We describe convenient preparations of N,N′-dialkyl-1,3-propanedialdiminium chlorides, N,N′-dialkyl-1,3-propanedialdimines, and lithium N,N′-dialkyl-1,3-propanedialdiminates in which the alkyl groups are methyl, ethyl, isopropyl, or tert-butyl. For dialdiminium salts, N2C3 backbone is always trans-s-trans configuration. Three isomers present solution except for tert-butyl compound, only two pre...

The capacities to inhibit coumarin 7-hydroxylase activity of human cytochrome P450 2A6 (CYP2A6) by organosulfur compounds were evaluated. Five dialkyl sulfides and five dialkyl disulfides, with alkyl chains from methyl to amyl, were examined. In addition to these chemicals, diallyl sulfide, diallyl disulfide, allyl methyl sulfide, allyl n-propyl sulfide, allyl phenyl sulfide, diphenyl sulfide, ...

The ammonia monooxygenase (AMO) of Nitrosomonas europaea is a metalloenzyme that catalyses the oxidation of ammonia to hydroxylamine. We have identified histidine 191 of AmoA as the binding site for the oxidized mechanism-based inactivator acetylene. Binding of acetylene changed the molecular mass of His-191 from 155.15 to 197.2 Da (+42.05), providing evidence that acetylene was oxidized to ket...

Protonation of the reactive intermediates generated in the raction between dalkyl acetylenedicarboxylates and triphenylphosphine by isonitrosoacetophenone leads to vinyltriphenylphosphonium salts, which undergo intramolecular Wittig reaction to produce dalkyl 4-phenyl-N-hydroxypyrrole-2,3-dicarboxylates in moderate yields.

We have investigated, by means of ab initio and DFT calculations, the magnitude of through-space spin-spin couplings (JCH and JHH) in CH/π bonded van der Waals dimers involving acetylene, and in a structurally related covalent compound (4ethynylphenanthrene). Within regions where the interaction is stabilizing JHH couplings are very small (< 0.1 Hz) for all complexes. In the acetylene-methane c...

Acetylene-black paste without a light scattering layer was applied to meso-porous TiO2 photo-electrode films with a crystalline framework, a low residual carbon, and a tunable morphological pore size. The thermal-treated TiO2 photo-electrode films had an increased acetylene-black concentration with an increase in artificial pores and a decrease in residual carbon. The performance of dye-sensiti...

There is a wealth of information on the genetic regulation and biochemical properties of bacterial C4-dicarboxylate transport systems. In sharp contrast, there are far fewer studies describing the transport and assimilation of C5-dicarboxylates among bacteria. In an effort to better our understanding on this subject, we identified the structural and regulatory genes necessary for the utilizatio...

An ultra-high vacuum experimental study of acetylene chemisorption on Pt(111) and Pt(100) and of the reaction of hydrogen with the acetylene adsorbate has established distinguishing features of carbon-hydrogen bond breaking and making processes as a function of pressure, temperature, and surface crystallography. The rates for both processes are substantially higher on the Pt(100) surface. Net a...

A simple model is proposed for calculating the reaction yield of a surface reaction of molecules chemisorbed on regular surfaces. An application to benzene from acetylene tricyclization on Pd(111) is performed. The analysis relies on random adsorption of acetylene on the clean crystal surface. The benzene yield is calculated in terms of the acetylene coverage. Analytical results are compared wi...

Transporters of the dicarboxylate amino acid-cation symporter family often mediate uptake of C(4)-dicarboxylates, such as succinate or l-malate, in bacteria. A member of this family, dicarboxylate transporter A (DctA) from Corynebacterium glutamicum, was characterized to catalyze uptake of the C(4)-dicarboxylates succinate, fumarate, and l-malate, which was inhibited by oxaloacetate, 2-oxogluta...