Rhodanine

The adsorption of Cu(II), Ni(II), Zn(II), and Pb(II) from aqueous solutions on acrylonitrile copolymer sorbents was studied. We prepared five types of sorbents from polyacrylonitrile by varying its concentration in the initial polymer solution and the composition of the coagulation bath, aiming to achieve a different porous structure. The specific area, pore volume, and pore radius of the sorbents were determined on a porosimeter. The porous structure was studied by scanning electron microscopy. Modification of sorbents with sodium hydroxide and hydroxylamine was carried out to form amidooxyme and carboxylic groups with proven complex-forming properties toward heavy metal ions. The optimal pH of the sorption of metal ions was found. The adsorption kinetics were investigated. The order of polymer sorbents toward the sorption of Pb(II), Cu(II), Ni(II), and Zn(II) ions, and the order of heavy metal uptake were determined for all types of sorbents. The effectiveness of heavy metal desorption and the coefficient of recovery of sorption ability were determined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3036–3044, 2002; DOI 10.1002/app.2334

Electrogenerated magnesium-associated cyanomethyl anions/bases obtained from the electrochemical reduction of acetonitrile and the oxidation of a sacrificial magnesium rod were successfully used to promote the addition of carbon disulfide to primary benzylic amines. Alkylation with ethyl 3-bromopropionate acid ester or with ethyl 2-bromoacetate acid ester yields the corresponding ring-opened carbamodithioate compounds or cyclic rhodanine derivatives, respectively. The effect of the amount of electrogenerated base on the yield of reaction was also evaluated.

A fast and efficient protocol for the generation of substituted 5-arylidene rhodanines in a sequential one-pot two-step process combining the "Holmberg method" and the Knoevenagel condensation under microwave-assisted conditions has been developed. The final compounds 11a-k have been obtained in high yield and purity after a simple precipitation from methanol, making this procedure facile, practical, and rapid to execute.

A novel compound inhibiting HIV-1 integrase has been identified by means of virtual screening techniques. A small family of structurally related molecules has been synthesized and biologically evaluated with some of the compounds possessing micromolar activity both in enzymatic and cellular assays.A novel compound inhibiting HIV-1 integrase has been identified by means of virtual screening techniques. A small family of structurally related molecules has been synthesized and biologically evaluated with some of the compounds possessing micromolar activity both in enzymatic and cellular assays.

To study the in vivo effect of epalrestat (Epa), an aldose reductase inhibitor, on the generation of oxygen-derived free radicals by neutrophils from poorly controlled NIDDM patients (HbA1c > 10%). A total of 31 diabetic patients were randomly divided into two groups: an Epa(+) group of 16 patients treated with 150 mg/day epalrestat and an Epa(-) group of 15 patients treated without epalrestat. A control group of 20 age- and sex-matched normal healthy subjects also participated. HbA1c, postprandial plasma glucose (PPG), and neutrophil bactericidal function were measured before and at the end of the drug treatment period (4 weeks). Neutrophil bactericidal function was measured as chemilu-minescence amplified by a Cypridina luciferin analog (CLA), which is dependent on O2- generation, and by luminol (L), which is highly dependent on OCl- generation, in response to formyl-methonyl-leucyl-phenylalanine (fMLP). At the start of the experiment, both CLA-dependent chemiluminescence (CLA-DCL) and L-dependent chemiluminescence (L-DCL) were clearly decreased in diabetic subjects (64 and 54%, respectively; P < 0.05) compared with control subjects (2,182 +/- 144 and 3,221 +/- 173 kc.min-1.10(-6) cells, respectively). At the end of the experiment, CLA-DCL and L-DCL in the Epa(+) group were significantly improved by 44 and 46%, respectively; however, these values were still lower than the corresponding results in the control group. HbA1c and PPG in both the Epa(+) and Epa (-) groups were significantly higher than in the control group, and treatment had no effect on either HbA1c or PPG. These data suggest that epalrestat may be a useful drug to prevent infection by improving the impaired O2- and OCl- generation by neutrophils from poorly controlled NIDDM patients.

The use of β-lactam antibiotics is compromised by resistance, which is provided by β-lactamases belonging to both metallo (MBL)- and serine (SBL)-β-lactamase subfamilies. The rhodanines are one of very few compound classes that inhibit penicillin-binding proteins (PBPs), SBLs and, as recently reported, MBLs. Here, we describe crystallographic analyses of the mechanism of inhibition of the clinically relevant VIM-2 MBL by a rhodanine, which reveal that the rhodanine ring undergoes hydrolysis to give a thioenolate. The thioenolate is found to bind via di-zinc chelation, mimicking the binding of intermediates in β-lactam hydrolysis. Crystallization of VIM-2 in the presence of the intact rhodanine led to observation of a ternary complex of MBL, a thioenolate fragment and rhodanine. The crystallographic observations are supported by kinetic and biophysical studies, including (19)F NMR analyses, which reveal the rhodanine-derived thioenolate to be a potent broad-spectrum MBL inhibitor and...