In Vitro Evaluation and Bioinformatics Analysis of Schiff Bases Bearing Pyrazole Scaffold as Bioactive Agents: Antioxidant, Anti-Diabetic, Anti-Alzheimer, and Anti-Arthritic

In continuation of our research programs for the discovery, production, and development of the pharmacological activities of molecules for various disease treatments, Schiff bases and pyrazole scaffold have a broad spectrum of activities in biological applications. In this context, this manuscript aims to evaluate and study Schiff base-pyrazole molecules as a new class of antioxidant (total antioxidant capacity, iron-reducing power, scavenging activity against DPPH, and ABTS radicals), anti-diabetic (α-amylase% inhibition), anti-Alzheimer's (acetylcholinesterase% inhibition), and anti-arthritic (protein denaturation% and proteinase enzyme% inhibitions) therapeutics. Therefore, the Schiff bases bearing pyrazole scaffold (22a, b and 23a, b) were designed and synthesized for evaluation of their antioxidant, anti-diabetic, anti-Alzheimer's, and anti-arthritic properties. The results for compound 22b demonstrated significant antioxidant, anti-diabetic (α-amylase% inhibition), and anti-Alzheimer's (ACE%) activities, while compound 23a demonstrated significant anti-arthritic activity. Prediction of in silico bioinformatics analysis (physicochemical properties, bioavailability radar, drug-likeness, and medicinal chemistry) of the target derivatives (22a, b and 23a, b) was performed. The molecular lipophilicity potential (MLP) of the derivatives 22a, b and 23a, b was measured to determine which parts of the surface are hydrophobic and which are hydrophilic. In addition, the molecular polar surface area (PSA) was measured to determine the polar surface area and the non-polar surface area of the derivatives 22a, b and 23a, b. This study could be useful to help pharmaceutical researchers discover a new series of potent agents that may act as an antioxidant, anti-diabetic, anti-Alzheimer, and anti-arthritic.

Anti-inflammatory activity of novel derivatives of pyrazolo [3,4d] pyridazine against digestive system inflammation

The digestive system is exposed to severe inflammation as a result of taking some medications that have gastrointestinal side effects. Sixty Swiss-albino male mice were randomly distributed into six groups to treat inflammations of the colon, stomach, and small intestine caused by taking high doses of diclofenac (D), with two novel synthesized compounds, pyrazolo [3,4 d] pyridazine derivatives (Co1 and Co2). Myeloperoxidase enzyme activity was determined in the colon and small intestinal tissues. Serum contents of TNF-α, IL-22, IgG, and IgM were determined by ELISA. Histopathological examinations of the colon, small intestinal, and stomach tissues were microscopically analyzed. TNF-α, IL-22, and TNFSF11 gene expression were measured in the colon, intestinal, and spleen using qRT-PCR. Diclofenac caused surface columnar epithelial cell loss, focal necrosis of the gastric mucosa, inflammatory cell infiltration, and congested blood vessels in the stomach, colon, and small intestinal tissues. Co1 component was found to be better than Co2 component in reducing the focal necrosis of gastric mucosa and improving the histological structures of the stomach, colon, and small intestinal tissues. After 14 days, the activity of the myeloperoxidase enzyme was increased in group D and decreased in groups DCo1, DCo2, Co1, and Co2. Serum concentrations of TNF-α and IgG were increased, while IL-22 and IGM were reduced in the D, DCo1, and DCo2 groups compared with the Co1 and control groups. TNF-α gene was upregulated in the D group and downregulated in the Co1 group, while the IL-22 gene was downregulated in the D group and upregulated in the Co1 group compared with the control group. The CO1 component may be useful in reducing digestive system inflammation.

Investigations of Electronic, Structural, and In Silico Anticancer Potential of Persuasive Phytoestrogenic Isoflavene-Based Mannich Bases

Isoflavenes have received the greatest research attention among the many groups of phytoestrogens. In this study, various isoflavene-based Mannich bases were selected for their theoretical studies. The purpose of this research was to discover the binding potential of all the designated Mannich bases acting as inhibitors against cancerous proteins EGFR, cMet, hTrkA, and HER2 (PDB codes: 5GTY, 3RHK, 6PL2, and 7JXH, respectively). For their virtual screening, DFT calculations and molecular docking studies were undertaken using in silico software. Docking studies predicted that ligands 5 and 15 exhibited the highest docking score by forming hydrogen bonds within the active pocket of protein 6PL2, ligands 1 and 15 both with protein 3RHK, and 7JXH, 12, and 17 with protein 5GTY. Rendering to the trends in polarizability and dipole moment, the energy gap values (0.2175 eV, 0.2106 eV) for the firm conformers of Mannich bases (1 and 4) replicate the increase in bioactivity and chemical reactivity. The energy gap values (0.2214 eV and 0.2172 eV) of benzoxazine-substituted isoflavene-based Mannich bases (9 and 10) reflect the increase in chemical potential due to the most stable conformational arrangements. The energy gap values (0.2188 eV and 0.2181 eV) of isoflavenes with tertiary amine-based Mannich bases (14 and 17) reflect the increase in chemical reactivity and bioactivity due to the most stable conformational arrangements. ADME was also employed to explore the pharmacokinetic properties of targeted moieties. This study revealed that these ligands have a strong potential to be used as drugs for cancer treatment.

Alleviative effects of pinostrobin against cadmium-induced renal toxicity in rats by reducing oxidative stress, apoptosis, inflammation, and mitochondrial dysfunction

Introduction

Cadmium (Cd) is a highly toxic heavy metal that can be found everywhere in the environment and can have harmful effects on both human and animal health. Pinostrobin (PSB) is a bioactive natural flavonoid isolated from Boesenbergia rotunda with several pharmacological properties, such as antiinflammatory, anticancer, antioxidant, and antiviral. This investigation was intended to assess the therapeutic potential of PSB against Cd-induced kidney damage in rats.

Methods

In total, 48 Sprague Dawley rats were divided into four groups: a control, a Cd (5 mg/kg), a Cd + PSB group (5 mg/kg Cd and 10 mg/kg PSB), and a PSB group (10 mg/kg) that received supplementation for 30 days.

Results

Exposure to Cd led to a decrease in the activities of catalase (CAT), glutathione reductase (GSR), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX), whereas levels of reactive oxygen species (ROS) and malondialdehyde (MDA) increased. Cd exposure also caused a substantial increase in urea, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and creatinine levels. Moreover, a noticeable decline was noticed in creatinine clearance. Moreover, Cd exposure considerably increased the levels of inflammatory indices, including interleukin-1b (IL-1b), tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), nuclear factor kappa-B (NF-kB), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) activity. Cd treatment decreased the expression of the antiapoptotic markers (Bcl-2) while increasing the expression of apoptotic markers (Bax and Caspase-3). Furthermore, Cd treatment substantially reduced the TCA cycle enzyme activity, such as alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase. Moreover, mitochondrial electron transport chain enzymes, succinatedehydrogenase, NADH dehydrogenase, cytochrome c-oxidase, and coenzyme Q-cytochrome reductase activities were also decreased following Cd exposure. PSB administration substantially reduced the mitochondrial membrane potential while inducing significant histological damage. However, PSB treatment significantly reduced Cd-mediated renal damage in rats.

Conclusion

Thus, the present investigation discovered that PSB has ameliorative potential against Cd-induced renal dysfunction in rats.

Exploring Antimicrobial Features for New Imidazo[4,5-b]pyridine Derivatives Based on Experimental and Theoretical Study

5-bromopyridine-2,3-diamine reacted with benzaldehyde to afford the corresponding 6-Bromo-2-phenyl-3H-imidazo[4,5-b]pyridine (1). The reaction of the latter compound (1) with a series of halogenated derivatives under conditions of phase transfer catalysis solid–liquid (CTP) allows the isolation of the expected regioisomers compounds (2–8). The alkylation reaction of (1) gives, each time, two regioisomers, N3 and N4; in the case of ethyl bromoactate, the reaction gives, at the same time, the three N1, N3 and N4 regioisomers. The structures of synthesized compounds were elucidated on the basis of different spectral data (1H NMR, 13C NMR), X-Ray diffraction and theoretical study using the DFT method, and confirmed for each compound. Hirshfeld surface analysis was used to determine the intermolecular interactions responsible for the stabilization of the molecule. Density functional theory was used to optimize the compounds, and the HOMO-LUMO energy gap was calculated, which was used to examine the inter/intra molecular charge transfer. The molecular electrostatic potential map was calculated to investigate the reactive sites that were present in the molecule. In order to determine the potential mode of interactions with DHFR active sites, the three N1, N3 and N4 regioisomers were further subjected to molecular docking study. The results confirmed that these analogs adopted numerous important interactions, with the amino acid of the enzyme being targeted. Thus, the most docking efficient molecules, 2 and 4, were tested in vitro for their antibacterial activity against Gram-positive bacteria (Bacillus cereus) and Gram-negative bacteria (Escherichia coli). Gram-positive bacteria were more sensitive to the action of these compounds compared to the Gram-negative, which were much more resistant.

An all-solid-state potentiometric sensor modified with multi-walled carbon nanotubes (MWCNTs) for silicate assessment and water-quality testing

A simple and cost-effective approach is proposed for silicate ion determination. The approach is based on designing an all-solid-state potentiometric sensor. The plasticized polyvinyl chloride (PVC) membrane sensor is based on the ion-association complex [Ni(bphen)₃]²⁺[SiO₃]^2- as a sensory recognition material. The sensor is modified with multi-walled carbon nanotubes (MWCNTs) as an ion-to-electron transducer material. The performance characteristics of the new silicate-selective electrode were evaluated using a potentiometric water-layer test, potentiometric measurements, impedance spectroscopy, and current-reversal chronopotentiometry. The developed electrodes exhibited a low detection limit (0.11 μg mL^-1) over a wide linear range (4.0 × 10^-6 to 1.0 × 10^-3 M) and near-Nernstian sensitivity (slope = -28.1 ± 1.4 mV per decade). They presented a very short response time (<5 s) over the pH range 6-12 and provided acceptable reliability, ease of design and miniaturization, and high potential stability, in addition to good accuracy and precision. The sensors exhibited enhanced selectivity for silicate over many common interfering anions, such as SO₄^2-, NO₃^-, CH₃COO^-, CO₃^2-, Cl^-, S^2-, and PO₄^3-. These results could qualify the developed sensor to be used in a successful way for the trace determination of silicate ions in different matrices. The developed method was successfully applied to the potentiometric detection of silicate in different pre-packaged bottled drinking water samples.

Nα-1, 3-Benzenedicarbonyl-Bis-(Amino Acid) and Dipeptide Candidates: Synthesis, Cytotoxic, Antimicrobial and Molecular Docking Investigation

Purpose

The objective of our work was to prepare a potent and safe antimicrobial and anticancer agents, through synthesis of several peptides and examine their biological activities, namely as, cytotoxically potent and antimicrobial and antifungal agents.

Introduction

Multidrug-resistant microbial strains have arisen against all antibiotics in clinical use. Infections caused by these bacteria threaten global public health and are associated with high mortality rates.

Methods

The main backbone structure for the novel synthesized linear peptide is Nα-1, 3-benzenedicarbonyl-bis-(Amino acids)-X, (3–11). A computational docking study against DNA gyrase was performed to formulate a mode of action of the small compounds as antimicrobial agents.

Results

The peptide-bearing methionine-ester (4) exhibited potent antimicrobial activity compared to the other synthesized compounds, while, peptide (8), which had methionine-hydrazide fragment was the most potent as antifungal agent against Aspergillus niger with 100% inhibition percent. Compounds (6 and 7) showed the highest potency against breast human tumor cell line “MCF-7” with 95.1% and 79.8% of cell inhibition, respectively. The nine compounds possessed weak to moderate antiproliferative effect over colon tumor cell line. The docking results suggest good fitting through different hydrogen bond interactions with the protein residues. In silico ADMET study also evaluated and suggested that these compounds had promising oral bioavailability features.

Conclusion

The tested compounds need further modification to have significant antimicrobial and antitumor efficacy compared to the reference drugs.

Novel heterocyclic hybrids of pyrazole targeting dihydrofolate reductase: design, biological evaluation and in silico studies

A novel series of pyrazole analogues including hydrazones, pyrazolo[4,3-c]-pyridazines, pyrazolo[3,4-e][1,2,4]triazine and pyrazolo[3,4-d][1,2,3]triazoles was designed, synthesised and screened for their in vitro antimicrobial and DHFR inhibition activity. Compounds bearing benzenesulphonamide moiety incorporated with 3-methyl-5-oxo-1H-pyrazol-4(5H)-ylidene) hydrazine 3a or 6-amino-7-cyano-3-methyl-5H-pyrazolo[4,3-c]pyridazine 6a revealed excellent and broad spectrum antimicrobial activity comparable to ciprofloxacin and amphotericin B as positive antibiotic and antifungal controls, respectively. Furthermore, these derivatives proved to be the most active DHFR inhibitors with IC₅₀ values 0.11 ± 1.05 and 0.09 ± 0.91 µM, in comparison with methotrexate (IC₅₀ = 0.14 ± 1.25 µM). The in silico studies were done to calculate the drug-likeness and toxicity risk parameters of the newly synthesised derivatives. Additionally, the high potency of the pyrazole derivatives bearing sulphonamide against DHFR was confirmed with molecular docking and might be used as an optimum lead for further modification.

Integrated all-solid-state sulfite sensors modified with two different ion-to-electron transducers: rapid assessment of sulfite in beverages

An integrated all-solid-state screen-printed ion-selective potentiometric sensor for rapid assessment of sulfite ion in beverages, based on analytical transduction, is described. The constructed potentiometric cell incorporates a polymeric membrane sulfite ion-selective electrode based on cobalt(ii) phthalocyanine (CoPC) as a recognition material and an Ag/AgCl reference electrode with a polyvinyl butyral reference membrane. Two different solid-contact transducers, namely multi-walled carbon nanotubes (MWCNTs) and polyaniline (PANI) were used for a comparative study. The presented sensors exhibited a rapid Nernst response across the concentration ranges from 2.0 × 10-6 to 2.3 × 10-3 M and from 5.0 × 10-6 to 2.3 × 10-3 M with detection limits equal to 1.1 × 10-6 M and 1.5 × 10-6 M for sensors based on MWCNTs and PANI, respectively. The proposed sensors manifested high selectivity and sensitivity, enhanced stability and low cost that provides a wide number of potential applications for food analysis. Good performance characteristics were obtained for the proposed method after applying the validation requirements. Method precision, accuracy, bias, trueness, repeatability, reproducibility, and uncertainty are examined. These analytical capabilities support the rapid and direct determination of sulfite in different beverage samples. The analytical results were verified and compared with the standard iodometric method.

Correction: Integrated all-solid-state sulfite sensors modified with two different ion-to-electron transducers: rapid assessment of sulfite in beverages

Correction for ‘Integrated all-solid-state sulfite sensors modified with two different ion-to-electron transducers: rapid assessment of sulfite in beverages’ by Hisham S. M. Abd-Rabboh et al., RSC Adv., 2021, 11, 3783–3791, DOI: 10.1039/D0RA09903A.

Novel sulindac derivatives: synthesis, characterisation, evaluation of antioxidant, analgesic, anti-inflammatory, ulcerogenic and COX-2 inhibition activity

A new series of N′-(substituted phenyl)-2-(1-(4-(methylsulfinyl) benzylidene)−5-fluoro-2-methyl-1H-inden-3-yl) acetohydrazide derivatives (1 – 25) were prepared in good yields in an efficient manner. All the compounds were fully characterised by the elemental analysis and spectral data. Synthesised compounds were evaluated for antioxidant activity by DPPH method. Compounds 7 (R = 3-methoxyphenyl), 3 (R = 4-dimethylaminophenyl) and 23 (R = 2,4,5-trimethoxy phenyl) substitutions were found to be having highly potent antioxidant activity. Compound 3, with para dimethylaminophenyl substitution was found to be having highest antioxidant activity. It was further evaluated in vivo for various analgesic, anti-inflammatory, ulcerogenic and COX-2 inhibitory activity in different animal models. Lead compound 3 was found to be significant anti-inflammatory and analgesic agent. It was also evaluated for ulcerogenic activity and demonstrated significant ulcerogenic reduction activity in ethanol and indomethacin model. The LD₅₀ of compound 3 was found to be 131 mg/kg. The animals treated with compound 3 prior to cisplatin treatment resulted in a significant reduction in COX-2 protein expression when compared to cisplatin-treated group. Sulindac derivative with para dimethylaminophenyl substitution was found to be the most potent antioxidant, anti-inflammatory and analgesic agent as well as with significant gastric sparing activity as compared to standard drug sulindac. Compound 3 significantly downregulated liver tissue COX‐2 gene expression.

Solid-State Membrane Sensors Based on Man-Tailored Biomimetic Receptors for Selective Recognition of Isoproturon and Diuron Herbicides

Solid-contact ion-selective electrodes (SC-ISEs) have shown great potential for routine and portable ion detection. The introduction of nanomaterials as ion-to-electron transducers and the adoption of different performance-enhancement strategies have significantly promoted the development of SC-ISEs. Herein, new solid-contact ion-selective electrodes, along with the implementation of multiwalled carbon nanotubes (MWCNTs) as ion-to-electron transducers and potassium tetrakis (p-chlorophenyl) borate (KTpClB) as lipophilic ionic additives, were presented for the detection of isoproturon (IPU) and diuron (DU) herbicides. Molecularly imprinted polymers (MIPs), with special molecule recognition properties for isoproturon (IPU) and diuron (DU), were prepared, characterized, and introduced as sensory recognition materials in the presented electrodes. Sensors revealed a near-Nernstian response for both isoproturon (IPU) and diuron (DU) with slopes of 53.1 ± 1.2 (r² = 0.997) and 57.2 ± 0.3 (r² = 0.998) over the linear ranges of 2.2 × 10^-6-1.0 × 10^-3 M and 3.2 × 10^-6-1.0 × 10^-3 M with detection limits of 8.3 × 10^-7 and 1.4 × 10^-6 M, respectively. The response time of the presented sensors was found to be <5 s and the lifetime was at least eight weeks. The sensors exhibited good selectivity towards isoproturon (IPU) and diuron (DU) in comparison with some other herbicides, alkali, alkaline earth, and heavy metal ions. The presented sensors were successfully applied for the direct determination of isoproturon (IPU) and diuron (DU) in real water samples.

Synthesis, Docking, Computational Studies, and Antimicrobial Evaluations of New Dipeptide Derivatives Based on Nicotinoylglycylglycine Hydrazide

Within a series of dipeptide derivatives (5–11), compound 4 was refluxed with d-glucose, d-xylose, acetylacetone, diethylmalonate, carbon disulfide, ethyl cyanoacetate, and ethyl acetoacetate which yielded 5–11, respectively. The candidates 5–11 were characterized and their biological activities were evaluated where they showed different anti-microbial inhibitory activities based on the type of pathogenic microorganisms. Moreover, to understand modes of binding, molecular docking was used of Nicotinoylglycine derivatives with the active site of the penicillin-binding protein 3 (PBP3) and sterol 14-alpha demethylase’s (CYP51), and the results, which were achieved via covalent and non-covalent docking, were harmonized with the biological activity results. Therefore, it was extrapolated that compounds 4, 7, 8, 9, and 10 had good potential to inhibit sterol 14-alpha demethylase and penicillin-binding protein 3; consequently, these compounds are possibly suitable for the development of a novel antibacterial and antifungal therapeutic drug. In addition, in silico properties of absorption, distribution, metabolism, and excretion (ADME) indicated drug likeness with low to very low oral absorption in most compounds, and undefined blood–brain barrier permeability in all compounds. Furthermore, toxicity (TOPKAT) prediction showed probability values for all carcinogenicity models were medium to pretty low for all compounds.

A New Validated Potentiometric Method for Sulfite Assay in Beverages Using Cobalt(II) Phthalocyanine as a Sensory Recognition Element

A simple potentiometric sensor is described for accurate, precise, and rapid determination of sulfite additives in beverages. The sensor is based on the use of cobalt phthalocyanine as a recognition material, dispersed in a plasticized poly(vinyl chloride) matrix membrane. o-Nitrophenyl octyl ether (o-NPOE) as a membrane solvent and tri-dodecylmethyl- ammonium chloride (TDMAC) as ion discriminators are used as membrane additives. Under the optimized conditions, sulfite ion is accurately and precisely measured under batch and flow injection modes of analysis. The sensor exhibits fast and linear response for 1.0 × 10-2-1.0 × 10-6 M (800-0.08 µg/mL) and 1.0 × 10-1-5.0 × 10-5 M (8000-4 µg/mL) sulfite with Nernstian slopes of -27.4 ± 0.3 and -23.7 ± 0.6 mV/concentration decade under static and hydrodynamic modes of operation, respectively. Results in good agreement with the standard iodometric method are obtained.Validation of the assay method is examined in details including precision, accuracy, bias, trueness, repeatability, reproducibility, and uncertainty and good performance characteristics of the method are obtained. The sensor response is stable over the pH range of 5 to 7 without any significant interference from most common anions. The advantages offered by the proposed sensor (i.e., wide range of assay, high accuracy and precision, low detection limit, reasonable selectivity, long term response stability, fast response, and long life span and absence of any sample pretreatment steps) suggest its use in the quality control/quality assurance routine tests in beverages industries, toxicological laboratories and by inspection authorities.

Synthesis and Characterization of CuFe2O4 Nanoparticles Modified with Polythiophene: Applications to Mercuric Ions Removal

In this research, CuFe₂O₄ nanoparticles were synthesized by co-precipitation methods and modified by coating with thiophene for removal of Hg(II) ions from aqueous solution. CuFe₂O₄ nanoparticles, with and without thiophene, were characterized by x-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX), high-resolution transmission electron microscopy (HRTEM) and Brunauer-Emmett-Teller (BET). Contact time, adsorbent dose, solution pH, adsorption kinetics, adsorption isotherm and recyclability were studied. The maximum adsorption capacity towards Hg²⁺ ions was 7.53 and 208.77 mg/g for CuFe₂O₄ and CuFe₂O₄@Polythiophene composite, respectively. Modification of CuFe₂O₄ nanoparticles with thiophene revealed an enhanced adsorption towards Hg²⁺ removal more than CuFe₂O₄ nanoparticles. The promising adsorption performance of Hg²⁺ ions by CuFe₂O₄@Polythiophene composite generates from soft acid-soft base strong interaction between sulfur group of thiophene and Hg(II) ions. Furthermore, CuFe₂O₄@Polythiophene composite has both high stability and reusability due to its removal efficiency, has no significant decrease after five adsorption-desorption cycles and can be easily removed from aqueous solution by external magnetic field after adsorption experiments took place. Therefore, CuFe₂O₄@Polythiophene composite is applicable for removal Hg(II) ions from aqueous solution and may be suitable for removal other heavy metals.

Biological Evaluation and Molecular Docking with In Silico Physicochemical, Pharmacokinetic and Toxicity Prediction of Pyrazolo[1,5-a]pyrimidines

Pyrazolo[1,5-a]pyrimidines 5a–c, 9a–c and 13a–i were synthesized for evaluation of their in vitro antimicrobial properties against some microorganisms and their immunomodulatory activity. The biological activities of pyrazolo[1,5-a]pyrimidines showed that the pyrazolo[1,5-a]pyrimidines (5c, 9a, 9c, 13a, 13c, 13d, 13e and 13h) displayed promising antimicrobial and immunomodulatory activities. Studying the in silico predicted physicochemical, pharmacokinetic, ADMET and drug-likeness properties for the pyrazolo[1,5-a]pyrimidines 5a–c, 9a–c and 13a–i confirmed that most of the compounds (i) were within the range set by Lipinski’s rule of five, (ii) show higher gastrointestinal absorption and inhibition of some CYP isoforms, and (iii) have a carcinogenicity test that was predicted as negative and hERG test that presented medium risk. Moreover, the molecular docking study demonstrated that the compounds 5c, 9a, 9c, 13a, 13c, 13d, 13e and 13h are potent inhibitors of 14-alpha demethylase, transpeptidase and alkaline phosphatase enzymes. This study could be valuable in the discovery of a new series of drugs.

Modified Screen-Printed Potentiometric Sensors based on Man-Tailored Biomimetics for Diquat Herbicide Determination

Screen-printed platforms integrated with molecularly imprinted polymers (MIP) were fabricated and characterized as potentiometric sensors for diquat (DQ). The synthesized MIP beads were studied as sensory carriers in plasticized poly(vinyl chloride) membranes. The sensors were constructed by using poly(3,4-ethylenedioxythiophene) (PEDOT) as solid-contact material to diminish charge-transfer resistance and water layer potential. Conventional ion-selective electrodes (ISEs) with internal filling solution were used for comparison. The designed electrodes showed near Nernstian slopes of 28.2 ± 0.7 (r² = 0.999) over the concentration range of 1.0 × 10-6-1.0 × 10-2 M with the limit of detection 0.026 µg/mL over the pH range 4.2-9.0. The electrode exhibited good selectivity for diquat cations over a large number of organic and inorganic cations. The sensor was successfully introduced for direct measurement of diquat content in commercial pesticide preparations and different spiked potato samples. The results showed that the proposed electrode has a fast and stable response, good reproducibility, and applicability for direct assessment of diquat content. The proposed potentiometric method is simple and accurate in comparison with the reported HPLC methods. Besides, it is applicable to turbid and colored sample solutions.

Paper Strip and Ceramic Potentiometric Platforms Modified with Nano-Sized Polyaniline (PANi) for Static and Hydrodynamic Monitoring of Chromium in Industrial Samples

Screen-printed membrane sensors based on the use of paper and ceramic substrates are fabricated, characterized, and used for rapid batch and continuous monitoring of CrIII in the form of CrO42- in some industrial products and wastewater samples. Strips of paper and ceramic platforms (15 × 5 mm) were covered with conductive carbon paint and then modified with polyaniline (PANI) film, to act as an ion-to-electron transducer, followed by a drop casting of plasticized poly (vinyl chloride) (PVC) Rhodamine-B chromate membrane as a recognition sensing material. In a 5.0 mmol L-1 Trizma buffer solution of pH ~8, the fabricated paper and ceramic based membrane sensors exhibited a near Nernstian response for CrVI ion with slopes of -29.7 ± 0.5 and -28.6 ± 0.3 mV decade-1, limit of detection 2.5 × 10-5 and 2.4 × 10-6 mol L-1 (1.3-0.12 µg mL-1), and linear concentration range 7.5 × 10-3-5.0 × 10-5 and 7.5 × 10-3-1.0 × 10-5 mol L-1 (390-0.5 µg mL-1), respectively. Both sensors exhibited fast and stable potentiometric response, excellent reproducibility, and good selectivity with respect to a number of common foreign inorganic species. Impedance spectroscopy and chronopotentiometry data revealed a small resistance and a larger double layer capacitance due to the presence of the intermediate polyaniline (PAN) conductive layer. Furthermore, the formation of a water layer between the ion selective membrane (ISM) and the underlying conductor polymer and between the conducting polymer and the carbon conducting surface was greatly reduced. The developed disposable solid-contact potentiometric sensors offer the advantages of simple design, long term potential stability, flexibility, miniaturization ability, short conditioning time, and cost effectiveness that enable mass production. The sensors were successfully used for static and hydrodynamic measurements of total chromium in some leather tanning wastewater and nickel-chrome alloy samples. The results compare favorably with data obtained by atomic absorption spectrometry.

Novel Solid-State Potentiometric Sensors Using Polyaniline (PANI) as A Solid-Contact Transducer for Flucarbazone Herbicide Assessment

Novel potentiometric solid-contact ion-selective electrodes (SC/ISEs) based on molecularly imprinted polymers (MIPs) as sensory carriers (MIP/PANI/ISE) were prepared and characterized as potentiometric sensors for flucarbazone herbicide anion. However, aliquat S 336 was also studied as a charged carrier in the fabrication of Aliquat/PANI/ISEs for flucarbazone monitoring. The polyaniline (PANI) film was inserted between the ion-sensing membrane (ISM) and the electronic conductor glassy carbon substrate (GC). The sensors showed a noticeable response towards flucarbazone anions with slopes of −45.5 ± 1.3 (r² = 0.9998) and −56.3 ± 1.5 (r² = 0.9977) mV/decade over the range of 10⁻²–10⁻⁵, 10⁻²–10⁻⁴ M and detection limits of 5.8 × 10⁻⁶ and 8.5 × 10⁻⁶ M for MIP/PANI/ISE and Aliguat/PANI/ISE, respectively. The selectivity and long-term potential stability of all presented ISEs were investigated. The short-term potential and electrode capacitances were studied and evaluated using chronopotentiometry and electrochemical impedance spectrometry (EIS). The proposed ISEs were introduced for the direct measurement of flucarbazone herbicide in different soil samples sprayed with flucarbazone herbicide. The results agree well with the results obtained using the standard liquid chromatographic method (HPLC).

Potentiometric PVC-Membrane-Based Sensor for Dimethylamine Assessment Using A Molecularly Imprinted Polymer as A Sensory Recognition Element

A new simple potentiometric sensor is developed and presented for sensitive and selective monitoring of dimethylamine (DMA). The sensor incorporates a molecularly imprinted polymer, with a pre-defined specific cavity suitable to accommodate DMA. The molecularly imprinted polymer (MIP) particles were dispersed in an aplasticized poly(vinyl chloride) matrix. The MIP is synthesized by using a template molecule (DMA), a functional monomer (acrylamide, AM), cross-linker (ethylene glycol dimethacrylate, EGDMA) and initiating reagent (benzoylperoxide, BPO). Using Trizma buffer solution (5 mmol L^-1, pH 7.1), the sensor exhibits a rapid, stable and linear response for 1.0 × 10^-5 to 1.0 × 10^-2 mol L^-1 DMA⁺ with a calibration slope of 51.3 ± 0.3 mV decade^-1, and a detection limit of 4.6 × 10^-6 mol L^-1 (0.37 µg mL^-1). The electrode exhibited a short response time (10 s) and stable potential readings (± 0.5 mV) for more than 2 months. Potentiometric selectivity measurements of the sensor reveal negligible interferences from most common aliphatic and aromatic amines. High concentration levels (100-fold excess) of many inorganic cations do not interfere. The sensor is successfully used for quantification of low levels of DMA down to 0.5 µg mL^-1. Verification of the presented method was carried out after measuring the detection limit, working linearity range, ruggedness of the method, accuracy, precision, repeatability and reproducibility. Under flow-through conditions, the proposed sensor in its tubular form is prepared and introduced in a two-channel flow injection setup for hydrodynamic determination of DMA. The sampling rate is 50-55 samples h^-1. The sensor is used to determine DMA in different soil samples with an accuracy range of 97.0-102.8%.

Tailor-Made Specific Recognition of Cyromazine Pesticide Integrated in a Potentiometric Strip Cell for Environmental and Food Analysis

Screen-printed ion-selective electrodes were designed and characterized for the assessment of cyromazine (CYR) pesticide. A novel approach is to design tailor-made specific recognition sites in polymeric membranes using molecularly imprinted polymers for cyromazine (CR) determination (sensor I). Another sensor (sensor II) is the plasticized PVC membrane incorporating cyromazine/tetraphenyl borate ion association complex. The charge-transfer resistance and water layer reached its minimal by incorporating Polyaniline (PANI) solid-contact ISE. The designed electrodes demonstrated Nernstain response over a linear range 1.0 × 10-2-5.2 × 10-6 and 1.0 × 10-2-5.7 × 10-5 M with a detection limit 2.2 × 10-6 and 8.1 × 10-6 M for sensors I and II, respectively. The obtained slopes were 28.1 ± 2.1 (r2 = 0.9999) and 36.4 ± 1.6 (r2 = 0.9991) mV/decade, respectively. The results showed that the proposed electrodes have a fast and stable response, good reproducibility, and applicability for direct measurement of CYR content in commercial pesticide preparations and soil samples sprayed with CYR pesticide. The results obtained from the proposed method are fairly in accordance with those using the standard official method.

Single-Piece All-Solid-State Potential Ion-Selective Electrodes Integrated with Molecularly Imprinted Polymers (MIPs) for Neutral 2,4-Dichlorophenol Assessment

A novel single-piece all-solid-state ion-selective electrode (SC/ISE) based on carbon-screen printed is introduced. Polyaniline (PANI) is dissolved in a membrane cocktail that contains the same components used for making a conventional ion-selective polyvinyl chloride (PVC) matrix membrane. The membrane, having the PANI, is directly drop-casted on a carbon substrate (screen-printed-carbon electrode). PANI was added to act as an intermediary between the substrate and the membrane for the charge transfer process. Under non-equilibrium sensing mechanism, the sensors revealed high sensitivity towards 2,4-dichlorophenol (DCP) over the linearity range 0.47 to 13 µM and a detection limit 0.13 µm. The selectivity was measured by the modified separate solution method (MSSM) and showed good selectivity towards 2,4-DCP over the most commonly studied ions. All measurements were done in 30 mm Tris buffer solution at a pH 5.0. Using constant-current chronopotentiometry, the potential drift for the proposed electrodes was checked. Improvement in the potential stability of the SPE was observed after the addition of PANI in the sensing membrane as compared to the corresponding coated-wire electrode (membrane without PANI). The applicability of the sensor has been checked by measuring 2,4-DCP in different water samples and the results were compared with the standard HPLC method.

Improved Solid-Contact Nitrate Ion Selective Electrodes Based on Multi-Walled Carbon Nanotubes (MWCNTs) as an Ion-to-Electron Transducer

Possible improvement of the performance characteristics, reliability and selectivity of solid-contact nitrate ion-selective electrodes (ISE) (SC/NO3--ISE) is attained by the application of a nitron-nitrate (Nit+/NO3-) ion association complex and inserting multi-walled carbon nanotubes (MWCNTs) as an ion-to-electron transducer between the ion sensing membrane (ISM) and the electronic conductor glassy carbon (GC) substrate. The potentiometric performance of the proposed electrode revealed a Nernstian slope -55.1 ± 2.1 (r² = 0.997) mV/decade in the range from 8.0 × 10-8-1 × 10-2 M with a detection limit of 2.8 × 10-8 (1.7 ng/mL). Selectivity, repeatability and reproducibility of the proposed sensors were considerably improved as compared to the coated disc electrode (GC/NO3--ISE) without insertion of a MWCNT layer. Short-term potential stability and capacitance of the proposed sensors were tested using a current-reversal chronopotentiometric technique. The potential drift in presence of a MWCNT layer decreased from 167 μVs-1 (i.e., in absence of MWCNTs) to 16.6 μVs-1. In addition, the capacitance was enhanced from 5.99 μF (in absence of MWCNTs) to 60.3 μF (in the presence of MWCNTs). The presented electrodes were successfully applied for nitrate determination in real samples with good accuracy.

Antibacterial Evaluation, In Silico Characters and Molecular Docking of Schiff Bases Derived from 5-aminopyrazoles

A series of Schiff bases 14-25 were designed and synthesized for evaluation of their antibacterial properties against multi-drug resistant bacteria (MDRB). The antibacterial activities of Schiff bases 14-25 showed that most of the synthesized compounds displayed a significant antibacterial activity. Assessment of in silico ADMET properties (absorption, distribution, metabolism, excretion and toxicity) of Schiff bases illustrates that all derivatives showed agreement to the Lipinski's rule of five. Further enzymatic assay aided by molecular docking study demonstrated that compound 18 is a potent inhibitor of staphylococcus aureus DNA gyrase and dihydrofolate reductase kinases. This study could be valuable in the discovery of new potent antimicrobial agents.

Gold Plate Electrodes Functionalized by Multiwall Carbon Nanotube Film for Potentiometric Thallium(I) Detection

Solid-contact potentiometric ion-selective electrodes (SC-ISEs) for thallium determination have been designed using multiwall carbon nanotubes (MWCNTs) as the ion-to-electron transducer. Dispersed MWCNTs were drop-casted over a gold plate electrode. Two different crown ethers were used in the sensing membrane for the recognition of thallium (I). Sensorsbased on dibenzo-18-crown-6 (DB18C6) as a neutral carrier and NaTPB as an anionic additive exhibited a near Nernstian response of 57.3 mV/decade towards Tl+ ions over the activity range 4.5 × 10-6-7.0 × 10-4 M, with a limit of detection of 3.2 × 10-7 M. The time required to achieve 95% of the steadyequilibrium potential was <10 s. The complex formation constant (log βML) between dibenzo-18-crown-6 and thallium (I) (i.e., 5.99) was measured using the sandwich membrane technique. The potential response was pH independent over the range 3.0-9.5. The introduction of MWCNTs as an electron-ion-transducer layer between gold plate and the sensing membrane lead to a smaller membrane resistance and a large double layer capacitance, which was proven using impedance spectra and chronopotentiometry (i.e., 114.9 ± 12 kΩ, 52.1 ± 3.3 pF, 200 ± 13.2 kΩ, and 50 ± 4.2 µF). Additionally, reduction ofthe water layer between the sensing membrane and the underlying conductor wastested. Thus, it is clear that MWCNTs can be used as a transducing layer in SC-ISEs. The proposed sensor was introduced as an indicator electrode for potentiometric titration of single and ternary mixtures of I-, Br-, and S2- anions.

Synthesis and Molecular Docking of New Thiophene Derivatives as Lactate Dehydrogenase-A Inhibitors

BACKGROUND & OBJECTIVE

A series of novel derivatives possessing the thiophene moiety were synthesized using ethyl 5'-amino-2,3'-bithiophene-4'-carboxylate as the starting material.

METHODS

The new synthesized derivatives were screened as lactate dehydrogenase (LDH) inhibitors. LDH plays an important role in glucose metabolism in cancer cells and can affect tumor genesis and metastasis.

RESULTS

3-Substituted p-tolylthieno[2,3-d]pyrimidin-4(3H)-ones 4 were the most potent inhibitors in this study compared to Galloflavin reference drug.

CONCLUSION

Molecular docking studies on the Human Lactate Dehydrogenase active site were carried out on the synthesized compounds and the MolDock scores ranged between -127 to -171.

Non-Equilibrium Potential Responses towards Neutral Orcinol Using All-Solid-State Potentiometric Sensors Integrated with Molecularly Imprinted Polymers

Molecularly imprinted polymer (MIP) receptors have been synthesized, characterized, and applied as new selective receptors in solid-contact ion selective electrodes (ISEs) towards non-dissociated 3,5-dihydroxytoluene (orcinol). Two monomers, namely methacrylic acid (MAA) and acrylamide (AA), were used in the preparation of MIP receptors. Graphene (Gr) was used as the solid contact material between the sensing membrane and the electrical contact substrate. Based on non-equilibrium sensing mechanism, the proposed sensors reveal observably enhanced detection sensitivity towards orcinol with detection limits 1.7 × 10⁻⁵ and 3.3 × 10⁻⁶ M for sensors based on MIP/MAA and MIP/AA, respectively. The selectivity coefficients measured by the modified separate solution method (MSSM) for the proposed sensors showed good selectivity towards orcinol over most common other phenols and inorganic anions. All measurements were made in the presence of 30 mM phosphate buffer solution (PBS) with a pH of 7.0. Potential stability for the proposed sensors was tested by constant-current chronopotentiometry. No water films were formed between the sensing membrane and the electron conductor substrate. The applicability of MIP/MAA incorporated ISE has been checked by recovery test of orcinol in the presence of soil matrix and by standard addition method.

Synthesis and antihepatotoxic activity of dihydropyrimidinone derivatives linked with 1,4-benzodioxane

Purpose: To evaluate the antihepatotoxic activity of dihydropyrimidinone derivative linked with 1,4-benzodioxane. Methods: A series of novel dihydropyrimidinone derivatives linked with 1,4-benzodioxane moiety were synthesized in good yield. Modern spectroscopic techniques and elemental analysis were used for the identification of the synthesized compounds. The hepatoprotective properties of compound 2, 4-(4-nitrophenyl)-5-(2,3-dihydro-1,4-benzodioxin-6-ylcarbonyl)-3,4-dihydropyrimidin-2(1H)-one, was evaluated in a carbon tetrachloride (CCl4)-induced hepatotoxicity rat model. Results: Administration of compound 2 prior to CCl4 exposure produced a dose-dependent decrease in the levels of elevated biochemical parameters compared with the standard drug silymarin. CCl4 induced oxidative stress, increased lipid profile, and decreased high-density lipoprotein (HDL) levels. Compound 2 (20 mg/kg) significantly reduced the lipid profile and significantly improved HDL levels in a dose-dependent manner. CCl4 treatment increased malondialdehyde (MDA) level and decreased nonprotein thiol (NP-SH) and total protein (TP) in liver tissues. Pretreatment of rats with compound 2 (20 mg/kg) decreased MDA level and increased NP-SH and TP in liver tissues. Histopathological examination of liver tissues also confirmed the hepatoprotective activity of compound 2. Conclusion: These results demonstrate the antihepatotoxic activity of compound 2 in CCl4-induced hepatotoxicity model.

A Comparative Study of the Anticancer Activity and PARP-1 Inhibiting Effect of Benzofuran-Pyrazole Scaffold and Its Nano-Sized Particles in Human Breast Cancer Cells

Breast cancer is considered the most common and deadly cancer among women worldwide. Nanomedicine has become extremely attractive in the field of cancer treatment. Due to the high surface to volume ratio and other unique properties, nanomaterials can be specifically targeted to certain cells and tissues to interact with the living systems. The strategic planning of this study is based on using the nanoprecipitation method to prepare nanoparticles BZP-NPs (3.8-5.7 nm) of the previously prepared benzofuran-pyrazole compound (IV) BZP which showed promising cytotoxic activity. The capacity of BZP and BZP-NPs to suppress the growth of human breast tumor MCF-7 and MDA-MB-231 cells was evaluated using MTT assay. The IC50 doses of BZP and BZP-NPs targeting normal breast cells MCF-12A exceeded those targeting the cancer cells by >1000-fold, demonstrating their reasonable safety profiles in normal cells. Furthermore, cell cycle analysis, apoptosis induction detection, assessment of p53, Bcl-2, caspase-3, and PARP-1 levels of BZP and its nano-sized-BZP-NPs particles were also evaluated. Although the obtained results were in the favor of compound IV in its normal-sized particles, BZP-NPs appeared as a hit compound which showed improved cytotoxicity against the tested human breast cancer cells associated with the induction of pre-G1 apoptosis as well as cell cycle arrest at G2/M phase. The increase in caspase-3 level, upregulation of p53, and downregulation of Bcl-2 protein expression levels confirmed apoptosis. Furthermore, ELISA results exhibited that BZP-NPs produced a more favorable impact as a PARP-1 enzyme inhibitor than the parent BZP.

Potent Anti-Ovarian Cancer with Inhibitor Activities on both Topoisomerase II and V600EBRAF of Synthesized Substituted Estrone Candidates

A series of 16-(α-alkoxyalkane)-17-hydrazino-estra-1(10),2,4-trien[17,16-c]-3-ol (3a–l) and estra-1(10),2,4-trien-[17,16-c]pyrazoline-3-ol derivatives (4a–d) were synthesized from corresponding arylidines 2a,b which was prepared from estrone 1 as starting material. Condensation of 1 with aldehydes gave the corresponding arylidine derivatives 2a,b which were treated with hydrazine derivatives in alcohols to give the corresponding derivatives 3a–l, respectively. Additionally, treatment of 2a,b with methyl- or phenylhydrazine in ethanolic potassium hydroxide afforded the corresponding N-substituted pyrazoline derivatives 4a–d, respectively. All these derivatives showed potent anti-ovarian cancer both in vitro and in vivo. The mechanism of anti-ovarian cancer was suggested to process via topoisomerase II and ^V600EBRAF inhibition.

Synthesis of a vanadyl (IV) folate complex for the treatment of diabetes: spectroscopic, structural, and biological characterization

Background

This study aimed to design a compound with folic acid (FAH₂) and vanadyl (IV) for use in the treatment of diabetes.

Materials and methods

A novel vanadyl (IV) FAH₂ complex was synthesized and characterized [(FA^2-)(VO²⁺)]⋅3H₂O. The speculated structure of this folate complex was determined using physicochemical techniques including microanalytical analysis, conductivity studies, spectroscopic examination, magnetic measurements, thermogravimetric analyses, and morphological X-ray powder diffraction, and scanning and transmission electron microscopies. The anti-diabetic therapeutic potential of the complexes was tested in a 30-day streptozotocin-induced diabetes rat model.

Results

The conductivity test of the complex implied electrolyte behavior. The spectroscopic assessments of the isolated dark yellow solid complex revealed that FAH₂ acts as a bidentate ligand. The coordination process with two vanadyl (IV) ions occurred through the deprotonation of both carboxyl groups of FAH₂ in a regular square pyramid arrangement at a 2(FA)^2-: 2(VO)²⁺ molar ratio. XRD, SEM, and TEM analyses revealed the complex crystalline nature of the complex. Treating diabetic rats with vanadyl (IV) FAH₂ complex significantly improved many biological parameters relevant to diabetes pathology with minimal toxicity.

Conclusion

The data generated in this study indicate that the synthesized vanadyl (IV) folate complex acts as a model of anti-diabetic agent.

Design, Synthesis, and Molecular Docking Study of Novel Heterocycles Incorporating 1,3,4-Thiadiazole Moiety as Potential Antimicrobial and Anticancer Agents

A new series of 5-(3,5-dinitrophenyl)-1,3,4-thiadiazole derivatives were prepared and evaluated for their in vitro antimicrobial, antitumor, and DHFR inhibition activity. Compounds 9, 10, 13, and 16 showed strong and broad-spectrum antimicrobial activity comparable to Amoxicillin and Fluconazole as positive antibiotic and antifungal controls, respectively. Compounds 6, 14, and 15 exhibited antitumor activity against four human cancer cell lines, CCRF-CEM leukemia, HCT-15 colon, PC-3 prostate, and UACC-257 melanoma cell lines using Doxorubicin as a reference drug. Compounds 10, 13, 14, and 15 proved to be the most active DHFR inhibitors with an IC₅₀ range of 0.04 ± 0.82–1.00 ± 0.85 µM, in comparison with Methotrexate (IC₅₀ = 0.14 ± 1.38 µM). The highly potent DHFR inhibitors shared a similar molecular docking mode and made a critical hydrogen bond and arene‒arene interactions via Ser59 and Phe31 amino acid residues, respectively.

Design and Synthesis of Novel Thiosemicarbazones as Potent Anti-breast Cancer Agents

Background:

Thiosemicarbazones and its derivatives received a great pharmaceutical importance due to their prominent biological activities.

Methods:

A series of disubstituted thiosemicarbazone derivatives (1-12) were designed and synthesized as pure compounds in good yield. All the synthesized compounds were analyzed by spectral data. The anticancer activity of all the compounds was performed against breast cancer MCF-7 and MDA-MB-231 cell lines.

Results:

Most of the compounds showed activity against breast cancer MCF-7 and MDA-MB-231 cell lines with (IC50 = 12.25 &#181;M ‒ 185.35 &#181;M) and (IC50 = 12.97 &#181;M ‒ 107.33 &#181;M), respectively. Compound 9 presented (IC50 = 12.76 &#181;M and 12.97 &#181;M) against MCF-7 and MDA-MB-231 cell lines, respectively.

Conclusion:

Compound 9, was found to exhibit significant anti-breast cancer activity. This compound was further evaluated for side population percent inhibition assay on the breast cancer cell line MCF-7 at 5 and 10 &#181;M concentration. It showed superiority to block side population by more than 80% at 5 μM concentration compared to the reference drug verapamil.

Single-Piece Solid Contact Cu2+-Selective Electrodes Based on a Synthesized Macrocyclic Calix[4]arene Derivative as a Neutral Carrier Ionophore

Herein, a facile route leading to good single-walled carbon nanotubes (SWCNT) dispersion or poly (3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) based single-piece nanocomposite membrane is proposed for trace determination of Cu²⁺ ions. The single-piece solid contact Cu²⁺-selective electrodes were prepared after drop casting the membrane mixture on the glassy-carbon substrates. The prepared potentiometric sensors revealed a Nernstian response slope of 27.8 ± 0.3 and 28.1 ± 0.4 mV/decade over the linearity range 1.0 × 10^-3 to 2.0 × 10^-9 and 1.0 × 10^-3 to 1.0 × 10^-9 M with detection limits of 5.4 × 10^-10 and 5.0 × 10^-10 M for sensors based on SWCNTs and PEDOT/PSS, respectively. Excellent long-term potential stability and high hydrophobicity of the nanocomposite membrane are recorded for the prepared sensors due to the inherent high capacitance of SWCNT used as a solid contact material. The sensors exhibited high selectivity for Cu²⁺ ions at pH 4.5 over other common ions. The sensors were applied for Cu²⁺ assessment in tap water and different tea samples. The proposed sensors were robust, reliable and considered as appealing sensors for copper (II) detection in different complex matrices.

Synthesis of Novel Uracil Non-Nucleosides Analogues of 3,4-Dihydro-2-Alkylthio-6-benzyl-4-oxopyrimidines and 6-benzyl-1-ethoxymethyl-5-isopropyluracil

A series of new uracil non-nucleosides analogues of S-DABO's was synthesised by reaction of 5-alkyl-6-( p-chlorobenzyl)-2-thiouracils with chloroethyl dialkylamine hydrochloride, N-(2-chloroethyl)-pyrrolidine hydrochloride, N-(2-chloroethyl)-piperidine hydrochloride or appropriate haloethers. Novel emivirine analogues were synthesised by silylation of 5-alkyl-6-( p-chlorobenzyl)uracils and treatment with bromomethyl methyl ether, chloromethyl ethyl ether or benzyl chloromethyl ether. Compounds 6-( p-chlorobenzyl)-5-ethyl-1-ethyloxymethyluracil (9e) and 1-benzyloxymethyl-6-(4-chlorobenzyl)-5-ethyluracil (9f) showed activity against wild-type HIV-1 strain III B in MT-4 cells.

Synthesis and in vivo anti-ulcer evaluation of some novel piperidine linked dihydropyrimidinone derivatives

Dihydropyrimidinone derivatives containing piperidine moiety were synthesised in a good yield. All the compounds were confirmed by elemental analysis and spectral data. Anti-ulcer activity of novel dihydropyrimidinone-piperidine hybrids (1-18) was evaluated. Among them, four compounds (3, 8, 11 and 15) were found to be most active in 80% ethanol-induced ulcer experimental animal model. All the potent compounds were further evaluated for anti-ulcer activity by different in vivo anti-ulcer models to study the effect of compounds on anti-secretory and cytoprotective activities. All the active compounds inhibited the formation of gastric ulcers and increased the formation of gastric mucin secretion. Compound 15 was found to be the most potent compound of the series as anti-ulcer agent. Additional experimental studies on lead compound 15 will result in a new class of orally active molecule for anti-ulcer activity.

A One-Pot Biginelli Synthesis and Characterization of Novel Dihydropyrimidinone Derivatives Containing Piperazine/Morpholine Moiety

Enaminones, 4-methyl-1-[4-(piperazin/morpholin-1-yl) phenyl] pent-2-en-1-one (IIa⁻b) were synthesized by refluxing 1-[4-(piperazin/morpholin-1-yl) phenyl] ethan-1-one (Ia⁻b) with dimethylformamide dimethylacetal (DMF⁻DMA) without any solvent. The three dimensional structure of enaminone (IIb) containing morpholine moiety was confirmed by single crystal X-ray crystallography. Finally, the dihydropyrimidinone derivatives (1⁻20) were obtained by reacting enaminones (IIa⁻b) with urea and different substituted benzaldehydes in the presence of glacial acetic acid. Dihydropyrimidinone derivatives containing piperazine/morpholine moiety were synthesized in a good yield by means of simple and efficient method.

Synthesis of a new insulin-mimetic anti-diabetic drug containing vitamin A and vanadium(IV) salt: Chemico-biological characterizations

Diabetes patients suffer from chronic disorders in the metabolism due to high blood sugar caused by anomalies in insulin excretion. Recently, vanadium compounds have been prepared and functionalized to decrease the level of hyperglycemia. Vitamin A boosts beta cell activity; therefore, the lack of this vitamin plays a role in the development of type 2 diabetes. The aim of this article focused on the synthesis of a new anti-diabetic drug formed from the complexation of a vanadium(IV) salt with vitamin A. Vitamin A acts as a unidentate chelate through the oxygen of its -OH group. The vanadium(IV) compound is surrounded by two vitamin A molecules. The [VO(vitamin A)2(H2O)2] compound was synthesized in a binary solvent system consisting of MeOH/H2O (1:1 ratio) in alkaline media at pH = 8. This compound was characterized using Fourier transform infrared spectra (FT-IR), electronic spectra (UV-vis), effective magnetic moment, electron spin resonance (ESR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermal analysis (thermogravimetry (TG)-differential thermal analysis (DTA)). Anti-diabetic efficiency for the vanadium(IV) compound was assessed in streptozotocin (STZ)-induced diabetic mice. The results of the animal studies demonstrate the ability of the vanadium(IV) complex to act as an anti-diabetic agent, as measured by improvements of lipid profile, antioxidant activity (superoxide dismutase), malondialdehyde (MDA), glutathione, methionine synthase, and kidney and liver functions.

Crystal structure of 3-amino-1-(4-bromophenyl)-9-methoxy-1H-benzo[f]chromene-2-carbonitrile, C21H15BrN2O2

C21H15BrN2O2, triclinic, P1̅ (no. 2), a = 8.6873(3) Å, b = 9.9252(3) Å, c = 11.0013(3) Å, α = 77.977(2)°, β = 70.989(2)°, γ = 89.321(2)°, V = 875.55(5) Å3, Z = 2, Rgt(F) = 0.0369, wRref(F2) = 0.1043, T = 296(2) K.

Crystal structure of 3-amino-8-methoxy-1-(4-methoxy phenyl)-1H-benzo[f]chromene-2-carbonitrile, C22H18N2O3

C22H18N2O3, monoclinic, C2/c (no. 15), a = 35.4037(10) Å, b = 6.0294(2) Å, c = 20.1702(7) Å, β = 122.239(4)°, V = 3641.8(2) Å3, Z = 8, R gt(F) = 0.0482, wR ref(F 2) = 0.1406, T = 296(2) K.