Chorismate is a key intermediate in the biosynthesis of many aromatic compounds, including the aromatic amino acids. Chorismate synthase (CS) is an enzyme responsible for the biosynthesis of chorismate. Although several proposals have been made, the role of this enzyme is still unclear. In this work, therefore, the QM-MM adiabatic mapping calculations at the AM1-CHARMM27 level were performed. T...

The reaction pathways of PCB-77 in the atmosphere with ·OH, O2, NO x , and 1O2 were inferred based on density functional theory calculations with the 6-31G* basis set. The structures the reactants, transition states, intermediates, and products were optimized. The energy barriers and reaction heats were obtained to determine the energetically favorable reaction pathways. To study the solvation ...

high spin states in the neutron rich nucleus 191os has been populated for the first time using the82se+192os deep-inelastic reaction at 460 mev beam energy using the alpi accelerators at the laboratorynazionali di legnaro, italy. high fold γ-γ coincidences were acquired with the 4π spectrometer gaspdetector array, consisting of 40 compton-suppressed, large-volume germanium detectors with an inn...

We compare the chlorophyll fluorescence decay kinetics of the wild type and the D2-H117N mutant photosystem II reaction centers isolated from Chlamydomonas reinhardtii. The histidine residue located at site 117 on the D2 polypeptide of photosystem II is a proposed binding site for one of two peripheral accessory chlorophylls located in the reaction center complex. The peripheral accessory chlor...

N-alkoxyheterocycles can act as powerful one-electron acceptors in photochemical electron-transfer reactions. One-electron reduction of these species results in formation of a radical that undergoes N-O bond fragmentation to form an alkoxy radical and a neutral heterocycle. The kinetics of this N-O bond fragmentation reaction have been determined for a series of radicals with varying substituen...

Alcohol concentration dependences of photoinduced charge separation (CS) reaction of zinc tetraphenyl-porphyrin (ZnTPP) and duroquinone (DQ) were investigated in benzonitrile by a nanosecond laser flash photolysis technique. The photoinduced CS reaction was accelerated by the addition of alcohols, whereas the addition of acetonitrile caused little effect on the CS reactions. The simple theory w...

The isomerization reactions of HOOX --> HOXO --> HXO2 (X = Cl, Br, I) have been studied by using the density functional theory. The breakage and formation of the chemical bonds of the titled reactions have been discussed by the topological analysis method of electronic density. The calculated results show that there is a transitional structure of a three-membered ring on each of the isomerizati...

the aim of this paper is to study the kinetic study carbonylation of methanol using of the homogeneous rhodium catalyst and ch3i as the promoter in acid media based on monsanto process. the reaction was carried out in liquid media in the constant pressures 20,28 and 40 atm. and temperatures 170 to185oc, espect to the  initial  reactant concentrations and co pressure.  it was identified that the...

in the present study, an attempt has been made to synthesize 3-methyl-4-arylmethylene isoxazole-5(4h)-one derivatives through sonication of hydroxylamine hydrochloride, ethyl acetoacetate and benzaldehyde derivatives in the presence of imidazole as a novel and effective catalyst in aqueous media. this green reaction under ultrasound irradiation has advantageous compared to conventional procedur...