Copper-based metal-organic frameworks (BDC-Cu MOFs) as supporters for α-amylase: Stability, reusability, and antioxidant potential.

Copper-based metal-organic frameworks (BDC-Cu MOFs) were synthesized via a casting approach using 1,4-benzene dicarboxylic (BDC) as organic ligand and their properties characterized. The obtained materials were then utilized to immobilize the α-amylase enzyme. The chemical composition and functional components of the synthesized support (BDC-Cu MOFs) were investigated with Fourier transform infrared spectroscopy (FTIR), the surface morphology was determined with scanning electron microscopy (SEM), and the elemental composition was established with energy dispersive X-ray (EDX) analyses. X-ray diffraction (XRD) was employed to analyze the crystallinity of the synthesized DBC-Cu MOFs. The zeta potentials of DBC-Cu MOFs and DBC-Cu MOFs@α-amylase were determined. The immobilized α-amylase demonstrated improved catalytic activity and reusability compared to the free form. Covalent attachment of the α-amylase to BDC-Cu provided an immobilization yield (IY%) of 81% and an activity yield (AY%) of 89%. The immobilized α-amylase showed high catalytic activity and 81% retention even after ten cycles. Storage at 4 °C for eight weeks resulted in a 78% activity retention rate for DBC-Cu MOFs@α-amylase and 49% retention for the free α-amylase. The optimum activity occurred at 60 °C for the immobilized form, whereas the free form showed optimal activity at 50 °C. The free and immobilized α-amylase demonstrated peak catalytic activities at pH 6.0. The maximum reaction velocities (Vmax) values were 0.61 U/mg of protein for free α-amylase and 0.37 U/mg of protein for BDC-Cu MOFs@α-amylase, while the Michaelis‒Menten affinity constants (Km) value was lower for the immobilized form (5.46 mM) than for the free form (11.67 mM). Treatments of maize flour and finger millet samples with free and immobilized α-amylase resulted in increased total phenolic contents. The enhanced antioxidant activities of the treated samples were demonstrated with decreased IC50 values in ABTS and DPPH assays. Overall, immobilization of α-amylase on BDC-Cu MOFs provided improved stability and catalytic activity and enhanced the antioxidant potentials of maize flour and finger millet.

Pro-Apoptotic Activity of Epi-Obtusane against Cervical Cancer: Nano Formulation, In Silico Molecular Docking, and Pharmacological Network Analysis.

Cancer is a major disease that threatens human health all over the world. Intervention and prevention in premalignant processes are successful ways to prevent cancer from striking. On the other hand, the marine ecosystem is a treasure storehouse of promising bioactive metabolites. The use of such marine products can be optimized by selecting a suitable nanocarrier. Therefore, epi-obtusane, previously isolated from Aplysia oculifera, was investigated for its potential anticancer effects toward cervical cancer through a series of in vitro assays in HeLa cells using the MTT assay method. Additionally, the sesquiterpene was encapsulated within a liposomal formulation (size = 130.8 ± 50.3, PDI = 0.462, zeta potential -12.3 ± 2.3), and the antiproliferative potential of epi-obtusane was investigated against the human cervical cancer cell line HeLa before and after encapsulation with liposomes. Epi-obtusane exhibited a potent effect against the HeLa cell line, while the formulated molecule with liposomes increased the in vitro antiproliferative activity. Additionally, cell cycle arrest analysis, as well as the apoptosis assay, performed via FITC-Annexin-V/propidium iodide double staining (flow cytofluorimetry), were carried out. The pharmacological network enabled us to deliver further insights into the mechanism of epi-obtusane, suggesting that STAT3 might be targeted by the compound. Moreover, molecular docking showed a comparable binding score of the isolated compound towards the STAT3 SH2 domain. The targets possess an anticancer effect through the endometrial cancer pathway, regulation of DNA templated transcription, and nitric oxide synthase, as mentioned by the KEGG and ShinyGo 7.1 databases.

Synthesis and characterization of nano crystallite carboxamide-based iron(III) complexes: SOD mimetic activity, antibacterial and anticancer activity and molecular docking study.

Three carboxamide-based ligands and their iron(III) complexes were prepared and structurally characterized. Analytical, thermal and mass spectra measurements showed a 1:1 stoichiometric (M:L) of the synthesized iron(III) complexes. The distorted octahedral geometry of the present iron(III) complexes was assigned based on the results of spectroscopy and magnetometry. Processing of X-ray diffraction data for powder samples by the software Expo 2014 confirmed the octahedral geometry of the three iron(III) complexes. Electrochemical properties of the present iron(III) complexes were studied by cyclic voltammetric measurements. The present iron(III) complexes exhibit SOD like activity with IC50 values of 16.45, 15.24 and 9.70 µM. The drive forces (-λ or ΔG°) controlling these biocatalytic reactions were determined and correlated with catalytic activity. The proposed catalytic mechanistic implications for the conversion of O2•- to H2O2 and H2O were discussed. The antimicrobial activity has been studied in vitro against G(+) and G(-) pathogenic bacteria. The in vitro anticancer activity of the carboxamide-based ligands and their iron(III) complexes against human Hepatocellular carcinoma (HepG-2) cell lines was examined. The obtained results demonstrated the potent anticancer activity of iron(III) complexes with increased safety on normal cells compared to cisplatin. Molecular docking calculations confirmed the experimental findings of the antibacterial and anticancer activities of both free ligands and their iron(III) chelates.Communicated by Ramaswamy H. Sarma.

In Situ Coating of Polydopamine-AgNPs on Polyester Fabrics Producing Antibacterial and Antioxidant Properties.

Nanoparticles are increasingly utilized as coating materials to improve the properties of polyester textiles. In this work, polyester textiles were successfully fabricated, with hydrazide groups serving as ligands for the entrapment of sliver ions and subsequent reduction to AgNPs. Polydopamine (PDA) was used in this work to impart antibacterial and antioxidant properties to the polyester textiles through its phenolic hydroxyl groups, which can convert silver ions into AgNPs. Moreover, glucose was used as a reducing agent to create AgNPs-loaded polyester hydrazide. ATR-FTIR, SEM, EDX, thermogravimetric analysis (TGA), and tensile strength were used to characterize the pristine polyester, the polyester hydrazide, the PDA-coated AgNP-loaded polyester hydrazide and the AgNP-loaded polyester hydrazide. A broth test was also used to investigate the textile's antimicrobial activities against Escherichia coli and Staphylococcus aureus. Overall, the composite nanocoating with PDA-AgNPs demonstrated good tensile strength and antioxidant and antibacterial characteristics, implying the practicality of PDA-AgNPs coating polyester for biomedical textile applications.

Tuning the structural and catalytic properties of copper(II)-based complexes containing pyridine-2,6-diimines.

Four mononuclear penta coordinated copper(II) chelates, [CuLnBr2] nH2O, containing the tridentate neutral ligands, pyridine-2,6-diimine (Ln), were prepared via the template technique. Analytical and several physicochemical methods have been used to characterize the prepared metal chelates. Square-pyramidal stereochemistry was described to the current copper(II) complexes. DFT technique has been applied to optimize the structure of the running diimines and their corresponding copper-based compounds. Ligand substitution study performed to link the catalytic potency of the candidate oxidase mimics and their lability characters. Spectral investigations reveal that nature of substituents of the chelated ligands effectively tuning the Lewis acidity of copper(II) centers. Biomimetics of redox proteins specifically containing copper were examined towards the aerobic oxidation of polyphenol. Kinetic studies with the stopped-follow technique showed a close association between the Lewis acidity of the copper(II) nuclei of the prepared chelates and their oxidase-like activity. The catalytic activity of the natural enzyme (catechol oxidase from sweet potatoes) measured and compared with that for the present CuII chelates. The thermodynamic parameter drive force (ΔG° or λ) of the performed oxidation processes was determined from the values of redox potential of the chemical species involved in these catalytic reactions. The proposed catalytic reactions pathways have been discussed based on the outcomes of the kinetic investigations.Communicated by Ramaswamy H. Sarma.

Urolithins: The Gut Based Polyphenol Metabolites of Ellagitannins in Cancer Prevention, a Review.

Cancer as a disease continues to ravage the world population without regard to sex, age, and race. Due to the growing number of cases worldwide, cancer exerts a significant negative impact on global health and the economy. Interestingly, chemotherapy has been used over the years as a therapeutic intervention against cancer. However, high cost, resistance, and toxic by-effects to treatment have overshadowed some of its benefits. In recent times, efforts have been ongoing in searching for anticancer therapeutics of plant origin, focusing on polyphenols. Urolithins are secondary polyphenol metabolites derived from the gut microbial action on ellagitannins and ellagic acid-rich foods such as pomegranate, berries, and nuts. Urolithins are emerging as a new class of anticancer compounds that can mediate their cancer-preventive activities through cell cycle arrest, aromatase inhibition, induction of apoptosis, tumor suppression, promotion of autophagy, and senescence, transcriptional regulation of oncogenes, and growth factor receptors. In this review, we discussed the growing shreds of evidence supporting these secondary phenolic metabolites' anticancer properties. Furthermore, we have pointed out some of the future directions needed to establish urolithins as anticancer agents.

Hydroxyapatite-decorated ZrO2 for α-amylase immobilization: Toward the enhancement of enzyme stability and reusability.

Herein, the immobilization of α-amylase onto hydroxyapatite (HA) and hydroxyapatite-decorated ZrO2 (10%wt) (HA-ZrO2) nanocomposite were investigated. The immobilization yield was 69.7% and 84% respectively. The structural differences were characterized using X-Ray diffraction, attenuated total reflectance-Fourier transform infrared spectra, Raman, and scanning electron microscope. After 10 repeated cycles, the residual activity of immobilized α-amylase onto HA and HA-ZrO2 nanocomposite was 46% and 70%, respectively. The storage stability was recorded to be 27%, 50% and 69% from its initial activity in the case of free and immobilized enzyme onto HA and HA-ZrO2 nanocomposite, respectively after 8 weeks. The pH-activity profile and temperature revealed pH 6.0 and temperature 50 °C as the optimal values of free α-amylase, while the optimum values for α-amylase on HA and HA-ZrO2 was shifted to pH 6.5 and 60 °C after immobilization. The immobilized α-amylase onto HA-ZrO2 showed comparatively higher catalytic activity than the free α-amylase. The Km value after the immobilization process onto HA was 2.1 folds highly than that of the free enzyme. In conclusion, it can be inferred that HA-ZrO2 is more sustainable and beneficial support for enzyme immobilization and it represents promising supports for different uses of α-amylase in the biomedical applications.

Antimicrobial, anticancer and antioxidant activities of nano-heart of Phoenix dactylifera tree extract loaded chitosan nanoparticles: In vitro and in vivo study.

This study aimed to present a new heart of P. dactylifera (HP) extract loaded chitosan nanoparticles and estimate its anticancer, antimicrobial, antioxidant activity and free radical scavenger effect (in vitro). This nano-supplement may prevent doxorubicin cardiotoxicity and nephrotoxicity in rat model. The HP extract was loaded on chitosan nanoparticles producing HP-ChNPs, then characterized. The antioxidant properties of the HP-ChNPs was assessed in vitro. The antibacterial activity against three-gram positive bacteria and two gram-negative bacteria were done. The in vitro studies of cytotoxicity against MCF7, CaCo3, and Hela cell lines were also evaluated. Then, the protective effect of the HP-ChNPs (2 mg/kg, IP) was evaluated against doxorubicin induce organ toxicity in a rat model. The in vitro studies revealed the antibacterial, anticancer and antioxidant activities of the HP-ChNPs. The in vivo study demonstrates reduction of heart and kidney apoptosis with increased programmed cell death protein-1 (PD-1); as the major anticancer drug (doxorubicin) pathway is to release free radicals with decreased PD-1 levels and induction of apoptosis. In conclusion, the HP-ChNPs, in a very small dose, might be a promising supplement to avoid doxorubicin toxicity with improvment the antioxidant enzymes without affecting its anticancer activity.

Purification and biochemical characterization of Arabian balsam α-amylase and enhancing the retention and reusability via encapsulation onto calcium alginate/Fe2O3 nanocomposite beads.

In this study, Arabian balsam α-amylase was purified using the three-step purification method with 9.8-fold purification and 7% recovery. The purified α-amylase's molecular weight was 85 kDa. Calcium alginate incorporated with iron (III) oxide nanoparticles was applied as an immobilizing support for α-amylase. The immobilized α-amylase was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. In addition, the optimum conditions for immobilization efficiency, immobilization time, reusability, kinetic parameters, and the effect of pH for the immobilization process were examined. After storage, about 87% of the initial activity was maintained at 4 °C for 60 days. The immobilized enzyme exhibited enhanced stability compared to the soluble enzyme in relation to pH and temperature. The immobilized enzyme provided the following kinetic variables: 0.455 mg/mL, 4050 s-1, 28.57 µmol maltose/mL, and 8900 s-1 mg-1 mL for Km, kcat, Vmax, and kcat/Km, respectively, compared with 1.798 mg/mL, 5980 s-1, 42.19 µmol maltose/mL, and 3326 s-1 mg-1 mL for the soluble enzyme. The total phenolic contents of the soluble and immobilized α-amylase-treated wheat kernels were increased by 1.26 and 1.31 fold, respectively. Purified α-amylase from Arabian balsam can thus be successfully used to enhance the antioxidant capacity of cereals.

Chemoprotective role of an extract of the heart of the Phoenix dactylifera tree on adriamycin-induced cardiotoxicity and nephrotoxicity by regulating apoptosis, oxidative stress and PD-1 suppression.

Cardiotoxicity and nephrotoxicity due to the abnormal production of free radicals have been observed in patients treated with the anticancer antibiotic adriamycin (ADR). The aim of the present study was to evaluate the role of the heart of palm extract in preventing oxidative stress, cardiotoxicity and nephrotoxicity induced by ADR. In this work, an aqueous ethanolic extract of the heart of the Phoenix dactylifera tree (HP) was investigated. The polyphenol content was evaluated by gas chromatography-mass spectrometry (GC-MS) and High-performance liquid chromatography (HPLC). The protective effect of the HP-extract (250 and 500 mg/kg, p.o.) was evaluated along with ADR administration (cumulative dose 15 mg/kg, IP) in rats. The HP-extract (500 mg/kg) treated group showed significant reductions in cardiotoxicity and nephrotoxicity serum markers, apoptotic percentage, and caspase-3 and cyclooxygenase-2 level, with an improvement in antioxidant enzymes in both heart and kidney homogenate, compared with the ADR-induction group. The cardiac and kidney programmed cell death protein-1 (PD-1) was increased in high dose HP-extract treated rats after being inhibited by ADR administration. In conclusion, the HP-extract might be a promising food supplement for preventing the cardiotoxicity and nephrotoxicity induced by ADR administration.

Immobilisation of α-amylase on activated amidrazone acrylic fabric: a new approach for the enhancement of enzyme stability and reusability.

In this study, amidrazone acrylic fabric was applied as an immobilising support for α-amylase. The immobilised α-amylase was characterised by Fourier transform infrared spectroscopy and scanning electron microscopy. Furthermore, the optimum conditions for immobilisation efficiency, immobilisation time, reusability, kinetic parameters and pH, for the immobilisation process were examined. The study demonstrated that with 4% cyanuric chloride, and a pH of 7.0, the highest immobilization efficiency of 81% was obtained. Around 65% of the initial activity was maintained after storage at 4 °C for 8 weeks. The immobilised enzyme retained 53% of its original activity after being reused 15 times and exhibited improved stability compared with the free enzyme in relation to heavy metal ions, pH, temperature and inhibitors. The immobilised enzyme presented kinetic parameters of 2.6 mg starch and 0.65 µmol maltose/mL for Km and Vmax respectively, compared with 3.7 mg starch and 0.83 µmol maltose/ mL for the free enzyme. The improvements in the enzyme's catalytic properties, stability and reusability obtained from immobilisation make amidrazone acrylic fabric support a good promising candidate for bio-industrial applications.

A novel peroxidase from Arabian balsam (Commiphora gileadensis) stems: Its purification, characterization and immobilization on a carboxymethylcellulose/Fe3O4 magnetic hybrid material.

A novel plant peroxidase was isolated from the stem of Arabian balsam (Commiphora gileadensis) and purified using ammonium sulfate, followed by ion exchange chromatography (DEAE-Sepharose) and gel filtration (Sephcryl S-200). The newly isolated peroxidase was characterized as having a specific activity of 9503.3 unit/mg of protein after 20.3-fold purification, which yielded a recovery of 18.5%. Based on the subunit size, the purified peroxidase was a 40 kDa monomeric structure and presented high thermostability, as it was entirely stable at 55 °C for 30 min and retained approximately 13.6% of its activity at 85 °C. The optimal pH exhibited a broad value range (pH 7.0- 7.5). The kinetic parameters for the purified peroxidase were obtained. To increase the enzyme durability, efficiency and reusability, the peroxidase was entrapped onto a carboxymethyl cellulose/Fe3O4 magnetic hybrid material. The immobilized enzyme was characterized by scanning electron microscopy (SEM) and FT-IR spectroscopy. It was tested at different pH values, storage times and temperatures, and its kinetic behavior was assessed. The immobilized enzyme maintained its activity upon storage at 4 and 25 °C for 8 weeks, and upon recycling for up to 15 uses. Arabian balsam peroxidase appears to be candidate for industrial applications.

Study of reactivity of cyanoacetohydrazonoethyl-N-ethyl-N-methyl benzenesulfonamide: preparation of novel anticancer and antimicrobial active heterocyclic benzenesulfonamide derivatives and their molecular docking against dihydrofolate reductase.

This article describes the synthesis of some novel heterocyclic sulfonamides having biologically active thiophene 3, 4, 5, 6, coumarin 8, benzocoumarin 9, thiazole 7, piperidine 10, pyrrolidine 11, pyrazole 14 and pyridine 12, 13. Starting with 4-(1-(2-(2-cyanoacetyl)hydrazono)ethyl)-N-ethyl-N-methylbenzenesulfonamide (2), which was prepared from condensation of acetophenone derivative 1 with 2-cyanoacetohydrazide. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H NMR, 13C NMR, 19F NMR and MS spectral data. All the newly synthesized heterocyclic sulfonamides were evaluated as in-vitro anti-breast cancer cell line (MCF7) and as in-vitro antimicrobial agents. Compounds 8, 5 and 11 were more active than MTX reference drug and compounds 12, 7, 4, 14, 5 and 8 were highly potent against Klebsiella pneumonia. Molecular operating environment performed virtual screening using molecular docking studies of the synthesized compounds. The results indicated that some prepared compounds are suitable inhibitor against dihydrofolate reductase (DHFR) enzyme (PDBSD:4DFR) with further modification.

Headspace sorptive solid phase microextraction (HS-SPME) combined with a spectrophotometry system: A simple glass devise for extraction and simultaneous determination of cyanide and thiocyanate in environmental and biological samples.

A simple, low cost and efficient headspace sorptive solid phase microextraction (HS-SPME) method for determination of cyanide has been developed. The system comprises of a glass tube with two valves and a moveable glass slide fixed at its centre. It includes an acceptor phase polyurethane foam treated mercury (II) dithizonate [Hg(HDz)2-PUF] complex fixed inside by a septum cap in a cylindrical configuration (5.0cm length and 1.0cm diameter). The extraction is based upon the contact of the acceptor phase to the headspace and subsequently measuring the absorbance of the recovered mercury (II) dithizonate from PUFs sorbent. Unlike other HSSE, extraction and back - extractions was carried out in a closed system, thereby improving the analytical performance by preventing the analyte loss. Under the optimized conditions, a linear calibration plot in the range of 1.0-50.0µmolL(-1) was achieved with limits of detection (LOD) and quantification (LOQ) of 0.34, 1.2µmolL(-1) CN(-), respectively. Simultaneous analysis of cyanide and thiocyanate in saliva was also performed with satisfactory recoveries.

Synthesis, spectroscopic properties, molecular docking, anti-colon cancer and anti-microbial studies of some novel metal complexes for 2-amino-4-phenylthiazole derivative.

This article describes the synthesis of novel bidentate Schiff base (H2L) from condensation of 2-amino-4-phenylthiazole (APT) with 4,6-diacetylresorcinol (DAR) in the molar ratio 2:1. We studied interaction of ligand (H2L) with transition metal ions such as Cr(III), Fe(III), Cu(II), Zn(II) and Cd(II). The ligand (H2L) has two bidentate sets of (N-O) units which can coordinate with two metal ions to afford novel binuclear metal complexes. The directions of coordinate bonds are from nitrogen atoms of azomethine groups and oxygen atoms of the phenolic groups. Structures of the newly synthesized complexes were confirmed by elemental analysis, IR, UV, (1)H NMR, ESR, TGA and mass spectral data. All of the newly synthesized complexes were evaluated for their antibacterial and anti-fungal activities. They were also evaluated for their in vitro anticancer activity against human colon carcinoma cells (HCT-116) and mammalian cells of African green monkey kidney (VERO). The Cu(II) complex with selectivity index (S.I.)=21.26 exhibited better activity than methotrexate (MTX) as a reference drug with S.I. value=13.30, while Zn(II) complex with S.I. value=10.24 was found to be nearly as active as MTX. Molecular docking studies further helped in understanding the mode of action of the compounds through their various interactions with active sites of dihydrofolate reductase (DHFR) enzyme. The observed activity of Fe(III) and Cu(II) complexes gave rise to the conclusion that they might exert their action through inhibition of the DHFR enzyme.