Cascade process for direct synthesis of indeno[1,2-b]furans and indeno[1,2-b]pyrroles from diketene and ninhydrin

Molecular Diversity - Novel and efficient multicomponent reactions (MCRs) involving diketene, ninhydrin (indane-1,2,3-trione) and one primary amine (3CR) or two different primary amines (4CR) were...     

Macrocyclic gold(I) complexes and [2]catenanes containing carbonyl functionalized diacetylide ligands

The carbonyl derivatized bis(alkyne) O=C(4-C₆H₄OCH₂CCH)₂ was converted into the imine derivatives RN=C(4-C₆H₄OCH₂CCH)₂ [R=OH, NHC(O)NH₂, NHC₆H₃-2,4-(NO₂)₂] and into the 4-bromomethyl-1,3-dioxolane derivative BrCH₂C₂H₃O₂C(4-C₆H₄OCH₂CCH)₂. The alkyne units in these compounds react with [AuCl(SMe₂)] in the presence of base to form the corresponding digold(I) diacetylide complexes, that exist as insoluble oligomers or polymers. They reacted with the diphosphines Ph₂PZPPh₂ [Z=CC, trans-HC=CH and (CH₂)_n, n=3–5] to give macrocyclic gold(I) complexes of the type [Au₂(μ-LL)(μ-PP)], where LL is the diacetylide and PP the diphosphine ligand. The ability of these macrocyclic complexes to self-assemble to [2]catenanes has been studied. The ketone and imine derivatives do not form [2]catenanes because the orientation of the aryl groups is unfavorable, but the 1,3-dioxolane derivatives may catenate if the ring size is optimum.     

Validation of Reference Genes for Silver Nanotoxicity Analysis in MCF-7 Cell Line

Following the increasing use of silver nanoparticles (AgNPs) and the growing exposure to these particles, nanotoxicity has become a general concern among researchers around the world. Although quantitative real time PCR (RT-qPCR) is the technique of choice in genotoxicity assessment, use of unconfirmed reference genes could result in data misinterpretation. GeNorm and NormFinder algorithms assist in the selection of appropriate reference genes in RT-qPCR expression analysis. Using these two algorithms, here, the stability of six reference genes’ expression including GAPDH, ACTB, UBC, TBP, HPRT-1 and YWHAZ was evaluated in MCF-7 cells treated with different concentrations (under IC50 estimated by MTT assay) of AgNP. results showed that cytotoxicity can occur in a dose dependent fashion in MCF-7 cells with IC50 value of 5.495 µg/ml. Cumulative analysis by geNorm and NormFinder programs indicated that the normalization of the RT-qPCR data under AgNPs treatment in MCF-7 cells would be greatly improved utilizing two reference genes including TBP and GAPDH. This study is the first investigation for the selection of suitable reference genes for RT-qPCR analysis in MCF-7 cells treated with different concentration of AgNPs, and could be used in future researches established to reveal mechanisms underlying nanosilver exposure.     

A novel pseudo six-component synthesis of functionalized pyrazoles in ethanol by cascade reaction

Molecular Diversity - Novel-substituted pyrazoles were synthesized using an aminal-based approach. The key steps in the synthetic strategy involve the formation of 1,1-dihydrazino-2-nitroethylene...     

Determination of the isoflavone genistein in soybeans by high-performance liquid chromatography following cloud point extraction

A simple and sensitive method has been developed for preconcentration and determination of genistein in soybeans. This method is based on cloud point extraction (CPE) of genistein from soybeans using ethylene glycol monoalkyl ether (Genapol X-080) as a nonionic surfactant. The concentration of extracted genistein was determined by HPLC with a UV detector. Optimum experimental conditions were established. With 5% Genapol X-080 (v/v), a liquid/solid ratio of 25:1 mL/g, and ultrasonic-assisted extraction at 40 degrees C for 45 min, the extraction percentage of genistein reached its highest value. The preconcentration factor for genistein was about 16.5. The RSD for seven replicate measurements and the LOD were +/- 4.45% and 15.0 ng/mL, respectively. CPE is simple, inexpensive, and suitable for extraction of genistein from soybean. It uses environmentally friendly surfactants and offers a convenient alternative to more conventional extraction systems.     

A Straightforward Synthesis of 2‐[1‐Alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic Acid Derivatives via Domino Michael Addition?Cyclization Reaction

A new and efficient synthesis of 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives by a one‐pot three‐component reaction between primary amine, dialkyl acetylenedicarboxylate, and itaconic anhydride (=3,4‐dihydro‐3‐methylidenefuran‐2,5‐dione) is reported. The reaction was performed without catalyst and under solvent‐free conditions with excellent yields. Notably, the ready availability of the starting materials, and the high level of practicability of the reaction and workup make this approach an attractive complementary method to access to unknown 2‐[1‐alkyl‐5,6‐bis(alkoxycarbonyl)‐1,2,3,4‐tetrahydro‐2‐oxopyridin‐3‐yl]acetic acid derivatives. The structures were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of domino Michael addition? cyclization reaction is proposed (Scheme 2).