anesthetic agent as well as lidocaine, bupivacaine and mepivacaine (Fig. 1). Unlike bupivacaine and mepivacaine, which are racemic mixtures of the enantiomers containing equal proportion of the (S) and (R) forms, ropivacaine is exclusively the (S)-enantiomer. Since the (R)-enantiomer in the racemic aminoamide has known to be toxic, ropivacaine potentially provides lower toxicity on heart and ce...

A chiral liquid chromatographic method was developed for the enantiomeric purity of Levofloxacin in drug substance as well as in drug product. The chromatographic separation was achieved on Chiralpak IC 150 X 2.1mm X 5μm, column using a mobile phase system consisting of n-hexane and isopropyl alcohol in the ratio of 95:5 (v/v). The mobile phase was pumped through column at the flow rate of 1 mL...

L-Thyroxine (L-T4), the naturally occurring thyroid hormone has been used for the treatment of thyroid dysfunctions, while D-T4 is not active in the thyroid and is used for the treatment of hyperlipidemia. Therefore, a convenient and reliable enantiomer separation method has been of great interest in the biological and pharmacological research field. Several groups reported the chromatographic ...

Microreaction and membrane technologies offer optimal conditions for controlling enantiomer synthesis purification processes in continuous production, with numerous advantages over batch manufacturing. One of the many forces driving development such production single optical isomers is need enantiomerically pure pharmaceutical drugs because enantiomers may display opposite therapeutic effects o...

Racemic R,S-salbutamol is taken to relieve bronchial constriction. Only the R-enantiomer has bronchodilating properties. The S-enantiomer has been proposed to cause in vitro bronchial hyperreactivity in guinea-pigs. Stereoselective elimination of salbutamol has been shown, with S-salbutamol being eliminated at a slower rate than R-salbutamol. This study questioned whether rates of stereoselecti...

The stereoselective pharmacokinetics of BOF-4272 enantiomers in rats and dogs was investigated by simultaneously measuring concentrations in arterial, portal, and venous plasma, the liver, and the kidney at 2 h after the oral administration of the racemic drug. The concentrations of BOF-4272 enantiomers were measured using high-performance liquid chromatography. The concentrations of the S(-) e...

Phenylahistin is a fungal diketopiperazine derived from isoprenylated (Phe-DeltaHis) cyclodipeptide. The (-)-enantiomer is a cell cycle inhibitor, which can be potentially used as an antitumor agent. By contrast, the (+)-enantiomer exhibits no antimicrotubule activity. To better understand the differences that could arise from a difference of bioavailability, we investigated the interaction and...

Opposite enantiomers of [Ru(phenanthroline)(3)](2+) affect the persistence length of DNA differently, a long speculated effect of helix kinking. Our molecular dynamics simulations confirm a substantial change of duplex secondary structure produced by wedge-intercalation of one but not the other enantiomer. This effect is exploited by several classes of DNA operative proteins.

In this work, the transesterification of methyl estolides (ME) extracted from lipid component present in sewage scum was investigated. Methyl 10-(R)-hydroxystearate (Me-10-HSA) and Fatty Acid Esters (FAMEs) were obtained a single step. A three-level four factorial Box–Behnken experimental design used to study effects methanol amounts, catalyst, temperature, reaction time on using aluminum chlor...