Synthesis of Some New 1,2,3,4‐Tetrahydropyrimidine‐2‐thione and Their Thiazolo[3,2‐a]pyrimidine,Thiazino and Benzothiazepine Derivatives

The starting N‐(2‐pyridyl)‐6‐methyl‐4‐phenyl‐2‐thioxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxamide ( 4 ) was used as a key intermediate for the synthesis of new 1,2,3,4‐tetrahydropyrimidine‐2‐thione and their thiazolo[3,2‐a]pyrimidine, thiazino and benzothiazipen derivatives. The reaction of 4 with haloketones in ethanol catalyzed by base afforded the corresponding thiophenopyrimidine and pyrimidothiazipine derivatives 5 , 6 , 7 , 8 , 9 , 10 . Methylation and formylation of 4 led to the pyrimidine derivatives 15 and 16 , respectively. The preventative compounds were established on the basis of elemental and spectral data.     

Synthesis and Reactions of Some Novel Nicotinonitrile,Thiazolotriazole, and Imidazolotriazole Derivatives for Antioxidant Evaluation

The novel 2-(1H)-pyridone, the lead compound of the pyridone derivative 1, reacted with an electrophilic reagent (ethyl chloroacetate) to give the corresponding ester 2. Condensation of compound 2 with thiosemicarbazide and/or hydrazine hydrate afforded the mercaptotriazole and the corresponding acetic acid hydrazide derivatives 3 and 4, respectively. The latter compound reacted with ethyl acetoacetate, ethyl cyanoacetate, and maleic anhydride to give compounds 5, 6, and 7, respectively. Alkylation of compound 3 with methyl iodide or chloroacetic acid afforded methylsulfanyltriazole and thiazolotriazole derivatives 8 and 9, respectively. Compound 8 reacted with glycine to afford the imidazotriazole derivative 10. Both compounds 9 and 10 reacted with glucose and benzaldehyde to give compounds 11, 12, 13, and 14, respectively. Some of the prepared products were selected and subjected to screening for their antioxidant activity.     

Evaluation of some new heterocycles bearing 2-oxoquinolyl moiety as immunomodulator against highly pathogenic avian influenza virus (H5N8)

The hydrazide obtained from furan-2(3H)-one integrated with a quinolin-2(1H)-one core reported previously by our research group was utilized as a building block synthon to obtain some pyrrolone, pyridazinone, oxadiazole, and triazole derivatives through treating with some carbon electrophilic reagents, for example, chloroacetyl chloride, benzoyl chloride, acetic anhydride, carbon disulfide, 3,4-dimethoxybenzaldehyde, and 2-oxoquinolin-3-carbaldehyde to achieve the target heterocycles. The newly synthesized compounds were evaluated as immunomodulator against highly pathogenic avian influenza virus (H₅N₈). The compounds 1 , 11 , and 17 displayed the highest potency (100% protection).     

Magnetoelectronic properties of ferromagnetic compounds Rb2TaZ6 (Z = Cl,Br) for possible spintronic applications

Highly spin-polarized ferromagnetic materials are essential for efficient spintronic devices. Here, 100% spin-polarized compounds Rb₂TaZ₆ (Z = Cl, Br) studied via density functional theory are reported. These compounds show stability in the ferromagnetic phase with cubic symmetry and half metallic behavior, thereby exhibiting a nonzero direct band gap in the spin-down channel and zero band gap in the spin-up configuration. The Ta-d sates contribute mainly to the net magnetic moments as explained by the crystal field theory and density of states. High Curie temperatures of 960.35 and 1021.74 K for Ra₂TaCl₆ and Rb₂TaBr₆, along with maximum spin polarizability, make these compounds favorable for efficient spintronic applications.     

Production of Verbascoside,Isoverbascoside and Phenolic Acids in Callus,Suspension, and Bioreactor Cultures of Verbena officinalis and Biological Properties of Biomass Extracts

Callus, suspension and bioreactor cultures of Verbena officinalis were established, and optimized for biomass growth and production of phenylpropanoid glycosides, phenolic acids, flavonoids and iridoids. All types of cultures were maintained on/in the Murashige and Skoog (MS) media with 1 mg/L BAP and 1 mg/L NAA. The inoculum sizes were optimized in callus and suspension cultures. Moreover, the growth of the culture in two different types of bioreactors—a balloon bioreactor (BB) and a stirred-tank bioreactor (STB) was tested. In methanolic extracts from biomass of all types of in vitro cultures the presence of the same metabolites—verbascoside, isoverbascoside, and six phenolic acids: protocatechuic, chlorogenic, vanillic, caffeic, ferulic and rosmarinic acids was confirmed and quantified by the HPLC-DAD method. In the extracts from lyophilized culture media, no metabolites were found. The main metabolites in biomass extracts were verbascoside and isoverbascoside. Their maximum amounts in g/100 g DW (dry weight) in the tested types of cultures were as follow: 7.25 and 0.61 (callus), 7.06 and 0.48 (suspension), 7.69 and 0.31 (BB), 9.18 and 0.34 (STB). The amounts of phenolic acids were many times lower, max. total content reached of 26.90, 50.72, 19.88, and 36.78 mg/100 g DW, respectively. The highest content of verbascoside and also a high content of isoverbascoside obtained in STB (stirred-tank bioreactor) were 5.3 and 7.8 times higher than in extracts from overground parts of the parent plant. In the extracts from parent plant two iridoids—verbenalin and hastatoside, were also abundant. All investigated biomass extracts and the extracts from parent plant showed the antiproliferative, antioxidant and antibacterial activities. The strongest activities were documented for the cultures maintained in STB. We propose extracts from in vitro cultured biomass of vervain, especially from STB, as a rich source of bioactive metabolites with antiproliferative, antioxidant and antibacterial properties.     

Promoting Effect of Soluble Polysaccharides Extracted from Ulva spp. on Zea mays L. Growth

Seaweeds can play a vital role in plant growth promotion. Two concentrations (5 and 10 mg/mL) of soluble polysaccharides extracted from the green macroalgae Ulva fasciata and Ulva lactuca were tested on Zea mays L. The carbohydrate and protein contents, and antioxidant activities (phenols, ascorbic, peroxidase, and catalase) were measured, as well as the protein banding patterns. The soluble polysaccharides at 5 mg/mL had the greatest effect on the base of all of the parameters. The highest effects of soluble polysaccharides on the Zea mays were 38.453, 96.76, 4, 835, 1.658, 7.462, and 38615.19, mg/mL for carbohydrates, proteins, phenol, µg ascorbic/mL, mg peroxidase/g dry tissue, and units/g tissue of catalase, respectively. The total number of protein bands (as determined by SDS PAGE) was not changed, but the density of the bands was correlated to the treatments. The highest band density and promoting effect were correlated to 5 mg/mL soluble polysaccharide treatments extracted from Ulva fasciata in Zea mays, which can be used as a biofertilizer.     

Diffusive Propagation of Wave Packets in a Fluctuating Periodic Potential

We consider the evolution of a tight binding wave packet propagating in a fluctuating periodic potential. If the fluctuations stem from a stationary Markov process satisfying certain technical criteria, we show that the square amplitude of the wave packet after diffusive rescaling converges to a superposition of solutions of a heat equation.     

Synthesis and characterization of silver-polypyrrole film composite

In this work, we report the chemical polymerization of pyrrole to obtain thin film of polypyrrole (PPy) hydrochloride deposited onto the electrode of the quartz crystal microbalance (QCM). The film in the base form was exposed to a solution of AgNO₃. Electroless reduction for silver ions by the PPy film took place and silver particles were adsorbed onto the film surface. The silver particles content at the PPy films were analyzed by QCM and the results showed that the concentrations of silver uptakes increase as the original AgNO₃ solution increases. The morphology of the surface of the PPy film and the silver-PPy film composite were studied by the scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDX). They showed that the obtained silver particles have spherical, cubic and tetrahedral structures. X-ray diffraction (XRD) and Fourier transformed infra-red spectroscopy (FTIR) were used to characterize the structure of the powder composite. This work reveals the capability of PPy film coating on QCM in sensing and removing silver from several environmental samples.     

Metal chelates of thiazole-2-ylthiourea

Summary The formation constants of 1-phenyl-3-thiazole-2-ylthiourea complexes with some bivalent metal ions (Cu^II, Ni^II, Zn^II and Mn^II) have been determined in 75% EtOH–H₂O. Complexes of Cu^II, Ni^II, Zn^II, Hg^II and Pd^II have been isolated and characterized by conductance, i.r., electronic spectra and magnetic measurements. The ligand forms ML complexes with Cu^II and Hg^II and ML₂ with Ni^II, Zn^II and Pd^II, where L is the uninegatively charged bidentate ligand and binds through the ring nitrogen and thiocarbonyl sulphur atoms.