the high performance liquid chromatography (hplc) enantioseparation of four β-blocking agents metoprolol, bisoprolol, propranolol and atenolol was performed on amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase using n-hexane-ethanol-diethylamine (dea) as the mobile phase and related chiral recognition mechanisms were discussed. enantiomeric separation of the fourβ-blockers was ...

Consideration of chirality is now an integral part of drug research and development and the regulatory process. There is no choice! Enantiomeric forms of a drug can differ in potency, toxicity, and behavior in biological systems. Enantiomers of all chiral bioactive molecules have to be separated and tested. The Food and Drug Administration (FDA, U.S.A.), and regulatory authorities in Europe, Ch...

Recently, it was discovered that a-chiral smectic layers can undergo a phase transition into a polar smectic. The new phase is fundamentally different from that of the existing chiral SmC* ferroelectrics. In this paper we examine the underlying mechanism responsible for the new form of ferroelectricity. A Landau theory is presented to discuss the competition between ferroelectricity and other f...

Chiral domains have been prepared by evaporation of a two-dimensionally chiral molecule, naphtho[2,3-a]pyrene (NP), onto the hexagonal Au(111) surface in an ultrahigh vacuum environment. High-resolution UHV scanning tunneling microscopy (STM) showed that NP formed chiral domains consisting of only one 2D enantiomer rather than racemic two-dimensional unit cells. A structural model is proposed t...

Skyrmions, topologically protected vortex-like nanometric spin textures in magnets, have been attracting increasing attention for emergent electromagnetic responses and possible technological applications for spintronics. In particular, metallic magnets with chiral and cubic/tetragonal crystal structure may have high potential to host skyrmions that can be driven by low electrical current excit...

In this paper we study the vertex operator algebra Dch(H,Γ) constructed from fixed points of chiral differential operators on upper half plane which is holomorphic at all cusps, under action a congruence subgroup Γ. To end, introduce an SL(2,R)-invariant filtration labeled by partition pairs and its successive quotient. We show that quotient cuspidal condition isomorphic to space modular forms....

In staggered QCD, many staggered baryons correspond to each physical state. Taste violations lift the continuum degeneracies of the baryons and introduce nonzero off-diagonal elements in the mass matrix. While presenting no problem of principle, these splittings and mixings complicate analyses of simulation results. However, in special cases operators with good SU(3) quantum numbers can be used...

We have synthesized a series of structurally novel chiral ionic liquids which have a either chiral cation, chiral anion, or both. Cations are an imidazolium group, while anions are based on a borate ion with spiral structure and chiral substituents. Both (or all) stereoisomeric forms of each compound in the series can be readily synthesized in optically pure form by a simple one-step process fr...

The first total syntheses of (+)- and (-)-subereamollines A and B are reported. The enantiomeric forms of the natural products were obtained by preparative chiral HPLC separation of the corresponding racemates.