N-[4-[[(2,4-diamino-6-pterdinyl)methyl]amino]benzoyl]-L/D-glutamic acid (L/D-AMT) is an investigational drug in phase 1 clinical development that consists of the L-and D-enantiomers of aminopterin (AMT). L/D-AMT is obtained from a novel process for making the L-enantiomer (L-AMT), a potent oral antiinflammatory agent. The purpose of these studies was to characterize oral uptake and safety in th...

Smuggling of methamphetamine is affected by enforced regulation and international situation, resulting in changes of precursors and synthetic methods used. Enantiomer ratio of methamphetamine can provide information concerning its precursor and synthetic method. This information is useful for the prevention of smuggling methamphetamine and its precursor, and resultant reduction of methamphetami...

We demonstrate quantum mechanically how to resolve enantiomers from an oriented racemic mixture taking advantage of photodissociation. Our approach employs a femtosecond ultraviolet (UV) laser pulse with specific linear polarization achieving selective photodissociation of one enantiomer from a mixture of L and R enantiomers. As a result, the selected enantiomer is destroyed in the electronical...

The chiral analysis of terpenes in complex mixtures essential oils, necessary for authentication, has been further developed using tagging molecular rotational resonance (MRR) spectroscopy. One analyte that is particular interest linalool (3,7-dimethyl-1,6-octadien-3-ol), a common natural terpene found botanicals with its enantiomers having unique flavor, fragrance, and aromatherapy characteris...

Acetolactate decarboxylase catalyzes the conversion of both enantiomers of acetolactate to the (R)-enantiomer of acetoin, via a mechanism that has been shown to involve a prior rearrangement of the non-natural (R)-enantiomer substrate to the natural (S)-enantiomer. In this paper, a series of crystal structures of ALDC complex with designed transition state mimics are reported. These structures,...

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...

In order to meet the strong demand for storage and retrieval of chiral separations, we have developed Chirbase a database built on Chembasee from Molecular Design Limited, a very powerful and well spread software. Chirbase allows the selection of the most promising conditions for a given chiral separation by searching and retrieving at the same time molecular fragments issued from the compound ...

Halohydrin dehalogenase (HheC) from Agrobacterium radiobacter AD1 catalyzes the reversible intramolecular nucleophilic displacement of a halogen by a hydroxyl group in vicinal haloalcohols, producing the corresponding epoxides. The enzyme displays high enantioselectivity toward some aromatic halohydrins. To understand the kinetic mechanism and enantioselectivity of the enzyme, steady-state and ...