Synthesis of Selenium(0) and Zinc(II) Biomolecules in Nano-Structured Forms as New Antioxidant Agents: Chemical and Biological Studies

Russian Journal of General Chemistry - In this paper, two new complexes of selenium caffeine, [Se(Caf)4], and zinc α-tocopherol, [Zn(α-Tpl)2(NO3)2], are synthesized. The structures of...     

Preparation and Spectroscopic of Vanadyl(Ⅱ) Vitamin D_3 Amino Acid Mixed Complexes as Insulin Mimetic Drug

A new six intraperitoneal injection insulin-mimetic vanadyl(Ⅱ) compounds [(VD-1₃)(VO+2)(AA-1_n)] (where (n=1～6); AA₁=isoleucine, AA₂=threonine, AA₃=proline, AA₄=phenylalanine, AA₅=lysine and AA₆=glutamine) were synthesized by the chemical reactions between vitamin D₃ (VD₃), VOSO₄ and amino acids (AA_n) with equal molar ratio 1∶1∶1 in neutralized media. The structures of these complexes were elucidated by spectroscopic methods like, infrared and solid reflectance spectroscopes. Magnetic moments and electronic spectra reveal square pyramid geometrical structure of the complexes. The infrared spectra assignments of these complexes revealed that the chelation towards vanadyl(Ⅳ) ions existed via deprotonation of the hydroxyl group of VD₃ drug ligand and so amino acids act as bidentate ligand via N-amino and O-carboxylate groups. The anti-diabetic efficiency of these complexes were evaluated against streptozotocin induced diabetic male albino rats.     

Chitosan/CuO nanocomposite films mediated regioselective synthesis of 1,3,4-trisubstituted pyrazoles under microwave irradiation

Copper oxide-chitosan nanocomposite was synthesized simply via simple solution casting method and was characterized by different analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and Thermogravimetric analysis (TGA). The copper oxide content in the prepared nanocomposite film was estimated from the Energy-dispersive X-ray spectroscopy (EDS) and the copper content in the sample was found to be 12.57 wt%. From the XRD pattern, the average particle size was calculated using Debye-Scherrer formula and was found to be 33.5 nm. The TGA curves showed that the thermal stability of the hybrid nanocomposite was found to be superior to the native CS, which is attributed to the existence of the thermally stable CuO. The chitosan/CuO nanocomposite has proven to be an excellent heterogeneous base catalyst for regioselective 1,3-dipolar cycloaddition of hydrazonoyl chlorides 1a-j with enamine 2 to give 1,3,4-trisubstituted pyrazoles 3a-j in excellent yields. The performance of the nanocomposite was optimized by varying several reaction conditions.     

Preparation and optical properties of novel symmetrical hexadecachlorinatedphthalocyaninato zinc(II) spin coated thin films

Novel symmetrical 1,4,8,11,15,18,22,25-octahexyloxy-2,3,9,10,16,17,23,24-octa-(3,5- dichlorophenoxy)phthalocyaninato zinc(II) was synthesized and characterized by ¹H NMR, ¹³C NMR, MS, UV–Vis, XRD, and IR spectrometry. The synthesized ZnPc complex is soluble in various organic solvents such as CH₂Cl₂, THF, acetone, and ethyl acetate. This property helped to obtain thin films of the new ZnPc complex by spin coating method. The surface morphology of the thin films was investigated by atomic force microscopy, AFM, and showed that the molecules grow in stacks of rows. The spectrophotometric measurements of transmittance (T) and reflectance (R) spectra were carried out in the wavelength range 190–3000 nm.     

Medium Controlled Stoichiometric Complexation of Penicillin G—Potassium Drug with Se(IV), Nb(V), Ta(V), and Te(IV) Chlorides: Physicochemical and Antitumor Activity of the Complexes

Four new 1: 1 ratio of Se⁺⁴, Nb⁺⁵, Ta⁺⁵, and Te⁺⁴ penicillinate complexes are synthesized in the reaction of penicillin potassium salt (Pin-G-K) with Se(IV), Nb(V), Ta(V), and Te(IV) chlorides. Structures of the synthesized complexes are characterized by elemental analysis, conductivity, magnetic susceptibility, IR, UV-Vis, ¹H and ¹³C NMR, and mass spectra, SEM, TEM, and XRD. Diamagnetic and electronic spectral studies allow to elucidate the geometry of penicillinate chelates around central metal ions. The monomeric structures of Pin-G complexes with six or eight coordinated metal ions are proposed. The metal ions are coordinated toward Pin-G as tridentate chelates via the amide and β-lactam carbonyl, and monodentate carboxylate groups. According to powder XRD the complexes have crystalline to poly crystalline nature. In vitro antimicrobial activity of Pin-G complexes is tested against four bacteria pathogens: G^? (Klebsiella and Escherichia coli) and G+ (Staphylococcus epidermidis and Staphylococcus aureus). Anti-tumor activity of the Pin-G complexes is assessed against human hepato cellular carcinoma (HepG-2) and human breast cancer (MCF-7) tumor cell lines.

     

Equilibrium and Kinetic Study of Anionic and Cationic Pollutants Remediation by Limestone–Chitosan–Alginate Nanocomposite from Aqueous Solution

In this work, low-cost and readily available limestone was converted into nanolimestone chitosan and mixed with alginate powder and precipitate to form a triple nanocomposite, namely limestone—chitosan–alginate (NLS/Cs/Alg.), which was used as an adsorbent for the removal of brilliant green (BG) and Congo red (CR) dyes in aqueous solutions. The adsorption studies were conducted under varying parameters, including contact time, temperature, concentration, and pH. The NLS/Cs/Alg. was characterized by SEM, FTIR, BET, and TEM techniques. The SEM images revealed that the NLS/Cs/Alg. surface structure had interconnected pores, which could easily trap the pollutants. The BET analysis established the surface area to be 20.45 m²/g. The recorded maximum experimental adsorption capacities were 2250 and 2020 mg/g for CR and BG, respectively. The adsorption processes had a good fit to the kinetic pseudo second order, which suggests that the removal mechanism was controlled by physical adsorption. The CR and BG equilibrium data had a good fit for the Freundlich isotherm, suggesting that adsorption processes occurred on the heterogeneous surface with a multilayer formation on the NLS/Cs/Alg. at equilibrium. The enthalpy change (ΔH⁰) was 37.7 KJ mol⁻¹ for CR and 8.71 KJ mol⁻¹ for BG, while the entropy change (ΔS⁰) was 89.1 J K⁻¹ mol⁻¹ for CR and 79.1 J K⁻¹ mol⁻¹ BG, indicating that the adsorption process was endothermic and spontaneous in nature.     

Gold Doping of Silver Nanoclusters: A 26‐Fold Enhancement in the Luminescence Quantum Yield

A high quantum yield (QY) of photoluminescence (PL) in nanomaterials is necessary for a wide range of applications. Unfortunately, the weak PL and moderate stability of atomically precise silver nanoclusters (NCs) suppress their utility. Herein, we accomplished a ≥26‐fold PL QY enhancement of the Ag₂₉(BDT)₁₂(TPP)₄ cluster (BDT: 1,3‐benzenedithiol; TPP: triphenylphosphine) by doping with a discrete number of Au atoms, producing Ag_29?xAu_x(BDT)₁₂(TPP)₄, x=1–5. The Au‐doped clusters exhibit an enhanced stability and an intense red emission around 660 nm. Single‐crystal XRD, mass spectrometry, optical, and NMR spectroscopy shed light on the PL enhancement mechanism and the probable locations of the Au dopants within the cluster.