Volume 238, Issue 2

In the present work, silver-doped zirconium oxide nanocomposites were synthesized by hydrothermal method and characterized by XRD, FTIR, FESEM and EDX techniques. The existence of zirconium and silver in the finished nanocomposites from the produced material is investigated using XRD and FTIR. The estimated particle diameter size range for crystallites is 10–16 nm. In addition, the obtained Ag/ZrO 2 nanocomposites were analyzed the biocidal activity of two separate bacteria Escherichia coli ( E. coli ), Staphylococcus aureus ( S. aureus ), and two separate fungal Aspergillus niger ( A. niger ), Candida albecans , pure AgO, ZrO 2 and Ag doped ZrO 2 nanocomposites were also examined. This Ag doped ZrO 2 (10 %) nanocomposites have a larger zone of inhibition than other human diseases, according to the results of the biocidal activity.

The mechanism of the Ni(0)-catalyzed cycloaddition reaction of 2-cyclobutanone with alkyne was studied using the function M06-2X with two basis sets. The computational results indicate that the reaction occurs through two independent pathways, one of which is related to the coordinating of C=O bond of oxidative addition of 2-cyclobutanone to the Ni(0) center (pathway 1), and the other involves coordination of C(sp 3 )–H bond (pathway 2) to form an intermediate containing either a Ni–C(O) or Ni–C (sp 3 ) bond, then insertion an alkyne into either Ni–C(O) or Ni–C(sp 3 ) bond. In the last step, the products are formed and the catalyst is regenerated through the reductive elimination. Our computational results are consistent with previous computational studies for cycloaddition of 3-azetidinone to alkyne except that the mechanism takes place through two independent pathways, i.e. there are no transition states or intermediates involved in the two pathways, which is contrary to what it has been indicated in previous studies. In addition, our results show that the Ni-catalyzed cycloaddition reaction of the 3-azetidinone with the alkyne is more active compared to the 2-cyclobutanone by free energy of 10.4 and 9.3 kcal/mol according to pathway 1 (7.4 and 8.1 kcal/mol according to pathway 2) calculated by the M06-2X(I) and M06-2X(II) methods, respectively. An analysis of the electrophilic and nucleophilic indices of the reactants was carried out.

In this work, two different reducing agents namely sodium hydroxide and potassium hydroxide (NaOH and KMnO 4 ) were used to synthesis of manganese oxide (Mn 2 O 3 ) nanoparticles by the co-precipitation method and examined for the electrochemical applications. The as-prepared Mn 2 O 3 nanoparticles using NaOH precursor, dried in a hot oven at 80 °C for 6 h (MN-1) and then annealed for 7 h at 600 °C (MN-2). Similarly, Mn 2 O 3 nanoparticles were prepared using KMnO 4 precursor, dried in a hot oven at 80 °C for 6 h (MK-1) and then annealed for 7 h at 450 °C (MK-2), respectively. The influences of reducing agents on structural, morphological and optical properties were investigated. The structural analysis revealed the prepared samples had tetragonal crystal structures with better crystallinity. FT-IR spectral analysis revealed the characteristic bonds of Mn–O–Mn were observed in the region of 486–573 cm −1 . The FE-SEM and HR-TEM images showed coral-like and nanorod structures for samples MN-2 and MK-2, with exhibited lattice value of 0.27 nm related to the (222) plane. The presence of the elements manganese (Mn) and oxygen (O) was confirmed by EDAX mapping. The XPS study confirmed that the oxidation state of the prepared samples was +2. The UV-Vis spectra suggested that the adsorption edge was blue-shifted compared to the sample MN-2. Cyclic voltammetry (CV) and galvanostatic charge–discharge experiments demonstrated that charge storage in Mn 2 O 3 exhibited faradic-dominated capacitive behavior. MN-2 nanorod structures were obtained at excellent specific capacitance value of 196 F g −1 compared to MK-2 nanoparticles. Based on this study, Mn 2 O 3 nanoparticles was recommended as exceptional electrode materials for efficient supercapacitor applications due to its superior electrical conductivity, large surface area and redox properties.

New palladium(II) complexes containing coumarin derivatives such as (E)-3(2-(2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinyl)oxazol-4-yl)-2H-chromen-2-one ( HL 1 ), (E)-7-hydroxy-3(2-(2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinyl)oxazol-4-yl)-2H-chromen-2-one ( HL 2 ) were successfully designed and synthesized from the reaction of K 2 [PdCl 4 ] with ligands HL 1&2 with in Methanol medium. The ligands and complexes were characterized by various analytical and spectral techniques such as FT-IR, UV–Vis, 1 H NMR and 13 C NMR spectral techniques. From the spectral data we confirmed that the ligands neutrally coordinated with Pd(II) ion via their lactone oxygen, azomethine nitrogen and oxazolyl ring nitrogen atoms. The electrolytic nature of the complexes was confirmed by using conductivity experiments. Further anticancer activity of the compounds has examined with HeLa (human cervical cancer) cells along with the cisplatin as positive control and the obtained results revealed that the complexes possess significant anticancer activity and non-toxic towards HUVEC (human umbilical vein endothelial) cells.

The Vellar estuary are predominated by mudflats and having dense mangrove vegetation, these mangrove act as major nursery ground feeding for a various marine animal like fin and shellfishes. The current study is an effort to gather baseline study data for the area near the Vellar estuary mangroves. Since, Temperature, Nitrate, pH, Salinity, Ammonia, Inorganic phosphate, Dissolved Oxygen and Silicate is a key factor affecting chemical and biological water reactions, as well as controlling photosynthesis in coastal regions and influencing temperatures in swamp, flora and fauna in the estuary. Therefore, unique seasonal variation was observed in the present study. The increasing trend in nutrients levels are observed in summer to monsoon and low in summer seasons. These oscillations of hydrological parameters support primary production in this Vellar estuary.

In this research work, bicomponent structures of salicylic acid were synthesized by reflux condition. The cofomers used were 1-10-phenanthroline, 5-chlorobenzotiazole, and 2-amino-5-methylpyridine. The yield of resultant crystals was calculated at about 60–70 %. It was concluded that bicomponent polymorphs 1–3 were formed by treating salicylic acid (SA) with 10-phenathroline (1-10-Phen), 5-chlorobenzotiazole (5-ClB), and 2-amino-5-methylpyridine (2A-5M-P) respectively. The intermolecular interactions were further confirmed by their computational studies. Molecular docking revealed that the binding nature of salicylic acid can be tuned upon cocrystallization or molecular salt formulation. Antioxidant and antibacterial activities (against Gram-positive and Gram-negative bacteria) were also performed in this study. The MP, and FT-IR, were used for the structure elucidation.

The effectiveness of 5-acetyl-4-(3-methoxyphenyl)-6-methyl-1-phenyl-3,4-dihydropyrimidin-2(1H)-one as a corrosion inhibitor for mild steel in acidic conditions was investigated herein through the experimental and theoretical approach. Experimental results demonstrated that this compound acts as a reliable corrosion inhibitor ( η  %) for mild steel in acidic environments, with its inhibition efficiency increasing as the inhibitor concentration rises. Adsorption behavior on the mild steel surface followed Langmuir and Temkin adsorption isotherms. Electrochemical polarization tests indicated that the compound exhibited a mixed corrosion type, and impedance spectroscopy revealed an increase in charge transfer resistance with higher inhibitor concentrations. Examination of the mild steel surface using SEM and Atomic Force Microscopy (AFM) confirmed the formation of a protective film. Wettability characteristics were assessed using the contact angle method. Frontier molecular orbital analysis revealed the HOMO and LUMO values for both the neutral and protonated forms of the compound. At 289 °C, the interaction energy for adsorption was found to be approximately −146.3006 kJ/mol for the neutral system and −135.8122 kJ/mol for the protonated system, while at 318 °C, the corresponding values were −140.6106 kJ/mol and −147.6022 kJ/mol. These findings collectively suggest the potential industrial utility of the investigated inhibitor as an effective corrosion inhibitor.

The primary goal of this study is to discover a sustainable, renewable, and ecologically friendly anticorrosive inhibitor. Anticorrosion analysis of Capsicum annuum fruit extract (CAFE) was examined under hydrodynamic solution at 1500 rpm in 15 % on P110 steel. Results of the assessment showed that CAFE inhibits the corrosion of P110 steel and the rate of corrosion is significantly reduced on increasing its dosing amount. CAFE exhibits the maximum anticorrosive efficiency to 89.5 % (CAFE/800 mg/L) and 92.2 % (CAFE + KI/600 mg/L). The CAFE shows the chemical nature of inhibition effect. The maximum and minimum charge transfer resistance ( R ct ) and double layer capacitance ( C dl ) are 239.5 Ω cm −1 and 27 μF/cm 2 with the addition of CAFE indicate the corrosion inhibition mitigation. The corrosion mitigation is caused by the adsorption of CAFE molecules on P110 steel surface via Temkin isotherm with chemical mechanism adsorption. The metal surface appearance was visualized via scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). The interaction among the most active constituent i.e., Capsaicin (RCM) sulfate reducing bacteria (SRB) protein was examined by molecular docking. Additionally, an atomic level study of RCM was performed using DFT and MD.

Cervical cancer is one of the most prevalent cancer-related diseases, causing accelerated morbidity and mortality rates in low-income countries and African states. This study explores the potential of (3 R ,3′ R )-2,2′,3,3′-tetrahydroneoprzewaquinone (TDN) as a treatment for cervical cancer by investigating its structural and molecular properties using molecular modelling technique, which include; DFT, molecular docking, molecular dynamic simulation. The results are promising, with TDN demonstrating exceptional stability in the energy gap ( E g ) as well as through natural bond order analysis (NBO). π → σ* electronic transitions were found to contribute mainly to the molecule’s stability, with an outstanding total stabilization energy ( E (2) ). Docking exercises showed that TDN binds more favorably to the pro-apoptotic receptor 4s0o with a stronger H-bond compared to the conventional DOX drug, which interacted less effectively with TDN and more strongly with the anti-apoptotic protein, forming an outstanding strong H-bond. Molecular dynamics simulations also revealed that TDNʼs interaction with the pro-apoptotic protein (TDN_4S0o) was more stable than the standard DOX drug (DOX_4s0o). The H-bond plot indicated that TDN could effectively interact with both anti and pro-apoptotic receptors, forming approximately 1 to 4 hydrogen bonds between TDN_1g5M with respect to each picosecond (ps) ranging from 0 to 1000 ps. In contrast, the number of hydrogen bonds fluctuated when DOX interacted with the anti-apoptotic protein (1g5M), ranging from 1 to 5 H-bonds. Overall, these results suggest that TDN may be a promising drug candidate for cervical cancer treatment.

Drug–drug interactions occur when two or more molecules interact, potentially altering their effectiveness and cause adverse effect to human health. Caffeine is known to interact with many other drug molecules. Our study was designed to shed insights on characteristics of non-covalent interaction (NCI) and quantify the prevalence of drug–drug interaction between the caffeine and ascorbic acid molecule in gas phase and solvent phase (water) using Density Functional Theory. It was found that caffeine and ascorbic acid molecules interact with one another through hydrogen bonds (HBs) in various ways which can be deduced from the optimized structures and the resulting calculation of binding energy was observed −14.65 kcal/mol and −11.62 kcal/mol in gas and water phase respectively. The Natural Bond Orbital analysis confirmed that the highest stabilization energy interactions are the same interactions which are found to be the possible hydrogen bonds. The RDG, AIM, LED analyses confirmed the delocalisation and localisation of the electron in the complex. The understanding of the non-covalent interaction between caffeine and ascorbic acid may help to further study the drug effectiveness and drug delivery systems.