Punica granatum pericarp extract catalyzed green chemistry approach for synthesizing novel ligand and its metal(II) complexes: Molecular docking/DNA interactions

Study on the interaction mechanism between (-)-epigallocatechin-3-gallate and myoglobin: Multi-spectroscopies and molecular simulation

(-)-Epigallocatechin-3-gallate (EGCG) is remarkably efficacious in inhibiting the browning of red meat. We therefore propose a hypothesis that EGCG forms complexes with myoglobin, thereby stabilizing its structure and thus preventing browning. This study investigated the interaction mechanism between EGCG and myoglobin. EGCG induced static quenching of myoglobin. Noncovalent forces, including hydrogen bonds and van der Waals, primarily governing the interactions between myoglobin and EGCG. The interactions primarily disrupted myoglobin's secondary structure, thus significantly reducing surface hydrophobicity by 53% (P < 0.05). The modification augmented the solubility and thermal stability of myoglobin. The radius of gyration (Rg) value fluctuated between 1.47 and 1.54 nm, and the hydroxyl groups in EGCG formed an average of 2.93 hydrogen bonds with myoglobin. Our findings elucidated the formation of stable myoglobin-EGCG complexes and the myoglobin-EGCG interaction, thus confirming our initial hypothesis.

Multi-site sulfonation of lignin for the synthesis of a high-performance dye dispersant

Sulfonated lignin-based dye dispersants have intensively attracted attention due to their low cost, renewability and abundant sources. However, their utilization is limited by the low content of sulfonic groups and high content of hydroxyl groups in their complex lignin structure, which results in various problems such as high reducing rate of dye, severe staining of the fibers and uneven dyeing. Here, the multi-site sulfonated lignin-based dispersants were prepared with high sulfonic group content (2.20 mmol/g) and low hydroxyl content (2.43 mmol/g). When using it as the dispersant, the dye uptake rate was improved from 69.23 % to 98.55 %, the reducing rate was decreased from 20.82 % to 2.03 %, the K/S value was reduced from 0.69 to 0.02, and the particle sizes in dye system before and after high temperature treatment were stabilized below 0.5 μm. Besides, the dispersion effect was significantly improved because no obvious separation between dye and water was observed even if without the assistance of grinding process. In short, the multi-site sulfonation method proposed in this work could remarkably improve the performances of the lignin-based dye dispersants, which would facilitate the development of the dye dispersion and the high value utilization of lignin.

Investigation of bisindole-linked pyrimidine moieties: synthesis using strantium-aluminum supported strontium aluminate nanophosphors catalyst, DNA reactivity, and in silico molecular docking studies

In this communication, an innovative and straightforward protocol for the one-pot catalytic synthesis of bis(indolyl)pyrimidine derivatives and their DNA binding abilities is presented. The synthesis involves the condensation of indole with diverse substituted pyrimidine-5-carbaldehydes, employing cost-effective and reusable Sr-Al supported nanophosphors, specifically strontium aluminate (SrAl2O4), as a catalyst. In particular, this method does not require the use of toxic solvents. The Sr-Al supported nanophosphorus catalyst exhibited sustained activity over multiple cycles and showed no significant decline while maintaining its strictly heterogeneous properties. The bis(indolyl)pyrimidine derivatives were extensively characterized using spectroscopic and analytical techniques. Furthermore, the interaction between these derivatives and CT-DNA was investigated by absorption spectroscopy, viscosity measurement, and in silico molecular docking studies. Photoinduced cleavage studies demonstrated the photonuclease activity of the compound against pUC19 DNA upon exposure to UV-visible radiation.

Exploring the interaction mechanism of chlorogenic acid and myoglobin: Insights from structure and molecular dynamics simulation

This study focused on non-covalent complex of myoglobin-chlorogenic acid (Mb-CA) and the changes in conformation, oxidation, and microstructure induced by varying concentrations of CA (10-40 μmol/g Mb). Employing molecular docking and dynamics simulations, further insights into the interaction between Mb and CA were obtained. The findings revealed that different CA concentrations enhanced Mb's thermal stability, while diminishing particle size, solubility, and relative content of metmyoglobin (MetMb%). The optimal interaction occurred at 40 μmol/g Mb. Furthermore, CA exhibited static quenching of Mb, with thermodynamic analysis confirming a 1:1 complex formation. These insights deepen our understanding of interaction between Mb and CA, providing valuable clarity.

A comprehensive and systemic review of ginseng-based nanomaterials: Synthesis, targeted delivery, and biomedical applications

Among 17 Panax species identified across the world, Panax ginseng (Korean ginseng), Panax quinquefolius (American ginseng), and Panax notoginseng (Chinese ginseng) are highly recognized for the presence of bioactive compound, ginsenosides and their pharmacological effects. P. ginseng is widely used for synthesis of different types of nanoparticles compared to P. quinquefolius and P. notoginseng. The use of nano-ginseng could increase the oral bioavailability, membrane permeability, and thus provide effective delivery of ginsenosides to the target sites through transport system. In this review, we explore the synthesis of ginseng nanoparticles using plant extracts from various organs, microbes, and polymers, as well as their biomedical applications. Furthermore, we highlight transporters involved in transport of ginsenoside nanoparticles to the target sites. Size, zeta potential, temperature, and pH are also discussed as the critical parameters affecting the quality of ginseng nanoparticles synthesis.

Trimesic acid-modified magnetic gum as a highly efficient and recyclable biocatalyst for the one-pot green synthesis of condensation reactions

In this work, a novel and efficient magnetic biocatalyst was designed, prepared and identified using cherry tree gum as a biopolymer functionalized with 1,3,5-benzenetricarboxylic acid (gum@Fe₃O₄@BTA). The obtained biocatalyst was prepared using available and cheap materials in an easy process. This biocatalyst was used as an efficient catalyst with high catalytic activity for the synthesis of a three-component one-pot protocol and four-component one-pot protocol of tetrahydro-4H-chromene derivatives and polyhydroquinoline derivatives in EtOH green solvent under reflux conditions, respectively. The synthesized heterogeneous biocatalysts were identified and analyzed by FT-IR, EDS, FESEM, TGA and XRD techniques. The synthesis of tetrahydro-4H-chromene and polyhydroquinoline derivatives by using this biocatalyst has advantages such as high efficiency, short reaction time, simple work method, absence of dangerous solvents, environmentally friendly conditions, easy separation of the biocatalyst by an external magnet, and the ability reuse for five periods without significant decrease in catalytic activity.

Synthesis and biological activity, and molecular modelling studies of potent cytotoxic podophyllotoxin-naphthoquinone compounds

A new approach for the synthesis of podophyllotoxin-naphthoquinone compounds using microwave-assisted three-component reactions is reported in this study. Novel podophyllotoxin-naphthoquinone derivatives with modification on ring E were synthesized. All the synthetic compounds were assessed in terms of their cytotoxicity profile against four cancer cell lines (KB, HepG2, A549, and MCF7), and noncancerous Hek-293 cell lines. Notably, treatment of SK-LU-1 cells with compounds 5a and 5b resulted in G2/M phase arrest of the cell cycle, caspase-3/7 activation, and apoptosis. Additionally, molecular docking studies were performed and showed important interaction of two compounds against residues in the colchicine-binding-site of tubulin as well. Taken together, compounds 5a and 5b were identified as potent anticancer agents.

A new approach for the synthesis of podophyllotoxin-naphthoquinone compounds using microwave-assisted three-component reactions is reported in this study.

Enhancement of thermostability and catalytic properties of ammonia lyase through disulfide bond construction and backbone cyclization

Ammonia lyases have great application potential in food and pharmaceuticals owing to their unique ammonia addition reaction and atom economy. A novel methylaspartate ammonia-lyase, EcMAL, from E. coli O157:H7 showed high catalytic activity. To further strengthen its thermostability and activity, disulfide bond and backbone cyclization (cyclase) variants were constructed by rational design, respectively. Among them, variant M3, with a disulfide bond introduced, exhibited a 2.3-fold increase in half-life at 50 °C, while cyclase variant M8 showed better performance, with 25.9-fold increases. The synergistic promotion effect of this combinational strategy on activity and stability was also investigated, and the combined mutant M9 exhibited a 1.1-fold improvement in catalytic efficiency while maintaining good thermostability. Circular dichroism analysis and molecular dynamics simulation confirmed that the main sources of improved thermostability were reduced atomic fluctuation and a more stable secondary structure. To our knowledge, this is the first example of combining the introduction of disulfide bonds with cyclase construction to improve enzyme stability, which was characterized by modification away from the enzyme active center, and provided a new method for adjusting enzyme thermostability.

First Organic–Inorganic Hybrid Compounds Formed by Ge-V-O Clusters and Transition Metal Complexes of Aromatic Organic Ligands

Three compounds based on Ge-V-O clusters were hydrothermally synthesized and characterized by IR, UV-Vis, XRD, ESR, elemental analysis and X-ray crystal structural analysis. Both [Cd(phen)(en)]2[Cd2(phen)2V12O40Ge8(OH)8(H2O)]∙12.5H2O (1) and [Cd(DETA)]2[Cd(DETA)2]0.5[Cd2(phen)2V12O41Ge8(OH)7(0.5H2O)]∙7.5H2O (2) (1,10-phen = 1,10-phenanthroline, en = ethylenediamine, DETA = diethylenetriamine) are the first Ge-V-O cluster compounds containing aromatic organic ligands. Compound 1 is the first dimer of Ge-V-O clusters, which is linked by a double bridge of two [Cd(phen)(en)]2+. Compound 2 exhibits an unprecedented 1-D chain structure formed by Ge-V-O clusters and [Cd2(DETA)2]4+ transition metal complexes (TMCs). [Cd(en)3]{[Cd(η2-en)2]3[Cd(η2-en)(η2-μ2-en)(η2-en)Cd][Ge6V15O48(H2O)]}∙5.5H2O (3) is a novel 3-D structure which is constructed from [Ge6V15O48(H2O)]12− and four different types of TMCs. We also synthesized [Zn2(enMe)3][Zn(enMe)]2[Zn(enMe)2(H2O)]2[Ge6V15O48(H2O)]∙3H2O (4) and [Cd(en)2]2{H8[Cd(en)]2Ge8V12O48(H2O)}∙6H2O (5) (enMe = 1,2-propanediamine), which have been reported previously. In addition, the catalytic properties of these five compounds for styrene epoxidation have been assessed.

Sparfloxacin - Cu(II) - aromatic heterocyclic complexes: synthesis, characterization and in vitro anticancer evaluation

Two new copper(II) complexes of sparfloxacin (sf), [Cu(Hsf)(HPB)(H₂O)](ClO₄)₂ (1) and [Cu(Hsf)(PBT)(H₂O)](ClO₄)₂ (2) (where HPB = 2-(2'-pyridyl)benzimidazole and PBT = 2-(4'-pyridyl) benzothiazole), have been synthesized and characterized by physicochemical and spectroscopic techniques. The oil-water partition coefficient (log P) values of complexes 1 and 2 were 1.47 and 1.71, respectively. By studying the interaction between the complexes and DNA, it was found that the complexes could bind to DNA through an intercalation mode. Moreover, both complexes were evaluated for antitumor activity, revealing that the complexes displayed good inhibitory activity toward the tested cancer cell lines (human lung carcinoma A549 cells, human hepatocellular carcinoma Bel-7402 cells and human esophageal carcinoma Eca-109 cells), but showed relatively low toxicity against normal human hepatic LO2 cells. In particular, the antitumor mechanism of the complexes on Eca-109 cells was investigated by morphological analysis, apoptosis analysis and determination of cell cycle arrest, mitochondrial membrane potential, reactive oxygen species (ROS) levels, and release of cytochrome c and Ca²⁺. The results demonstrated that the complexes could induce loss of intracellular mitochondrial functions and increase of ROS levels, which led to an increase of Ca²⁺ levels and the release of cytochrome c into the cytoplasm. In addition, the cell cycle was arrested in the G2/M phase, and western blot analysis showed that the caspase family was activated. These results fully proved that the complexes could induce apoptosis through DNA damage and loss of mitochondrial functions, accompanied by the regulation of endogenous proteins.

Fabricate, advancement, molecular docking and DNA reactivity of preferred divalent metal(II) complexes attributing (E)-N'-((6-hydroxybenzo[d]oxazol-5-yl) methylene)isonicotinohydrazide

A series of metal(II) complexes (M=Co (II), Ni(II) and Cu(II)) supported by Schiff base ligand (L=(E)-N'-((6-hydroxybenzo[d]oxazol-5-yl)methylene)isonicotinohydrazide) has been designed and developed from condensation of 6-hydroxybenzo[d]oxazole-5-carbaldehyde and isoniazid. The ligand (H₂L) and its metal(II) complexes were structurally characterized utilizing a variety of physicochemical and spectroscopic approaches. The study shows that Schiff bases (H₂L) act as monobasic tridentate ONO ligand and conform to octahedral geometry according to the general formula [M(HL)₂]. Furthermore, the interaction of these complexes with CT-DNA was investigated at pH = 7.2, utilizing UV-visible absorption, and viscosity measurement. In order to determine the mechanism of binding of the metal(II) complexes to the B-DNA dodecamer, docking studies were conducted using an AutoDock Vina 1.2.0 tool. The photo induced cleavage reveals that the ligand (H₂L) and its complexes have UV-visible photo nuclease properties against pUC19 DNA by agarose gel electrophoresis technique. Studies showed that the complexes evaluated firmly bind to CT-DNA via intercalative mode and provides a distinctive pattern of DNA binding.

Synthesis of calixresorcarenes using magnetic poly triazine-benzene sulfonamide-SO3H

The purpose of this work is to develop a magnetically recyclable immobilized base catalyst for the green synthesis of calixresorcarenes. To achieve this, poly triazine-benzene sulfonamide (PTBSA) has been coated on magnetic Fe₃O₄ nanoparticles and subsequently chlorosulfonic acid has been supported to obtain Fe₃O₄@PTBSA-SO₃H. The structure of nano-Fe₃O₄@PTBSA-SO₃H was characterized by TEM, XRD, FT-IR, VSM, WDX, EDX, TGA/DSC and FE-SEM. The catalytic efficiency of this catalyst was also investigated in the synthesis of novel calixresorcarene derivatives. The advantages of heterogeneous nature, catalytic activity and the recyclability of the polymer support were also strengthened by advanced surface treatment. These key factors (basic sites, acidic sites and heterogeneity) play essential roles in the catalyst performance. This procedure has some advantages such as short reaction time, clean and fast work-up and easy separation of the catalyst by an external magnet.

Magnetic poly triazine-benzene sulfonamide-SO₃H was investigated for the synthesis of calixresorcarenes.