Kf Values Research Articles

Selective Novel Metal‐Coordinated Biomedical Agents Encompassing Tetradentate Salen Ligand: Structural Elucidation, DFT Calculation, Cytotoxic, and Antioxidant Activities Supported by Molecular Docking Approach

ABSTRACTSeveral physicochemical and analytical methods were employed to elucidate the structural analysis of some novel complexes derived from the {3,4‐bis‐[(3‐ethoxy‐2‐hydroxy‐benzylidene)‐amino]‐phenyl}‐phenyl‐methanone (ESAB ligand). Decomposition point determination, elemental analysis (CHN), spectroscopy (IR, NMR, and mass spectrometry), conductivity, magnetic susceptibility, UV–Vis spectrum study, and theoretical investigations were among these methods. With conductance values ranging from 7.5 to 15.12 Ω−1 cm2 mol−1, molar conductance values showed that the Zn (II), Cu (II), and Ru (III) complexes are nonelectrolytes in fresh DMSO solutions, with the exception of the ESABRu complex, which is a monoelectrolyte. According to IR spectra, the ligand uses the (N & O) donor sites from the (C=N & C‐O) groups in the ligand moiety to coordinate through the metal ions in a tetradentate form. A 1:1 (metal:ligand) molar ratio was proposed by Job's approach based on analytical data from solution complexation. According to the stability constant (Kf) values, the complexes' stability order was found to be ESABRu > ESABCu > ESABZn. The pH profile showed that the complexes under study are stable throughout a broad pH range, usually between pH = 4 and pH = 10. The complexes' geometric structures and ligand coordination capabilities were inferred with the use of magnetic and electronic spectrum studies. The DFT method uses quantum chemical simulations to evaluate the electronic structures of the ligand under investigation and its complexes. The unbound ligand's B3LYP level, B3LYP/6/311G* degree, and the complexes' B3LYP/6/311G**/LANL2DZ functional categories were employed in the computations of the density function concept (DFT). The findings revealed the consistency between the experimental and DFT computations. Natural bond orbital (NBO) analysis was used to investigate bond strength between molecules' charge exchange, hyperconjugative connections, and molecular equilibrium. By computing the hyperpolarizability (β) and molecular polarizability (α) parameters, the ensuing nonlinear optical properties were investigated, leading to a number of surprising optical properties for the produced compounds. The antipathogenic activity of the generated materials was experimentally verified against a subset of gram (+) and gram (−) bacteria as well as some fungi using the agar well diffusion method. Additionally, hepatic cellular carcinomas, cells from colon and breast cancer, were utilized to test the cytotoxic activity of the ESAB ligand and its metal chelates. Furthermore, the examined compounds' ability to suppress the DPPH radical was examined. Additionally, simulations of molecular docking were performed to ascertain how the produced compounds attached to the specific protein binding sites.

Untreated plant waste of the Mediterranean region as bioadsorbent of persistent organic pollutants

The excessive and/or improper use of plant protection products (PPPs) can generate alarming levels of residues in the environment, compromising both soil fertility and food safety. Various organic wastes released in large amounts by agro-industrial activity are currently studied and applied as bioadsorbents for water and soil decontamination. This study explored the capacity of untreated orange peel, olive stones and pistachio shells to adsorb the PPPs oxyfluorfen (OXY), metribuzin (MET) and imidacloprid (IMI), and the xenoestrogen bisphenol A (BPA) from water. The physicochemical, microstructural, and spectroscopic characteristics of the adsorbents were first evaluated using TXRF, SEM and FTIR-ATR techniques. Adsorption kinetics showed that each pollutant was rapidly (∼24 h) retained by all adsorbents according to a pseudo-second order model, which suggested a prevalent chemisorption. Interpretation of the sorption isotherm data with various theoretical equations showed that all molecules on all adsorbents preferentially followed the Freundlich model. Among the materials, olive stones showed the highest adsorbent capacity with KF values equal to 713, 317, 359 and 736 mg kg−1 for OXY, MET, IMI, and BPA, respectively. The desorption of each compound from all materials was hysteretic. Based on the overall results obtained, it appears that all three materials tested may have interesting applications for the retention of organic pollutants, especially very hydrophobic ones. This paves the way for further investigations into natural adsorbents as sustainable tools for environmental remediation.

(Digital Presentation) Advanced Nanomagnetic Adsorbents for Heavy Metal Removal

Heavy metal contamination in water is a significant and persistent environmental challenge, as demonstrated by the 2015 lead contamination crisis in Flint, Michigan. Such contamination primarily arises from industrial activities and improper waste management practices, with key contributors being industries like metalworking, electronics manufacturing, and mining. Heavy metals in water are notorious for their toxic, mutagenic, and carcinogenic effects, posing serious health risks to humans, including potential birth defects in unborn children. The impact of these pollutants is far-reaching, affecting not only human health but also ecosystems and biodiversity.One of the most common methods for remediating heavy metal contamination is adsorption. However, conventional adsorbents often suffer from drawbacks, such as difficulties in separating them from the contaminated water and issues with charge affinity. These limitations underscore the need for the development of novel adsorbents that can efficiently address these challenges. Among the promising candidates are nanomagnetic adsorbents, which offer distinct advantages due to their colloidal stability and minimal internal diffusion resistance.This study focuses on the use of nanoporous magnetic organic-silicate CTAB (NMSC) as a potential solution for the removal of chromium (Cr(VI)) from aqueous media. The adsorption behavior of NMSC was analyzed through isotherm studies, which revealed that the Freundlich model best described the adsorption process, with a high correlation coefficient (R² = 0.988). The model's n value of 0.898 and Kf value of 0.319 mg/g indicate a high affinity and heterogeneity of the adsorbent. Additionally, kinetic studies showed that the adsorption process followed a second-order kinetics model (R² = 0.984), further demonstrating the effectiveness of NMSC. These findings suggest that NMSC holds great potential as an efficient adsorbent for heavy metal removal, offering a viable solution to mitigate the harmful effects of heavy metal contamination in water systems. References A Elmekawy, Q Quach, TM Abdel-Fattah, Nanomaterials 14 (13), 1143 (2024)SELME Mahmoud, TM Abdel-Fattah, ME Mahmoud, E Díaz, Environmental Nanotechnology, Monitoring & Management 22, 100977 (2024)SELME Mahmoud, D Ursueguia, ME Mahmoud, TM Abdel-Fattah, E Díaz, Biomass Conversion and Biorefinery, 1-1 (2023)A Elmekawy, Q Quach, TM Abdel-Fattah, Scientific Reports 13 (1), 12845 (2023)Omar H. Elsayed-Ali, Hani E. Elsayed-Ali and Tarek M. Abdel-Fattah, Journal of Hazardous Materials, 185 (2-3), 1550-1557 (2011)Alya Elsayed-Ali, Tarek Abdel-Fattah, Hani Elsayled-Ali, Hani, Journal of Chemical Education, 88(8), 1126-1129 (2011).TM Abdel-Fattah, ME Mahmoud, Chemical engineering journal 172 (1), 177-183 (2011)TM Abdel-Fattah, ME Mahmoud, MM Osmam, SB Ahmed, Journal of Environmental Science and health, part A 49 (9), 1064-1076 (2014)ME Mahmoud, TM Abdel-Fattah, MM Osman, SB Ahmed, Journal of Environmental Science and Health, Part A 47 (1), 130-141 (2012)TM Abdel-Fattah, B Bishop, Journal of Environmental Science and Health, Part A 39 (11-12), 2855-2866 (2004)ME Mahmoud, MM Osman, SB Ahmed, TM Abdel-Fattah, The Scientific World Journal 2012 (2012)ME Mahmoud, SS Haggag, TM Abdel-Fattah, Polyhedron 26 (14), 3956-3962 (2007)ME Mahmoud, AA Yakout, MT Abed El Aziz, MM Osman, TM Abdel-Fattah, Journal of Environmental Science and Health, Part A 50 (10), 1072-1081 (2015)H Namkoong, E Biehler, G Namkoong, TM Abdel-Fattah, ACS omega 7 (44), 39931-39937 (2022)

Enhanced remediation of acetochlor-contaminated soils using phosphate-modified biochar: Impacts on environmental fate, microbial communities, and plant health

Given that acetochlor (ACT) persists in soil for extended periods, disrupting microbial community structure and causing phytotoxicity to sensitive crops, this study investigated the potential of phosphate-modified biochar (PBC-800) to remediate ACT-contaminated soil. Incorporating 0.5 % PBC-800 into fluvo-aquic, red, and black soils increased their adsorption capacities by 80.4 mg g−1, 76.6 mg g−1, and 76.0 mg g−1, respectively. Even after six months of aging, the Kf values remained 1.6 to 5.1 times higher than in untreated soils. PBC-800 also accelerated ACT degradation across all three soil types, reducing residual ACT levels by 34.3 % to 76.4 % after 60 days, and shortening the degradation half-life by 5 to 7 days. High-throughput sequencing revealed that ACT reduced soil microbial diversity and disrupted community structure, while 0.5 % PBC-800 amendments promoted the growth of degradation-capable genera such as Rhodococcus, Lysobacter, and Gemmatimonas, enhancing microbial ecosystem stability. Furthermore, the amendment of soil with 0.5 % PBC-800 reduced ACT residue concentrations in maize and soybeans by 76.5 % to 82.9 %, and restored plant biomass, leaf chlorophyll content, and mesophyll cell ultrastructure to levels comparable to the control. Therefore, amending ACT-contaminated soil with PBC-800 mitigates ecological and environmental risks, boosts microbial activity, and safeguards plant health.

Adsorption and mineralization of metalaxyl-m and chlorpyrifos in irrigated Mediterranean soil under the effects of salinity.

To evaluate the effects of salinity on the fate of pesticides in a Mediterranean irrigated system, experiments were carried out under laboratory conditions to determine the adsorption, desorption, and mineralization of chlorpyrifos (CPF) and metalaxyl-M (MET) in a soil sample from an irrigated field in northern Tunisia. Adsorption/desorption isotherms and mineralization kinetics data were obtained over a realistic range of salinities via batch equilibrium and incubation techniques. On the basis of the experimental results, MET has a lower sorption capacity than CPF does, and the adsorption data for both compounds were better fitted by the Freundlich equation, with Kf values of 0.477, 0.486, 0.426, 0.444 and 0.474 L kg-1 for MET and 38.994, 39.084, 40.644, 44.055 and 45.185 L kg-1 for CPF at salinities of 0, 1, 2, 5 and 10 g L-1, respectively. According to the mineralization experiments, increasing salinity increased the half-lives of both pesticides. For MET, the DT50 values in unsterilized soil were 206.68, 220.74, 222.16, and 238.73 days, and those in sterilized soil were 2772.58, 4077.33, 6301.33, and 8664.33 days at salinities of 0, 1, 2, 5, and 10 g L⁻1, respectively. For CPF, the DT50 values were 115.52, 138.62, 157.53, and 177.73 days in unsterilized soil and 346.57, 533.19, 693.14, and 990.21 days in sterilized soil. In terms of leaching behavior, the calculated groundwater ubiquity score (GUS) values for the MET and CPF indicate that the MET is classified as a leacher and that the CPF is classified as a nonleacher.

Raw feedstock vs. biochar from olive stone: Impact on the sorption–desorption of diclosulam and tropical soil improvement

The addition of carbon-rich materials, such as raw feedstocks (RAW) and biochars, to agricultural soils is on the rise. This activity has many advantages, such as improving fertility, increasing water retention, and sequestering carbon. However, they can also increase the sorption of residual herbicides in the soil, reducing the effectiveness of weed control. Thus, the objective of this study was to evaluate soil improvement and the sorption–desorption process of diclosulam in soil unamended and amended with RAW from olive stone and their biochars produced in two pyrolysis temperatures (300 and 500 °C). Oxisol was used in this study, unamended and amended with RAW and biochars (BC300 and BC500) in a rate of 10% (w w−1). The sorption–desorption process was assessed by batch-equilibrium experiments and the analysis was performed using high-performance liquid chromatography (HPLC). The addition of the three materials to the soil increased the contents of pH, organic carbon, P, K, Ca, Mg, Zn, Fe, Mn, Cu, B, cation exchange capacity, base saturation and decreased H + Al. The unamended soil had Kf (Freundlich sorption coefficient) values of diclosulam sorption and desorption of 1.56 and 12.93 mg(1 − 1/n) L1/n Kg−1, respectively. Unamended soil sorbed 30.60% and desorbed 13.40% of herbicide. Soil amended with RAW, BC300, and BC500 sorbed 31.92, 49.88, and 30.93% of diclosulam and desorbed 13.33, 11.67, and 11.16%, respectively. The addition of RAW and biochars from olive stone has the potential to change the soil fertility, but does not interfere with the bioavailability of diclosulam in weed control under field conditions, since the materials slightly influenced or did not alter the sorption–desorption of diclosulam.

Synthesis, Structural Determination, DFT Calculation and Biological Evaluation Supported by Molecular Docking Approach of Some New Complexes Incorporating (E)‐N'‐(3,5‐di‐Tert‐Butyl‐2‐Hydroxybenzylidene) Isonicotino Hydrazide Ligand

ABSTRACTThe synthesis and structural analysis of complexes derived from (E)‐N′‐(3,5‐di‐tert‐butyl‐2‐hydroxybenzylidene) isonicotino hydrazide (ITB ligand) were examined using multiple analytical techniques. These techniques included TGA, decomposition point determination, elemental analysis (CHN), spectroscopic (IR, NMR, mass spectrometry) analysis, magnetic susceptibility, conductivity, as well UV–Vis spectrum analysis, along with theoretical studies. Molar conductance values indicated that the Cd (II), Co (II), Cu (II), Ni (II), and Zn (II) complexes are non‐electrolytes in fresh DMSO solutions, with conductance values ranging from 8.5 to 14.35 Ω−1 cm2 mol−1. IR spectra suggested which the ligand coordinates through the metal ions in a tridentate fashion, utilizing the (N & O) donor sites from the (CN & CO & CO) groups in the hydroxybenzylidene moiety. Analytical data from solution complexation, job's method suggested a 1:1 (metal:ligand) molar ratio. The stability order of the complexes was determined as ITBCo > ITBCu > ITBNi > ITBZn > ITBCd, consistent with the stability constant (Kf) values. The pH profile indicated that the studied complexes exhibit stability upon a wide pH scale, typically between (pH = 4:10). Magnetic and electronic spectral analyses helped deduce the ligand coordination abilities and the geometric structures of the complexes. In vitro (antimicrobial & anticancer) performances of the studied complexes were tested versus various (microbial strains & cancer cell lines), revealing higher activity in the chelates assessed to the free (ITB) ligand. The antioxidant potential was also assessed using the DPPH assay. Finally, molecular docking was performed toward estimate the binding efficiency between various protein receptors and the compounds, with results aligning with the biological investigations.

Preparation of pyrolytic coke/uio-66 composite and its effectiveness for removing mono-ethylene glycol (MEG) from aqueous environments

In the present study, the potential of pyrolytic coke (PC) and PC modified with UiO-66 nanoparticles as adsorbents for removing mono-ethylene glycol (MEG) from aqueous solutions was studied. Different experimental techniques were used to investigate the properties of adsorbents. The modification of the PC surface (6.91 m2/g) with UiO-66 significantly enhanced the specific surface area of the PC/UiO-66 composites, increasing it to 379.31 m2/g. Maximum MEG adsorption using PC (84.21%) and PC/UiO-66 (96.75%) was recorded at pH equal to 5 and 7, MEG quantity of 100 mg/L, temperature of 25 °C, adsorbent dosage of 1 g/L, and treatment time of 120 min, respectively. The Langmuir isotherm adsorption capacities for MEG removal using PC and PC/UiO-66 were determined to be 265 mg/g and 291 mg/g, respectively. The KF and AT values for the MEG adsorption were obtained at 128.1 mg/g (L/mg)1/n and 11.05 L/g, indicating the more pronounced affinity of the PC/UiO-66 towards MEG than the PC sample. The enthalpy, entropy, and Gibbs free energy were determined to be negative; thus, the MEG adsorption was exothermic and spontaneous in the range of 25–50 °C. The results demonstrated that the experimental data adheres to a pseudo-first-order kinetic. The adsorbents were recycled up to five stages, and the results showed that after five cycles, no significant decrease in the adsorption efficiency occurred, making them suitable for repeated utilization in the adsorption process.

Adsorption behavior and mechanism of different types of (aged) microplastics for napropamide in soils

The role of microplastics (MPs) as pollutant carriers and their influence on the fate of organic pollutants has received considerable attention. However, the impacts of MPs on the adsorption of amide herbicides in soil, have not been investigated. In this study, non-biodegradable (polyethylene, PEM) and biodegradable (polybutylene adipate terephthalate, PBATM) MPs were aged by exposure to one month of ultraviolet irradiation. The impacts of MPs on the adsorption of napropamide (Nap) in two agricultural soils (black soil [BS] and fluvo-aquic soil [CS]) were investigated through batch experiments. The findings suggested that the adsorption of Nap onto PEM was mainly governed by physical processes, while, chemical mechanisms, should not be overlooked on PBATM. With the addition of 0.2% MPs, the maximum adsorption capacity (Qm) and adsorption distribution coefficient (KF) of soil containing PEM (soil-PEM) were higher than that of soil-PBATM, however, the Qm and KF values of soil-PBATM for Nap were higher when the addition of MPs was 2%. After UV aging, the increased specific surface area of MPs led to an increased adhesion of soil particles. These were attributed to the different surface properties and concentrations of different (aged) MPs, resulting in differences in the inhibition effect by soil particles. The adhesion of soil particles was confirmed by X-ray photoelectron spectroscopy. Additionally, regardless of the addition of MPs, the Qm values of BS for Nap were higher than those for CS. In summary, MPs can alter the adsorption of Nap in soil, influencing both its mobility within the soil ecosystem and the environmental risk.

Factorial design-aided derivatization-free fluorimetric ultrasensitive assay of vonoprazan with application in uniformity of dosage units and plasma samples analysis: Comprehensive and comparative greenness and whiteness assessment

This study presents a novel derivatization-free spectrofluorimetric method for the quantification of vonoprazan (VPZ) that is characterized by its high sensitivity, environmental friendliness, and cost-effectiveness. Notably, this method eliminates the requirement for pre-derivatization, extraction procedures, large amounts of organic solvents, and/or expensive instrumentation, which distinguishes it from previous approaches. The approach employed in this study relies on the formation of an association complex between VPZand the xanthene dye acid red 87 (AR87) under acidic conditions. The stability of the VPZ-AR87 complex was determined to be remarkably high, with a complex formation constant (Kf) value exceeding 2 x 106 M−1. The fluorimetric measurements rely on the quantitative and selective quenchingof the dye’s native fluorescence emission at 545 nm. The experimental parameters were optimized utilizing a quality-by-design 23 full factorial design. This strategy yielded a highly favorable linearity range of 10.0 to 400.0 ng/mL, with a correlation coefficient (r) of 0.9997. The presented methodology exhibited a high level of sensitivity, as evidenced by its ability to detect concentrations as low as 1.2 ng/mL. This sensitivity enabled its successful application for the estimation of VPZ in human plasma samples with high %recoveries (98.21–101.67) and low %RSD values (<1.52). Furthermore, content uniformity testing of low-dose VPZ tablets was performed according to United States Pharmacopeia guidelines. Greenness and whiteness metrics analysis showed a significant advantage of the proposed method over previously reported fluorimetric methods. Validation of the developed approach was carried out in accordance with ICHQ2 (R1) guidelines.

New silica-based adsorbents for water purification: Removal of short- and long-chain perfluoroalkyl sulfonic acids (PFSA) at sub-nanomolar concentrations

Perfluoroalkyl acids (PFAAs) are widespread in the aquatic environment and also measurable in ground and drinking water. Because of the insufficient PFAA elimination in conventional water treatment processes, e. g. active carbon based methods, consumers in areas with contaminated water supplies are exposed to an elevated health hazard. For this purpose, the applicability of five differentially fluorinated silica-based adsorbents (HSU00107954-958) to remove the potentially human toxic perfluoroalkyl sulfonic acids(PFSAs) perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid (PFBS) from water was investigated with regard to removal efficiencies (REs) and equilibrium loadings. During the adsorbent screening at nanomolar concentrations (20.0–33.4 nmol L−1) maximum REs of 46.9% for PFBS (HSU00107954), 79.4% for PFHxS (HSU00107954), and between 86.5 to 96.7% for PFOS (HSU00107956, and HSU00107954, respectively) have been achieved. Even at picomolar concentrations (< 400 pmol L−1) HSU00107954 was still able to eliminate PFBS and PFHxS with an efficiency of 46.3–51.2% and 79.1–88.2%, respectively. Analyses of the equilibrium loadings of the functionalized adsorbents in the concentration range 40.1 pmol to 3.34 nmol L−1 resulted in appropriate linearized Freundlich isotherms for all investigated PFSA. Compared to literature-based Freundlich adsorption coefficients (KF) for granular activated carbon (GAC), the determined KF values (nmol(1−n) Ln m−2) of the most efficient adsorbents HSU00107956 and HSU00107954 for each PFSA were significantly 8–10 and 50–60 times higher, respectively. These proven increased adsorption capacities relative to activated carbon possibly indicate specific PFSA selectivities of the functionalized macroporous silica adsorbents.

Kinetics of Tofu Pulp as Copper Metal Adsorbent on the Waste of the Silver Craft Industry

Liquid waste originating from the silver crafts industry is heavy metal waste that is dangerous for the surrounding environment, one of which is copper (Cu). Copper is a heavy metal that can have toxic effects on human health. Based on these problems, processing is needed to reduce the pollutants produced. One of the technologies used is adsorption using a natural adsorbent that is efficient and easy to obtain, namely tofu dregs. Adsorption using tofu dregs is because tofu contains protein. This protein has the ability to absorb amino acids which form two charged ions (zwitter ions). Toxic metals can be bound to proteins as metallothionein. This research aims to determine the efficiency of using tofu dregs as an absorbent for copper metal (Cu) and to determine the effect of contact time and adsorption isotherms on copper metal adsorption. 1 gram of tofu dregs was used with 25 ml of waste and then contacted with a magnetic plate stirrer at varying times of 30, 60, 90, 120 and 150 minutes. The concentrations of all copper metals were analyzed using an Atomic Absorption Spectrophotometer. Next, each copper metal content was calculated using a copper metal standard calibration curve. Identification using an Infrared Spectrophotometer showed that the tofu dregs waste in this study contained the functional groups -OH, N-H (stretching), C-H (aliphatic), C=O, -OH (bending vibration), and C-O. From the research it was found that the copper metal content in the sample was 19.5979 ppm. The optimum contact time for copper metal adsorption is 120 minutes, which results in an optimum adsorption efficiency for copper metal, namely 54.88%. The isotherm equation that corresponds to the adsorption of copper metal using tofu dregs waste is the Freundlich isotherm with a Kf value of 0.072 L/g and a 1/n value of 2.366. This shows that the adsorption of copper metal occurs in a multilayer layer on the surface of the tofu dregs adsorbent, which illustrates the occurrence of physical adsorption. Tofu dregs waste is an effective adsorbent for reducing copper metal levels in silver craft waste.

Characteristics candlenut shell-based activated Carbon for reduction Iron (Fe) in surface water from Bratasena Tulang Bawang, Lampung

Candlenut shells are only used as fuel, and some are thrown away, so their use has not been maximized. Because of their high carbon content, candlenut shells may be used to create adsorbents. This study looks at how different activator concentrations of KOH activators can be used to make adsorbents from candlenut shells. The study will investigate how various activator concentrations affect the ability of adsorbents based on candlenut shells to bind molecules. Furthermore, the investigation will examine the possible uses of these adsorbents in diverse sectors, including air purification and wastewater treatment. This research was carried out using the Completely Randomized Design (CRD) method, which consisted of 1 activator KOH concentration of 0.5 M, 1 M, 1.5 M, 2 M, and 2.5 M with 3 replications each. The finding demonstrated that adsorbent products activated with 0.5 M KOH yield the highest quality and satisfied SNI 06-3770-1995 requirements for an ash and water content of 10.21% and 0.98%, respectively. The adsorbent product has an iodine absorption capacity of approximately 639.39 mg/g, comparable to SNI 06-3770-1995. For iron metal, the adsorbent product exhibits an adsorption capacity and absorption efficiency of 0.14 mg/g and 98.30%, respectively. The Freundlich adsorption isotherm model is suitable for this investigation, with a Kf value of 0.14 mg/g and an R2 of 0.9999.

Glycosylated flavonoid kaempferitrin: Electroanalytical detection and the proposal of an oxidation mechanism supported by quantum chemical calculations

In this work, the electrochemical behavior of the glycosylated flavonoid kaempferitrin was studied, and an electroanalytical methodology was developed for its determination in infusions of Bauhinia forficata using a boron-doped diamond electrode (BDD). The electrochemical behavior of the flavonoid was studied by cyclic voltammetry, and two irreversible oxidation peaks at 0.80 and 1.0 V vs Ag/AgCl were observed. The influence of the pH on the voltammograms was examined, and higher sensitivity was found at pH 7.0. The electrochemical process corresponding to peak 1 at 0.80 V is predominantly diffusion-controlled, as the study shows at varying scan rates. An analytical plot was obtained by square wave voltammetry at optimized experimental conditions (frequency = 100 s−1, amplitude = 90 mV, and step potential = 8 mV) in the concentration range from 3.4 μmol L−1 to 58 μmol L−1, with a linearity of 0.99. The limit of detection and limit of quantification values were 1.0 μmol L−1 and 3.4 μmol L−1, respectively. Three samples of Bauhinia forficata infusions (2 g of sample in 100 mL of water) were analyzed, and the KF values found were 5.0 × 10−4 mol L−1, 3.0 × 10−4 mol L−1, and 7.0 × 10−4 mol L−1, with recovery percentages of 98 %, 106 % and 94 %, respectively. Finally, experiments were performed with two other flavonoids (chrysin and apeginin) to compare and propose an electrochemical oxidation mechanism for kaempferitrin, which was supported by quantum chemical calculations.

Experimental and artificial intelligence optimization of paint wastewater (PWW) coagulation using novel Phaseolus vulgaris seed extract (PVSE)

This study investigated the application of artificial intelligence algorithms (AIA) in the coagulation treatment of paint wastewater anchored by novel Phaseolus vulgaris seed extract (PVSE). Untreated wastewater discharge harms the ecosystem, and therefore harmful industrial effluent, such as paint wastewater, must be brought to safe discharge levels before being released into the environment. In addition to AIA, comprehensive characterization tests, coagulation kinetics, and process optimization were also executed. Characterization results revealed that total solid in the PWW was above allowable standard, justifying the need for effective particle decontamination. The XRD and FTIR characterization indicated that PVSE structure is amorphous with abundant amine groups. Results of analysis of variance (ANOVA) obtained from process modeling indicated that the coagulation-flocculation process was a nonlinear quadratic system (F-value = 45.51) which was mostly influenced by PVSE coagulant dosage (F-value = 222.48; standardized effect = 14.85). Artificial intelligence indicated that neural network training effectively captured the nonlinear nature of the system in ANN (RMSE = 0.00040194; R = 0.98497), and ANFIS (RMSE = 0.003961) algorithms. Regression coefficient obtained from process modeling highlighted the suitability of RSM (0.9662), ANN (0.9739), and ANFIS (0.9718) in forecasting the coagulation-flocculation process, while comparative statistical appraisal authenticated the superiority of ANN model over RSM and ANFIS models. The coagulation kinetics experiment, which used a coagulation kinetic model, revealed a constant flocculation constant (Kf-value) for all jar test batches and a strong association between the Menkonu coagulation-flocculation constant (Km) and Kf values. Best removal efficiency of 97.01 % was obtained using ANN coupled genetic algorithm optimization (ANN-GA) at PVSE dosage of 4 g/L, coagulation time of 29 min and temperature of 25.1oC.

Melamine-Maleic Acid Polyamide Adduct / Polyacrylonitrile Nanofibers as a Novel Adsorbent for Removal of Methyelene Blue Dye from Aqueous Solutions

Efficient removal of methylene blue (MB) dye from aqueous solutions is crucial for addressing environmental pollution. This study investigates the potential of Melamine-maleic acid polyamide adduct/polyacrylonitrile (ME-MA amide polymer/PAN) nanofibers as a novel adsorbent for MB dye removal. Characterization via scanning electron microscopy (SEM) revealed surface morphology changes, with fiber diameters ranging from 1 to 3 μm. Thermal stability analysis demonstrated enhanced stability for ME-MA/PAN compared to pure PAN fibers. Fourier transform infrared (FT-IR) analysis confirmed the presence of hydroxyl, amide, and thiol groups on the nanoparticle surface, covalently attached to the nanofiber surface. Through electrospinning, ME-MA/PAN composites were synthesized, showing promising capabilities for dye removal. Optimal conditions were observed at pH 12 and a ME-MA PAN dose of 0.02 g. MB removal efficiency increased with higher initial dye concentrations, peaking at 30 mg/L, and higher temperatures up to 40°C. Adsorption isotherm models indicated Langmuir adsorption capacity (Qm) of 111.10 mg g−1 and a separation factor (RL) of 0.297, with Freundlich constants (1/n) and KF values of 0.418 and 22.9, respectively. Kinetic and thermodynamic studies revealed favorable conditions for MB dye removal, validating ME-MA amide polymer/PAN nanofiber composites as environmentally friendly and effective materials for eliminating toxic MB dye from aqueous solutions. This research highlights the potential of ME-MA/PAN nanofibers in addressing dye pollution, suggesting their application in wastewater treatment for sustainable environmental management. Further investigation into regeneration methods and scalability is recommended for practical implementation in real-world scenarios.

Biometric indices of eight fish species from the catchment area of Kaptai lake, Bangladesh

Biometric indices viz. i) Length-weight relationships (LWRs), ii) form factor (a0.3) and iii) condition factors (relative KR and Fulton's KF) were presented for 8 fish species collected from Kaptai lake at five sampling points including Rangamati Sadar, Barkal, Naniarchar, Langadu and Kaptai upazila. A total of 3204 individuals belonging to 3 families were measured and weighed between August 2020 to April 2021 by the catch assessment survey with different types of fishing gear (seine net, current net, gill net and lift net). Calculations were made for the parameters a and b of the eq. W = aTLb. The analysis of covariance (ANCOVA) revealed significant differences between stations in LWRs for all species (P < 0.01). The parameter b of the LWRs ranged from 2.34 (Parambassis lala) to 3.34 (Ailia coila) with a mean value of 2.98 (SE: 0.11) and 50% of its fall within the interval 2.9–3.2. Results showed that 3 species showed positive allometric growth (Gonialosa manminna, Ailia coila, and Eutropiichthys vacha), 3 showed negative allometric growth (Gudusia chapra, Chanda baculis, and Parambassis lala), and 2 exhibited isometric growth (Corica soborna, Chanda nama). The findings further indicated that the LWRs of 8 species were highly correlated (r2 > 0.90, P < 0.001). The a3.0 value estimated for eight species varied from 0.0043 to 0.0114. The KR value ranged from 0.26 to 4.97 and KF value ranged from 0.17 to 2.89; showed significant differences of KR and KF between stations for eight species. As per FishBase, a new record for the maximum size of C. soborna and C. baculis was documented as 7.1 cm and 8.1 cm, respectively. This research is the first to provide information on biometric indices for six species (C. soborna, C. nama, C. baculis, P. lala, A. coila and E. vacha) in Kaptai Lake, which may aid in management and conservation throughout the country, including their geographical distribution.

Inclusion Complexes of Ethanamizuril with β- and Hydroxypropyl-β-Cyclodextrin in Aqueous Solution and in Solid State: A Comparison Study.

Ethanamizuril (EZL) is a new anticoccidial drug developed by our Shanghai Veterinary Research Institute. Since EZL is almost insoluble in water, we conducted a study to improve the solubility of EZL by forming inclusion complexes with β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD). In this study, we performed molecular docking and then systematically compared the interactions of EZL with β-CD and HP-β-CD in both aqueous solution and the solid state, aiming to elucidate the solubilization effect and mechanism of cyclodextrins (CDs). The interactions were also examined in the solid state using DSC, PXRD, and FT-IR. The interactions of EZL with CDs in an aqueous solution were investigated using PSA, UV-vis spectroscopy, MS, 1H NMR, and 2D ROESY. The results of phase solubility experiments revealed that both β-CD and HP-β-CD formed inclusion complexes with EZL in a 1:1 molar ratio. Among them, HP-β-CD exhibited higher Kf (stability constant) and CE (complexation efficiency) values as well as a stronger solubilization effect. Furthermore, the two cyclodextrins were found to interact with EZL in a similar manner. The results of our FT-IR and 2D ROESY experiments are in agreement with the theoretical results derived from molecular simulations. These results indicated that intermolecular hydrogen bonds existing between the C=O group on the triazine ring of EZL and the O-H group of CDs, as well as the hydrophobic interactions between the hydrogen on the benzene ring of EZL and the hydrogen of CDs, played crucial roles in the formation of EZL/CD inclusion complexes. The results of this study can lay the foundation for the future development of high-concentration drinking water delivery formulations for EZL.

Fabrication, physicochemical characterization and theoretical studies of some new mixed ligands complexes based on N-(1H-benzimidazol-2-yl)-guanidine and 1, 10-phenanthroline: DNA interaction, biological applications and molecular docking approach

The fabrication and structural identification of mixed ligand chelates resulting from 1-(1H-benzimidazol-2-yl) guanidine (BIG = main ligand) and 1,10-Phenanthroline (phen) (secondary ligand). The tested compounds were investigated using TGA, CHN, spectra analysis (FT-IR, Mass spectra, NMR), melting point, magnetic moments, molar conductance, Ultraviolet–Visible spectroscopy as well computational studies. The conductance results showed that the tested Pd(II), VO(II) and Ag(I) chelates have electrolytes in fresh solutions of DMSO lies in the range 38.12–118.87 Ω−1 cm2 mol−1 except, Cu(II) chelate is a non-electrolyte it is value equal 15.16 Ω−1 cm2 mol−1. FT-IR spectrum displays that the tested main ligand is coordinated with metal ions in a bi-dentate behavior with N, N donor sites of the HN=C and C=N. While the second ligand coordinated with metal ions through its N2 atom in the pyridine ring. Moreover, the obtained analytical data regarding complexation in solution, molar ratio and continuous variation methods suggest 1M: 1 L molar ratio. Also the stability constant of tested complexes was identified in solution state and the formation constants (Kf) were evaluated by applying continuous-variation method. Stability of complexes was arranged by BIGPAg > BIGPVO > BIGPCu > BIGPPPd in agreement with Kf values. The pH profile revealed that the wide range of pH stability of the tested complexes is at pH = 4- 10 in most of them. Magnetic and electronic spectra are applied to deduce the coordinating ability of the tested ligands and the geometric structure of the studied chelates. That data of magnetic susceptibility for ternary mixed chelates are locked to an octahedral geometry for Cu(II) & VO(II) chelates due to the data of (μeff = 1.8 and 1.83 B.M) respectively and Pd(II) and Ag(I) chelates are diamagnetic with square planar and tetrahedral geometry, respectively. The TGA study of these studied complexes displays that the hydrated H2O, acetate, nitrate, and acetylacetonate anions are removed in the first (45°C-180°C) and second degradation steps followed directly by degradation of the studied ligands in the following stages. The thermodynamic factors, like ΔS*, ΔH*, E*, A and ΔG* are evaluated from the TGA curves and explained. The DFT/B3LYP computation method was applied for the estimation of the MEP, (HUMO & LUMO) energy for the studied compounds. In-silico assay was executed by two different approaches over compounds to evaluate their biological behavior and degree of interaction with biological systems, before practical application. BIGPPd complex displayed priority in interaction with various protein. In-vitro assay was then carried out for compounds against different microbes and BIGPPd showed high antimicrobial activity with inhibition zones are established to be 45.75 ± 0.10 and 41.95 ± 0.05 mm against B. Cereus and G. Candidum at 25 µg/mL. Also, their cytotoxic behavior was examined against MCF-7, HepG2 and HCT-116 carcinoma cell lines, high cytotoxicity was clearly recorded with BIGPPd complex with IC50% are established to be (5, 6.25 and 7.14 µg/mL) respectively. Furthermore, antioxidant activity was examined, and the complexes exhibited high reactivity with trapping free radicals. The BIGPPd exhibited significant free radical scavenging activity with an IC50 value of 20.15 μg/ml. The interaction of metal chelates with DNA was detected by gel electrophoreses, viscosity and spectral studies. Spectrophotometric titration and viscosity studies expose that each of tested complex is an avid binder to DNA. The intrinsic binding constants were calculated for all the tested compounds could bind to Ct-DNA generally through replacement, intercalative mode & minor groove binding of interactions with the sequence: BIGPVO (6.05×104) > BIGPCu > BIGPPd> BIGPAg >BIG (1.16×103). This may be due to enhanced hydrophobic & electrostatic interaction of aromatic rings. Finally, such complexes may be considered as a promising bioactive agent.

The influence mechanism of environmental factors on DGT adsorbing sulfonamides and the migration between water and sediment

Obtaining the sulfonamides (SAs) concentrations in the water body and sediment bulk was a prerequisite to reveal their transport and partitioning behavior in sediment-water environments and accurately assess their ecological risk. In the present study, the influences of multifactor interactions on the performance of o-DGTs with XAD-18 binding gels were analyzed by central combination experiments and response surfaces analysis, in which the target compounds were 9 SAs. The results indicated that dissolved organic matter (DOM), pH, and suspended particulate matter (SS) had significant effects on the o-DGT sampling, whereas this o-DGT was independent of the ionic strength (IS). Concentning the composite influence of the four factors, the interaction between DOM and SS posed the most significant effect on all 9 SAs compounds. Subsequently, an o-DGT and DIFS model was applied to explore the SAs migration between the water-sediments interface. The difference between desorption rate (kb) and adsorption rates (kf) values suggested that the kinetics of SAs was dominated by adsorption. Moreover, the short-term sediment-water partitioning of SAs was clarified on the basis of distribution coefficient (Kdl) for the labile SAs, among which the sulfadiazine (SDZ) had the largest labile pool. The ability of sediments to release SAs to the liquid phase as a sink was determined by response time (Tc). Among the 9 SAs, the long-term release of soseulfamethoxypyridazine (SMP) from the solid phase of sediments would have a potential risk to the aquatic environment, to which more attention should be paid in the future.