Investigations on Hydrolytic Activities from Stachybotrys microspora and Their Use as an Alternative in Yeast DNA Extraction

Stachybotrys microspora is a filamentous fungus characterized by the secretion of multiple hydrolytic activities (cellulolytic and non-cellulolytic enzymes). The production of these biocatalysts was studied under submerged culture using glucose, cellulose, and wheat bran as carbon sources. Endoglucanases, pectinases, xylanases, β-glucanases, chitinases, and proteases were induced on cellulose-based medium and repressed on glucose in both strains with higher amounts produced by the mutant. β-glucosidases were roughly equally produced by both strains under glucose and cellulose conditions. The yield of chitinases, β-glucanases, and proteases produced by Stachybotrys strains was as much higher than the commercialized lysing enzyme called “zymolyase,” currently used in yeast DNA extraction. In this context, we showed that S. microspora hydrolases can be successfully applied in the extraction of yeast DNA.     

The Prognostic Value of Histidine-Rich Glycoprotein RNA in Breast Tissue Using Unmodified Gold Nanoparticles Assay

The aim of is this study is to explore the role of tissue histidine-rich glycoprotein (HRG) RNA as a promising clinically useful biomarker for breast cancer patients prognosis using nanogold assay. Expression of the HRG RNA was assessed by gold nanoparticles and conventional RT-PCR after purification by magnetic nanoparticles in breast tissue samples. The study included 120 patients, 60 of which were histologically proven breast carcinoma cases, 30 had benign breast lesions and 30 were healthy individuals who had undergone reductive plastic surgery. ER, PR and HER2 status were also investigated. The prognostic significance of tissue HRG RNA expression in breast cancer was explored. The magnetic nanoparticles coated with specific thiol modified oligonucleotide probe were used successfully in purification of HRG RNA from breast tissue total RNAs with satisfactory yield. The developed HRG AuNPs assay had a sensitivity and a specificity of 90 %, and a detection limit of 1.5 nmol/l. The concordance rate between the HRG AuNPs assay with RT-PCR after RNA purification using magnetic nanoparticles was 93.3 %. The median follow-up period was 60 months. Among traditional prognostic biomarkers, HRG was a significant independent prognostic marker in relapse-free survival (RFS). HRG RNA is an independent prognostic marker for breast cancer and can be detected using gold NPs assay, which is rapid, sensitive, specific, inexpensive to extend the value for breast cancer prognosis.     

Enhancement of Cerium Sorption onto Urea-Functionalized Magnetite Chitosan Microparticles by Sorbent Sulfonation—Application to Ore Leachate

The recovery of strategic metals such as rare earth elements (REEs) requires the development of new sorbents with high sorption capacities and selectivity. The bi-functionality of sorbents showed a remarkable capacity for the enhancement of binding properties. This work compares the sorption properties of magnetic chitosan (MC, prepared by dispersion of hydrothermally precipitated magnetite microparticles (synthesized through Fe(II)/Fe(III) precursors) into chitosan solution and crosslinking with glutaraldehyde) with those of the urea derivative (MC-UR) and its sulfonated derivative (MC-UR/S) for cerium (as an example of REEs). The sorbents were characterized by FTIR, TGA, elemental analysis, SEM-EDX, TEM, VSM, and titration. In a second step, the effect of pH (optimum at pH 5), the uptake kinetics (fitted by the pseudo-first-order rate equation), the sorption isotherms (modeled by the Langmuir equation) are investigated. The successive modifications of magnetic chitosan increases the maximum sorption capacity from 0.28 to 0.845 and 1.25 mmol Ce g⁻¹ (MC, MC-UR, and MC-UR/S, respectively). The bi-functionalization strongly increases the selectivity of the sorbent for Ce(III) through multi-component equimolar solutions (especially at pH 4). The functionalization notably increases the stability at recycling (for at least 5 cycles), using 0.2 M HCl for the complete desorption of cerium from the loaded sorbent. The bi-functionalized sorbent was successfully tested for the recovery of cerium from pre-treated acidic leachates, recovered from low-grade cerium-bearing Egyptian ore.     

Destabilisation of magnesium hydride by germanium as a new potential multicomponent hydrogen storage system

MgH(2) has too high an operating temperature for many hydrogen storage applications. However, MgH(2) ball-milled with Ge leads to a thermodynamic destabilisation of >50 kJ mol(-1)(H(2)). This has dramatically reduced the temperature of dehydrogenation to 130 °C, opening up the potential for Mg-based multicomponent systems as hydrogen stores for a range of applications.     

Response Characteristics of Copper‐Selective Polymer Membrane Electrodes Based on a Newly Synthesized Macrocyclic Calix[4]arene Derivative as a Neutral Carrier Ionophore

A novel macrocyclic calix[4]arene derivative was examined as an ionophore for ion‐selective polymeric membrane electrode toward Cu⁺² ions. The sensor showed a near Nernstian response for Cu(II) ions over a concentration range from 8.1×10^?6 to 1.0×10^?2 mol L^?1 with a slope of 34.2±0.4 mV per concentration decade in an acidic solution (pH 5). The limit of detection was 0.47 µg mL^?1. It had a response time of <20 s and can be used for at least 3 months without any divergence in potentials. The influence of plasticizer as well as the amount of lipophilic anionic site additive in the sensing membrane was discussed. It was shown that membrane electrodes formulated with the ionophore and appropriate anionic additive exhibited enhanced potentiometric response toward Cu²⁺ over all other cations tested. Since selectivity toward Cu²⁺ ions is decreased in the presence of high amount of the anionic additive, the ionophore can function as neutral carriers within the organic membrane phase. Validation of the assay method revealed good performance characteristics, including long life span, good selectivity for Cu²⁺ ions over a wide variety of other metal ions, long term response stability, and high reproducibility. The sensors were used for direct measurement of copper content in different rocks collected from different geological zones. The results agreed fairly well with data obtained using atomic absorption spectrometry.     

New method for the synthesis of 4-aryl-3,4-dihydro-2H-benzo[g]chromene-2,5,10-triones

Abstract

We report herein a new method for the synthesis of 4-aryl-3,4-dihydro-2H-benzo[g]chromene-2,5,10-triones 4 that proceeds in good yields (74–86%) and mild reaction conditions between readily available 2-amino-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromene-3-carbonitriles 1, and formic acid (88%), at reflux for 6?h. In addition, we have also studied the antioxidant activities using DPPH and total TAC methods.     

Synthesis of Phosphonodithioate,Oxathiaphosphinin, Oxathiaphosphole,and Dithiaphosphole Derivatives from the Reaction of Lawesson's Reagent with Phenolic Mannich Bases and Oxime Derivatives

The reaction of Lawesson's reagent 1a, with niclosamide 2 proceeded by thionation and formation of carbothioamide 3 and the zwitterionic oxathiaphosphinin 4a. LR reacted with 8-hydroxyquinoline (5), 2-methylquinoline-4-ol (7), and β-naphthol (9) to give the phosphonodithioates 6, 8, or 10. The reaction of LR with the Mannich bases 11 and 14 afforded the oxathiaphosphinins 13 and 15, whereas the phosphonodithioates 17 and 19 were isolated in the case of Mannich bases 16 and 18. LR reacted with phthalimide Mannich base 20 to give the dithione 21 and N-methylphthalimide (22). Reaction of ketone monoxime 23 with LR resulted in the formation of the oxathiaphosphole 24 and the dithiaphosphole 25, whereas the monoxime 26 afforded the thioxoethanone thioxime 27. Ketone dioximes 28 and 34 afforded the phosphonodithioates 29 and 36, respectively, when they were allowed to react with LR, whereas the dioxime 30 gave compounds 32 and 33. Moreover, the molluscicidal potency of the newly synthesized compounds against Biomphalaria glabrata snails was studied, too.     

Preparation of novel azidopyrazole derivatives with anticipated cytotoxic and antimicrobial activities

The reactions of azidopyrazole with some of primary amines and active methylene compounds were studied. Structures of the prepared compounds were identified using spectroscopic techniques. The reactions mechanisms were also proposed. The cytotoxic and antimicrobial activities were also examined for the newly synthesized compounds.     

Synthesis and Biological Evaluation of Halogenated E-Stilbenols as Promising Antiaging Agents

The increased risk of illness and disability is related to the age inevitable biological changes. Oxidative stress is a proposed mechanism for many age-related diseases. The crucial importance of polyphenol pharmacophore for aging process is largely described thanks to its effects on concentrations of reactive oxygen species. Resveratrol (3,5,4′-trihydroxy-trans-stilbene, RSV) plays a critical role in slowing the aging process but has a poor bioavailabity after oral intake. In this present work, a series of RSV derivatives was designed, synthesized, and evaluated as potential antioxidant agents. These derivatives contain substituents with different electronic and steric properties in different positions of aromatic rings. This kind of substituents affects the activity and the bioavailability of these compounds compared with RSV used as reference compound. Studies of Log P values demonstrated that the introduction of halogens gives the optimum lipophilicity to be considered promising active agents. Among them, compound 6 showed the higher antioxidant activity than RSV. The presence of trifluoromethyl group together with a chlorine atom increased the antioxidant activity compared to RSV.     

Synthesis and antitumor activity of some nitrogen heterocycles bearing pyrimidine moiety

Synthesis of novel pyrimidine derivatives 4-16 was accomplished by heterocyclization of polarized system, for example, Chalcone. Claisen-Schmidt condensation of 2-acetyl naphthalene with 4-(N, N-dimethylaminobenzaldehyde) afforded chalcone 3 , which was utilized for synthesis various pyrimidine derivatives by treatment with urea, thiourea, and guandine hydrochloride in ethanolic sodium hydroxide solution. The reactivity of the synthesized pyrimidine derivatives towards different nucleophilic and electrophilic reagent were examined. The constructions of the newly synthesized pyrimidine derivatives were elucidated from their spectral and elemental analysis. All the synthesized compounds were tested in vitro for their anticancer activities against HePG-2 and MCF-7 cell lines. Some of them posses a wide range of pharmacological activity. Finally, a molecular docking study was conducted to reveal the probable interaction with the dihydrofolate reductase (DHFR) active site.