric acid modification of the original AC by SEM analysis. The particle size increased from 387.65 nm to 502.07 nm for the M-PAC adsorbent. The FTIR spectrum indicates that structures connected to aromatic rings get formed in the M-PAC adsorbent as a result of the modification. The highest NOM removal for the original powdered activated carbon (PAC), 47%, was observed at 36 hours of contact time. On the other hand, M-PAC adsorbent achieved 40% NOM removal at contact times of 72 hours and above. It was concluded that the pseudo-second order kinetic model better represented NOM adsorption for both adsorbents.

An insight into the characteristics of some oxidized low-grade coals of Indian origin

ABSTRACT The conversion of coal to a hydrophilic state presents a significant challenge for process engineers, especially when treating oxidized coals in flotation-based beneficiation plants. Flotation of oxidized coal often requires a substantial consumption of oily collectors, resulting in unacceptably low yields. To address this, several pre-processing methods have emerged for coal deoxidation, including mild grinding, surface activation, and ultrasonic or microwave treatment. However, their effective application depends on a thorough understanding of the degree of oxidation in the coals. Therefore, it is crucial to gain insights into the nature of oxidized coal before initiating the deoxidation process. This present study provides various characterization techniques such as XRD, SEM-EDS, FTIR Spectroscopy, Raman Spectroscopy, TGA, and Zeta Potential Analysis employed on oxidized low-grade coals. The study revealed that the proximate analysis of low-grade coals KC, DC, RC, and PC contains varying ash percentages of 32.65%, 44.47%, 25.44%, and 37.53%, respectively, with SiO2 and Al2O3 comprising over 80% of the total ash. XRD characterizations identified quartz and kaolinite as major mineral phases in all samples, while SEM-EDS confirmed rough coal surfaces with peeling, off-white aggregations, and surface pores. HGI value ranging from 80 to 91 was attributed to partial decomposition and surface cracking due to oxidation. FTIR spectra revealed pronounced oxidation behavior, with strong −OH peaks in the 3600–3700 cm−1 range. Zeta potential analysis affirmed the oxidized nature of the coals with a pH below 3.1 and an extremely negative zeta potential beyond 3.1. The findings mentioned above showcase the distinct characteristics of oxidized low-grade coals, which serve as crucial indicators for exploring coal beneficiation, especially through the flotation process.

Tailoring of Gelatin-Chitosan Nanofibers Functionalized with Eucalyptus Essential Oil via Electroblowing for Potential Food Packaging and Wound Dressing Applications

AbstractIn recent years, new approaches to fabricating nanofiber networks for potential applications in wound dressing and food packaging have been in the spotlight. This study aimed to produce functional webs based on gelatin, chitosan, and eucalyptus essential oil using the electro-blowing method instead of traditional spinning methods such as electrospinning. The resultant nanofiber webs exhibit promising morphological characteristics, including reduced fiber diameters, enhanced air permeability, and improved thermal stability. The integration of chitosan and eucalyptus essential oil overcomes limitations associated with gelatin, offering enhanced mechanical properties, antibacterial efficacy, and potential attributes for wound healing and food packaging. The combination of gelatin and chitosan contributes to biodegradability and biocompatibility, crucial for developing materials compatible with the natural environment. The addition of eucalyptus essential oil provides an additional layer of antimicrobial protection, aligning with sustainability goals in wound care and active food packaging. A comprehensive analysis encompassing SEM morphologies, fiber diameters, air permeability, FTIR spectra, TGA thermograms, and contact angle measurements establishes a thorough understanding of the fabricated nanofiber webs’ characteristics. Despite the favorable properties exhibited by the developed nanofiber webs for wound healing and food packaging applications, the incorporation of eucalyptus essential oil resulted in a reduction in tensile strength and elongation ratios. This observation highlights the necessity for further optimization and fine-tuning of the formulation to strike a balance between antimicrobial benefits and mechanical properties. Distinguished by its unique combination of gelatin, chitosan, and eucalyptus essential oil, this research contributes to the advancement of nanofiber technology, expanding knowledge in the field and paving the way for the development of advanced materials with enhanced therapeutic properties for wound healing and food packaging. Graphical Abstract

N1,N10-dihydroxydecanediamide: Its separation performance and action mechanism for malachite, calcite and quartz

In this study, a novel collector, N1,N10-dihydroxydecanediamide (DHH) was synthesized in our lab and introduced in flotation of malachite ore. The separation performance and action mechanism of DHH were explored and compared with octyl hydroxamic acid (OHA). The results of single mineral flotation tests indicated that DHH exhibited a stronger collecting ability to malachite and better selectivity against quartz and calcite than OHA, and floated out 94 % malachite, 8.5 % quartz and 17 % calcite at pH = 10 with a collector concentration of 60 mg/L. The FTIR spectra, zeta-potential tests and XPS tests proved that DHH could absorb onto malachite surface though a chemical mode. DFT calculation results showed that DHH anion owned a stronger affinity to malachite than DHH molecular and OHA anion/molecular, and its bis-minerophilic groups could form C(=O)NHO-Cu bond with surface Cu atom. It exhibited that DHH was an excellent candidate and capable for high efficiency flotation of malachite ore.

Enhancing the efficiency of hemp fiber dyeing with natural dyes: Indigo and lac

Hemp fibers dyed with natural dyes are environmentally sustainable, but it is typically difficult to achieve an intense shade and washing durability. In this study, mercerization and cationization using polyelectrolyte, Poly-diallyldimethylammonium chloride (polyDADMAC), were chosen to enhance the dyeing efficiency and mechanical properties. Indigo and lac were chosen as natural dyes due to their widespread use. SEM demonstrated that untreated fibers contained the non-cellulose boundary layer on the surfaces, but after mercerization, the surfaces were smoother, making them suitable for absorbing natural dyes. In agreement with the FT-IR, the spectra of non-cellulose disappeared after mercerizing. Following cationization, the FT-IR spectra confirmed the consequences of using poly-DADMAC. Tensile testing demonstrated that mercerized hemp yarns were 34.1% stronger compared to untreated hemp yarns due to the decrease in non-cellulose content and that the intermolecular attraction of cellulose was not disturbed. The color strength and fastness properties were described by the K/S value. Mercerization considerably affected the K/S of indigo dyeing, while cationization affected lac dyeing significantly. Besides that, both treatments improved fastness properties as well.

Physicochemical analysis of deterioration affecting the darkening of rock art in Maros-Pangkep, South Sulawesi, Indonesia

This study investigates the darkening processes affecting Maros-Pangkep rock art through a comprehensive multianalytical approach. We integrate in-situ color index measurements using Nix color Pro 2 with various physicochemical characterization techniques, including optical microscopy, XRF, SEM-EDS, Raman spectroscopy, and FTIR. By examining microbial, geochemical, and anthropogenic factors on rock art pigment samples, we establish a clear correlation between the formation of blackish-gray layers and reduced chromaticity values, indicating a significant darkening process. The shift in pigment color from vibrant red or purple to a prevailing blackish-gray hue is attributed to surface accumulation. Surface morphology analysis reveals distinct blackish deposits and delicate white fibrous structures on darkened rock art. Elemental composition analysis demonstrates heightened blackish deposit formation and increased phosphorus content in darkened samples. SEM-EDS characterization exposes gypsum morphology, with filament-like structures prevailing in heavily darkened samples, highlighting the role of both geochemical and microbial factors in deposit layer formation. FTIR spectra results confirm the presence of gypsum minerals, which are attributed to the substrate minerals and/or mineral weathering product, and unveil the existence of organic compounds, indicating microbial activity. Additionally, Raman spectroscopy reveals the anthropogenic contribution, notably soot deposition produced by human activities, to the darkening of rock art. This study underscores the need for a holistic preservation approach addressing natural, human, and microbial impacts on cultural heritage sites. Further research is also needed to conduct cross-sectional stratigraphical analysis to understand the accurate mechanism of the deterioration process on the rock art. Moreover, excavation measures regarding the possible relationship of soot deposition with human activities are also important to be carried out at the sites.

Synthesis of conducting polymer by gamma Co-60 ray in aqueous solution

This report presents the findings of a study on the synthesis of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) using gamma Co-60 radiation in an aqueous solution saturated with N2 gas, containing 5 mM EDOT monomer and 0.2 M isopropanol. Gamma radiation with doses ranging from 12 kGy to 58 kGy from a gamma Co-60 source was employed. To assess the chemical composition of the solution before and after irradiation, UV-Vis and FTIR absorption spectra were examined. The results indicated the formation of yellow suspensions in the solution after irradiation, along with the emergence of dimers, oligomers, and PEDOT polymers as evidenced by UV-Vis spectra. The dried powders obtained from the irradiated solutions confirmed the successful synthesis of PEDOT, exhibiting distinct chemical structural characteristics in the FTIR spectra. These findings demonstrate the effective radiation-induced synthesis of conducting PEDOT polymer using gamma Co-60 irradiation.

Design and Biocompatibility of Biodegradable Poly(octamethylene suberate) Nanoparticles to Treat Skin Diseases.

Biodegradable aliphatic polyester formulations as carriers for topical drug delivery show the potential to encapsulate structurally different therapeutic compounds. Poly(octamethylene suberate) (POS) nanoparticles (POS-NPs) were used as a matrix to encapsulate four therapeutic molecules used to treat skin disorders: caffeine (CF), quercetin (QR), hydrocortisone (HC), and adapalene (AD). Hydrophobicity and chemical structure of bioactive compounds (BCs) influenced the physicochemical stability of drug-loaded nanoparticles. The particle size of drug-loaded nanoparticles was between 254.9 nm for the CF-POS-NP and 1291.3 for QR-POS-NP. Particles had a negative charge from -27.6 mV (QR) to -49.2 mV (HC). Drug loading content for all BC-POS-NPs varies between 36.11 ± 1.48% (CF-POS-NP) and 66.66 ± 4.87% (AD-POS-NP), and their entrapment efficiency is relatively high (28.30 ± 1.81% and 99.95 ± 0.04%, respectively). Calorimetric analysis showed the appearance of polymorphism for AD- and HC-loaded systems and the drug's complete solubilisation into all nanoparticle formulations. FTIR and NMR spectra showed apparent drug incorporation into the polymer matrix of NPs. The encapsulation of BCs enhanced the antioxidative effect. The prepared POS nanoparticles' cytotoxicity was studied using two dermal cell lines, keratinocyte (HaCaT) cells and fibroblasts (HDFn). The nanoparticle cytotoxic effect was more substantial on HaCaT cell lines. A reconstructed human epidermis (RHE) was successfully used to investigate the penetration of polymeric NPs. Based on permeation and histology studies, HC-POS-NPs and CF-POS-NPs were shown not to be suitable for dermal applications with the explored drug concentrations. AD presents a high permeation rate and no toxic impact on RHE.

Synthesis , Evaluation of the Biological Activity and Anti-Oxidant for Some Heterocyclic Compounds Seven-membered Rings Derived from Schiff Bases

In this study, Some new Compounds have been Synthesized including the preparation of some Schiff bases (P1,P2,R4) from the reaction Benzdine , 2- aminoanthracine-9,10-dione compounds with two moles of various aldehydes The second stage includes preparation of new heterocyclic compounds seven membered rings ( Oxazepine, Oxazepane)(P1C1,P1C2,P1C3,P2C1,P2C2,P2C3,R4C1,R4C2,R4C3) using the microwave method . The prepared compounds were characterized by FT-IR, 1H-NMR, and 13C-NMR spectra in addition melting points were measured for all compounds and reactions was followed by TLC (Thin Layer Chromatography).Finally, the synthesized compounds are tested against Gram-positive(Staphylococcus aureus) and Gram-negative bacteria (Escherichia Coli) to study their biological activity, the results showed high biological effectiveness of some derivatives (P1,P2,R4,P1C1,P1C2,P1C3,P2C1,P2C2,R4C1) compared with Ciprofloxacin drug and study anti-oxidant for the R4C2 compound which gave good results. .

Colchicine-capped ZnO nanoparticles: Elucidation of their cytotoxicity potential against MDA-MB 231 cancer cells

This research descibes a pioneering approach aimed at preparing zinc oxide nanoparticles (ZnO-NPs) with colchicine as the reducing and capping agent. Colchicine-loaded ZnO-NPs (CHZnO-NPs) were prepared by adding colchicine to the zinc sulfate heptahydrate solution. The CHZnO-NPs formulation was then characterized to determine the morphology, size, crystallinity, elemental composition and vibrational properties. Upon characterization, CHZnO-NPs were studied for their cytotoxic effect against the breast cancer cell line (MDA-MB-231). The successful biosynthesis of CHZnO-NPs was initially confirmed visually by the changes in the mixture color, from light-yellow to white cloudy. The best CHZnO-NPs formulation selected was F3, which possessed 10 mg/mL of colchicine. Formulation (F3) had the smallest mean particle diameter of 43.77 nm and the lowest zeta potential of −19.60 mV. It also had 92.21 ± 0.012 % encapsulation efficiency and 20.86 ± 0.005 % drug loading. Formulation (F3) displayed a hexagonal wurtzite structure with irregular morphology. The observation of colchicine peaks on the FTIR spectra of F3 proved the role of colchicine as a reducing and capping agent during the synthesis of ZnO-NPs. Besides, the in-vitro cell cytotoxicity study on the MDA-MB-231 cell line revealed a significant reduction in cell proliferation at the concentration of 25 μg of colchicine and F3. Further, studies on the cellular migration potential also demonstrated concentration-dependent activity. Overall, CHZnO-NPs were shown to be successfully synthesized via an environmental-friendly procedure and colchicine acted as a capping agent to regulate the particle size, and aggregation, in addition to its anticancer properties.

Controlled porosity intelligent aerogel based on chitosan nanofiber, anthocyanins and starch nanoparticles: Preparation, characterization and application in monitoring food spoilage

The aim of this study was to design a food freshness colorimetric aerogel with controlled porosity based on chitosan nanofibers (CHNF), Ixiolirion tataricum anthocyanins (ITA), and starch nanoparticles (SNPs). Two size-controlled SNPs were produced via nanoprecipitation (133.3 nm; SNP-A) and H2SO4 hydrolysis methods (86.2 nm; SNP-B) and were used for controlling the porosity and morphological characteristics of aerogel solid support. According to FE-SEM images, the porosity of smart aerogels improved after SNPs incorporation, and SNP-B was able to decrease the disrupting effect of ITA on 3D porous network of aerogels. The formation of hydrogen bonds between the CHNF and ITA molecules was confirmed by FT-IR analysis and the absence of obvious change in the FT-IR spectra approved the physical entrapment of SNPs. The improvement in the crystallinity and thermal stability of the aerogels after SNPs loading was confirmed by the XRD and TGA tests, respectively. The SNPs loaded aerogels showed color variation from red to green over the pH range of 2–12. In addition, the SNP-B-incorporated aerogel exhibited high sensitivity to ammonia vapor and good color response reversibility. The CHNF/SNP-B/ITA aerogel with the best porosity and sensitivity was used for monitoring food spoilage and could differentiate minced beef into three stages: fresh, medium fresh, and spoiled, facilitating simple observation of freshness-spoilage progression. This research opens a new insight to develop advanced and highly sensitive indicators capable of monitoring freshness/spoilage in protein-based food products.

Spectroscopic studies under properties of chlorpromazine conjugated to gold nanoparticles

Scientific studies have demonstrated that conjugates of anticancer drugs with metal nanoparticles (MeNPs) lead to a more effective deactivation of tumor cells compared to free drugs. Similarly, it has been established that conjugates of antibiotics with MeNPs exhibit higher biocidal activity against bacteria than their unbound counterparts. However, limited information is available regarding conjugates formed from drugs other than anticancer and antibiotics. Therefore, our research aims to develop synthesis methods for conjugates of chlorpromazine (CPZ), a neuroleptic, with gold nanoparticles (AuNPs). CPZ-AuNP conjugates were prepared through a ligand exchange reaction conducted on the surface of quasi-spherical, negatively charged citrate-stabilized TC-AuNPs with an average size of 55 ± 5 nm. UV–vis spectroscopy was employed to determine the stability range of the conjugates under controlled conditions of pH and ionic strength. Based on electrokinetic measurements, it was observed that the zeta potential of CPZ-AuNP conjugates strongly depends on the amount of CPZ adsorbed on the TC-AuNP surface. Additionally, the conjugates exhibited an isoelectric point at pH 8.8. Surface-enhanced Raman spectroscopy (SERS) and surface-enhanced infrared absorption spectroscopy (SEIRA) were employed to elucidate the adsorption structure of CPZ on TC-AuNPs. The interpretation of the spectra was conducted based on the Raman and FTIR spectra of CPZ, along with calculations performed using Density Functional Theory (DFT). The results indicated that CPZ primarily interacts with the TC-AuNP surface through the angularly oriented phenothiazine ring and the propylene bridge. Furthermore, it was demonstrated that the C-N-C fragment is perpendicular to the surface of the TC-AuNP with which it interacts. The findings from this analysis suggest the potential for further research on the use of these conjugates in biomedical applications.

Synthesis, DFT investigation, ADME-T properties, molecular docking and molecular dynamics simulation of new α-aminophosphonate inhibitor targeting Mpro and RdRp enzymes in SARS-CoV-2

A specific α-aminophosphonate molecule, namely diethyl (phenyl (4-pyridinylamino) methyl) phosphonate (α-DAP), as a potential SARS-CoV-2 inhibitor, has been synthesized via a Kabachnick-Fields reaction, a three-component, dalfampridine, benzenecarbaldehyde and triethoxyphosphine, and its molecular structure was confirmed by spectroscopic and physicochemical methods such FT-IR, UV–vis, melting point, 1H NMR, 13C NMR and 31P NMR spectra. The Density Functional Theory (DFT) at the B3LYP/6–31 G (d, p) level was used to calculate the optimized structure, reactivity, stability of the target molecule. In this context, several characteristics have been calculated and the obtained theoretical results are in good agreement with the experimental ones. Also, predicted ADME-T were performed and the obtained parameters indicated that the compound under investigation should have good oral bioavailability. In addition, the molecular docking has been used, further, the compound showed high potential docking with SARS-CoV-2 major protease (Mpro) and RNA dependent RNA polymerase (RdRp). Finally, the molecular dynamics simulation demonstrated the stability of the protein-ligand interaction and offered insights into the specific amino acid residues participating in the binding process.

Uncalcined Zn/Al Carbonate LDH and Its Calcined Counterpart for Treating the Wastewater Containing Anionic Congo Red Dye

In this investigation, Zn/Al carbonate layered double hydroxide (ZAC-LDH) and its derived material on calcination were synthesized for removing the anionic azo dye Congo red (CR) from wastewater. Numerous factors were methodically investigated, including temperature, adsorbent dosage, pH, starting Dye Concentration (DC), and contact time. The CR elimination percentage dropped as the initial DC increased from 25 mg/L to 100 mg/L at 30 °C for uncalcined LDH, and from 97.96% to 89.25% for calcined LDH. The pH analysis indicates that the highest level of dye removal was recorded within the acidic pH range through the electrostatic attraction mechanism. The sorption kinetics analysis results demonstrated that the pseudo-second-order kinetic model exhibited a stronger fit to both uncalcined LDH and CZA-LDH, with the maximum correlation coefficient value. The Van’t Hoff plots indicate the spontaneous nature of the physisorption process with a negative ΔG° (<−20 kJ/mol), while the endothermic adsorption process exhibited a positive ΔH°. The X-ray diffraction of calcined LDH reveals a significant intercalation of CR dye molecules, both prior to and following adsorption, showcasing a distinctive memory effect. The Brunauer–Emmett–Teller (BET) gas sorption measurements were performed to support the mesoporous nature of ZAC-LDH and CZA-LDH. The FTIR spectrum confirms the interaction of dye molecules on the surface of uncalcined and calcined LDH. These findings emphasize the efficacy of both the synthesized LDHs in removing CR dye, with CZA-LDH demonstrating superior efficiency compared to uncalcined LDH in the context of CR removal from wastewater.

Type of pectin affects the functionality of potato protein-pectin conjugates in emulsions

This study investigated the effect of the molecular structure of pectin on conjugate formation and its functionality in plant protein-based emulsions. For this purpose, high-methoxylated, low-methoxylated, amidated citrus pectin and their mixtures with potato protein were vacuum-dried at defined process conditions. The change in free amino groups, colour and molecular weight distribution assessed conjugation. The side reaction, such as pectin degradation, was monitored by the degree of methoxylation, galacturonic acid content and intrinsic viscosity. In addition, FT-IR and hydrophobicity measurements were performed to determine the changes in chemical structure due to the occurring reactions. The ζ-potential, solubility and oil droplet size reflected the functionality of the conjugated samples.The results confirm that, apart from the conjugation of protein and pectin, where the most significant decrease in free amino groups was obtained with an increasing degree of methoxylation or presence of amide groups, undesirable degradation of pectin occurring, resulting in a broad molecular weight distribution of the conjugate samples. The conjugate formation was the highest with amidated pectin. The FT-IR measurements confirmed the formation of Maillard conjugates. The FT-IR spectra showed a decrease in the intensity signals of amide I and amide II and the formation of new C–N bond maxima. In addition, the conjugation caused the shift of the protein's isoelectric point to the acidic environment, resulting in higher solubility and improved emulsion stability at the isoelectric point of the protein.Regarding emulsion stability, the conjugates with amidated pectin performed best and achieved the narrowest oil droplet size distribution over a wider pH range. Emulsion-stabilising properties of conjugates with high- and low-methoxylated pectin differed only slightly. To better understand the underlying mechanisms for emulsion stabilisation, future research will focus on the interfacial properties of the conjugates as determined by interfacial shear rheology and pendant drop analysis.

New Series of Ni(II), Cu(II), Zr(IV), Ag(I), and Cd(II) Complexes of Trimethoprim and Diamine Ligands: Synthesis, Characterization, and Biological Studies

New compounds series of [M(TMP)(en)]X·nH2O and [M(TMP)(PD)]X·nH2O, where M = Ni2+, Cu2+, Zr4+, Ag+, Cd2+, TMP = trimethoprim, en = ethylenediamine, PD = o-phenylene and X= Cl− or NO3−, were prepared. The compounds were characterized using techniques including melting points, conductance, elemental analysis, FTIR, NMR, and mass spectroscopy. FTIR spectra indicated TMP acted like a bi-dentate ligand, combining via the nitrogen atoms of azomethine and pyrimidine amino groups. Diamine ligands (en or o-PD) are coordinated via two nitrogen atoms. Prepared compounds showed monomeric behavior and adopted a 6-coordinate octahedral geometry based on magnetic susceptibility and UV spectra. Conductivity measurements revealed Zr(IV) compounds were 1:2 conductive, while Ag+ and Cd2+ were 1:1 conductive; Ni2+ and Cu2+ compounds were non-conductive. Antibacterial tests on compounds and ligands against Bacillus subtilis and Staphylococcus aureus demonstrated broad-spectrum antibacterial activity. The mixed metal compounds revealed an observable tendency of antibacterial activity in the order Zr > Cd = Ag > Cu, making Zr(IV) compounds the most biologically active among them against S. aureus (Gram-positive) while the same compounds showed less antibacterial activity against B. subtilis (Gram-negative) than the free ligand.

Insights on kraft lignin degradation in an anaerobic environment

Lignin is an aromatic macromolecule and one of the main constituents of lignocellulosic materials. Kraft lignin is generated as a residual by-product of the lignocellulosic biomass industrial process, and it might be used as a feedstock to generate low molecular weight aromatic compounds. In this study, we seek to understand and explore the potential of ruminal bacteria in the degradation of kraft lignin. We established two consortia, KLY and KL, which demonstrated significant lignin-degrading capabilities. Both consortia reached maximum growth after two days, with KLY showing a higher growth and decolorization rate. Additionally, SEM analysis revealed morphological changes in the residual lignin from both consortia, indicating significant degradation. This was further supported by FTIR spectra, which showed new bands corresponding to the C-H vibrations of guaiacyl and syringyl units, suggesting structural transformations of the lignin. Taxonomic analysis showed enrichment of the microbial community with members of the Dickeya genus. Seven metabolic pathways related to lignin metabolism were predicted for the established consortia. Both consortia were capable of consuming aromatic compounds such as 4-hydroxybenzoic acid, syringaldehyde, acetovanillone, and syringic acid, highlighting their capacity to convert aromatic compounds into commercially valuable molecules presenting antifungal activity and used as food preservatives as 4-hydroxyphenylacetic, 3-phenylacetic, and phenylacetic acids. Therefore, the microbial consortia shown in the present work are models for understanding the process of lignin degradation and consumption in bacterial anaerobic communities and developing biological processes to add value to industrial processes based on lignocellulosic biomass as feedstock.

Design and fabrication of magnetically recoverable SnO2/CoFe2O4 nanocomposite for enhanced visible light-driven wastewater treatment

This study emphasizes the critical importance of ensuring the availability of clean and secure water resources amid global concerns about water contamination, highlighting the necessity for effective and enduring methods to eliminate hazardous pollutants. The research introduces a sustainable approach to environmental protection through the creation of a high-performance photocatalyst, employing a co-precipitation route to incorporate CoFe2O4 onto SnO2 for efficient wastewater treatment under solar light irradiation. Comprehensive composition and morphological studies of the SnO2/CoFe2O4 composites are conducted using techniques such as XRD, SEM, TEM, Raman, UV–Vis, PL spectra, and FT-IR spectra. The synergistic behavior of the SnO2/CoFe2O4 composite results in efficient separation of electron/hole pairs, reducing the recombination rate and leading to improved photocatalytic performance under solar-light illumination. Notably, the rate constant for Chromium (VI) removal reaches 87 % and the degradation of Rhodamine 6G attains 92 % within 105 mins intervals. The catalyst demonstrates stability and ease of regeneration through a five-cycle recycle study, further supporting its potential for practical application in wastewater treatment.

Evaluating solubility, stability, and inclusion complexation of oxyresveratrol with various β-cyclodextrin derivatives using advanced computational techniques and experimental validation

Oxyresveratrol (OXY), a natural stilbenoid in mulberry fruits, is known for its diverse pharmacological properties. However, its clinical use is hindered by low water solubility and limited bioavailability. In the present study, the inclusion complexes of OXY with β-cyclodextrin (βCD) and its three analogs, dimethyl-β-cyclodextrin (DMβCD), hydroxypropyl-β-cyclodextrin (HPβCD) and sulfobutylether-β-cyclodextrin (SBEβCD), were investigated using in silico and in vitro studies. Molecular docking revealed two binding orientations of OXY, namely, 4′,6′-dihydroxyphenyl (A-form) and 5,7-benzenediol ring (B-form). Molecular Dynamics simulations suggested the formation of inclusion complexes with βCDs through two distinct orientations, with OXY/SBEβCD exhibiting maximum atom contacts and the lowest solvent-exposed area in the hydrophobic cavity. These results corresponded well with the highest binding affinity observed in OXY/SBEβCD when assessed using the MM/GBSA method. Beyond traditional simulation methods, Ligand-binding Parallel Cascade Selection Molecular Dynamics method was employed to investigate how the drug enters and accommodates within the hydrophobic cavity. The in silico results aligned with stability constants: SBEβCD (2060 M−1), HPβCD (1860 M−1), DMβCD (1700 M−1), and βCD (1420 M−1). All complexes exhibited a 1:1 binding mode (AL type), with SBEβCD enhancing OXY solubility (25-fold). SEM micrographs, DSC thermograms, FT-IR and 1H NMR spectra confirm the inclusion complex formation, revealing novel surface morphologies, distinctive thermal behaviors, and new peaks. Notably, the inhibitory impact on the proliferation of breast cancer cell lines, MCF-7, exhibited by inclusion complexes particularly OXY/DMβCD, OXY/HPβCD, and OXY/SBEβCD were markedly superior compared to that of OXY alone.