Analysis of sulfate metabolites of the doping agents oxandrolone and danazol using high performance liquid chromatography coupled to tandem mass spectrometry.

The direct detection of sulfate conjugates of anabolic androgenic steroids (AAS) can be a powerful tool in doping control analysis. By skipping the solvolysis step analysis time can be reduced, and due to long term sulfate metabolites the detection time can be significantly extended as demonstrated for some AAS. This study presents the successful identification of sulfate metabolites of the doping agents oxandrolone and danazol in excretion urines by high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). The sulfate conjugate of 17ß-hydroxymethyl-17α-methyl-18-nor-2-oxa-5α-androsta-13-en-3-one could be identified as a new metabolite of oxandrolone. Sulfate conjugates of the danazol metabolites ethisterone and 2α-hydroxymethylethisterone were identified in an excretion urine for the first time. In addition, these sulfate conjugates were synthesized successfully. For a confirmation analysis, the number of analytes can be increased by additional sulfate conjugates of danazol metabolites (2-hydroxymethyl-1,2-dehydroethisterone and 6ß-hydroxy-2-hydroxymethylethisterone), which were also identified for the first time. The presented validation data underline the suitability of the identified sulfate conjugates for doping analysis with regard to the criteria given by the technical documents of the World Anti-Doping Agency (WADA).

Switching on fluorescence for selective visual recognition of naringenin and morin with a metal-organic coordination polymer of Zn(bix) [bix=1,4-bis(imidazol-1-ylmethyl)benzene].

Flavonoids such as naringenin and morin are ubiquitous in a wide range of foods isolated from plants, and have diverse effects on plants even on human health. Here, we establish a selective visual method for recognition of aringenin and morin based on the "switched on" fluorescence induced by a metal-organic coordination polymer of Zn(bix) [bix=1,4-bis(imidazol-1-ylmethyl)benzene]. Owing to the coordination interaction of aringenin and morin with Zn(II) from the polymeric structure of Zn(bix), the conformational free rotation of naringenin and morin is restricted leading to relatively rigid structures. And as a consequence, the fluorescence is switched on. While luteolin and quercetin, holding a very similar structure with naringenin and morin, have no such fluorescence enhancement most likely owing to the 3'-hydroxy substitution in the B ring. Under 365 nm UV lamp light, we can visually recognize and discriminate naringenin and morin from them each other and luteolin as well as quercetin based on the colors of their emission. With this recognition system, the detection of naringenin and morin in human urine was made with satisfactory results.

Marked individual variation in isoflavone metabolism after a soy challenge can modulate the skeletal effect of isoflavones in premenopausal women.

Soy-isoflavones may act as estrogenic agonists or antagonists depending on the endogenous hormone status. These clinical effects can be exerted variably in individuals by the metabolic ability to produce a more potent metabolite than precursors. The objective of this randomized, double-blind, placebo-controlled study was to investigate the skeletal effect of isoflavones according to their metabolic variability in premenopausal women. Volunteers were randomly assigned to receive either soy-extract isoflavones (n=32) or lactose (n=21) once a day for three menstrual cycles. After intervention, the urinary excretions of isoflavones and their metabolites were significantly higher in the soy group than in the placebo group and showed a large inter-individual variation. Women in the soy group were divided into subgroups according to their ability to excrete more potent metabolites. Serum osteocalcin and urine deoxypyridinoline showed a tendency to increase after a challenge in equol high-excretors. Serum osteocalcin concentration in the genistein high-excretors increased significantly after a challenge (P=0.04) but did not increase in either the placebo or genistein low-excretors. An estrogenic antagonistic effect of isoflavones on bone turnover was observed in premenopausal women who are able to produce more potent metabolites.

A fast liquid chromatographic/mass spectrometric screening method for the simultaneous detection of synthetic glucocorticoids, some stimulants, anti-oestrogen drugs and synthetic anabolic steroids.

A fast liquid chromatographic/mass spectrometric (LC/MS/MS) screening method for the detection, in urine, of synthetic glucocorticoids, stimulants (formoterol, modafinil and mesocarb), anti-oestrogens (finasteride, exemestane, anastrozole, letrozole and formestane) and synthetic anabolic steroids (stanozolol, gestrinone and tetrahydrogestrinone) is described. All these drugs (and/or their urinary metabolites) can be simultaneously extracted by a single liquid/liquid extraction step, at alkaline pH, after enzymatic hydrolysis with beta-glucuronidase, and assayed in 7 min by LC/MS/MS using electrospray ionization in positive ion mode and multiple reaction monitoring as the acquisition mode. All compounds show good reproducibility of both the retention times (CV% <2%) and the relative abundances (CV% <10%). The limits of detection for the anti-oestrogens, glucocorticoids and steroids are in the range of 1-30 ng/mL, and for the stimulants are in the range of 100-200 ng/mL, thus satisfying the minimum required performance limits of the World Anti-Doping Agency.

Biomonitoring of urinary tamoxifen and its metabolites from breast cancer patients using nonaqueous capillary electrophoresis with electrospray mass spectrometry.

Tamoxifen is an antiestrogen drug used to treat breast cancer. We have extracted tamoxifen and several of its metabolites from urine of patients with both metastatic (stage IV) and locally confined (stages I, II, and III) breast cancer. Analysis of these metabolites was performed by nonaqueous capillary electrophoresis with electrospray-mass spectrometry. Peak heights from extracted ion current electropherograms of the metabolites were used to establish a metabolic profile for each patient. We demonstrate substantial variation among patient profiles, statistically significant differences in the amount of urinary tamoxifen N-oxide found in stages I, II, and III compared to stage IV breast cancer patients, and statistically significant differences in the amount of 3,4-dihydroxytamoxifen found in progressors compared to nonprogressors with metastatic (stage IV) cancer.

The measurement of the isoflavone daidzein by time resolved fluorescent immunoassay: a method for assessment of dietary soya exposure.

We report a novel method for the measurement of urinary daidzein that is suitable for assessment of dietary soya exposure. The method incorporates the following features: (i) a highly specific monoclonal antibody to daidzein (clone 4E4) raised through the 7 position of daidzein and (ii) a europium labeled ovalbumin daidzein conjugate. In the present format, dilute urine samples of subjects who ingested soy milk are hydrolyzed with beta-glucuronidase for 30 min on rabbit anti-mouse coated plates. Afterwards, the specific monoclonal antibody to daidzein, clone 4E4, and europium labeled ovalbumin daidzein conjugate are added. After 1 h incubation, the wall bound fluorescence of europium is measured by time resolved fluorescence and is inversely proportional to the concentration of daidzein over the range 0.1-10 ng daidzein/well. The method demonstrates good sensitivity, precision and comparability with the chemical method GC-FID. Unlike the chemical method, the present immunoassay technique for daidzein is applicable for the measurement of large amounts of samples in epidemiological studies for the assessment and monitoring of human exposure to soya food.

High-performance liquid chromatographic method for the determination of toremifene and its major human metabolites.

A high-performance liquid chromatographic method has been developed for the measurement of toremifene and its major human metabolites in plasma and urine. We have simplified other published methods, such that our assay uses protein precipitation in place of organic extraction, and ultraviolet detection instead of photochemical activation followed by fluorescence detection. In a stability study toremifene and metabolites remained unchanged for up to seven weeks at -70 degrees C. This simple and specific assay allowed toremifene and three metabolites to be quantitated for pharmacokinetic analyses in a high-dose Phase I trial.