Experimental and Theoretical Biological Probing of Schiff Bases as Esterase Inhibitors: Structural, Spectral and Molecular Insights.

The present study was designed to evaluate the in vitro and in silico potential of the Schiff bases (Z)-4-ethoxy-N-((5-nitrothiophen-2-yl)methylene)benzenamine (1) and (Z)-2,4-diiodo-6-((2-methyl-3-nitrophenylimino)methyl)phenol (2). These Schiff bases were synthesized according to a reported method using ethanol as a solvent, and each reaction was monitored on a TLC until completion of the reaction. The structures of both compounds were elucidated using spectroscopic techniques such as UV-Vis, FTIR, 1H NMR and 13C NMR. Molecular structure was determined using single-crystal XRD, which revealed that compounds 1 and 2 were monoclinic and triclinic, respectively. Hirshfeld surface analysis (HS) and 2D fingerprint plots were used to determine the intermolecular interactions along the contact contribution in the crystalline molecules. The structures of both compounds were optimized through a hybrid functional method B3LYP using the 6-31G(d,p) basis set, and various structural parameters were studied. The experimental and theoretical parameters (bond angle and bond length) of the compounds were compared with each other and are in close agreement. The in vitro esterase potential of the synthesized compounds was checked using a spectrophotometric model, while in silico molecular docking studies were performed with AutoDock against two enzymes of the esterase family. The docking studies and the in vitro assessment predicted that such molecules could be used as enzyme inhibitors against the tested enzymes: acetylcholine esterase (AChE) and butyrylcholine esterase (BChE).

Bioassay-Guided Alkaloids Isolation from Camellia sinensis and Colchicum luteum: In Silico and In Vitro Evaluations for Protease Inhibition.

Bioassay-guided isolation from Camellia sinensis (Theaceae) and Colchicum luteum (Liliaceae) utilizing an in vitro model of protease assay revealed colchicine (1) and caffeine (2) from chloroform fractions, respectively. Their structures were validated using spectral techniques. The purified compounds were further optimized with Gaussian software utilizing the B3LYP functional and 6-31G(d,p) basis set. The result files were utilized to determine several global reactivity characteristics to explain the diverse behavior of the compounds. Colchicine (1) showed a higher inhibition of protease activity (63.7 ± 0.5 %age with IC50 = 0.83 ± 0.07 mM), compared with caffeine (2) (39.2 ± 1.3 %age). In order to determine the type of inhibition, compound 1 was further studied, and, based on Lineweaver-Burk/Dixon plots and their secondary replots, it was depicted that compound 1 was a non-competitive inhibitor of this enzyme, with a Ki value of 0.690 ± 0.09 mM. To elucidate the theoretical features of protease inhibition, molecular docking studies were performed against serine protease (PDB #1S0Q), which demonstrated that compound 1 had a strong interaction with the different amino acid residues located on the active site of this understudied enzyme, with a high docking score of 16.2 kcal/mol.

Anti-Inflammatory Oxicams as Multi-donor Ligand Systems: pH- and Solvent-Dependent Coordination Modes of Meloxicam and Piroxicam to Ru and Os.

The nitrogen- and sulfur-containing 1,2-benzothiazines meloxicam and piroxicam are widely used as nonsteroidal anti-inflammatory drugs. Intrigued by the presence of multiple donor atoms and therefore potentially rich coordination chemistry, we prepared a series of organometallic Ru and Os compounds with meloxicam and piroxicam featuring either as mono- or bidentate ligand systems. The choice of the solvent and the pH value was identified as the critical parameter to achieve selectively mono- or bidentate coordination. The coordination modes were confirmed experimentally by NMR spectroscopy and single crystal X-ray diffraction analysis. Using DFT calculations, it was established that complexes in which meloxicam acts as a bidentate N,O donor are energetically more favorable than coordination as O,O and S,O donor systems. Since meloxicam and piroxicam derivatives have shown anticancer activity in the past, we aimed to compare the complexes with mono- and bidentate ligands on their in vitro anticancer activity. However, stability studies revealed that only the latter complexes were stable in [D6 ]DMSO/D2 O (5:95) and therefore no direct comparisons could be made. The meloxicam complexes 1 and 2 showed moderate cytotoxicity, whereas the piroxicam derivatives 5 and 6 were hardly active against the utilized cell lines.

Beyond graphene: exploring the potential of MXene anodes for enhanced lithium-sulfur battery performance.

The high theoretical energy density of Li-S batteries makes them a viable option for energy storage systems in the near future. Considering the challenges associated with sulfur's dielectric properties and the synthesis of soluble polysulfides during Li-S battery cycling, the exceptional ability of MXene materials to overcome these challenges has led to a recent surge in the usage of these materials as anodes in Li-S batteries. The methods for enhancing anode performance in Li-S batteries via the use of MXene interfaces are thoroughly investigated in this study. This study covers a wide range of techniques such as surface functionalization, heteroatom doping, and composite structure design for enhancing MXene interfaces. Examining challenges and potential downsides of MXene-based anodes offers a thorough overview of the current state of the field. This review encompasses recent findings and provides a thorough analysis of advantages and disadvantages of adding MXene interfaces to improve anode performance to assist researchers and practitioners working in this field. This review contributes significantly to ongoing efforts for the development of reliable and effective energy storage solutions for the future.

Pharmacological and Therapeutic Potential of Berbamine: A Potent Alkaloid from Genus Berberis.

Berbamine (Ber) is an active medicinal bisbenzylisoquinoline alkaloid, which is usually obtained from different plants of the genus Berberis (family Berberidaceae) and is used to cure various disorders in traditional Chinese and Ayurvedic systems of medicine. Numerous in-vitro and in-vivo studies revealed the apoptotic and cytotoxic potential of Ber against different cell lines (SMMC-7721, A549, MDA-MB-231, and K562) by upregulating pro-apoptotic (Bax, p53) and downregulating anti-apoptotic (Bcl-2, survivin) proteins. Other pharmacological attributes ascribed to Ber included cardioprotective, anti-diabetic, anti-inflammatory, antimalarial, antioxidant, anti-hypercholesterolemic, and anti-allergic. Moreover, the synergistic effect of Ber improved the therapeutic potential of different drugs (paclitaxel (PTL), gemcitabine, dexamethasone, doxorubicin (DOX), and celecoxib) in different models. Various attempts could fabricate biologically active derivatives of Ber, such as 4-chlorobenzoyl berbamine (CBB) and O-4- ethoxyl-butyl-berbamine (EBB). The review focuses on the medicinal applications of Ber, particularly anti-cancer, cardioprotective, and anti-inflammatory, along with the mechanism of action.

Synthesis of dimeric 1,2-benzothiazine 1,1-dioxide scaffolds: molecular structures, Hirshfeld surface analysis, DFT and enzyme inhibition studies.

1,2-Benzothiazines are bioactive compounds with diverse pharmacological properties. We report here the synthesis of a series of dimers containing 1,2-benzothiazine scaffolds as potential pharmacophores. The characterization of compounds was done using analytical techniques such as FT-IR, 1H NMR, and elemental analyses. The molecular structures of the compounds (5-8) were confirmed by X-ray crystallography. The molecular interactions in compounds (5-8) were determined by Hirshfeld Surface Analysis (HSA). Density functional theory (DFT) investigations were carried out to calculate vibrational properties, NMR behaviour, dipole moments, molecular electrostatic potential (MEP), frontier molecular orbital (FMO), natural bonding orbital (NBO) analysis and global reactivity descriptors. The global reactivity descriptors indicated the charge transfer reactions and stabilized as follows: 8 > 7 > 6 > 5. In FMO analysis a substantial HOMO-LUMO gap, ranging from 4.43 to 5.12 eV, with high LUMO values was observed for all compounds, while the highest value for linear polarizability was found in compound 8. The in vitro and in silico studies confirm that compound 8 is more active toward AChE and BChE enzymes.

Healthcare workers' knowledge and risk perception regarding the first wave of COVID-19 in Khyber Pakhtunkhwa, Pakistan: an online cross-sectional survey.

Background: Increased COVID-19 transmission among the populace may be caused by healthcare workers (HCWs) who lack knowledge, awareness, and good preventive practices. Additionally, it may cause elevated stress levels, anxiety, poor medical judgement, and situational overestimation. Objectives: The present survey aimed to assess knowledge and risk perception regarding COVID-19 among HCWs in Khyber Pakhtunkhwa (KP), Pakistan. Methodology: A web-based online, pre-tested questionnaire comprising 26 items was circulated via social media in April 2020 amongst HCWs in major tertiary care facilities in KP. Results: The study's results, revealing both the commendable knowledge levels among HCWs about COVID-19 and their heightened risk perception, highlight the critical need for targeted interventions to address the potential impact on self-protective behaviour and mental health within this vital workforce. This insight is important for designing strategies that not only enhance HCWs' well-being but also ensure the continued effectiveness of healthcare delivery during pandemics. The percentage mean score (PMS) of COVID-19 knowledge was 85.14±10.82. Male HCWs and those with an age older than or equal to 32 years demonstrated a higher knowledge score (85.62±11.08; P=0.032 and 87.59±7.33, P=0.021, respectively). About 76% of HCWs feared contracting COVID-19. Nearly 82% of respondents were mentally preoccupied with the pandemic and also terrified of it. 'Of these, 81% were nurses, 87% had a job experience of 6-8 years and 54.45% were frontline workers. Feelings of panic and concern about the pandemic were found to be more in HCWs who were physicians above the age of 32, and who had 3-5 years of work experience. HCWs' overall risk perception was found to be significantly different between males (7.04±2.26) and females (8.01±1.97), job experience of 6-10 years (8.04±177) with 3-5 years and younger than or equal to 2 years job experience (7.18±2.43,6.93±2.22), respectively, and between frontline HCWs (7.50±2.10) and non-frontline HCWs (6.84±2.40). Conclusion: HCWs demonstrated good knowledge about COVID-19. As the risk perception of COVID-19 among HCWs is high, it can raise concerns about their self-protective behaviour, and mental health. These issues need to be addressed.

Recyclable Cu-Ag bimetallic nanocatalyst for radical scavenging, dyes removal and antimicrobial applications.

An ecofriendly and cost effective green method has been used for the synthesis of recyclable, high functional nanoparticles. Bimetallic nanoparticles (BmNPs), Cu-Ag, have been synthesized using beetroot extract as reducing and capping agent. Formation of BmNPs was initially confirmed by UV-visible analysis, having distinct peaks of Ag at 429 nm and Cu at 628 nm. FTIR analysis also confirmed the association of bioactive phytochemicals with Cu-Ag nanoparticles. Crystallinity and morphology of BmNPs was determined through X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS) and energy dispersion X-ray spectroscopy (EDAX). The size of spherical shape Cu-Ag BmNPs was found to be 75.58 nm and EDAX studies confirmed the percent elemental composition of Cu and Ag in synthesized nanocatalyst. Results of different analysis provided supported evidences regarding the formation of BmNPs. Catalytic potential of BmNPs was tested for the degradation of rhodamine B (Rh-B), methylene blue (MB) and methyl orange (MO) dyes. Cu-Ag BmNPs exhibited outstanding catalytic activity for the degradation of selected organic dyes and percent degradation was recorded more than 90% for each dye. In addition, antiradical property of BmNPs was tested employing DPPH● and ABTS●+ assays and it was found to be promising. Synthesized BmNPs also exhibited strong antimicrobial activity against Salmonella typhimurium and Bacillus subtilis. Recyclability of nanoparticles was also evaluated and recovery from dye degradation reaction mixture was successfully achieved. The recovered nanoparticles exhibited same catalytic potential for the degradation of Rh-B. The objective of the current study was to synthesize BmNPs Cu-Ag employing a cost effective green method having promising catalytic, antiradical and antimicrobial potential. Further, BmNPs were reused after recovery from catalytic reactions, proving that BmNPs can be recycled having the same efficiency as that of a freshly prepared Cu-Ag BmNPs.

Synthesis, crystal structure, spectroscopic and computational investigations of the newly synthesized Schiff bases scaffold as enzyme inhibitor.

The current project was planned to access the enzyme inhibition potential of the synthesize imines; (E)-2-(2-hydroxy-4,5-dimethoxybenzylideneamino)benzonitrile 1 and (E)-2-(((3-hydroxy-4-methylphenyl)imino)methyl)-4-methoxyphenol 2 by the reported protocol of our continuous research and also assess their theoretical function in term of in silico action. The structural characterization of imines was done through advanced techniques i.e., FTIR, 1H NMR, 13C NMR, and UV spectroscopy. Moreover, a single X-Ray diffraction technique (SCXRD) was employed for real structural identification of imines dimensions, which revealed that compound 1 has a triclinic crystal system although 2 has a monoclinic one. A 2D fingerprint plot and Hirshfeld surface analysis (HS) was employed in the crystalline assembly of compounds to check intermolecular contacts and also their degree of contributions. Both compounds were optimized by B3LYP functional mode using a certain basis set (6-31G). The practical data (XRD) and theoretical data (DFT) of both molecules were compared and found between a sound coherence. Molecular docking studies in term of in silico assessment were conducted against enzymes of the esterase and alpha-glucosidase family. The docking outputs give a forecast about compounds that could be employed as protein inhibitors against analyzed protein surfaces.

Multifunctional catalyst-assisted sustainable reformation of lignocellulosic biomass into environmentally friendly biofuel and value-added chemicals.

Rapid urbanization is increasing the world's energy demand, making it necessary to develop alternative energy sources. These growing energy needs can be met by the efficient energy conversion of biomass, which can be done by various means. The use of effective catalysts to transform different types of biomasses will be a paradigm change on the road to the worldwide goal of economic sustainability and environmental protection. The development of alternative energy from biomass is not easy, due to the uneven and complex components present in lignocellulose; accordingly, the majority of biomass is currently processed as waste. The problems may be overcome by the design of multifunctional catalysts, offering adequate control over product selectivity and substrate activation. Hence, this review describes recent developments involving various catalysts such as metallic oxides, supported metal or composite metal oxides, char-based and carbon-based substances, metal carbides and zeolites, with reference to the catalytic conversion of biomass including cellulose, hemicellulose, biomass tar, lignin and their derivative compounds into useful products, including bio-oil, gases, hydrocarbons, and fuels. The main aim is to provide an overview of the latest work on the use of catalysts for successful conversion of biomass. The review ends with conclusions and suggestions for future research, which will assist researchers in utilizing these catalysts for the safe conversion of biomass into valuable chemicals and other products.

2,6-Dibromo-4-chloro-aniline.

The title compound, C(6)H(4)Br(2)ClN, is almost planar (r.m.s. deviation = 0.024 Å) and two intra-molecular N-H⋯Br hydrogen bonds generate S(5) rings. In the crystal, N-H⋯Br hydrogen bonds link the mol-ecules into chains propagating in [010].

2,3-Dihydro-1λ(6),2-benzothia-zine-1,1,4-trione.

In the title compound, C(8)H(7)NO(3)S, the benzene ring is oriented at a dihedral angle of 69.25 (7)° to the S and O atoms of the sulfonyl group. The heterocyclic ring approximates to an envelope, with the N atom in the flap position. In the crystal, mol-ecules are linked by N-H⋯O(c) (c = carbon-yl) hydrogen bonds, forming C(5) chains along [001]. Two R(2) (2)(10) loops arise from pairs of C-H⋯O hydrogen bonds and a weak aromatic π-π stacking inter-action [centroid-centorid separation = 3.8404 (11) Å] also occurs.

4-Hy-droxy-2-methyl-1,1-dioxo-2H-1λ,2- benzothia-zine-3-carb-oxy-lic acid hemihydrate.

In the title compound, C(10)H(9)NO(5)S·0.5H(2)O, two geometrically different organic mol-ecules are present. The benzene rings and the carboxyl-ate groups are oriented at dihedral angles of 13.44 (4) and 21.15 (18)°. In both mol-ecules, an intra-molecular O-H⋯O hydrogen bond generates an S(6) ring. In the crystal, both moleucles form inversion dimers linked by pairs of O-H⋯O hydrogen bonds to generate R(2) (2)(8) loops. The dimers are consolidated into chains extending along [100] by bridging O-H⋯O hydrogen bonds from the water mol-ecule. A weak C-H⋯O hydrogen bond also occurs.

2,2'-(4-Methyl-4H-1,2,4-triazole-3,5-di-yl)dibenzene-sulfonamide.

In the title compound, C(15)H(15)N(5)O(4)S(2), the dihedral angles between the central 1,2,4-triazole ring and the pendant benzene rings are 55.61 (10) and 68.59 (10)°; the dihedral angle between the benzene rings is 63.66 (9)°. Intra-molecular N-H⋯N and N-H⋯O hydrogen bonds generate S(7) and S(12) rings, respectively. In the crystal, sheets extending in the (101) plane arise, with the mol-ecules linked by C-H⋯O, N-H⋯N and N-H⋯O inter-actions. A C-H⋯π inter-action further consolidates the structure.

2-(1H-Benzimidazol-2-yl)-N-[(E)-(dimethyl-amino)-methyl-idene]benzene-sulfonamide.

The asymmetric unit of the title compound, C(16)H(16)N(4)O(2)S, contains two mol-ecules (A and B) with similar conformations: the benzene rings are oriented at dihedral angles of 80.94 (10)° and 84.54 (10)° with their adjacent 1H-benzimidazole groups. In the crystal, the mol-ecules are connected by N-H⋯N hydrogen bonds, forming separate C(4) chains of both the A and B mol-ecules along [010]. The A and B chains are cross-linked by several C-H⋯O inter-actions involving the benzene rings and the sulfonyl groups, which lead to R(2) (1)(5) loops in the linkage of the chains.

4-Hy-droxy-2-methyl-1,1-dioxo-N-phenyl-2H-1λ(6),2-benzothia-zine-3-carboxamide.

In the title mol-ecule, C(16)H(14)N(2)O(4)S, the thia-zine ring adopts a twist chair conformation with the N and adjacent C atom displaced by 0.966 (3) and 0.386 (4) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The dihedral angle between the mean planes of the benzene rings is 37.65 (10)°. The mol-ecular structure features an intra-molecular O-H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds.

N-Benzyl-4-hy-droxy-2-methyl-1,1-dioxo-2H-1λ(6),2-benzothia-zine-3-carboxamide.

In the title mol-ecule, C(17)H(16)N(2)O(4)S, the heterocyclic thia-zine ring adopts a half-chair conformation, with the S and N atoms displaced by 0.546 (4) and 0.281 (4) Å, respectively, on opposite sides of the mean plane formed by the remaining ring atoms. The mol-ecular structure is stabilized by an intra-molecular O-H⋯O hydrogen bond. The two aromatic rings are inclined to one another by 42.32 (11)°. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers. The dimers are linked via a series of C-H⋯O inter-actions, leading to the formation of a three-dimensional network.

2-(N-Cyclo-hexyl-carbamo-yl)benzene-sulfonamide.

The asymmetric unit of the title compound, C(13)H(18)N(2)O(3)S, contains two mol-ecules with similar conformations. In both mol-ecules, the cyclo-hexyl rings adopt chair conformations, with the attached N atom in an equatorial orientation and an intra-molecular N-H⋯O hydrogen bond generates an S(7) ring. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules and a C-H⋯O hydrogen bond is also observed. The crystal studied was a racemic twin.

Effect of Fear, Treatment, and Hunting Cooperation on an Eco-Epidemiological Model: Memory Effect in Terms of Fractional Derivative.

In this paper, we have studied a fractional-order eco-epidemiological model incorporating fear, treatment, and hunting cooperation effects to explore the memory effect in the ecological system through Caputo-type fractional-order derivative. We have studied the behavior of different equilibrium points with the memory effect. The proposed system undergoes through Hopf bifurcation with respect to the memory parameter as the bifurcation parameter. We perform numerical simulations for different values of the memory parameter and some of model parameters. In the numerical results, it appears that the system is exhibiting a stable behavior from a period or chaotic nature with the increase in the memory effect. The system also exhibits two transcritical bifurcations with respect to the growth rate of the prey. At low values of prey's growth, all species go to extinction, at moderate values of prey's growth, only preys (susceptible and infected) can survive, and at higher values of prey's growth, all species survive simultaneously. The paper ended with some recommendations.

3-[(E)-(2,4-Dichloro-pbenzyl-idene)amino]-benzoic acid.

In the crystal of the title compound, C(14)H(9)Cl(2)NO(2), inversion-related dimers with R(2) (2)(8) ring motifs are formed by inter-molecular O-H⋯O hydrogen bonding. The 3-amino-benzoic acid group and the 2,4-dichlobenzaldehyde moiety subtend a dihedral angle of 55.10 (2)°. The H atom of the carboxyl group is disordered over two sites with equal occupancies.