With the aim of improving the available drugs for the treatment of Chagas disease, individual enantiomers of nifurtimox were characterized. The results indicate that the enantiomers are equivalent in their in vitro activity against a panel of Trypanosoma cruzi strains; in vivo efficacy in a murine model of Chagas disease; in vitro toxicity and absorption, distribution, metabolism, and excretion...

A nonlinear autocatalysis of a chiral substance is shown to achieve homochirality in a closed system, if the back-reaction is included. Asymmetry in the concentration of two enantiomers or the enantiometric excess increases due to the nonlinear autocatalysis. Furthermore, when the backreaction is taken into account, the reactant supplied by the decomposition of the enantiomers is recycled to pr...

Phaleria macrocarpa (Scheff.) Boerl., a member of the Thymelaeaceae, is traditionally used in Indonesia as medicinal plant against cancer. In this context, we isolated the lignans pinoresinol, lariciresinol and matairesinol from different parts of this plant. The enantiomeric composition of these lignans was determined by chiral column analysis. Pinoresinol and lariciresinol were mixtures of bo...

A new cyclohexenone compound was isolated as a mixture of enantiomers from a culture filtrate of Lasiodiplodia theobromae. The relative structure was determined to be 4,5-dihydroxy-3-methyl-cyclohex-2-enone on the basis of MS, (1)H-NMR, and (13)C-NMR spectroscopic analyses, including 2D-NMR experiments. Resolution of the enantiomers was conducted by a coupling reaction with (S)-MTPA-Cl followed...

The absolute configuration of three 4-aryl-3, 4-dihydro-2(1H)-pyrimidones (Biginelli compounds, DHPMs) was established by comparison of the typical circular dichroism (CD) spectra of individual enantiomers with reference samples of known absolute configuration. The enantiomers were obtained by semipreparative separation of racemic mixtures on a Chiralcel OD-H chiral stationary phase. The method...

The alpha-ethyl phenethylamine derivative 1-(1,3-benzodioxol-5-yl)-2-butanamine was prepared. An asymmetric synthesis was used to prepare the enantiomers of this compound and the related alpha-methyl homologue (MDA). The racemates and enantiomers of both compounds were evaluated in the two-lever drug discrimination assay in rats trained to discriminate saline from 0.08 mg/kg of LSD tartrate. St...

The use of a supercritical carbon dioxide reaction medium for the determination of the (R)- and (S)-enantiomers of mandelic acid (MA) is proposed. The process involves a previous derivatization step under supercritical conditions by which the carboxyl group is esterified with methanol, then followed by acylation of the hydroxyl group in methyl MA with pentafluoropropionic anhydride in the absen...

Merrillianoid (1), a racemic neolignan possessing the characteristic benzo-2,7-dioxabicyclo[3.2.1]octane moiety, was isolated from the branches and leaves of Illicium merrillianum. Chiral separation of 1 gave two enantiomers (+)-1 and (-)-1. The structure of 1 was established by comprehensive spectroscopic analysis and single crystal X-ray diffraction. The absolute configurations of enantiomers...

Single crystal X-ray diffraction has been used as one of the common methods for the unambiguous determination of the absolute stereostructure of chiral molecules. However, this method is limited to molecules containing heavy atoms or to molecules with the possibility of functionalization with heavy elements or chiral internal references. Herein, we report the determination of the absolute stere...

A reversed-phase high-performance liquid chromatographic method for separation of the enantiomers of ketoprofen in formulations and in plasma matrices has been developed and optimized. A central composite design was used to develop response models and Derringer’s desirability function was then used for simultaneous optimization of chiral resolution and analysis time. This procedure enabled disc...