Naftopidil (NAF) is widely used for the treatment of benign prostatic hyperplasia and prevention of prostate cancer in elderly men. These patients receive a combination of drugs, which involves high risk for drug-drug interaction. NAF exhibits superior efficacy but must be administered at a much higher dosage than other therapeutic drugs. We previously showed that extensive glucuronidation of N...

In the present study, several pharmacological tests in animals were carried out to assess potential anticonvulsant, local anesthetic and hemodynamic activity of novel 2- and 4-substituted aminobutanol chiral derivatives of xanthone (hydrochlorides of: (R,S)-2-[(7-chloro)-2-xanthonemethyl)]-N-methylaminobutan-1-ol (MH-2(R,S)), (R,S)-2-(4-xanthonemethyl)-aminobutan-1-ol (MH-20(R,S)) and (R,S)-2-[...

We report experimental results that show a large and symmetric population of D and L crystals moving into complete chiral purity, with one of the enantiomers completely disappearing. The results indicate (i) a new symmetry breaking process incompatible with the hypothesis of an initial single chiral phase or "mother crystal," (ii) that total symmetry breaking and complete chiral purity can be a...

A new chiral liquid-chromatographic method was developed for the enantiomeric separation of ofloxacin with a fluorescence detector. The enantiomers of ofloxacin were baseline resolved on a Chiralcel OD-H (250 mm x 4.6 mm, 5 microm) column using a mobile-phase system containing hexane-ethanol-methanol-acetic acid-diethylamine (70/20/10/0.45/0.05, v/v/v/v/v). The presence of diethylamine in the m...

Methods: An enantioselective reversed phase high performance liquid chromatographic method was developed and validated. The enantiomers of rivaroxaban was resolved on a Chiralcel OD-H (250 mm × 4.6 mm, 5 mm) column using a mobile phase system containing n-hexane –isopropanol (50: 50 v/v/) and column temperature at 35°C. The resolution between the enantiomers was not less than 2.0. The developed...

Microbial degradation of the chiral 2-phenylbutyric acid (2-PBA), a metabolite of surfactant linear alkylbenzene sulfonates (LAS), was investigated using both racemic and enantiomer-pure compounds together with quantitative stereoselective analyses. A pure culture of bacteria, identified as Xanthobacter flavus strain PA1 isolated from the mangrove sediment of Hong Kong Mai Po Nature Reserve, wa...

1. The affinities of the (R)- and (S)-enantiomers of hexahydro-difenidol (1) and its acetylenic analogues hexbutinol (2), hexbutinol methiodide (3) and p-fluoro-hexbutinol (4) (stereochemical purity greater than 99.8%) for muscarinic receptors in rabbit vas deferens (M1), guinea-pig atria (M2) and guinea-pig ileum (M3) were measured by dose-ratio experiments. 2. The (R)-enantiomers consistently...