Incubation of spinach chloroplast membranes for 90 minutes in the presence of 50 mm KCN and 100 mum HgCl(2) produces an inhibition of photosystem I activity which is stable to washing and to storage of the chloroplasts at -70 C. Subsequent exposure of these preparations to NH(2)OH and ethylenediaminetetraacetic acid destroys O(2) evolution and flow of electrons from water to oxidized p-phenylen...

The chemical oxidation polymerization of m-phenylenediamine (MPD) by ammonium persulfate (APS) at room temperature results in the formation of poly(m-phenylenediamine) (PMPD) microparticles. The subsequent treatment of such microparticles with an aqueous AgNO(3) solution produces Ag nanoparticle (AgNP)-decorated PMPD microparticles. It was found that as-formed AgNPs exhibited remarkable catalyt...

In this article, we report on the facile and rapid synthesis of conjugation polymer poly(p-phenylenediamine) nanobelts (PNs) via room temperature chemical oxidation polymerization of p-phenylenediamine monomers by ammonium persulfate in aqueous medium. We further demonstrate the proof-of-concept that PNs can be used as an effective fluorescent sensing platform for nucleic acid detection for the...

1. Conditions favouring the condensation of o-phenylenediamine with alpha-oxo acids to form substituted quinoxalines have been investigated. The best yields (85-100%) are obtained by incubation of the reagents in 2m-hydrochloric acid. Substitution of acetic acid for hydrochloric acid, or of halogen-substituted 1,2-diaminobenzenes for phenylenediamine, increases the initial rate of reaction, but...

The effects of phenylethylbiguanidide, decamethylenediguanidide, and octylguanidine have been studied with mung bean hypocotyl mitochondria (Phaseolus aureus var. Jumbo) supplied with malate, reduced nicotinamide adenine dinucleotide, succinate, or ascorbate-tetramethyl-p-phenylenediamine as substrates. The guanidines act as energy transfer inhibitors, all three inhibiting all three phosphoryla...

ni2+ supported on hydroxyapatite-core@shell γ-fe2o3 nanoparticles (γ-fe2o3@hap-ni2+) was found to be a useful catalyst for the synthesis of benzimidazole derivatives from o-phenylenediamine and aldehydes under solvent and solvent-free conditions at 80 °c. this reaction affords the corresponding benzimidazole derivatives compared with the classical reactions this method consistently gives a high...

We report the discovery of a novel dual inhibitor targeting fungal sterol 14α-demethylase (CYP51 or Erg11) and human 5-lipoxygenase (5-LOX) with improved potency against 5-LOX due to its reduction of the iron center by its phenylenediamine core. A series of potent 5-LOX inhibitors containing a phenylenediamine core, were synthesized that exhibit nanomolar potency and >30-fold selectivity agains...

We have developed a new method for determination of serum ceruloplasmin from its oxidase activity, in which o-dianisidine dihydrochioride is used as substrate. o-Dianisidine dihydrochloride is more stable than is the more widely used p-phenylenediamine substrate, and forms a stable product that is measured at 540 nm. Correlation was good between results of this method and those obtained with bo...

The ability of the electron transport particulate fraction of Azotobacter vinelandii strain O to oxidize tetramethyl-p-phenylenediamine (TMPD) and p-phenylenediamine (PPD) was examined in detail. The highest specific activity for TMPD and PPD oxidation concentrated in the A. vinelandii O R(3) fraction. The A. vinelandii O R(3) fraction was used to develop a standard manometric assay which gave ...