The use of femtosecond laser pulses to selectively trigger an asymmetric photoreaction is demonstrated in this study. Depending on the handedness of the laser polarization, more R- or S-enantiomers of a racemate are gradually destroyed, leading to the generation of enantiomeric excess. The kinetic evolution of this excess is detected with a sensitive polarimeter. Hence, discrimination between r...

The bacterial phosphotriesterase has been shown to catalyze the stereoselective hydrolysis of phosphinate esters. The wild-type enzyme preferentially hydrolyzes the SP-enantiomers of methyl phenyl p-X-phenylphosphinate esters by 3 orders of magnitude. The mutant enzyme, I106T/F132A/H254G/H257W, exhibits the opposite stereoselectivity and hydrolyzes the RP-enantiomer up to 30 times faster than t...

Palladium-catalyzed alkane arylation reactions with aryl halides are described for the preparation of 2,2-dialkyl-dihydrobenzofuran substrates. These reactions occur in excellent yield and very high selectivity for the formation of one sole product arising from a reaction at nearby methyl groups. Mechanistic and computational studies point to the involvement of a concerted, inner-sphere pallada...

The involvement of FMO in the N-oxygenation of CLZ was investigated by use of purified FMOs and human liver microsomes that contained the mean amount of immunoreactive FMO3 relative to other human liver microsomal preparations in a liver bank. In the microsomal preparation the involvement of FMO was indicated through enzyme inhibition by methimazole, heat inactivation, and protection against he...

On the basis of this plot it was found (1) that, with a preparation of hog pancreas as the source of esterase, an apparent deviation from theoretical behavior was the result of the simultaneous action of two enzymes on the substrate. In the present investigation it is found that the curves obtained with horse liver esterase display two rather sharp discontinuities that cannot be ascribed to sim...

[3H]Choline uptake was investigated in a highly enriched preparation of glomerular particles isolated from bovine cerebellar vermis. Kinetic analysis indicates that a high-affinity choline uptake system with a relatively low maximum uptake velocity is present. At a substrate concentration of 10(-7) M, [3H]choline uptake was shown to be sodium-dependent, hemicholinium-sensitive and non-reactive ...

Markov State Models provide a framework for understanding the fundamental states and rates in the conformational dynamics of biomolecules. We describe an improved protocol for constructing Markov State Models from molecular dynamics simulations. The new protocol includes advances in clustering, data preparation, and model estimation; these improvements lead to significant increases in model acc...

This review compiles the most recent advances described in literature on the preparation of noble metal nanoparticles induced by biological entities. The use of different free or substituted carbohydrates, peptides, proteins, microorganisms or plants have been successfully applied as a new green concept in the development of innovative strategies to prepare these nanoparticles as different nano...

In the conventional procedure of the preparation of aqueous semiconductor nanocrystals (NCs), the growth of NCs was mainly through the thermodynamics-favored Ostwald ripening process. It required additional energy to promote NC growth, such as reflux, hydrothermal method, microwave irradiation, and sonochemical synthesis. Energy-promoted growth usually led to the decomposition of mercapto-ligan...