Antibacterial and Antioxidant Compounds from Root Extracts of Gloriosa superba Linn: A Combined Experimental and Computational Study

Throughout history, medicinal plants have globally served as remedies for various ailments, and diseases. The roots of Gloriosa superba are traditionally used to treat antitumor, antimicrobial, and anti-inflammatory diseases. In this study, the roots of G. superba (320 g) were successively extracted with n-hexane, chloroform, and methanol to afford 530 mg (0.17%), 2.89 g (0.90%), and 17.78 g (5.56%) yields, respectively. Silica gel column chromatographic separation of the combined chloroform and methanol extracts gave 4-methoxy caffeic acid heptyl ester (1), desmosterol (2), 3-hydroxymethyl phenol (3), 3-Hydroxy-5-methoxy-benzoic acid (4), sucrose (5) and rutinose (6). In vitro antibacterial study revealed promising zone of inhibition value by chloroform extract against Klebsiella pneumoniae (13±0.00 mm) compared to gentamicin (15.86±4.67 mm). Desmosterol (2), 3-hydroxymethyl phenol (3), and 3-Hydroxy-5-methoxy-benzoic acid (4) displayed promising zone of inhibition against K. pneumonia (12.33±0.58, 11.33±1.53 and 11.33±1.15 mm, respectively) at 1000 μg/mL compared to gentamycin (15.86±4.67 mm at 100 μg/mL). Promising inhibition zone values were also displayed by desmosterol (2) and 3-Hydroxy-5-methoxy-benzoic acid (4) against Pseudomonas aeruginosa (14±1.00 and 14±1.73 mm, respectively) compared to gentamycin (25±2.52 mm).Chloroform extract displayed 95.14% DPPH radical scavenging value compared to ascorbic acid (96.11%) at 200 μg/mL. Compounds 2 and 4 displayed binding affinities of -7.8 and -6.5 Kcal/mol, respectively, against PqsA protein of P. aeruginosa, compared to amoxicillin (-7.3 kcal/mol). Therefore, the in vitro antibacterial and radical scavenging activity results suggest the potential uses of the root extracts of G. superba as promising antibacterial agents and free radical scavengers

A Four-Component Domino Reaction: An Eco-Compatible and Highly Efficient Construction of 1,8-Naphthyridine Derivatives, Their In Silico Molecular Docking, Drug Likeness, ADME, and Toxicity Studies

A multicomponent domino reaction of enaminone, malononitrile, and o-phthalaldehyde has been established, providing direct access to novel highly functionalized pentacyclic cyclopenta [b] indeno [1, 2, 3-de] [1,8] naphthyridine derivatives. The simplicity of execution, readily available substrates, high yields, excellent functional group tolerance, scalability, and good scores of environmental parameters make this synthetic strategy more sustainable and worthy of further attention. This one-pot transformation, which involved multiple steps and did not require the use of a catalyst, constructed four new C-C bonds, two new C-N bonds, and three new rings, with efficient use of all reactants. Furthermore, we performed in silico molecular docking analysis for prediction of anticancer (against human topoisomerase IIβ protein) and antimicrobial (against E.coli. DNA gyrase B protein) activities. Drug likeness and ADMET studies were also predicted. Overall investigation indicates that compound 6i may serve as a candidate that could be developed as potential anticancer and antimicrobial agent among all

Synthesis and Antibacterial, Antioxidant, and Molecular Docking Analysis of Some Novel Quinoline Derivatives

2-Chloroquinoline-3-carbaldehyde and 2-chloro-8-methylquinoline-3-carbaldehyde derivatives were synthesized through Vilsmeier formulation of acetanilide and N-(o-tolyl)acetamide. Aromatic nucleophilic substitution reaction was used to introduce various nucleophiles in place of chlorine under different reaction conditions. The carbaldehyde group was oxidized by permanganate method and reduced with metallic sodium in methanol and ethanol. The synthesized compounds were characterized by UV-Vis, IR, and NMR. The antibacterial activity of the synthesized compounds was screened against two Gram-positive bacteria (Bacillus subtilis ATCC6633 and Staphylococcus aureus ATCC25923) and two Gram-negative bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853). Most of the compounds displayed potent activity against two or more bacterial strains. Among them, compounds 6 and 15 showed maximum activity against Pseudomonas aeruginosa with mean inhibition zones of 9.67 ± 1.11 and 10.00 ± 0.44 mm, respectively, while ciprofloxacin showed mean inhibition zone of 8.33 ± 0.44 mm at similar concentration. On the other hand, compound 8 exhibited maximum activity against Escherichia coli with inhibition zones of about 9.00 ± 0.55 mm at 300 μg/mL and 11.33 ± 1.11 mm at 500 μg/mL. The radical scavenging activity of these compounds was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH), and all of them displayed moderate antioxidant activity, with compound 7 exhibiting the strongest activity. The molecular docking study of the synthesized compounds was conducted to investigate their binding pattern with DNA gyrase, all of them were found to have minimum binding energy ranging from –6.0 to –7.33 kcal/mol, and the best result was achieved with compound 11. The findings of the in vitro antibacterial and molecular docking analysis demonstrated that the synthesized compounds have potential of antibacterial activity and can be further optimized to serve as lead compounds

Synthesis, Molecular Docking Analysis, and Evaluation of Antibacterial and Antioxidant Properties of Stilbenes and Pinacol of Quinolines

Emergence of antimicrobial resistance to standard commercial drugs has become a critical public health concern worldwide. Hence, novel antimicrobials with improved biological activities are urgently needed. In this regard, a series of quinoline-stilbene derivatives were synthesized from substituted quinoline and benzyltriphenylphosphonium chloride using Wittig reaction. Furthermore, a novel pinacol of quinoline was synthesized by pinacolinazation of 2-methoxyquinoline-3-carbaldehyde which was achieved by aluminum powder-potassium hydroxide reagent combination at ambient temperature in methanol. The structures of the synthesized compounds were established based on their spectral data. The antibacterial activities of the synthesized compounds were evaluated in vitro by the paper disc diffusion method against two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). The best activity was displayed by compound 19 against E. coli with an inhibition zone of 16.0 ± 0.82 mm and 14.67 ± 0.94 mm at 500 and 250 μg/mL, respectively. This is close to ciprofloxacin which is used as a positive control. The results of in silico molecular docking evaluation of the compounds against E. coli DNA gyraseB were in good agreement with the in vitro antibacterial analysis. Compounds 19 (−6.9 kcal/mol) and 24 (−7.1 kcal/mol) showed the maximum binding affinity close to ciprofloxacin (−7.3 kcal/mol) used as positive control. Therefore, the antibacterial activity displayed by these compounds is encouraging for further investigation to improve the activities of quinoline-stilbenes by incorporating various bioisosteric groups in one or more positions of the phenyl nuclei for their potential pharmacological use. Findings of the DPPH radical scavenging assay indicated that some of the quinolone stilbenes and pinacol possess moderate antioxidant properties compared to ascorbic acid used as a natural antioxidant

Synthesis, Antibacterial, Antioxidant, and Molecular Modeling Studies of Novel [2,3′-Biquinoline]-4-Carboxylic Acid and Quinoline-3-Carbaldehyde Analogs

Currently, it has been common to see people being affected and dying from untreatable infections caused by multidrug-resistant (MDR) germs. To tackle this problem, developing new effective chemotropic agents is urgently needed. Hence, this project aims to design, synthesize, and evaluate their antibacterial and antioxidant activities of new series of [2,3′-biquinoline]-4-carboxylic acid and quinoline-3-carbaldehyde analogs. The molecular docking analysis of the compounds against E. coli DNA gyrase was computed to investigate the binding mode of the compounds within the active site of the enzyme. In this regard, a new series of [2,3′-biquinoline]-4-carboxylic acid and quinoline-3-carbaldehyde analogs were synthesized by utilization of Vilsmeier–Haack, Doebner, nucleophilic substitution, and hydrolysis reactions. The structures of the synthesized compounds were determined using UV-Vis, FT-IR, and NMR. The synthesized compounds were screened for their antibacterial activity against four bacterial strains using disc diffusion methods. The findings of the study revealed that seven of synthetic compounds possess good antibacterial activity compared to ciprofloxacin which was used as a positive control in the experiment. Among them, compounds 4, 9, and 10 displayed the highest mean inhibition zone of 13.7 ± 0.58, 16.0 ± 1.7, and 20.7 ± 1.5 mm, respectively, at 0.1 μg/μL. The radical scavenging property of these compounds was evaluated using DPPH radical assay where compounds 9 and 20 showed the strongest activity with IC50 values of 1.25 and 1.75 μg/mL, respectively. At the same concentration, the IC50 value of ascorbic acid was 4.5 μg/mL. The synthesized compounds were also assessed for their in silico molecular docking analysis. Compounds 4 (−6.9 kcal/mol), 9 (−6.9 kcal/mol), and 10 (−7.9 kcal/mol) showed the maximum binding affinity close to ciprofloxacin (−7.2 kcal/mol) used as a positive control. Thus, compounds 4, 9, and 10 showed the best antibacterial activities in both in vitro and molecular docking analyses among the synthetic compounds. The results of in silico molecular docking evaluation of the synthetic compounds against E. coli DNA gyrase B were in good agreement with the in vitro antibacterial analysis. Therefore, the antibacterial activity displayed by these compounds is encouraging for further investigation to improve the activities of [2,3′-biquinoline]-4-carboxylic acid by incorporating various bioisosteric groups in either of the quinoline rings

Solution Equilibrium Study of Complexation of Pb(II), Cd(II) and Hg(II) with L-histidine and L-glutamic Acid in Organic Media-water Mixture

Speciation of mixed ligand complexes of Pb(II), Cd(II) and Hg(II) with L-Histidine and L-glutamic acid were studied in varying amounts (0.0–50v/v) of Dimethylformamide-Water mixture by maintaining an ionic strength of 0.16mol dm-3 (NaNO3) at 310K. Titrations were carried out in the presence of different relative concentrations (M: L: X=1.0:2.5:2.5, 1.0:2.5:5.0, 1.0:5.0:2.5 in the case of Pb (II) and Cd(II) and 1.0:5.0:5.0, 1.0:5.0:10.0, 1.0:10.0:5.0 in the case of Hg(II)) were carried out with 0.4 mol dm-3 NaOH as titrant in Dimethylformamide- water mixture. Stability constants of ternary complexes were re?ned with MINIQUAD75. The best-?t chemical models were selected based on statistical parameters and residual analysis. The species detected were MLXH3, MLXH2, MLXH and ML2X for Pb(II), MLX2H2 and ML2X for Cd(II) and MLXH3 and MLXH2 for Hg(II). Extra stability of ternary complexes compared to their binary complexes was believed to be due to interactions outside the coordination sphere such as the formation of hydrogen bonds between the coordinated ligands, charge neutralization, chelate effect and stacking interactions and hydrogen bonding. The species distribution with pH at different compositions of Dimethylformamide and plausible equilibria for the formation of species were also presented. The bioavailability of the toxic metal ions is explained based on the speciation

Microwave-Assisted Synthesis of CuO Nanoparticles Using Cordia africana Lam. Leaf Extract for 4-Nitrophenol Reduction

Copper-oxide-based nanomaterials play an important role as a low-cost alternative to nanoparticles of precious metals for the catalytic reduction of 4-nitrophenols. In this study, CuO nanoparticles were synthesized by a microwave-assisted method using Cordia africana Lam. leaf extract for reduction or stabilization processes. The synthesized CuO nanoparticles (NPs) were characterized using X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The analysis indicated that nanocrystals of the monoclinic CuO phase having a cluster of agglomerated morphology with a crystallite size of about 9 nm were synthesized. We also evaluated the catalytic performance of CuO NPs against 4-nitrophenol (4-NP) reduction. The catalyst has shown excellent performance completing the reaction within 12 min. Furthermore, the performance of CuO NPs synthesized at different pH values was investigated, and results indicated that the one synthesized at pH 7 reduced 4-NP effectively in shorter minutes compared to those obtained at higher pH values. The CuO NPs synthesized using Cordia africana Lam. leaf extract exhibited a better reducing capacity with an activity parameter constant of 75.8 min−1·g−1. Thus, CuO synthesized using Cordia africana Lam. holds a potential application for the catalytic conversion of nitroarene compounds into aminoarene

Advances in tissue engineering through stem cell-based co-culture.

Stem cells are the future in tissue engineering and regeneration. In a co-culture, stem cells not only provide a target cell source with multipotent differentiation capacity, but can also act as assisting cells that promote tissue homeostasis, metabolism, growth and repair. Their incorporation into co-culture systems seems to be important in the creation of complex tissues or organs. In this review, critical aspects of stem cell use in co-culture systems are discussed. Direct and indirect co-culture methodologies used in tissue engineering are described, along with various characteristics of cellular interactions in these systems. Direct cell-cell contact, cell-extracellular matrix interaction and signalling via soluble factors are presented. The advantages of stem cell co-culture strategies and their applications in tissue engineering and regenerative medicine are portrayed through specific examples for several tissues, including orthopaedic soft tissues, bone, heart, vasculature, lung, kidney, liver and nerve. A concise review of the progress and the lessons learned are provided, with a focus on recent developments and their implications. It is hoped that knowledge developed from one tissue can be translated to other tissues. Finally, we address challenges in tissue engineering and regenerative medicine that can potentially be overcome via employing strategies for stem cell co-culture use

Advances in tissue engineering through stem cell-based co-culture.

Stem cells are the future in tissue engineering and regeneration. In a co-culture, stem cells not only provide a target cell source with multipotent differentiation capacity, but can also act as assisting cells that promote tissue homeostasis, metabolism, growth and repair. Their incorporation into co-culture systems seems to be important in the creation of complex tissues or organs. In this review, critical aspects of stem cell use in co-culture systems are discussed. Direct and indirect co-culture methodologies used in tissue engineering are described, along with various characteristics of cellular interactions in these systems. Direct cell-cell contact, cell-extracellular matrix interaction and signalling via soluble factors are presented. The advantages of stem cell co-culture strategies and their applications in tissue engineering and regenerative medicine are portrayed through specific examples for several tissues, including orthopaedic soft tissues, bone, heart, vasculature, lung, kidney, liver and nerve. A concise review of the progress and the lessons learned are provided, with a focus on recent developments and their implications. It is hoped that knowledge developed from one tissue can be translated to other tissues. Finally, we address challenges in tissue engineering and regenerative medicine that can potentially be overcome via employing strategies for stem cell co-culture use