The profiling and identification of the absorbed constituents and metabolites of Paeoniae Radix Rubra decoction in rat plasma and urine by the HPLC-DAD-ESI-IT-TOF-MS(n) technique: a novel strategy for the systematic screening and identification of absorbed constituents and metabolites from traditional Chinese medicines.

Paeoniae Radix Rubra (PRR, the dried roots of Paeonia lactiflora) is a commonly used traditional Chinese medicine (TCM). A clear understanding of the absorption and metabolism of TCMs is very important in their rational clinical use and pharmacological research. To find more of the absorbed constituents and metabolites of TCMs, a novel strategy was proposed. This strategy was characterized by the following: the establishment and utilization of the databases of parent compounds, known metabolites and characteristic neutral losses; the comparison of base peak chromatograms and ClogPs; and the use of the HPLC-DAD-ESI-IT-TOF-MS(n) technique. This strategy was first applied to screen and identify the absorbed constituents and metabolites of PRR decoction and paeoniflorin in rats. In total, 13 new absorbed constituents and 90 new metabolites of PRR decoction were detected. Among these metabolites, the structures of 70 metabolites were identified, and the conjugation types and structure skeletons of the other 20 metabolites were preliminarily determined. Moreover, 35 new metabolites of some constituents of PRR, i.e., 22 new metabolites of paeoniflorin, 10 new metabolites of gallic acid-related compounds, 1 new metabolite of (epi)catechin-related compounds, and 2 new metabolites of other compounds, were reported for the first time. The results also indicated that (epi)catechin-related compounds, gallic acid-related compounds and paeoniflorin were the main precursors of these metabolites. Phase I reactions (dehydroxylation, decarboxylation, dehydrogenation) and phase II reactions (sulfation, glucuronidation and methylation) were observed as the main metabolic pathways of PRR. According to the literature, the 11 absorbed constituents and 11 metabolites have various bioactivities. This study is the first to explore the absorption and metabolism of PRR decoction, and the result also is a notable improvement in the discovery of paeoniflorin metabolites in vivo. These findings enhance our understanding of the metabolism and Effective forms (the truly active structures) of PRR decoction and paeoniflorin.

An investigation of the antidepressant action of xiaoyaosan in rats using ultra performance liquid chromatography-mass spectrometry combined with metabonomics.

A rapid, highly sensitive, and selective method was applied in a non-invasive way to investigate the antidepressant action of Xiaoyaosan (XYS) using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) and chemometrics. Many significantly altered metabolites were used to explain the mechanism. Venlafaxine HCl and fluoxetine HCl were used as chemical positive control drugs with a relatively clear mechanism of action to evaluate the efficiency and to predict the mechanism of action of XYS. Urine obtained from rats subjected to chronic unpredictable mild stress (CUMS) was analyzed by UPLC-MS. Distinct changes in the pattern of metabolites in the rat urine after CUMS production and drug intervention were observed using partial least squares-discriminant analysis. The results of behavioral tests and multivariate analysis showed that CUMS was successfully reproduced, and a moderate-dose XYS produced significant therapeutic effects in the rodent model, equivalent to those of the positive control drugs, venlafaxine HCl and fluoxetine HCl. Metabolites with significant changes induced by CUMS were identified, and 17 biomarker candidates for stress and drug intervention were identified. The therapeutic effect of XYS on depression may involve regulation of the dysfunctions of energy metabolism, amino acid metabolism, and gut microflora changes. Metabonomic methods are valuable tools for measuring efficacy and mechanisms of action in the study of traditional Chinese medicines.

Quantitation of tetramethylene disulfotetramine in human urine using isotope dilution gas chromatography mass spectrometry (GC/MS and GC/MS/MS).

Tetramethylene disulfotetramine (tetramine) is a rodenticide associated with numerous poisonings was extracted and quantified in human urine using both gas chromatography/mass spectrometry (GC/MS) and GC/tandem mass spectrometry (MS/MS). 1200 µL samples were prepared using a (13)C(4)-labeled internal standard, a 96-well format, and a polydivinyl-benzene solid phase extraction sorbent bed. Relative extraction recovery was greater than 80% at 100 ng/mL. Following extraction, samples were preconcentrated by evaporation at 60°C, and reconstituted in 50 µL acetonitrile. One-microliter was injected in a splitless mode on both instruments similarly equipped with 30 m × 0.25 mm × 25 µm, 5% phenyl-methylpolysiloxane gas chromatography columns. A quantification ion and a confirmation ion (GC/MS) or analogous selected reaction monitoring transitions (GC/MS/MS) were integrated for all reported results. The method was characterized for precision (5.92-13.4%) and accuracy (96.4-111%) using tetramine-enriched human urine pools between 5 and 250 ng/mL. The method limit of detection was calculated to be 2.34 and 3.87 ng/mL for GC/MS and GC/MS/MS, respectively. A reference range of 100 unexposed human urine samples was analyzed for potential endogenous interferences on both instruments-none were detected. Based on previous literature values for tetramine poisonings, this urinary method should be suitable for measuring low, moderate, and severe tetramine exposures.

Simultaneous determination of two acute poisoning rodenticides tetramine and fluoroacetamide with a coupled column in poisoning cases.

A coupled column system was developed for the simultaneous determination of both rodenticides fluoroacetamide and tetramine in this paper by gas chromatography/mass spectrometry (GC/MS). A short length of strong polar column (1.5 m of Innowax) was coupled to the top of a 30 m of DB-5 ms with a quartz capillary column connector. Peak width at half height (W(h)) was used to evaluate the band broadening of the coupled column system. The length of the short couple column and oven temperature program were discussed according to W(h). The precisions of the coupled column were analyzed with peak area and retention time. Good linear correlations were found for both rodenticides. Typical samples were discussed for each rodenticide and some poisoning cases were presented.

Determination of tetramethylenedisulfotetramine in human urine with gas chromatograph-flame thermionic detection coupling with direct immersed solid-phase micro-extraction.

An analytical method for determination of tetramethylenedisulfotetramine (tetramine) in human urine by gas chromatography-flame thermionic detection (GC-FTD) coupling with a direct immersed solid-phase micro-extraction (DI-SPME) was developed. The enrichment effects of three fiber coatings of SPME for tetramine were compared. Results showed that the enrichment effect of polar 85 microm polyacrylate (PA) coating was better than that of apolar 100 and 7 microm polydimethylsiloxane (PDMS) coatings. Other experimental parameters, such as ionic strength, volume, temperature of sample solution and time for extraction, time and temperature for desorption, were also optimized. The correlation coefficient of the calibration curve was 0.9998 in the range of 0.082-41.0 ng/mL for tetramine. The limit of quantitation of tetramine in urine was 0.082 ng/mL. In this method, the sample pretreatment is simple and convenient. As a monitoring means, it has been successfully applied to detection of tetramine toxicosis in criminal cases, as well as clinical therapy of poisoned sufferer.

[Toxicokinetics of tetramethylene disulphotetramine].

OBJECTIVE: To explore toxicokinetics of tetramethylene disulphotetramine (TETS) in rabbit and the effects on toxicokinetics of TETS after activated charcoal by gavage. METHODS: Eight rabbits were exposed through gavage and vein respectively, the blood samples were collected from the center artery in ear of rabbit at an arranged time. Four rabbits were exposed after being intubated into urethra and common bile duct. The samples of bile and urine were collected at arranged times. After being exposed by gavage, activated charcoal (1 g/kg) was administrated in the activated charcoal group and the distilled water (1 g/kg) administrated to the controls. The samples of blood were collected from the center artery in ear of rabbit at arranged times. The contents of TETS in samples were determined by GC/NPD method. Analysed by the 3p87 soft, toxicokinetics parameters of TETS were acquired. RESULTS: TETS was eliminated very slowly in rabbit. The plasma half time in elimination phase (Tke1/2) of TETS was 56.9 hours in vein exposure group and 262.5 hours in oral exposure group respectively. The plasma clearance (CL) of it was only 15.4 ml.kg(-1).h(-1) in oral exposure group and 24.1 ml.kg(-1).h(-1) in vein exposure group. TETS was eliminated from urine in rabbit. The eliminated amount of it from urine was more 5 times than from bile. All parameters of toxicokinetics of TETS were significantly different between the activated charcoal group and the control. Compared to the control, Tke1/2 of TETS in the activated charcoal group was equal to 55%, CL was increased over 3-fold, area under the curve was equal to 30%. CONCLUSION: TETS was a poison eliminated very slowly in body. The eliminated amount of it from urine was more than from bile. The excretion of TETS could be quickened after activated charcoal by gavage.

Simultaneous determination of albiflorin and paeoniflorin in rat urine by solid-phase extraction and high-performance liquid chromatography following oral administration of Si-Wu decoction.

A high performance liquid chromatographic method (HPLC), together with solid phase extraction (SPE), was developed for simultaneous determination of albiflorin and paeoniflorin in rat urine after oral administration of Si-Wu decoction. The samples were pretreated with solid phase extraction using Extract-Cleantrade mark cartridges. Analysis of the extract was performed on a reversed-phase C18 column and a mobile phase made up of acetonitrile and 0.03% formic acid (17:83, v/v). UV detection was set at 230 nm. The assay was linear over the range 2.625-52.50 mg/mL for albiflorin and 3.875-77.50 microg/mL for paeoniflorin. The average percentage recoveries of three spiked urines were 97.01 +/- 3.32 and 102.32 +/- 6.97 for albiflorin and paeoniflorin, respectively. The intra-day precision (RSD) ranged from 0.21 to 1.79% at concentrations of 4.20, 10.50, 26.25 and 39.375 microg/mL of albiflorin and 0.12 to 2.92% at concentrations of 3.875, 10.85, 23.25 and 58.125 microg/mL of paeoniflorin, and inter-day precision (RSD) was from 1.02 to 1.86% for albiflorin and 0.94 to 3.30% for paeoniflorin, at the same four concentrations. This method was applied in order to analyze albiflorin and paeoniflorin in rat urine following oral administration of traditional Chinese medicinal preparation of Si-Wu decoction.

Identification of a testosterone-dependent unique volatile constituent of male mouse urine: 7-exo-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]-3-octene.

Investigations regarding the chemical composition of the volatiles in male mouse urine have recently enabled the structural elucidation of a hitherto unreported urinary component, 7-exo-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]-3-octene. This compound's uniqueness to mouse urine and its dependence on testosterone levels in the male suggest its probable role as a mouse pheromone or pheromone adjuvant.

The metabolic disposition of dezocine in rhesus monkeys and female rats given 14C-dezocine intragastrically.

The metabolic disposition of 14C-dezocine has been investigated in male rhesus monkeys and female rats given intragastric 1- and 5- mg/kg doses, respectively. In both species the dose appeared to be rapidly and extensively absorbed. Concentrations of radioactivity were detected in monkey plasma 15 min after drug administration (the earliest sampling time) and reached a peak between 0.5 and 2 hr, whereas in the rat, high concentrations of radioactivity were detected in plasma and most tissues at 15 min. Biliary secretion was extensive in the monkey, but in the monkey as well as in the rat, the ultimate excretion of the radioactive dose was primarily through renal elimination. Tissue uptake of unconjugated drug was extensive in both species, and concentrations of drug in brain were substantially higher than those in plasma. Metabolism was mainly by glucuronidation in both species and also by sulfate formation in the female rat. Two minor imine metabolites produced by N-oxidation were indicated after a comparison with synthetic standards.