A series of chiral vanadyl carboxylates derived from N-salicylidene-L-alpha-amino acids and vanadyl sulfate has been developed. These configurationally well defined complexes were examined for the kinetic resolution of double- and mono-activated 2 degrees alcohols. The best chiral templates involve the combination of L-tert-leucine and 3,5-di-t-butyl-, 3,5-diphenyl-, or 3,4-dibromo-salicylaldeh...

The pH-rate profile for inactivation of the RTEM-1 cysteine beta-lactamase by iodoacetate supports previous evidence [Knap & Pratt (1989) Proteins Struct. Funct. Genet. 6, 316-323] for the activation of the active-site thiol group by adjacent functional groups. The enhanced reactivity of iodoacetate, with respect to that of iodoacetamide, suggests the influence of a positive charge in the activ...

BACKGROUND Pyrimethamine [2,4-diamino-5-(p-chlorophenyl)-6-ethylpyrimidine] is an antifolate drug used in anti-malarial chemotherapy. Pyrimidine and aminopyrimidine derivatives are biologically important compounds owing to their natural occurrence as components of nucleic acids. RESULTS In the crystal structures of two organic salts, namely pyrimethaminium benzenesulfonate monohydrate 1 and 2...

The present study was carried out to investigate the potential of carboxylate group functionalized Multi-walled carbon nanotubes (MWCNT−COOH) adsorbent for the removal of Methyl orange (MO) textile dye from aqueous solutions. The effects of pH, shaking time and temperature on adsorption capacity were studied; the contact time to obtain equilibrium at 298 ˚K was fixed at 25 min. The effect of te...

The crystal and molecular structure of tert-butyl 4-(2-tert-butoxy-2-oxoethyl)piperazine-1-carboxylate is reported. The title compound crystallizes from a petroleum ether/ethyl acetate mixture in the monoclinic space group P 21/c with four molecules in the unit cell. The unit cell parameters are: a = 8.4007(2) Å, b = 16.4716(4) Å, c = 12.4876(3) Å; β = 90.948(1)° and V = 1727.71(7) Å. Bond leng...

The hydrolysis of beta-lactam antibiotics by the serine-beta-lactamases proceeds via an acyl-enzyme intermediate. In the class A enzymes, a key catalytic residue, Glu166, activates a water molecule for nucleophilic attack on the acyl-enzyme intermediate. The active site architecture raises the possibility that the location of the catalytic carboxylate group may be shifted while still maintainin...

The present study was carried out to investigate the potential of carboxylate group functionalized Multi-walled carbon nanotubes (MWCNT−COOH) adsorbent for the removal of Methyl orange (MO) textile dye from aqueous solutions. The effects of pH, shaking time and temperature on adsorption capacity were studied; the contact time to obtain equilibrium at 298 ˚K was fixed at 25 min. The effect of te...

The three-dimensional cocrystal structures of ovine prostaglandin G/H synthase-1 (PGHS-1) with S-flurbiprofen and murine PGHS-2 with S-flurbiprofen and indomethacin reveal that the carboxylate acid groups of these nonsteroidal anti-inflammatory drugs (NSAIDs) form a salt bridge with the guanidinium group of Arg120 in PGHS-1 and Arg106 in PGHS-2. Mutagenesis studies confirmed that the Arg120 res...

The mass spectra of products found by collisional activation of selected prostaglandins and thromboxanes were studied by tandem mass spectrometry as barium carboxylate salts and as carboxylate anions. Collision-induced dissociation (CID) of these closed shell ions generated by fast atom bombardment mass spectrometry reveals a wealth of structural information for these hydroxy acids. Decompositi...