Design,Synthesis, and Biochemical Evaluation of Alpha-Amanitin Derivatives Containing Analogs of the trans-Hydroxyproline Residue for Potential Use in Antibody-Drug Conjugates

Alpha-amanitin, an extremely toxic bicyclic octapeptide extracted from the death-cap mushroom, Amanita phalloides, is a highly selective allosteric inhibitor of RNA polymerase II. Following on growing interest in using this toxin as a payload in antibody-drug conjugates, herein we report the synthesis and biochemical evaluation of several new derivatives of this toxin to probe the role of the trans-hydroxyproline (Hyp), which is known to be critical for toxicity. This structure activity relationship (SAR) study represents the first of its kind to use various Hyp-analogs to alter the conformational and H-bonding properties of Hyp in amanitin.     

Electrochemical Sensing of Tryptophan and Tyrosine in Chronic Kidney Disease Patients Using Magnetic Core/Ag Nanoparticles Shell Nanocomposite Modified Electrode

Journal of Analytical Chemistry - This paper reports the production of a novel magnetic nanocomposite based on core-shell Fe3O4@Ag nanoparticles. Fe3O4@Ag nanoparticles were used to fabricate a...     

Preparation,characterization, and assessment of cytotoxicity,antioxidant, antibacterial,antifungal, and cutaneous wound healing properties of titanium nanoparticles using aqueous extract of Ziziphora clinopodioides Lam leaves

In recent decades, nanotechnology is growing rapidly owing to its widespread application in science and industry. The aim of the experiment was chemical characterization and evaluation of cytotoxicity, antioxidant, antibacterial, antifungal, and cutaneous wound healing activities of titanium nanoparticles using aqueous extract of Ziziphora clinopodioides Lam leaves (TiNPs@Ziziphora). These nanoparticles were characterized by fourier transformed infrared spectroscopy (FT‐IR), field emission scanning electron microscopy (FE‐SEM), energy dispersive X‐ray spectroscopy (EDS), and UV–visible spectroscopy. The synthesized TiNPs@Ziziphora had great cell viability dose‐dependently (Investigating the effect of the plant on human umbilical vein endothelial cells (HUVECs) cell line) and revealed this method was nontoxic. Then, 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free radical scavenging test was done to assess the antioxidant properties, which indicated similar antioxidant potentials for TiNPs@Ziziphora and butylated hydroxytoluene. Agar diffusion tests were applied to determine the antibacterial and antifungal characteristics. Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), and Minimum Fungicidal Concentration (MFC) were specified by macro‐broth dilution assay. The data were analyzed by SPSS 21 software (Duncan post‐hoc test). TiNPs@Ziziphora indicated higher antibacterial and antifungal effects than all standard antibiotics (p ≤ 0.01). Also, TiNPs@Ziziphora inhibited the growth of all bacteria at 2‐16 mg/ml concentrations and removed them at 2‐32 mg/ml concentrations (p ≤ 0.01). In case of antifungal properties of TiNPs@Ziziphora, they prevented the growth of all fungi at 2‐8 mg/ml concentrations and destroyed them at 2‐16 mg/ml concentrations (p ≤ 0.01). In vivo experiment, after creating the cutaneous wound, the rats were randomly divided into six groups: untreated control, treatment with Eucerin basal ointment, treatment with 3% tetracycline ointment, treatment with 0.2% TiO₂ ointment, treatment with 0.2% Z. clinopodioides ointment, and treatment with 0.2% TiNPs@Ziziphora ointment. These groups were treated for 10 days. For histopathological and biochemical analysis of the healing trend, a 3 × 3 cm section was prepared from all dermal thicknesses at day 10. Use of TiNPs@Ziziphora ointment in the treatment groups substantially reduced (p ≤ 0.01) the wound area, total cells, neutrophil, and lymphocyte and remarkably raised (p ≤ 0.01) the wound contracture, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate compared to other groups. In conclusion, the results revealed the useful non‐cytotoxic, antioxidant, antibacterial, antifungal, and cutaneous wound healing effects of TiNPs@Ziziphora.     

Biosynthesis of gold nanoparticles using Allium noeanum Reut. ex Regel leaves aqueous extract; characterization and analysis of their cytotoxicity,antioxidant, and antibacterial properties

Gold nanoparticles have unique and excellent medical and nonmedical properties and application compared with other metallic nanoparticles. Recently, they have been used for the prevention, control, and treatment of bacterial and fungal diseases. In the recent study, fresh and clean leaves of Allium noeanum Reut. ex Regel leaves have been used for the synthesis of gold nanoparticles. Also, we evaluated the cytotoxicity, antioxidant, and antibacterial properties of HAuCl₄, A. noeanum, and the synthesized nanoparticles (Au NPs). These nanoparticles were analyzed by FT‐IR, UV, XRD, EDS, FE‐SEM, and TEM tests. FTIR results offered antioxidant compounds in the plant were the sources of reducing power, reducing gold ions to Au NPs. In TEM images revealed an average diameter of 10‐30 nm. At the beginning of biological experiments, DPPH free radical scavenging test was carried out to examine the antioxidant property. Also, in the bacterial part of this study, the concentration of HAuCl₄, A. noeanum, and AuNPs with minimum dilution and no turbidity was considered MIC. To determine MBC, 60 μL of MIC and three preceding chambers were cultured on Muller Hinton Agar. The minimum concentration with no bacterial growth was considered MBC. Au NPs revealed excellent antioxidant potential against DPPH, non‐toxicity property against human umbilical vein endothelial cells, and antibacterial activities against Streptococcus pneumonia, Bacillus subtilis, Staphylococcus aureus, Staphylococcus saprophyticus, Salmonella typhimurium, Pseudomonas aeruginosa, Shigella flexneri, and Escherichia coli O157:H7. These findings show that the inclusion of A. noeanum extract improves the solubility of Au NPs, which led to a notable enhancement in the antioxidant and antibacterial effects.     

Using a Natural Surfactant for Synthesize of NiO and CuO Nanostructures via Simple and Fast Microwave Approach

NiO and CuO nanostructures were synthesized successfully via simple and fast microwave approach. Olive oil was chose as surfactant for stabilizing nanostructures. Different parameters such as microwave time and power and olive oil concentration were investigated on product size and morphology. The products were characterized with X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopy and energy dispersive spectrometry analysis.     

Assessment of antioxidant,cytotoxicity, antibacterial,antifungal, and cutaneous wound healing activities of green synthesized manganese nanoparticles using Ziziphora clinopodioides Lam leaves under in vitro and in vivo condition

In recent decades, nanotechnology is growing rapidly owing to its widespread application in medical science. The aim of the experiment was the evaluation of cytotoxicity, antioxidant, antibacterial, antifungal, and cutaneous wound healing activities of green synthesized manganese nanoparticles using Ziziphora clinopodioides Lam leaves (MnNPs@ZC). The synthesized MnNPs@ZC were characterized using different techniques including UV–Vis., FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDS). According to the XRD analysis, 48.10 nm was measured for the crystal size of nanoparticles. SEM images exhibited a uniform spherical morphology and size in the range of 47.58 to 70.26 nm for the biosynthesized nanoparticles. MnNPs@ZC revealed excellent non-cytotoxicity effect against human umbilical vein endothelial cells, antioxidant activity against DPPH, antibacterial properties against Gram-negative bacteria (Salmonella typhimurium, Pseudomonas aeruginosa, and Escherichia coli O157:H7) and Gram-positive bacteria (Streptococcus pneumonia, Staphylococcus aureus, and Bacillus subtilis), and antifungal potentials against Candida glabrata, Candida albicans, Candida guilliermondii, and Candida krusei. Also, use of MnNPs@ZC ointment decreased significantly (p ≤ 0.01) the wound area, total cells, neutrophil, and lymphocyte and raised significantly (p ≤ 0.01) the wound contracture, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate compared to other groups in experimental animals. In conclusion, synthesized MnNPs@ZC indicated antibacterial, antifungal, non-cytotoxicity, antioxidant, and cutaneous wound healing effects in a dose-depended manner. After confirming in the clinical trials, these nanoparticles can be used in human for the treatment of cutaneous and infectious diseases.     

Guaranteed cost nonlinear sampled-data control: applications to a class of chaotic systems

Nonlinear Dynamics - This paper addresses the guaranteed cost sampled-data controller synthesis and analysis problems with application to nonlinear chaotic systems. A linear parameter-varying (LPV)...     

Silica Sulfuric Acid: A Versatile and Reusable Catalyst for Synthesis of Coumarin-3-carboxylic Acids in a Solventless System

Synthesis of substituted coumarin-3-carboxylic acid via Knoevenagel condensation of meldrum's acid with ortho-hydroxyaryl aldehydes in solventless system is described.     

Recurrence Tracking Microscope Based on Two Magnetic Mirrors

We introduce a recurrence tracing microscope based on the reflection of cold atoms from two magnetic mirrors placed in parallel. A cantilever is attached perpendicularly to one of the two mirrors at the lower end that probes surface structures. The quantum dynamics in the system provides the matter waves to store information on the height and spacing between the nanostructures. We use the recurrence tracking microscope in static and dynamic modes to study arbitrary and periodic nanostructures.     

A Simple Synthesis of Stable Phosphorus Ylides Derived from 2-Benzoxazolinone and 2-Mercaptobenzoxazole

The reaction of triphenylphosphine with dialkyl acetylenedicarboxylates in the presence of a strong SH-acid or NH-acid, such as 2-mercaptobenzoxazole and 2-benzoxazolinone, has been studied. In some cases, stable phosphorus ylides are obtained in excellent yields. The ylide moiety of these compounds is strongly conjugated with the adjacent carbonyl group, and the rotation about the partial double bond in (E) and (Z) geometrical isomers is slow on the NMR time scale at an ambient temperature. Thus, these exist as a mixture of geometrical isomers.