Chemical Physics Impact最新文献

In this work, we present the spectroscopic and structural analysis of synthetic melanin incorporated within alginate films. We propose a synthesis methodology for alginate films with different concentrations of melanin. For this, Ca2${}^{+}$-crosslinked alginate films plasticized with glycerol (30% w/w) are used as a matrix to support melanin in a non-disolved state. The structural and morphological characteristics of the alginate-melanin films are evaluated. Furthermore, we analyze the structural and morphological characteristics of the obtained films and analyze their spectroscopic characteristics from the ultraviolet to the terahertz bands of the electromagnetic spectrum. This work demonstrates that alginate films are a viable option as a matrix for the analysis and characterization of non-dissolved melanin. Moreover, we determine the dependence of the analyzed physical and optical properties of the alginate-melanin films with respect to the melanin concentration and discuss the relevance of the observed changes. The analysis suggests the potential use of melanin-alginate films for further examination of non-dissolved melanin.

Synthetic plastics pose a major environmental threat and it is necessary to produce an alternative biopolymer. In the current study, the production of polyhydroxybutyrate (PHB) by Mesobacillus aurentius was enhanced using Response surface methodology (Box–Behnken design). This study explores the potential of aquabiofloc systems as a source of polyhydroxyalkanoates (PHB)-producing bacteria. The optimized medium conditions, as determined by Response Surface Methodology (RSM), included 18.68 g of sucrose, 4.0 g of yeast, an incubation period of 69.57 h, and a pH of 7.1. The ANOVA results revealed that the model developed for predicting PHA yield was highly significant (p < 0.05). The predicted PHA yield was 63.12%, while the experimental yield was 65.35%. The maximum production of PHA was obtained with sucrose and yeast as carbon and nitrogen sources. The extracted polymer was characterized using UV, FTIR, ¹H NMR, and SEM-EDAX analysis confirming the polymer to be PHB. The thermal stability of the produced PHA showed degradation temperatures ranging from 310 °C. The mechanical properties of the extracted PHA were also assessed, demonstrating tensile strength and viscosity of 22.4 MPa and 1.23 MPa. respectively. The antimicrobial activity of the produced PHA was evaluated, demonstrating significant inhibitory effects against both Gram-positive and Gram-negative bacterial strains as well as fungal strains. The Cytotoxicity assessment in HepG2 cells indicated that PHB is less toxic in nature. The findings highlight the promising role of marine bacteria, Mesobacillus aurentius, in the development of environmentally friendly biopolymers. This bacterium represents a novel candidate for PHB production, offering a potential alternative to petroleum-based plastics.

The nitrogen containing heterocyclic and chalcones moiety widely recognized as favorable combination of diagnostic and therapeutic facilities in medicinal chemistry. In particular, indole analogs play a very important medicinal role in pharmacology activities, hence, drugs like pindolol, indomethacin, oxypertine, ellipticine, arbidol and ate viridine are well known in market. In this view, the title compounds 4(a-j) were synthesized in good yield. The purified compounds were explained by spectroscopic procedures (FT-IR, 1H NMR, 13CNMR, and LC-MS), and lastly, all synthetic compounds have in-vitro efficacy assessed against the HeLa human cervical cancer and MCF-7 human breast cancer cell lines, and their efficacy was compared to that of the well-known anticancer drug methotrexate (Methotrexate). Compounds 4a, 4b, 4c, and 4e from the series (4a-j) demonstrated the most notable inhibitory activity. The cytotoxicity evaluation of these newly synthesized compounds revealed that 4a, 4b, 4c, and 4e were the most toxic to HeLa cells, with IC50 values for growth inhibition of 20.41 ± 3.14, 23.54 ± 3.27, 24.77 ± 2.14, and 26.10 ± 1.58, respectively. These compounds exhibited an even stronger growth-inhibitory effect on MCF-7 cells, with IC₅₀ values of 18.84 ± 2.69, 19.45 ± 3.14, 22.83 ± 2.68, and 21.80 ± 1.68, respectively. In comparison, methotrexate (Methotrexate) showed IC50 values of 28.29 ± 1.0 for HeLa cells and 45.08 ± 2.61 for MCF-7 cells. Additionally, compounds 4a, 4b, 4c, and 4e played a crucial role in interacting with the catalytic domain of PDE3, demonstrating IC₅₀ values for PDE3A inhibition of 8.05 ± 1.27, 7.55 ± 2.14, 15.09 ± 1.54, and 17.12 ± 3.14, respectively. These results are compared with Cilostazol, a known PDE inhibitor, which exhibited an IC50 of 0.00368 ± 3.14. In-silico studies revealed that compounds (4a, 4b, and 4c) are comparatively very efficient in binding with PDE3A which was further validated with MMGBSA and MDSs.

Antimicrobial resistance (AMR) is currently a global health concern, mostly caused by microorganisms like bacteria, viruses, parasites, and fungi that acquire resistance to antimicrobial drugs. Salmonella is responsible for a variety of diseases but mainly cause typhoid. The primary concern is the rise in resistance in both non-typhoid and typhoid strains of this species. To address this issue, it is necessary to identify novel targets and strategies for the development of new antibacterial drugs. Lipid A, a strong bacterial endotoxin that modulates the immune system in human, is a key component of the virulence factor generated during the salmonella infection. Lipid A is synthesized in case of Gram-negative bacteria by cascade of nine enzyme pathway. The second step in case of Lipid A biosynthesis, catalysed by LpxC, a Zn⁺ dependent metallo-amidase considered as rate limiting step. In this manuscript we have used protein-ligand interaction fingerprint (PLIF)–derived pharmacophore models to screen small molecules (natural products library from Zinc database, Asinex database, Thiophene analogues) against Salmonella typhi LpxC (StLpxC). Further top hit molecules were subjected to MD-simulation and ADMET studies. We identified three optimal compounds, s1_dl_mseq2, s1_ll_mseq2, and s2_ll_mseq8, that exhibit strong binding affinity towards the LpxC active site.

Nanocomposite, which comprise organic and inorganic materials have gained increasing interest in the application for enhanced sensing response to both reducing and oxidation gases. In this study, a nanocomposite is chemical polymerization synthesized by reinforcing Ag nanoparticles with different concentration doped into the matrix of Polypyrrole (PPy). This nanocomposite is used as a sensing platform for ammonia detection with different concentration (ppm). The homogeneous distribution of Ag nanoparticles onto the PPy matrix provides a smooth and dense surface area, further accelerating the transmission of electrons. The synergistic effect of PPy@Ag matrix is responsible for the outstanding conductivity, compatibility and catalytic power of the proposed gas sensor. The structure, morphology, and surface composition of as-synthesized samples were respectively, examined via X-ray diffraction, field emission scanning electron microscopy, Ultraviolet-visible spectroscopy, Thermogravimetric analysis and Fourier transform infrared spectroscopy. The results indicated that sensor based on the PPy@Ag5 (2 gm) nanocomposite showed the highest response toward ammonia as compare to pure PPy at room temperature with a response value is 58 % to 100 ppm. Overall, the obtained findings demonstrated that the PPy@Ag nanocomposite are promising materials for gas sensing applications in environmental monitoring.

As a part of the host-defense system of many organisms, defensins are considered a suitable option for treating infection agents. Using the molecular dynamics simulation, this work studied the effects of two important human antimicrobial peptides, human β-defensin 2 and human α-defensin 5 on the SARS-CoV-2 membrane. The results demonstrate that defensin peptides notably alter the bilayer membrane's structure and physicochemical activity leading to a hydrophobic mismatch that impacts transmembrane protein channel function. This study elucidates the antiviral mechanisms of defensins and their therapeutic potential, offering valuable insights for researchers in virology and public health seeking novel medications.

Many human disorders include NF-kB signaling pathways, making IKK a therapeutic target in cancer treatment. Inflammatory illnesses and cancer are examples. COVID-19 is one of several triggers that stimulate NF-kB signaling. The activation of the NF-kB pathway is necessary for COVID-19 to cease its development. To learn more about the mechanism and structural features essential to IKK inhibition (IC₅₀), molecular modeling studies have been undertaken on experimentally reported 503. QSAR analysis explores certain reported and hidden structural features critical for IKKβ inhibition. The OECD guidelines guided the construction of the QSAR model, which achieved all the endorsed threshold values for all validation parameters (R²tr:0.81, R²LMO:0.80, and R²ext:0.78). The present QSAR study shows that IKK inhibitory activity is linked to the following structural features: lipophilic hydrogen atoms within 2 A units of the molecule's center of mass; ring nitrogen atoms within one bond of planar nitrogen atoms; ring carbon atoms exactly four bonds from the non-ring nitrogen atoms; planar nitrogen atoms exactly four bonds from sp2 hybridized carbon atoms; and so on. Pharmacophore modeling highlighted QSAR-identified structural characteristics. To investigate binding, we docked all 503 molecules. The observation indicates that the QSAR and molecular docking/pharmacophore modeling findings are in agreement. Following this, we conducted 200 ns of molecular dynamics simulation to validate the molecular docking protocol. MMGBSA analysis determined the binding energy of the dock complex. Thus, the current study found unique pharmacophoric properties that may assist in optimizing lead/hit compounds for anti-IKKβ activity.

Porous-activated carbons (PAC) show a lot of applications in various fields due to their large surface area and appropriate pore volume, along with decent thermal, chemical, and mechanical stability. Because of these characteristics, PACs are the best choice as an electrode material in supercapacitors (SCs). Due to the utility of PACs, this work reports the transformation of polyvinyl chloride (PVC) into PAC with a surface area of 162.40 m²/g. The synthesized PAC exhibits a maximum specific capacitance (CSP) of 40 F/g at five mV/s in 1-ethyl-3- methylimidazolium thiocyanate ionic liquid (EMIM SCN-IL) electrolyte. Also, no degradation was recorded in the initial C_sp of the fabricated SC, even after 9000 cycles at room temperature. Additionally, using the same PAC in counter electrode dye-sensitized solar cell (DSSC) was also fabricated, and the cell was tested at 1 sun condition, which shows a fill factor of 59.37 % and an efficiency of 1.42 %.

Nucleoside derivatives are essential to medicinal chemistry because they provide biologically active drugs. A 5´-O-palmitoyl derivative (2) was obtained by directly treating cytidine (1) with palmitoyl chloride. New antimicrobial compounds were developed by transforming the 5´-O-acyl derivative into 2´,3´-di-O-acyl derivatives (3-7) with several functionalities. Physicochemical, spectroscopic, and elemental investigations were used to determine the structures of the synthesized compounds. XRD confirmed the crystalline structure of the synthesized compounds. Compounds 3 and 5 exhibited good antibacterial and antifungal activity against bacteria and fungi in vitro. MIC and MBC investigations were performed on compounds 3 and 5 on the basis of their effectiveness. Most of the compounds resulted in >77% fungal mycelial growth. Compound 6 had antiproliferative effects on EAC cells in vitro, with an IC₅₀ value of 1001.11 µg/ml. A DFT study was used to calculate the FMO and MEP parameters, whereas molecular docking identified microbial pathogen prescription drug possibilities. In silico docking studies of cytidine derivatives against the 4URO and 6COX receptors revealed that compounds 3 and 6 had the best docking. In a stimulating environment, a 100-ns MD simulation revealed stable conformation and binding patterns. MD simulation and MM-PBSA analysis of the 3-4URO and 6-6COX complexes indicated good receptor-best-docked molecule interactions. Finally, in vitro and in silico, SAR studies, the acyl chains, (CH₃(CH₂)₁₀CO-) and (C₆H₅CH=CHCO-) incorporated into sugar moieties were shown to have the most promising antimicrobial/anticancer drug-targeting potential.

This study involves a computational analysis of new D-π-A dyes obtained from triphenylamine (TPA), which contain various azo-dye components. The structural, molecular, electrical, and optical properties of these dyes were computed using Density Functional Theory (DFT) and Time-Dependent DFT, utilizing the B3LYP/6–31 G model. Our research specifically aimed to investigate the effects of incorporating different azo dye constituents in the para position of two phenyl groups of TPA. The results indicate that these alterations lead to notably broadened and red-shifted absorption spectra, as well as improved optoelectronic properties that are subject to additional tuning through the manipulation of the π-spacer. The excitation energies and HOMO-LUMO energy levels that have been estimated indicate the presence of effective electron injection and dye regeneration mechanisms. The results concerning the nonlinear optical (NLO) properties suggest that these dyes are likely to demonstrate superior performance in NLO applications. The factors encompassed in this study consist of light-harvesting efficiency (LHE), open-circuit photovoltage ($V_{\text{OC}}$), electron injection driving force ($\Delta G^{\text{inj}}$), dye regeneration driving force ($\Delta G_{\text{reg}}$), excited state lifetime (τ) and reorganization energy (${\lambda }_{\text{total}}$), which has a strong correlation with the electrical current density in a short-circuit ($J_{\text{SC}}$) and DSSC's overall effectiveness. This scientific attempt contributes to the systematic advancement of efficient dyes, demonstrating the possibility for enhanced efficiency in DSSCs. Further validation of computational forecasts and advancement of renewable energy technology necessitate future experimental synthesis and testing.