Sharif Digital Repository

The acetylation of phenols with acetic anhydride proceeded in excellent yields when it was catalyzed by gadolinium triflate immobilized on magnetically recyclable nanocomposites. This heterogeneous catalyst provided high catalytic activity with low loading level (1 mol%), because the Lewis acid catalyst was grafted on the surface of the nanocomposites. The catalysts were also easily recovered from the reaction mixture using a magnet and reused for six consecutive cycles  

Efficient synthesis of protected and unprotected chlorohydrins has been achieved by ring opening of epoxides with acetyl/benzoyl chloride and TMSCl using a catalytic amount of ZnO as a reusable catalyst. The applicability of ZnO is further extended by performing the cleavage of the natural product 5,6-epoxysitosterol with acetyl chloride. © 2009 Wiley Periodicals, Inc  

Acyclic and cyclic acetates of various alcohols and phenols were obtained in excellent yields under mild reaction conditions in the presence of a catalytic amount of sodium hydroxide under solvent-free conditions and microwave irradiation. Selective deprotection of acetate group from the corresponding phenolic compounds was carried out in the presence of LiClO4· 2H2O. Copyright © Taylor & Francis, Inc  

(Chemical Equation Presented) New 2-aryl-4-chloro-3-hydroxy-1H-indole-5,7- dicarbaldehydes were synthesized in three steps from acetophenone derivatives. By oxidation of acetophenones to aryl glyoxals using selenium dioxide and condensation with acetylacetone in the presence of ammonium acetate in water 3-acetyl-5-aryl-4-hydroxy-2-methyl-1H-pyrrols were obtained. 2-Aryl-4-chloro-3-hydroxy-1H-indole-5,7-dicarbaldehydes were synthesized via Vilsmeier-Haack reaction of pyrrole derivatives in moderate yields  

The derivatives of glucose such as glucosamine (β-D-GlcN) and N-acetyl-D-β-glucosamine (GlcNAc) are significant in several biological systems. D-GlcN has been used widely to treat osteoarthritis in humans and animal models as well as GlcNAc has been proposed as a treatment for autoimmune diseases. The DFT/B3LYP/6–311++G (d,p) method as well as QTAIM and NBO analyses were used to the acidity values of D-GlcN and GlcNAc sugars and their complexes with alkali ions in the gas phase. The Li+, Na+ and K+ prefer bi-dentate chelate in these complexes. The computed results indicate that metal ion affinity (MIA) in GlcNAc is higher than that in D-GlcN. There are direct correlations between the MIA... 

The aim of this study was to determine whether specific three-dimensional aortic shape features, extracted via statistical shape analysis (SSA), correlate with the development of thoracic ascending aortic dissection (TAAD) risk and associated aortic hemodynamics. Thirty-one patients followed prospectively with ascending thoracic aortic aneurysm (ATAA), who either did (12 patients) or did not (19 patients) develop TAAD, were included in the study, with aortic arch geometries extracted from computed tomographic angiography (CTA) imaging. Arch geometries were analyzed with SSA, and unsupervised and supervised (linked to dissection outcome) shape features were extracted with principal component... 

The preparation and electrochemical performance of the carbon nanotube-paste electrode modified with salophen complexes of cobalt(III) perchlorate, with various substituents on the salophen ligand, as well as their electrocatalytic activity toward the oxidation of N-acetylcysteine (NAC) is investigated. Several Schiff base complexes containing various nucleophilic and electrophilic functional groups were prepared, and their electrochemical characteristics for the electro-oxidation of NAC were evaluated using cyclic and differential pulse voltammetry (CV and DPV). The results revealed, the modified electrodes show an efficient and selective electrocatalytic activity toward the anodic... 

Introduction: This study was conducted to investigate the relationship of glomerular and tubular dysfunctions with glycaemic control, lipid, lipoprotein, apolipoproteins and antioxidant status in 72 patients with type 2 diabetes mellitus. Methods: Urine albumin concentration was measured by immunoturbidimetric and urine N-acetyl-beta-D-glucosaminidase (NAG) and alanine aminopeptidase (AAP) activities with colorimetric methods. Glycated haemoglobin was measured using affinity chromatography. Erythrocyte glu ta thione reductase and glutathione peroxidase activities and serum levels of malondialdehyde, lipids, lipoproteins and apolipoproteins were determined in patients with type 2 diabetes...