Enantioselective Chromatography: an Essential and Versatile Tool for the Analytical and Preparative Separation of Enantiomers

Chromatography on chiral stationary phases and electrophoresis in the presence of chiral selectors have become essential tools for the determination of enantiomeric purity in connection with synthesis and with biological studies of chiral molecules. Moreover, the chromatographic resolution of racemates on a preparative scale compels increasing recognition as alternative to 'preparing' pure enantiomers. The state-of-the-art of enantioselective chromatography in the analytical and preparative field is reviewed with particular emphasis on the achievements carried out in Switzerland

The Influence of High Intensity Training on Cardio-Respiratory Biomarkers, Aerobic Metabolism and Time Trial Performance in Recreationally-Trained Individuals

The purpose of this study was to investigate the influence of high intensity sprint training, interval training and aerobic training on cardio-respiratory biomarkers, aerobic metabolism and time trial performance in recreationally trained individuals. Twenty six men (mean ± SD age 20 ± 2 yr, height 169.3 ± 8.5 cm, weight 71.3 ± 6.2 kg) were split evenly between the three training protocols, plus a non exercising control group. All subjects in the experimental groups were randomly assigned 4 weeks of either aerobic training, high intensity sprint training or high intensity interval training. Changes in 60 km time trial performance, lactate threshold, maximal oxygen uptake (VO2max), resting metabolic rate (RMR), total and high density lipoprotein cholesterol (HDL), resting stroke volume (SV) and resting cardiac output (Q) were measured during the course of study pre and post intervention. Post intervention the HI training group displayed a significantly lower 60km time trial performance compared to both the aerobic group (2.9% P=0.002) and the interval training group (2.01% P=0.027), however this result was not a significant improvement within the group. No other variable changed significantly over the course of the training intervention. The implications of these results indicate that none of the tested training interventions are reliable routines to follow if the aim is to improve the aforementioned variables in a 4 week time scale, after following a pre-intervention 8 week aerobic training programme

2-[7-Chloro-1,1-dioxo-2-(2,4,5-trifluoro­benz­yl)-3,4-dihydro-2H-1,2,4-benzothia­diazin-4-yl]acetic acid

In the mol­ecule of the title compound, C16H12ClF3N2O4S, the thia­diazine ring adopts a half-chair conformation. The dihedral angle between the benzene ring of the benzothia­diazine ring system and trifluoro­phenyl group is 15.02 (7)°. In the crystal, centrosymmetrically related mol­ecules are linked into dimers via pairs of O—H⋯O hydrogen bonds, generating R 2 2(8) ring motifs. The dimers are further connected into a three-dimensional network by C—H⋯O hydrogen bonds

Stability of Chiral States, Role of Intermolecular Interactions and Molecular Parity Violation

We study the problem of stability of chiral states, also known as problem of chirality, within the framework of a two-dimensional approximation of a symmetric double-well potential. We show how the symmetry breaking of the potential due to the molecular parity violation can stop the tunneling in a coherent way, accordingly stabilize the chiral states. Then, we use the quantum Brownian motion within a linear Lindblad-type equation to model how the intermolecular interactions make the tunneling incoherent, thus inducing a racemization by dephasing. Finally, we investigate the normal physical conditions where the dephasing racemization does not suppress the effects of the molecular parity violation, accordingly the molecular parity violation may be observed experimentally.Comment: 5 pages, 2 Figure