Cellulose/cysteine based thiol-ene UV cured adsorbent: removal of silver (I) ions from aqueous solution

Cellulose - In the present study, a novel, eco-friendly, and simple polymeric adsorbent was obtained from cellulose acetate butyrate (CAB) and cysteine (Cys) to remove silver (I) ions in the...     

Novel Furochromone Derivatives: Synthesis and Anticancer Activity Studies

Medicinal plant extracts have been used for medical purposes throughout human history. In this study, khellin, having furochromone structure, which is obtained from a well‐known traditional medicinal plant, was selected. A series of furochromonyl compounds ( K1 – K14 ) were synthesized for their anticancer activities. Furochromonyl compounds ( K1 – K14 ) were synthesized by Knoevenagel reaction of substituted 2,4‐thiazolidinediones ( Ia – j )/rhodanines ( Ik – n ) with khellin‐2‐carboxaldehyde ( V ), and their cytotoxicity was investigated in 22 cancer cell lines, which were originated from tissues such as the liver, breast, colon, and cervix. As the first step, two hepatocellular carcinoma cell lines Huh7 and PLC/PRF/5 (Alexander cells) were treated with 10 μM of each compound for 72 h, and then sulforhodamine B assay was performed to analyze their anti‐growth activities. Ethyl 2‐(5‐((4,9‐dimethoxy‐5‐oxo‐5H‐furo[3,2‐g]chromen‐7‐yl)methylene)‐4‐oxo‐2‐thioxothiazolidin‐3‐yl)acetate ( K11 ) was found as the most cytotoxic compound of primary screening. Afterwards, 12 hepatocellular carcinoma, seven breast cancer, two colon cancer, and a cervical cancer cell lines were selected to test K11 for 72 h at multiple concentrations to determine 50% effective doses. Results showed that the 14 cell lines were affected by K11 quantities lower than 10 μM. The structure of K11 , which is particularly effective on breast cancers, can be used to slow down the progression of tumors. Furthermore, the discovery of more effective compounds can be carried out on the basis of this structure.     

A simple modification creates a great difference: new solid-base catalyst using methylated N-substituted SBA-15

A simple modification, methylation of the nitrogen-substituted mesoporous silica SBA-15, enhances the basicity of a solid-base catalyst. The methyl group donates an electron to the nitrogen atom in the silica framework. This catalyst accelerates Knoevenagel condensation using benzaldehyde and diethyl malonate, which conventional solid-base catalysts reported to date cannot do. This report demonstrates a possible new type of base catalyst using nitrogen-substituted mesoporous silica materials.     

On identity for eigenvalues of second order differential operator equation

In this study we investigate the spectrum and regularized trace of the second order differential operator equation with periodic boundary conditions.     

Spectroscopic determination of dipole-dipole interaction in solutions of trioctylammonium halides

Dimerization energies of trioctylammonium halides in carbon tetrachloride solution, associated as a result of dipole-dipole interaction, were calculated from the infrared absorption spectra. The values obtained were 5, 4, and 1.5 kcal/mole for the chloride, bromide, and iodide, respectively. The calculation showed that the dimers of these salts are contact dimers.     

Synthesis of poly (acrylamide-co-aconitic acid) adsorbents by gamma-irradiation,characterization, adsorption studies and application for cationic dyes removal

In this study, acrylamide (AAm)/aconitic acid (ACA) copolymers were prepared with two different mol% of aconitic acid 4%, 17% and were irradiated with gamma irradiation at different irradiation doses (4 - 25kGy). The percent yield was assigned by gravimetrical method. The effect of irradiation dose, pH and involved amounts of monomers (AAm/ACA) in hydrogels on swelling properties were investigated. The conversion of monomers to hydrogels was 100% at 25kGy. Poly(acrylamide-co-aconitic acid) P(AAm/ACA) hydrogels have been used for the adsorption of some aqueous solutions of dyes such as Methylene Blue (MB) and Safranine-O (S). The hydrogels were swollen in distilled water at pH 3, 5, 7, 8 and in aqueous solutions of dyes. The initial swelling rates of hydrogels are increased by increasing of pH. The effects of concentration of the aqueous solutions of dye and hydrogel composition on the adsorption were investigated. The adsorption is increased and changed depending on the structure of dye and composition of hydrogel.     

Guianofruits C–I from fruit oil of andiroba (Carapa guianensis,Meliaceae)

Two novel chukrasone-type limonoids, named Guianofruits C and D (1 and 2), a guianolide derivative named Guianofruit E (3), and four novel phragmalin–type limonoids named Guianofruits F–I (4–7), were isolated from the fruit oil of Carapa guianensis AUBLET (Meliaceae), a traditional medicine in Brazil and Latin American countries. Their structures were mainly elucidated based on spectroscopic analyses using 1D and 2D NMR techniques. The effects of compounds 1–6 on the production of NO by LPS-activated mouse peritoneal macrophages were investigated. Two new chukrasone-type limonoids, Guianofruits C (1) and D (2), exhibited moderate inhibitory activities.