Simple and Fast Picomolar Detection of Ochratoxin A Using a Reusable Label Free Aptasensor Built with a Layer‐by‐layer Procedure

A label free impedimetric aptasensor for simple, fast and reusable picomolar detections of Ochratoxin A (OTA) in grape juices was designed. Two main factors were observed to affect the accurate detections of the toxin: i‐lateral interactions between self‐assembled aptamers ii‐ adsorption of large molecules present in complex matrixes like grape juices. Lateral interactions between aptamers were minimized by constructing the aptasensor in a Layer‐by‐Layer procedure. The interferences associated to the unspecific and irreversible adsorption of large molecules present in grape juice, were reduced by submitting samples to ultrafiltration prior to analysis. With this protocol, a 0.12 pM limit of detection and 0.24 pM limit of quantification in spiked grape juices were achieved after only 5–7 mins of interaction with the samples. The presented aptasensor can be recovered after a simple immersion in hot water (90 °C) for ten minutes.     

Cytotoxic and apoptotic activities of novel Pd(II) complexes against human leukemia cell lines in vitro

In the investigation for alternative chemotherapeutic strategies against leukemia, Pd(II) complexes were synthesized and investigated for cytotoxic and apoptotic properties on two human leukemia cell lines (HL-60 and K562). Pd(II) complexes (Pd-5a and Pd-6a) with 5a and 6a as ligands were synthesized and characterized by ¹H-NMR and F-TIR. The cytotoxicity of the compounds was quantified using MTT method. Bax, Bcl-2, and caspase 3 gene expression levels were estimated using RT-qPCR. Here we show that Pd(II) complexes have important cytotoxic activity on human leukemia cell lines. RT-qPCR indicated that Bax and caspase 3 gene expression levels were increased after 24 h treatment with Pd-5a and Pd-6a complexes in both HL-60 and K562 cells at some selected dose. Furthermore, Bcl-2 gene expression level decreased after 24 h treatment with Pd-5a and Pd-6a complexes in K562 cells at all selected dose. In HL-60 cells, only one selected Pd-5a dose (25 µM) decreased the gene expression level of Bcl-2. The results obtained in the present investigation indicate that these two newly synthesized Pd(II) complexes have apoptotic effects at appropriate doses through caspase 3 and Bax genes and might represent a novel potentially active agents for the management of human leukemia cell lines.     

Synthesis,structural characterization,and anion interactions of new triazole-linked urea derivative fully substituted cyclotriphosphazene compounds

Three novel fully substituted urea derivative cyclotriphosphazene compounds 5–7 were synthesized by alkyne-azide 1,3-dipolar cycloaddition reaction of propargyl substituted ureas 2–4 with hexaazide substituted cyclotriphosphazene 1 in the presence of Cu(I) catalyst. All compounds were characterized with spectroscopic techniques such as FT-IR, ¹H, ¹³C, and ³¹P nuclear magnetic resonance and mass spectroscopy. Also, the usefulness of compounds 5–7 as anion carriers was investigated by ¹H NMR spectroscopy. For this purpose, ¹H NMR spectra of compounds 5–7 were recorded in the presence of tetrabutylammonium fluoride in DMSO-d₆. It was determined, that the urea protons in the compounds interact with fluoride.     

Unexpected course of Wittig reaction when using cinnamyl aldehyde as a substrate

When trans-cinnamyl aldehyde was used as a substrate of the Wittig reaction, instead of the olefination product, formation of four products with (E)-1,3-diphenylprop-2-en-1-ol and cinnamyl alcohol was observed being quite unexpected ones. The possible mechanism of this unusual reaction has been considered.     

A green one-pot three-component synthesis of α-aminophosphonates under solvent-free conditions and ultrasonic irradiation using Fe3O4@SiO2-imid-PMAn as magnetic catalyst

An efficient and environment friendly process for the synthesis of α-aminophosphonates has been devised. Through a one-pot three-component condensation of various aldehydes, amines, and triethyl phosphite in the presence of Fe₃O₄@SiO₂-imid-PMAⁿ nanoparticles as magnetic catalysts under solvent-free conditions and ultrasonic irradiation, α-aminophosphonates were obtained with excellent yields. The reactions under solvent-free conditions at room temperature are compared with the ultrasonic-assisted reactions. This new procedure has notable advantages such as short reaction time, excellent yields, easy purification, and the absence of any tedious workup or purification. The aforementioned catalyst could be easily recovered by an external magnetic field and can be reused for six consecutive reaction cycles without significant loss of activity. In addition, SEM and DLS of the catalyst after the reaction cycle were investigated.     

Injectable poly(ethylene glycol) hydrogels for sustained doxorubicin release

Water‐soluble poly(ethylene glycol) derivatives with multiple “clickable” mercapto groups or double bonds were facilely synthesized in a large scale by direct polycondensation of oligo(ethylene glycol) diol with mercaptosuccinic acid or maleic acid catalyzed by scandium trifluoromethanesulfonate under mild conditions. Injectable hydrogels containing doxorubicin hydrochloride (DOX · HCl) could be rapidly formed using these poly(ethylene glycol) derivatives as precursors via in situ thiol‐ene “click” reaction under physiological conditions without light, initiator, or metal catalyst. DOX · HCl could be sustained released from the hydrogels as a result of the hindrance of the three dimensional hydrogel network on the drug molecules, which makes this kind of DOX‐loaded hydrogels a promising candidate for localized tumor chemotherapy. Copyright © 2016 John Wiley & Sons, Ltd.     

Theoretical investigation of triazine based a star shape pyrrole monomer

In this work, we report a comprehensive theoretical investigation of electroactive star shaped pyrrole functionalized triazine monomer with two main goals. First goal of this work is to explore the physical and chemical properties of the monomer, then to investigate correlation between the experimental and the theoretical properties of monomer. The scale factor which is calculated from B3LYP/cc-pVDZ was determined as 0.985 for FT-IR and it is an important and reliable contribution to the literature. It is determined that the most appropriate basis set for this molecule. The other novel objective of this research is to investigate temperature effect on displacement of chlorine atoms in 2,4,6-trichloro-1,3,5-triazine. This method applied for the first time in the literature for triazines is especially crucial to the synthesis of unsymmetrical triazines.