Phospho sulfonic acid as efficient heterogeneous Brønsted acidic catalyst for one-pot synthesis of 14<Emphasis Type="Italic">H</Emphasis>-dibenzo[<Emphasis Type="Italic">a,j</Emphasis>]xanthenes and 1,8-dioxo-octahydro-xanthenes

A simple, efficient procedure for the preparation of phospho sulfonic acid PO(OSO₃H)₃ as a Brønsted acidic and recoverable heterogeneous catalyst is described, used for the one-pot synthesis of aryl-14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes. A cost-effective, simple and convenient procedure for the synthesis of aryl-14H-dibenzo[a,j]xanthenes was developed via a one-pot condensation from substituted benzaldehydes and β-naphthol under solvent-free conditions. The one-pot condensation of substituted benzaldehydes and 5,5-dimethyl-1,3-cyclohexanedione (dimedone) under solvent-free conditions leads to 1,8-dioxo-octahydro-xanthenes. These protocols afford a number of advantages, such as: excellent yields, very short reaction times, easy procedure, simple methodology and ease of preparation and regeneration of the catalyst.     

Difference gel electrophoresis analysis of Ras-transformed fibroblast cell-derived exosomes

Exosomes are membrane vesicles of endocytic origin released by many cell types. The molecular composition of exosomes reflects the specialised functions of their original cells. For example, these vesicles can mediate communication through their ability to bind to target cells, facilitating processes such as vascular homeostasis and antigen presentation. Although the proteomes of exosomes from several cell types are known, exploration of exosomes from additional cell types may improve our understanding of their potential physiological roles. Here, we describe the isolation and characterisation of exosomes isolated from the culture medium of murine fibroblast NIH3T3 cells and Ras-transformed NIH3T3 cells. The vesicular nature and size (30-100 nm) of the purified fibroblast exosomes was confirmed by electron microscopy. 2-D difference gel electrophoresis (DIGE) was used to compare protein profiles of exosomes secreted from NIH3T3 cells and Ras-transformed NIH3T3 cells. LC-MS/MS sequencing identified proteins in 188 protein spots in the exosomes from the two cell lines, many of which have been previously identified in exosomes from other cell types. However, some proteins identified are novel for fibroblast exosomes, such as Serpin B6. Over 34 proteins, including milk fat globule EGF factor 8 (lactadherin), collagen alpha-1 (VI), 14-3-3 isoforms, guanine nucleotide-binding proteins (G proteins), the eukaryotic translation initiation factors elF-3 gamma and elF-5A accumulated (>2-fold) in exosomes upon Ras-induced oncogenic transformation. Significantly, the 10.4-fold increase in v-Ha-Ras p21 protein in exosomes derived from Ras-transformed NIH3T3 cells suggests that exosome secretion may be implicated in eradication of obsolete proteins.     

An efficient method to set up a Lanczos based preconditioner for discrete ill-posed problems

Rezghi and Hosseini [M. Rezghi, S.M. Hosseini, Lanczos based preconditioner for discrete ill-posed problems, Computing 88 (2010) 79–96] presented a Lanczos based preconditioner for discrete ill-posed problems. Their preconditioner is constructed by using few steps (e.g., k) of the Lanczos bidiagonalization and corresponding computed singular values and right Lanczos vectors. In this article, we propose an efficient method to set up such preconditioner. Some numerical examples are given to show the effectiveness of the method.     

Radiolabeling of zoledronic acid with <Superscript>188</Superscript>Re as a new palliative agent radiotracer in treatment of bone tumors

Zoledronic acid is a bisphosphonates to treat bone problems. Rhenium-188-zoledronic acid could be used as a palliate agent in skeletal metastases. Radiolabeled product was prepared through optimized radiochemical procedures. The organs uptake especially bone uptake assessed in healthy animals mice. The radiochemical purity of the radiotracer was > 95% which was stable up to 24 h. Bone uptake (1.08?±?0.14% ID/g at 1 h) with retention of activity in bone up to 24 h (0.26?±?0.06% ID/g) was reached. This radiotracer can be used as a developing candidate for a palliative treatment of bone metastasis.     

Pd(0)‐ S‐propyl‐2‐aminobenzothioate immobilized onto functionalized magnetic nanoporous MCM‐41 as efficient and recyclable nanocatalyst for the Suzuki,Stille and Heck cross coupling reactions

The present work describes the use of Pd(0)‐ S‐propyl‐2‐aminobenzothioate Complex immobilized onto functionalized magnetic nanoporous MCM‐41(Fe₃O₄@MCM‐41@Pd‐SPATB) as efficient and recyclable nano‐organometallic catalyst for C–C bond formation between various aryl halides with phenylboronic acid (Suzuki reaction), aryl halides with triphenyltin chloride (Stille reaction), and aryl halides with n‐butyl acrylate (Heck reaction). All the reactions were carried out in PEG‐400 as green solvent with short reaction time and good to excellent yields. This catalyst was characterized by FT‐IR spectroscopy, XRD, TGA, VSM, ICP‐OES, TEM, EDX and SEM techniques. Ease of operation, high efficiency, recovery and reusability for five continuous cycles without significant loss of its catalytic activities or metal leaching are the noteworthy features of the currently employed heterogeneous catalytic system.     

A green method for the synthesis of pyrrole derivatives using arylglyoxals, 1,3-diketones and enaminoketones in water or water–ethanol mixture as solvent

Molecular Diversity - Three-component reaction between arylglyoxals, 1,3-dicetones and enaminoketones leads to new polyfunctionalized tetraone derivatives which may be easily converted to...     

Lecithin Treatment to Prevent Protein Adsorption onto Contact Lenses

Two types of new never worn lenses made of hydroxyethyl methacrylate (HEMA) were treated with lecithin followed by in vitro immersion into individual protein solutions. The amount of protein absorbed onto untreated and treated lenses was compared using UV absorption spectroscopy. Basing on the results obtained a conclusion was drawn that lecithin prevented the protein adsorption onto contact lenses, and the lecithin concentration affected the amount of the sorbed protein.