Volume 237, Issue 9

The prime objective of this study is to synthesize eco-friendly okra-psyllium based hydrogel through free radical crosslinking method by using citric acid-ammonium persulfate as a crosslinker-initiator system. Various techniques were used to explore the morphology, structure and thermal behaviour of the synthesized hydrogel via. Powdered X-ray diffraction studies, SEM and TGA techniques. Response surface methodology was performed to maximize the grafting percentage of the synthesized hydrogel up to 244 % and swelling percentage of 598 %. The physicochemical properties like salt-resistance behaviour and the impact of ionic strength on the swelling percentage of synthesized hydrogel were investigated and thus observed with the following trend as K +  > Ca 2+  > Fe 3+ . Furthermore, the synthesized sample showed an excellent bio-adsorbent behaviour for the removal of uranium with 97.75 % removal in 60 min and crystal violet dye removal up to 85.32 % in 24 h from contaminated water. Various kinetic and isotherm adsorption modelling were implied to probe the mechanism of adsorption with displayed interactions between the absorbate and the absorbent. The Langmuir isotherm model was well-fitted in dye adsorption case with regression co-efficient value of 0.99. In case of uranium, tempkin isotherm model was best fitted with regression co-efficient value as 0.92. Crystal violet dye adsorption favoured second-order kinetic model whereas the adsorption mechanism of uranium followed first-order kinetics. Hence, the revealed results depicted that the synthesized hydrogel served as a potential candidate for the effective removal of toxic dye (crystal violet) and metal ion (uranium) from aqueous media with a sustainable approach towards environment.

The selective fluorescence sensors are used for the analysis of toxic pollutants in the environment. In this study, phenol dansyl amide (PDA) was prepared as highly stable fluorescence ligand by using nucleophilic substitution reaction. Its interaction with eighteen different cations including Hg 2+ and series of anions were investigated by using UV-visible and fluorescent spectrophotometry. However, PDA significantly indicated high sensitivity and selective quenching effect towards mercury ion. Furthermore, Density Functional Theory (DFT) along with the B3LYP method was implemented to explore minimum energy complex and fluorescence mechanism. The computed results revealed that among four possible optimized complexes of PDA and Hg + ion, the first complex (PDA-Hg 2+ –I) was observed to be the most stable complex with the estimated energy difference of 8.91 kcal/mol and intermolecular charge transfer mechanism was observed in the same complex by HOMO and LUMO computation.

Herein, nickel ferrite-based photocatalysts with enhanced light utilizing electrical charge transport properties have been reported for environmental remediation applications. The cobalt and holmium co-doped nickel ferrite [Ni 1− x (Co) x Fe 2− y (Ho) y O 4 ] nanoparticles and bare nickel ferrite (NiFe 2 O 4 ) nanoparticles have been prepared via surfactant-supported wet-chemical techniques. The as-prepared ferritic photocatalyst’s structural, morphological, and light harvesting features have been examined in detail using well-known physical, electronic, and optical methods. The co-doped ferrite photocatalyst’s tuned structural features enable it to absorb maximum wavelengths from the U.V. and visible regions. This is because the co-doped Ni 1− x (Co) x Fe 2− y (Ho) y O 4 optical band gap is 1.73 eV; hence, the wavelength from the visible part possesses sufficient energies to trigger the electronic excitation in co-doped ferrite photocatalysts. Moreover, the co-doping-induced structural defects in the ferrite photocatalyst. These defects act as a reservoir for the charge species, mainly electrons, so the process of charge recombination is almost hampered for the Ni 1− x (Co) x Fe 2− y (Ho) y O 4 photocatalyst. In application terms, the photomineralization capabilities of doped and bare ferrite photocatalysts have been explored using crystal violet (CV) dye. The comparative photocatalytic evaluation of both nickel ferrite-based photocatalysts shows that co-doped ferrite degraded 96.02 % of CV dye. In comparison, the undoped one only degraded 64.84 % after 80 min of W-lamp light exposure. The results demonstrated that the Ho and Co co-doped ferrite photocatalyst exhibits excellent photocatalytic activity, suggesting its potential for environmental remediation applications in textile industrial discharges.

In view of ecobenign nature of green synthesis, iron oxide (Fe 3 O 4 ) nanoflakes are synthesized via a green route. Three different vegetables (spinach, broccoli and pumpkin) extracts were used for the synthesis of Fe 3 O 4 nanoflakes. X-ray diffraction (XRD) analyses confirm the formation of face centered cubic Fe 3 O 4 , while SEM analysis revealed the formation of nanoflakes. FTIR also confirm the Fe–O bands at 478 and 590 (cm −1 ) and the surface plasmon resonance (SPR) was observed at 280 nm. The magnetic properties were also investigated and Fe 3 O 4 prepared using spinach extract shows relatively low saturation magnetization (Ms) of ∼66 emu/g as compared to pumpkin (105 emu/g) and broccoli (130 emu/g) with ∼25Oe coercivity value. The antibacterial activity of Fe 3 O 4 nanoflakes was studied against Escherichia coli and Pseudomonas aeruginosa and a highly promising antibacterial activity was observed. Results revealed that the Fe 3 O 4 nanoflakes prepared via a green route could have potential applications in biomedical field.

In drug development, it is very important to study the physicochemical properties of drugs under various solution conditions in order to understand their mechanism of action and their interactions with bioactive compounds. In this regard, this study attempts to elucidate the effects of co-solvent and co-solute on the physicochemical properties of Montelukast sodium and its possible interactions with deoxyribonucleic acid (DNA). The physicochemical, volumetric and thermodynamic properties of Montelukast sodium were determined by various measurements such as density, viscosity and surface tension. Most of these measured parameters responded differently when ethanol (co-solvent) and sodium chloride (co-solvent) were added to the drug solution, and/or when the concentration and temperature of the drug solution were changed. Various solution properties such as flow behavior, surface activity and association behavior of Montelukast sodium were also affected by the addition of DNA. UV–Vis spectroscopy was also used to better understand the qualitative and quantitative strength of DNA-drug interactions in water. Using UV–Visible analysis, the Montelukast DNA binding constant (Kb) was determined to be 6.861 × 103 (L Mol −1 ). Physicochemical and spectroscopic results confirmed that there may be physicochemical type interactions between the drug and DNA. It is also proposed that hydrogen bonding can occur between the oxygen and hydrogen atoms of the Montelukast sodium and the hydrogen, oxygen and nitrogen atoms of the DNA molecule.

Seven novel molecular salts were synthesized from the commonly available 4-dimethylaminopyridine organic base and benzoic acid derivatives contain additional functional groups. Benzoic acids with additional hydroxyl, nitro, amino, and bromo functional groups, were successfully employed and investigated their role in non-covalent interactions within the supramolecular chemistry of heterosynthons solid-state architecture. The collection of all 4-dimethylamopyrinium salts of benzoates and phenolate was accomplished through the utilization of conventional solvent evaporation technique. The resulting molecular salts were afforded by deprotonation of the acidic moiety such as COOH, or OH to the ring N of 4-dimethylaminopyridine, establishing a strong charged-assisted hydrogen bond between the deprotonated group (benzoate or phenolate) and protonated ring N. The structure of compounds was fully elucidated by single X-ray diffraction, powder X-ray diffraction, 1 H NMR, FT-IR, and thermogravimetric analysis. The crystal packing is interpreted by the strong charge-assisted N–H⋯O hydrogen bond between the NH + and the corresponding deprotonated group and O–H⋯O, N–H⋯N hydrogen bonding. The analysis concluded that C–H⋯O, CH3⋯O, C–H⋯π, CH3⋯π, π–π, C–H⋯Br, and CH3⋯Br contacts contribute significantly to stabilizing and expanding the high-dimensionality (2D–3D framework) of the structures. The structures were thoroughly explored for their various bonding and nonbonding interactions, as well as their supramolecular chemistry in detail. The antimicrobial activities of all compounds were evaluated using the Oxford cup method.

Dental caries, a widespread oral infection affecting people worldwide, has significant societal impact due to its high prevalence. The issue of antibiotic resistance in the oral environment was investigated in rural areas in the antimicrobial susceptibility patterns and biofilm development in the bacteria causing dental caries. Cross-sectional study was conducted between September 2021 and October 2022. Standardized questionnaires were used to collect data on sociodemographic characteristics, behavioral habits, and clinical issues. The study included 900 individuals suspected of having dental caries, who were categorized into three groups based on their initial symptoms at the time of diagnosis. Among the patients, 61 % reported tooth discomfort only, 12 % experienced gum bleeding in addition to tooth discomfort, and 27 % had both problems. To assess the effectiveness of antibiotics and extracts against the identified pathogens, the collected samples were transferred to a microbiological laboratory. Data analysis was conducted using SPSS version 22. A statistically significant difference was concluded when the P-value was less than 0.05. Each strain possessed unique molecular and biochemical properties, allowing for their independent utilization without reliance on other strains.

Herein, we have scrutinized the influence of vitamin B3 (nicotinic acid) and its isomer isonicotinic acid at varying concentrations on the micellization properties of 1-tetradecyl-3-methylimidazolium bromide [C 14 mim] [Br] at a given temperature range of 298.15–308.15 K to further explore their advancement in medicinal chemistry. The behavior of ionic liquid at the surface was determined using tensiometry, while conductivity, steady-state fluorescence, and UV–visible spectroscopy were used to determine the behavior in bulk. Various thermodynamic, surface, and micellization parameters have been determined. The evaluated CMC values for the pure ionic liquid were found to increase with the increasing concentration of external additives (nicotinic acid and isonicotinic acid). Further, the negative ∆Gmic0${{\increment}G}_{\mathrm{m}\mathrm{i}\mathrm{c}}^{0}$ and ∆Hmic0${{\increment}H}_{\mathrm{m}\mathrm{i}\mathrm{c}}^{0}$ state the feasible and exothermic nature of the micellization process. The results attained employing different methods were correlated with each other and are found to be in good agreement. The results obtained from various studies indicate the presence of hydrophobic and electrostatic interactions occurring between the additives (nicotinic and isonicotinic acid) and the ionic liquid aggregates.

Mesoporous materials (MMs) in the Santa Barbara Amorphous (SBA) family can be used as catalysts or support materials (SMs) for catalysts because they have controllable pore structure, thermal and chemical stability, and their surface properties can be modified easily depending on the desired reaction type. Surfactant (Pluronic p123; it is a symmetric triblock copolymer comprising poly and its chemical formula; HO(CH 2 CH 2 O) 20 (CH 2 CH(CH 3 )O) 70 (CH 2 CH 2 O) 20 H), a silica source (such as Tetraethyl orthosilicate: TEOS; SiC8H20O4), and a solvent are used in the synthesis of the SBA family (SBA-15). The SBA-15 was given with the hydrothermal method (HM) a catalyst feature by loading the active substance at a rate of 10, 25 % (cadmium/silica) by mass. Esterification reactions (ERs) were carried out with Cd-SBA-15 (Cd/Si: 10–25 %) catalyst at a feed rate of 1/2 (methanol/acetic acid), in the presence of 0.4 g catalyst, at a reaction temperature of 373 K and for 6–48 h. After 48 h, the catalytic activity (CA) values were obtained as 65 and 68 %, respectively. The re-usability of the catalysts was repeated two times under the same experimental conditions. It was observed that the catalysts maintained their catalytic activity of 73.35 and 68.72 % (3 × 48 h). In addition, the limited effect of catalyst amount on acetic acid conversion was investigated by Response Surface Methodology, and Historical Data Design. Moreover, k 1 , k 2 , equilibrium constant and activation energy values were calculated using the pseudo-homogeneous kinetic model. The physical features of the catalysts were investigated by BET, XRD, FTIR, DRIFT, SEM/EDX, and MAPPING analysis methods.