Physicochemical Studies Research Articles

Structural, micro-structural and physico-chemical studies of Polyvinylpyroledene (PVP) added Cobalt ferrite (CoFe2O4) nanoparticles

To understand the structural and physico-chemical behavior of magnetic nanoparticle (CoFe2O4) is necessary for the selection of materials for various technological applications. The structural parameters derived from X-Ray diffraction (XRD) such as hopping length of site A (LA) and site B (LB), bond length between two A sites (dLA), two B sites (dLB), A and B (dLAB) and some related lengths. The micro-structural and magnetic studies from Fourier transform infrared spectroscopy (FTIR) and vibration sample magnetometer (VSM) analysis such as force constant, bond lengths between cation – anion (p, q, r, s) and cation - cation (b, c, d, e, f), and the angles between the bonds (θ1, θ2, θ3, θ4, θ5) values and trends were studied and it is merely suitable for 7.5 and 12.5 %. In addition some mechanical behavior obtained through their stiff constant C11 and C12 such as Young's modulus, bulk modulus, rigidity modulus and etc., The dielectric and electrochemical behavior of CoFe2O4 measured through AC conductivity (σAC), resistivity (ρAC) and electric modulus (M’, M’’ and M*) electrochemical parameters (V/I, impedance) through LCR and Cyclic voltameter measurements. The obtained results were interpreted and discussed extensively.

On the Rapid Synthesis of Reduced Graphene Oxide via Ultrasound-Promoted Eco-Friendly Reduction Approach and Its Effects on Physicochemical Properties.

The common synthesis approach of reduced graphene oxide (rGO) using toxic reducing agents poses a threat to environmental pollution. This study used banana peel extract as a green reducing agent for the synthesis of rGO. Ultrasonication was assimilated to expedite the synthesis process. For comparison, rGO was also produced by reducing GO with hydrazine treatment under conventional stirring. Both morphological (SEM) and physicochemical (FTIR and XRD) studies have revealed that banana peel extract can reduce GO to rGO, although its reducing effect is much weaker compared to hydrazine. Despite this, the rGO produced using banana peel extract with the assimilation of ultrasonication technique has a greater interlayer spacing than that formed under the conventional stirring method. In terms of electrical properties, the electrical conductance of hydrazine-produced rGO (5.69×10-6 S) is higher than the banana peel extract-produced rGO (3.55×10-6 S-4.56×10-6 S). Interestingly, it was found that most of the rGO produced by banana peel extract under ultrasound assistance has higher or comparable electrical conductance compared to the rGO produced by banana peel extract under stirring method. This implies the feasibility of using short-period ultrasound to replace conventional stirring in rGO synthesis.

Hydrogen Production from Methanol Steam Reforming over Fe-Modified Cu/CeO2 Catalysts.

Fe-modified Cu catalysts with CeO2 support, prepared by the impregnation method, were subjected to physicochemical analysis and catalytic tests in the steam reforming of methanol (SRM). Physicochemical studies of the catalysts were carried out using the XRF, TEM, STEM-EDS, XRD, TPR and nitrogen adsorption/desorption methods. XRD, TEM studies and catalytic tests of the catalysts were carried out at two reduction temperatures, 260 °C and 400 °C, to determine the relationship between the form and oxidation state of the active phase of the catalysts and the catalytic properties of these systems in the SRM. Additionally, the catalysts after the reaction were analysed for the changes in the structure and morphology using TEM methods. The presented results show that the composition of the catalysts, morphology, structure, form and oxidation state of the Cu and Fe active metals in the catalysts and the reaction temperature significantly impact their activity, selectivity and stability in the SRM process. The gradual deactivation of the studied catalysts under SRM conditions could result from the forming of carbon deposits and/or the gradual oxidation of the copper and iron phases under the reaction conditions.

Design and Evaluation of Clove Oil-Based Self-Emulsifying Drug Delivery Systems for Improving the Oral Bioavailability of Neratinib Maleate.

Neratinib maleate (NM), a tyrosine kinase inhibitor, is used in the treatment of breast cancer. NM is orally administered at a high dose of 290 mg due to its low solubility and poor dissolution rate at pH > 3, as well as gut-wall metabolism limiting its bioavailability. Self-emulsifying drug delivery systems (SEDDSs) of NM were developed in the current study to improve its oral bioavailability. The oily vehicle (clove oil) was selected based on the solubility of NM, while the surfactant and the cosurfactant were selected based on the turbidimetric analysis. Three different sets were screened for surfactant selection in the preparation of SEDDS formulations, the first set containing Cremophor® EL alone as the surfactant, the second set containing a mixture of Cremophor® EL (surfactant) and Caproyl® PGMC (cosurfactant), and the third set containing a mixture of Cremophor® EL (surfactant) and Capmul® MCM C8 (cosurfactant). Propylene glycol was used as the cosolubilizer in the preparation of SEDDSs. A series of studies, including the construction of ternary phase diagrams to determine the zone of emulsification, thermodynamic stability studies (involving dilution studies, freeze-thaw, and heating-cooling studies), turbidimetric analysis, and physicochemical characterization studies were conducted to identify the two most stable combinations of SEDDSs. The two optimized SEDDS formulations, TP16 and TP25, consisted of clove oil (45% w/w) and propylene glycol (5% w/w) in common but differed with respect to the surfactant or surfactant mixture in the formulations. TP16 was prepared using a mixture of Cremophor® EL (surfactant) and Caproyl® PGMC (cosurfactant) in a 4:1 ratio (50% w/w), while TP25 contained only Cremophor® EL (50% w/w). The mean globule sizes were 239.8 ± 77.8 nm and 204.8 ± 2.4 nm for TP16 and TP25, respectively, with an emulsification time of <12 s for both formulations. In vitro drug dissolution studies performed at different pH conditions (3.0, 4.5, 6.8) have confirmed the increase in solubility and dissolution rate of the drug by TP16 and TP25 at all pH conditions compared to plain NM. An oral pharmacokinetic study in female Wistar rats showed that the relative bioavailability (Frel) values of TP16 and TP25 over the plain NM were 2.18 (p < 0.05) and 2.24 (p < 0.01), respectively.

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.

Physicochemical, ADMET Properties, and Molecular Docking Studies of N-benzoyl-N’-naphtylthiourea Derivatives for Anti-Breast Cancer Activity

Background: N-benzoyl-N'-naphthylthiourea (BNTU) is a thiourea-derived compound that is predicted to have anti-breast cancer activity. However, their physicochemical properties, ADMET, and receptor-specific targets for their anti-breast cancer activity have not been reported. Objective: This study aimed to predict the physicochemical properties, ADMET, and anti-breast cancer activity of BNTU and its derivatives by in silico approach. Methods: The physicochemical and ADMET properties were predicted using the pkCSM online program and ProTox-II online tool. While the anti-breast cancer activity was predicted using the molecular docking method through the Molegro Virtual Docker (MVD) program on the HER-2 receptor. The parameter observed in the molecular docking method was the bond energy value or rerank score (RS). Compounds with small RS values were predicted to have a great activity. Results: Most BNTU derivatives had lower RS values than BNTU, especially 4TBBNTU, and 4CFBNTU, although their RS values were still higher than lapatinib and TAK-285. As for the reference ligand hydroxyurea, the RS value of BNTU and its derivatives was much lower. The physicochemical and pharmacokinetic properties (ADMET) of lapatinib and TAK-285 were not better than that of BNTU and its derivatives. Conclusion: Five compounds that deserve to be synthesized and tested for anti-breast cancer activity in vitro and in vivo are 4TBBNTU, 3CFBNTU, 4CFBNTU, 4OCBNTU, and the lead compound BNTU.

A grafting approach for nisin-chitosan bio-based antibacterial films: preparation and characterization

Nisin is a bacteriocin produced by Gram-positive lactic acid bacterium,Lactococcus lactisand currently recognized in the Generally Recognızed as Safe (GRAS) category due to its non-toxicity. Herein, nisin has been grafted to chitosan structure to obtain natural bio-active films with enhanced antibacterial activity. Grafting was performed using ethyl ester lysine diisocyanate and dimer fatty acid-based diisocyanate (DDI); two different close to fully bio-based diisocyanates and Disuccinimidyl suberate; a homo-bifunctional molecule acting as a crosslinker between amino groups. The grafting process allowed the chemical immobilization of nisin to chitosan structure. Physicochemical characterization studies showed the successful grafting of nisin. The antibacterial activity againstStaphylococcus aureuswas evident for all nisin modified chitosan films and best pronounced when DDI was used as a crosslinker with a maximum zone of inhibition of ∼13 mm. All nisin grafted chitosan films were cytocompatible and the cell viability of L929 fibroblasts were >80% pointing out the non-toxic structure. Considering the results of the presented study, bio-based diisocyanates and homo-bifunctional crosslinkers are effective molecules in synthesis of nisin grafted chitosan structures and the new chitosan based antibacterial biopolymers obtained after nisin modification come forward as promising non-toxic and bioactive candidates to be applied in medical devices, implants, and various food coating products.

Exploring the Efficiency of Magnetic Separation and Gravity Concentration for Valorizing Pb-Zn Smelter Slag in a Circular Economy Framework.

The presented work offers an innovative process scheme for valorizing Pb-Zn slag, which involves crushing, grinding, and separation techniques to concentrate valuable components (non-ferrous metals). This methodology could have a significant impact on the global beneficiation of metallurgical slags since it is significantly more simple, environmentally friendly, and cost-effective than standard pyro- and hydrometallurgical procedures. According to previous physicochemical and mineralogical studies, Pb-Zn slag is a valuable secondary raw material. This inhomogeneous technogenic resource contains substantial amounts of non-ferrous metals (Pb, Zn, Cu, and Ag). However, laboratory tests have indicated that the Pb-Zn slag contains highly uneven amounts of valuable metals, ranging from several g/ton to tens of g/ton. The main issue is that traditional metallurgical procedures for releasing beneficial elements are not commercially viable since the elements are "trapped" within the amorphous aluminosilicates or intergrowths of alloy grains and glassy phases. Gravity concentration (Wilfley 13 shaking table) and magnetic separation (Davis separator and disk separator) were used to obtain the final concentrate following comminution and grindability testing. The gravity concentration proved more effective. Namely, magnetic separators could not process nor adequately separate beneficial non-ferrous elements because they were merged together with iron-bearing minerals and aluminosilicates in amorphous Pb-Zn slag grains. With the gravity concentration approach, 12.99% of the processed slag belonged to ∆T fraction (concentration of non-ferrous metal alloys), while remaining 87% corresponded to the tailings fraction (∆L). The total amounts of recovered Pb, Zn, Cu, and Ag from ∆T and ∆L fractions were 5.28%, 6.69%, 0.58%, and 76.12 ppm and 1.22%, 6.05%, 0.43%, and 15.26 ppm, respectively. This streamlined approach to valorizing Pb-Zn slag can reduce the need for hazardous chemicals used in hydrometallurgical refinement operations, as well as the extremely high temperatures required for pyrometallurgical processing. This is the first study to investigate the viability of this novel methodology, which involves the direct examinations of the Pb-Zn slag feed with various alternative technologies for separation and concentration. After extracting the valuable metals, the amorphous aluminosilicate part of the Pb-Zn slag can be reapplied as an alternative raw material in the building sector, adding to the circularity of the suggested approach.

Synthesis of copper complexes for potential use in the diagnosis of Alzheimer's disease

Background: Since there is currently no cure for Alzheimer's disease (AD), it is important to develop methods that could contribute to its diagnosis and propose new therapeutic approaches for its treatment. Positron emission tomography (PET) is a medical imaging technique that can be used to diagnose Alzheimer's disease, as some radiotracers have been developed to detect amyloid plaques, one of the hallmarks of the disease. However, the radiotracers already used for the diagnosis of AD have a low half-life, which limits their use over the time and requires the presence of a cyclotron close to the examination site. The use of copper complexes could be a good alternative for the development of new radiotracers, since they can be used in PET imaging and have a longer half-life than the other radiotracers already used for AD diagnosis. Aim of the study: Design and synthesize copper complexes that could be used as PET radiotracers able to cross the blood brain barrier and detecting amyloid plaques.Material and methods: The first objective was to design a series of new copper complexes with the capacity to target amyloid plaques inside the brain and contribute to the rational synthesis of such complexes. To this end, theoretical models were used to predict the ability of the complex to cross the blood-brain barrier (BBB) which separates brain from de blood and is main gatekeeper for drugs entering the brain. The models employed consider the physicochemical properties of the molecules. Based on these models, one of the molecules was synthesized in ten steps. The key step in the synthetic strategy was the coupling of a monopicolinate-N-alkylated cyclam-based ligand with a moiety capable of recognizing Aβ plaques via a Buchwald-Hartwig coupling reaction. Potentiometric, spectrophotometric and electron paramagnetic resonance spectroscopic studies were performed to determine the structure and thermodynamic stability of the complex. In addition, the ability to target amyloid plaques was evaluated using brain sections from Alzheimer's disease patients and the cytotoxicity was evaluated using human neuronal cells.Results: A first complex has been designed and synthesized. The physicochemical studies performed indicate that this complex seem to be thermodynamically stable. In addition, cytotoxicity tests on human neuronal cells indicate low toxicity and labeling tests on brain sections from Alzheimer's patients suggest that the complex is capable of recognizing amyloid plaques. Conclusion: We have developed a novel copper complex that is able to detect recognize amyloid plaques. In the future this molecule could be used in PET and contribute to the diagnosis of Alzheimer's disease. From these results, we also propose to develop a new copper complex for tau PET imaging.

Design, Synthesis, and Biological and in silico Evaluation of Novel Indazole-pyridine Hybrids for the Treatment of Breast Cancer.

The prevalence of breast cancer presents a substantial global health concern, underscoring the ongoing need for the development of inventive therapeutic remedies. In this investigation, an array of novel indazole-pyridine hybrids (5a-h) have been designed and synthesized to assess their potential as candidates for treating breast cancer. Subsequently, we have conducted biological evaluations to determine their cytotoxic effects on the human MCF-7 breast cancer cell line. Furthermore, in silico analysis was conducted to estimate the inhibition potential of the compounds against TrkA (Tropomyosin receptor kinase A), a specific molecular target associated with breast cancer, through molecular docking. In silico physicochemical and pharmacokinetic predictions were made to assess the compounds' drug-like properties. Compound 5a emerged as the most active compound among the others with GI50 < 10 μg/ml. Besides, compound 5a showed high binding energy (BE -10.7 kcal/mol) against TrkA and was stabilized within the TrkA binding pocket through hydrophobic, H-bonding, and van der Waals interactions. In silico physicochemical and pharmacokinetic prediction studies indicated that compound 5a obeyed both Lipinski's and Veber's rule and displayed a versatile pharmacokinetic profile, implying compound 5a to appear as a viable candidate and that it could be further refined to develop therapeutic agents for potentially treating breast cancer. This study offers a promising direction for the advancement of innovative breast cancer treatments, highlighting the effectiveness of indazole-pyridine hybrids as potential anticancer agents. Further optimization and preclinical development are necessary to advance these compounds to clinical trials.

Development of ocular delivery systems for macitentan and ex vivo study of intraocular permeation

Macitentan is a drug that acts as a non-selective antagonist of endothelin receptors. It has been officially approved for the treatment of cases of pulmonary arterial hypertension. There are studies in animal models that indicate a therapeutic potential for this drug in the treatment of glaucoma, a degenerative eye disease marked by a progressive reduction in the visual field that can progress to irreversible blindness. In the present work, ophthalmic formulations of macitentan were developed with the aim of evaluating their potential to deliver the active ingredient to therapeutically relevant sites. An HPLC-DAD method was adapted from the literature and validated to quantify macitentan in each step. Physicochemical characterization studies of the formulations were performed, and a Franz vertical diffusion cell was used in an analysis of the in vitro/ex vivo permeation using cornea and sclera of porcine eyes to represent biological membranes. The developed formulations presented different permeation profiles according to the presence or absence of water in the base formulation and the type of viscosity promoting agent used. The formulations that showed the highest percentage of permeation were evaluated for mucus adhesiveness and the most promising were further analyzed for stability that included measuring drug content, pH, and viscosity. One formulation was developed for the ocular release of macitentan with a high percentage of drug permeation, adequate viscosity and stability that could represent an advancement in the treatment of glaucoma with a high potential for patient adherence.

Na2Zn0.5Co0.5P2O7 diphosphate: Sol-gel synthesis, physico-chemical studies, and prospects as a novel supercapacitor electrode material

For the first time, a mixed-metal diphosphate Na2Zn0.5Co0.5P2O7 has been successfully synthesized via the sol-gel method. The sample was characterized by means of XRD, DTA/TGA, SEM/EDX, UV–vis, Raman, IR and color measurements (CIE-L*a*b*). Its structure was determined through X-ray powder diffraction, in tetragonal system, with space group P42/mnm. The 3D structure of the material consists of infinite chains formed by [Zn/CoO4] tetrahedra and [P2O7] diphosphate units sharing corners. Sodium cations occupy two types of interstitial positions between the infinite chains [Zn/CoP2O7]2-. Raman and Infrared spectra of the studied phosphate have been investigated. A factor group analysis leads to determination of internal modes of the P2O74− anion. Tetrahedral environment of Co2+ ions was confirmed by mean of optical analysis, in which numerous bands in the region 475–675 nm, assigned to the forbidden and allowed d–d transitions of Co2+ are detected and the gap energy is extracted from Tauc and Kubelka-Munk plots. The prepared Na2Zn0.5Co0.5P2O7 diphosphate was extensively investigated for its potential use as an electrode material for supercapacitors. The electrode was prepared by depositing the active material on a conductive substrate (nickel foam) and demonstrated significant electrochemical performance with a specific capacitance of 277 F.g-1 at a scan rate of 5 mV.s-1. This outstanding performance underlines its relevance for supercapacitor applications.

Physico-chemical, chemical and microbial analytical studies of beejamrutha, jeevamrutha and vermicompost

Physico-chemical, chemical and microbial analytical studies of beejamrutha, jeevamrutha and vermicompost

Physico-chemical studies of non-aqueous binary liquid mixtures of N-methyl aniline with amino alcohols at various temperatures

ABSTRACT Densities (ρ), speeds of sound (u) and viscosities (η) for three binary mixtures of N-methyl aniline with amino alcohols (3-amino-propan-1-ol, 2-amino-2-methyl-propan-1-ol and 1-amino propan-2-ol) were measured at temperatures ranging from 303.15 to 313.15 K and at atmospheric pressure across the entire composition range. Excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of activation of viscous flow were calculated using experimental data. Partial molar properties and infinite dilution molar partial properties were also determined for each binary system. The Prigogine-Flory-Patterson theory is used to identify the most important interaction. The results of the Jouyban-Acree model are discussed in terms of the mean relative deviation and individual relative deviation between the calculated and experimental densities, speed of sound, and viscosities as an accuracy criterion. FTIR studies have also been added to confirm the experimental findings of the investigated mixtures.

Diversity analysis of cyanobacterial flora from the Tatapani Hot Spring of Chhattisgarh and exploration of their industrially as well as environmentally valuable properties

The present study investigates the cyanobacterial diversity of Tatapani hot spring, Chhattisgarh, India, using a polyphasic approach, their pigment system, biofuel properties and ability to bioremediate emerging pollutant triclosan. While the microscopic analyses of the natural samples reflected high cyanobacterial diversity with all morpho-forms, physicochemical studies revealed temperature being the major factor affecting the cyanobacterial distribution in the hot spring. Among the 22 collected cyanobacterial samples, 14 were grown successfully under laboratory conditions and 10 of them showed optimum growth at 45 °C. However, four strains displayed preference for lower temperature (27 °C) for optimum growth. The polyphasic characterization of 14 strains revealed that all the thermophiles belonged to the genus Mastigocladus whereas the strains Sytonema sp. TPJ-3, Calothrix sp. TPB-2, Westiellopsis sp. TPR-29 and Desikacharya sp. TPB-4 constituted the group of mesophiles. Calothrix sp. TPB-2 was identified as a novel genus (Neocalothrix thermalis) based on distinct morphology and phylogenetic position with unique ITS folding pattern. Additionally, our study disclosed the production of comparatively higher amounts of pigments and medium chain length fatty acids (C16 to C18) by the thermophilic strains, which indicated their potential to be used as feedstocks for pigments and biofuel production respectively. Although the triclosan bioremediation study reflected considerable triclosan removal efficiencies of all the strains, most impressive results were observed in case of Westiellopsis sp. TPR-29 (93.08 %) and Mastigocladus sp. TA-8 (91.92 %). Moreover, the in-silico study-based revelation of high triclosan binding ability of cyanobacterial laccase (−5.8 and − 5.4 kcal/mol) and catechol 2,3-dioxygenase (−5.9 and − 6.0 kcal/mol) suggested the probable triclosan degrading potential of Westiellopsis and Mastigocladus. Conclusively, the Tatapani hot spring represents a unique environment with the dominance of true-branched heterocytous thermophilic cyanobacteria that have enormous potential to remove triclosan and produce high amounts of pigments and medium chain length fatty acids.

Preparation, physicochemical, anticancer, and theoretical studies of mono‐ and bi‐nuclear Ni(II), Co(II), and Cd(II) complexes containing chromone moiety

Preparation, physicochemical, anticancer, and theoretical studies of mono‐ and bi‐nuclear Ni(II), Co(II), and Cd(II) complexes containing chromone moiety

Formation of cheese pattern when using monospecies cultures

The article presents the results of a study of the influence of monospecies gas-aroma-forming cultures Lactococcus lactis subsp. lactis biovar. diacetylactis (L. diacetylactis) and Leuconostoc subsp. on the peculiarities of pattern formation in cheeses with a low second heating temperature molded from a layer. The studied cultures were used at a dose of 0.6% of the total milk volume as as single starter microflora in the model cheeses (1-M and 2-M) and additional microflora along with the main lactococcal microflora (Lactococcus lactis subsp. lactis; Lactococcus cremoris) in the control cheeses (1-K and 2-K). The model and control cheeses were subjected to microbiological tests (total number of lactic acid microorganisms, number of L. diacetylactis and Leuconostoc subsp.), physicochemical (mass fraction of moisture, pH), biochemical (mass fraction of lactose) and organoleptic studies after pressing and during ripening at the age of 15, 30, 45, 60 days. It has been established that the use of a culture of citrate-fermenting lactococci L. diacetylactis ensures a stable lactic acid fermentation process during the production and ripening of the model and control cheeses, the formation of an elastic consistency and the desired pattern with eyes of a regular round shape. The use of the hetero-fermentative culture Leuconostoc subsp., as single starter microflora, does not guarantee the required level of lactic acid fermentation during cheese production and leads to an increase in the moisture content of the cheese mass after pressing and overacidification of the cheese in the first stages of ripening, which together contributes to the formation of an overly plastic consistency and an overdeveloped pattern in the form of cracks. The use of Leuconostoc subsp. as a gas-aroma-forming component of a traditional starter culture for semi-hard cheeses, also consisting of mesophilic lactococci Lc. lactis subsp. lactis and Lc. cremoris, causes the development of a nest-like pattern, which does not fully ensure the formation of the desired pattern with regular rounded eyes.

Synthesis, structural interpretation, DFT, molecular docking, antimicrobial assessment and cytotoxic profiling of a cadmium(II) hydroxamate complex: in vitro and in silico investigations

A Cd(II) complex of composition Cd(C11H9CONHO)2 has been synthesized by treating CdCl2 (anhydrous) with potassium 1-naphthaleneacetohydroxamate (C11H9CONHOK) (KHL) in 1:2 molar ratio in MeOH. Various physicochemical studies including elemental analysis, molar conductivity, FTIR, UV-visible,1H and 13C NMR spectroscopic techniques were employed to interpret the structure of the complex. O,O-Coordination has been proposed through the carbonyl and hydroxamic oxygen atoms and a distorted tetrahedral geometry around cadmium is supported by physicochemical and computational studies. Density Functional Theory studies have shown the stability of the complex and predict various structural parameters (bond lengths and angles). Chemical reactivity descriptors and Mulliken charge analysis were also calculated and analyzed. Molecular docking studies were conducted to analyze the interaction of the ligand and complex with two proteins, Escherichia coli Tem1 beta-lactamase (PDB ID = 1BTL) and Alternaria alternata major allergen alt a 1 (PDB ID = 4AUD). Further, the ligand and complex were tested in vitro for their antimicrobial activity against selected microbes such as S. aureus, S. typhi, E. coli, S. flexneri, Rhizoctonia solani, Alternaria alternata, and Fusarium Sambucinum. The complex was more effective against A. alternata, showing inhibition specifically against S. typhi and E. coli. In vitro cytotoxicity studies were conducted on Rhabdomyosarcoma RD cancer cell lines. The results revealed a reduction in cell viability, correlating with increasing concentrations of the compounds, thereby indicating efficient cytotoxic activity.

Physico-chemical studies and development of water-based drilling fluid formulations with carbon nanotube additives

The paper offers a comprehensive experimental study on the effect of carbon nanotube additives on the features of water-based drilling fluids. A similar study for this fluid has not been carried out before. Nanotubes were used to modify the drilling fluids. Weight concentration of nanomaterials in slurries was from 0.1 to 0.5 %. The formulation of stable drilling slurries modified by carbon nanotube were developed and refined. The study is focused on investigation of rheology, filtration and antifriction properties, temperature and colloidal stability of drilling fluids modified with carbon nanotubes. It is shown that carbon nanotube additives even in small concentrations can significantly change the features of water-based drilling fluids. A comparison was made between the effects of single- and multi-walled carbon nanotubes (SWCNT and MWCNT) on the characteristics of water-based drilling fluids. The study has shown that both types of nano-additives considerably change in the properties of the base fluid. Nevertheless, it was determined that in order to achieve a comparable effect on solution properties, an order of magnitude greater amount of MWCNT additives is required in comparison to single-walled carbon nanotubes.

Physicochemical and molecular docking studies of tween 20 in the presence of NaX salts and hydrotropes in aqueous media

An investigation has been conducted on the interaction between the plasma protein bovine serum albumin (BSA) and the surfactant T20 using various hydrotropes of sodium salt (NaX, where X is Sal and Benz). The acquired results provide a practical and efficient means to comprehend the binding process of the micellar system T20 to BSA. The predominant forces involved are hydrophobic forces and hydrogen bonding. The further study intends to investigate the impact of NaX (here, X represents Cl, Br, NO3, Sal, and Benz), on the T20 solution using various techniques including density (ρ), viscosity (η), sound velocity (U), dynamic light scattering (Dh), FT-IR spectroscopy, and molecular docking at varying temperatures. The values of ρ, η, and U increase as the concentration of Na salt increases. Conversely, when the temperature increases, the values of ρ and η fall, while the value of U increases. NaSal exhibits higher viscosity compared to other substances. The phase separation model was employed to calculate the standard Gibbs free energy ( Δ G CP 0 ), enthalpy ( Δ H CP 0 ), and entropy ( Δ S CP 0 ). The NaBenz exhibits the highest values of sound velocity while examining at different temperatures. The structural identification was performed using FT-IR data, which revealed good agreement with the available literature.