Interaction of daptomycin with lipid bilayers: a lipid extracting effect.

Daptomycin is the first approved member of a new structural class of antibiotics, the cyclic lipopeptides. The peptide interacts with the lipid matrix of cell membranes, inducing permeability of the membrane to ions, but its molecular mechanism has been a puzzle. Unlike the ubiquitous membrane-acting host-defense antimicrobial peptides, daptomycin does not induce pores in the cell membranes.

Pharmacokinetics of gastrodin and its metabolite p-hydroxybenzyl alcohol in rat blood, brain and bile by microdialysis coupled to LC-MS/MS.

Gastrodin is a pharmacologically active substance isolated from Gastrodia elata Blume with sedation, anti-convulsion and anti-epilepsy activities. A rapid and sensitive liquid chromatography technique coupled to tandem mass spectrometry (LC-MS/MS) system was developed to determine gastrodin and its metabolite p-hydroxybenzyl alcohol (HBA) in rat blood, brain and bile collected using microdialysis technique. The analytes were separated using a reversed phase column (4.

Analysis of brain distribution and biliary excretion of a nutrient supplement, gastrodin, in rat.

Gastrodin is a bioactive constituent of rhizome in Gastrodia elata Blume (Orchidaceae) The aim of this study is to develop a rapid and sensitive liquid chromatographic method coupled to microdialysis sampling system to measure the unbound of gastrodin in rat blood, brain and bile. Microdialysis probes were simultaneously inserted into the jugular vein, brain striatum and bile duct of each anesthetized rat for sampling after the administration of gastrodin (100 or 300 mg kg(-1)) through the femoral vein. Separation of unbound gastrodin from various biological fluids was applied to an RP-select B column (250 mm x 4.

Bioavailability of salvianolic acid B in conscious and freely moving rats.

Salvianolic acid B is an herbal ingredient isolated from Salvia miltiorrhiza. The aim of this study was to apply an automated blood sampling system coupled to a simple liquid chromatographic system to determine the bioavailability of salvianolic acid B in stress-free rats. The plasma sample (25 microl) was vortex-mixed with 50 microl of internal standard solution (chloramphenicol 10 microg/ml in acetonitrile) to achieve protein precipitation.

Determination and pharmacokinetic analysis of salvianolic acid B in rat blood and bile by microdialysis and liquid chromatography.

Salvianolic acid B is an herbal ingredient isolated from Salvia miltiorrhiza. An in vivo microdialysis sampling method coupled to high-performance liquid chromatography has been developed for continuous monitoring of protein-unbound salvianolic acid B in rat blood and bile. Microdialysis probes were inserted into the jugular vein/right atrium and bile duct of Sprague-Dawley rats, and a dose of 100 mg/kg salvianolic acid B was then administered via the femoral vein.

Measurement of daphnoretin in plasma of freely moving rat by liquid chromatography.

Daphnoretin (7-hydroxyl-6-methoxy-3,7'-dicoumaryl ether), isolated from Wikstronemia indica C.A. Mey.

Measurement of unbound cocaine in blood, brain and bile of anesthetized rats using microdialysis coupled with liquid chromatography and verified by tandem mass spectrometry.

To investigate the disposition of unbound cocaine in the rat blood, brain and bile, we demonstrate an in vivo multiple sampling microdialysis system coupled with liquid chromatography for cocaine assay and verified by tandem mass spectrometry. Three microdialysis probes were concurrently inserted into the jugular vein, bile duct and brain striatum of each anesthetized rat. After a period of 2 h post-surgical stabilization, cocaine (10 mg kg(-1)) was administered through the femoral vein.

Pharmacokinetics of metronidazole in rat blood, brain and bile studied by microdialysis coupled to microbore liquid chromatography.

Metronidazole is a synthetic nitroimidazole-derived antibacterial and antiprotozoal agent used for the treatment of infections involving gram-negative anaerobes. The aim of this study is to develop an in vivo microdialysis with microbore high-performance liquid chromatographic system for the pharmacokinetic study of metronidazole in rat blood, brain and bile. In addition, to investigate the disposition mechanism of metronidazole, the P-glycoprotein modulator and cytochrome P450 inhibitor were concomitantly administered.