15258-70-5Relevant academic research and scientific papers
Purification and characterization of Ocimum basilicum L. polyphenol oxidase
Dogan, Serap,Turan, Pinar,Dogan, Mehmet,Arslan, Oktay,Alkan, Mahir
, p. 10224 - 10230 (2005)
A partial characterization of polyphenol oxidase (PPO) activity in Ocimum basilicum L. is described. PPO in O. basilicum L. was extracted and purified through (NH4)2SO4 precipitation, dialysis, and a Sepharose 4B-L-tyrosin
Liquid-crystalline compound having dienyl moiety and liquid-crystal composition
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, (2008/06/13)
The present invention is concerned with a liquid crystalline compound expressed by general formula (1) STR1 wherein R1 represents cyano group, halogen atom, or a straight or branched alkyl group or halogenated alkyl group having 1 to 20 carbon
Screening test for insecticides interfering with cuticular sclerotization
Londershausen,Turberg,Spindler-Barth,Peter
, p. 315 - 323 (2007/10/03)
The potential of known and new insecticides to interfere with cuticle sclerotization was investigated using assays for key enzymes such as phenoloxidase, quinone methide isomerase and DOPA decarboxylase. Homogenates from the blowfly Lucilia cuprina and from the epithelial cell line from Chironomus tentans were used to examine the compounds under investigation. Phenoloxidases are known to oxidize DOPA, the substrate for DOPA decarboxylase. Since phenoloxidases were not detectable in C. tentans cell homogenates, inhibitor and kinetic studies were done for comparison with DOPA decarboxylase of this insect cell line. DOPA decarboxylase and phenoloxidase of L. cuprina exerted highest specific activities at early pupal stages (day 7). The apparent K(m) values for the two enzymes were 0.47(±0-21) mM and 0.71(±0.16) mM, respectively, using L-DOPA as substrate. DOPA decarboxylase from C. tentans had a K(m) value of 0.42(±0.18) mM. Quinone methide isomerase was most active in young pupae. In terms of substrate specificity for enzymic (mushroom-tyrosinase) production of different quinones from their corresponding catechols, that with dopamine quinone proved to be the most efficient. Synthesis of derivatives of L-DOPA and L-tyrosine led to a compound which inhibited both phenoloxidase and quinone methide isomerase. DOPA decarboxylase from L. cuprina and from cells of C. tentans was inhibited by carbidopa (IC50 values of 0.021(±0.011) μM and 0.031(±0.019) μM, respectively) and indomethacine (IC50 values of 22.6(±7.1) μM and 18.8(±9.7) μM). Both compounds exerted a competitive type of inhibition and were able to interfere with development of L. cuprina.
Manganese Porphyrin Catalyzed Homogeneous Aqueous Oxidation of Organic Molecules by Magnesium Monoperoxyphthalate (MMPP)
Zheng, Tu-Cai,Richardson, David E.
, p. 837 - 840 (2007/10/02)
Magnesium monoperoxyphthalate (MMPP) oxidizes a variety of organic molecules in neutral homogeneous aqueous solutions at room temperature.A water-soluble porphyrin complex, meso-tetrakis-(4-N-methylpyridyl)porhyrinatomanganese(III) chloride, Mn(III)TMPyP(4) Cl, acts as an efficient catalyst for the epoxidation and hydroxylation of water-soluble hydrocarbons.
Kinetics of the Reduction of a Tetra-μ-acetato-dirhodium Cation by Substituted 1,2- and 1,4-Dihydroxybenzene Compounds in Aqueous Perchlorate Media
Herbert, John W.,Macartney, Donal H.
, p. 1931 - 1936 (2007/10/02)
The kinetics of the reduction of the tetra-μ-acetato-dirhodium cation, +(+), by substituted 1,2- and 1,4-dihydroxybenzene compounds (H2Q) have been investigated in aqueous perchlorate media.The observed rate equation (below) is interpreted in terms of a rate- -d+>/dt=2(k1+k2K1/+>)+> determining one-electron oxidation of H2Q or HQ- to a semiquinone radical intermediate.The rate constants for the cross-reactions are correlated with the semiquinone reduction potentials by means of the Marcus relationship.Self-exchange rate constants for the dihydroxybenzene/semiquinone and semiquinone/quinone couples are discussed in terms of the inner-sphere and solvent reorganization energies for electron exchange.
