A rapid method for the purification of rat liver phosphorylase kinase 30,000-fold over homogenate values is described. The method allows the isolation of a near homogeneous preparation of phosphorylase kinase initially associated with the glycogen pellet to be accomplished within 24 h. The enzyme has Mr (apparent) = 1.3 million by gel filtration and is composed of subunits similar in size to th...

We already reported that an intramolecular benzylation of the imino moiety of bidentate iminopyrrolyl ligands afforded an amido-pyrrolyl complexes 1 and they exhibited better catalytic activity for ethylene polymerization compared to the corresponding bis(iminopyrrolyl) dichloro complexes of zirconium. In this contribution, we prepared amido-pyrrolyl complexes of zirconium (3a-d) and hafnium (4...

Chlorin e6 is a tricarboxylic acid degradation product of chlorophyll a. Four chlorin e6 bis(amino acid) conjugates were regioselectively synthesized bearing two aspartate conjugates in the 13(1),17(3)- and 15(2),17(3)-positions, or at the 13(1),15(2)via an ethylene diamine linker. One additional conjugate bearing two different amino acids, lysine at 13(1)via an ethylene diamine linker and an a...

The mono(cyclopentadienyl)titanium(II) complex CpTiCl(dmpe)2 has been prepared by treating (CpTiCl2)x with n-butyllithium in the presence of 1,2-bis(dimethylphosphino)ethane (dmpe). Subsequent treatment of this titanium(II) species with methyllithium or n-butyllithium affords the alkyl and hydride analogues CpTiMe(dmpe)2 and CpTiH(dmpe)2, respectively. The X-ray crystal structures of CpTiX(dmpe...

The face-to-face association of (E)-1,2-di(4-pyridyl)ethylene (bpen) molecules into rectangular motifs stabilized for the first time by chalcogen bonding (ChB) interactions is shown to provide photoreactive systems leading cyclobutane formation through single-crystal-to-single-crystal [2+2] photodimerizations. chelating bond donors are based on original aromatic, ortho-substituted bis(selenocya...

Ambient ionization mass spectrometry is achieved in a simple manner by loading a sample solution onto a corner of a microscope cover glass positioned in front of the inlet to a mass spectrometer and applying a high voltage to the sample. The resulting stream of charged droplets is stable, has no contamination from the substrate platform, and can be used repeatedly. The utility of droplet spray ...

Gold nanoparticles have been used for analytical and biomedical purposes for many years. In fact, the labeling of targeting molecules with nanoparticles has revolutionized the visualization of cellular or tissue components by electron microscopy. We report in this study the derivatization of tiopronin-protected nanoparticles with ethylenediamine and poly(ethylene glycol) bis(3-aminopropyl) term...

A comparative investigation of the aggregation in aqueous solution of a poly(ethylene oxide)-poly(propylene oxide)poly(ethylene oxide) block copolymer (PEO-PPO-PPO) (Pluronic F127) with a polydimethylsiloxane-graft-polyether (PDMS-PEO) has been done. The spectroscopic parameters obtained from absorption spectra of the 4,4,5,5tetramethylimidazoline-1-oxyl-3-oxide-2-undecyl (TEMIDO-undecyl) and f...

A cross-sectional study was conducted to evaluate nonoccupational biological exposure to 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) compounds and to identify the main factors associated with such exposure in a malaria endemic region in Mexico. Capillary gas column chromatography was used to determine levels of p,p'-DDT and its metabolites in plasma. The mean age of the 144 male partici...

Ethylene-bridged bis(hydroxylamino-1,3,5-triazine) compounds, that may serve as tetradentate ligands, were synthesized in three steps from 2,4,6-trichloro-1,3,5-triazine. These compounds demonstrate different rotation restrictions around the C(Ar)-N bonds due to their distinctive electronic structure as apparent from their resonative contributors. A dinuclear complex Ti 2(mu-L)2(OiPr)4 (L = bis...