Topic
Methasterone
About: Methasterone is a research topic. Over the lifetime, 7 publications have been published within this topic receiving 326 citations. The topic is also known as: 2alpha,17alpha-Dimethyldihydrotestosterone.
Papers
TL;DR: Since 2002 new 'designer' steroids such as prostanozol, methasterone, androstatrienedione etc have been offered on the nutritional supplement market and also cross-contamination with these steroids are expected.
Abstract: Since 1999 several groups have analyzed nutritional supplements with mass spectrometric methods (GC/MS, LC/MS/MS) for contaminations and adulterations with doping substances. These investigations showed that nutritional supplements contained prohibited stimulants as ephedrines, caffeine, methylenedioxymetamphetamie and sibutramine, which were not declared on the labels. An international study performed in 2001 and 2002 on 634 nutritional supplements that were purchased in 13 different countries showed that about 15% of the nonhormonal nutritional supplements were contaminated with anabolic-androgenic steroids (mainly prohormones). Since 2002, also products intentionally faked with high amounts of 'classic' anabolic steroids such as metandienone, stanozolol, boldenone, dehydrochloromethyl-testosterone, oxandrolone etc. have been detected on the nutritional supplement market. These anabolic steroids were not declared on the labels either. The sources of these anabolic steroids are probably Chinese pharmaceutical companies, which sell bulk material of anabolic steroids. In 2005 vitamin C, multivitamin and magnesium tablets were confiscated, which contained cross-contaminations of stanozolol and metandienone. Since 2002 new 'designer' steroids such as prostanozol, methasterone, androstatrienedione etc. have been offered on the nutritional supplement market. In the near future also cross-contaminations with these steroids are expected. Recently a nutritional supplement for weight loss was found to contain the beta2-agonist clenbuterol. The application of such nutritional supplements is connected with a high risk of inadvertent doping cases and a health risk. For the detection of new 'designer' steroids in nutritional supplements, mass spectrometric strategies (GC/MS, LC/MS/MS) are presented.
367 citations
TL;DR: The obtained derivatives provided a significant improvement in the ESI sensitivity, compared with those of underivatized molecules in positive LC-ESI-ion trap-MS full-scan mode.
Abstract: Background: Two-step derivatization procedures were developed for the enhancement of the positive ESI in LC–MS detection of anabolic androgenic steroids, a class of prohibited substances with limited ionization efficiency in atmospheric pressure interfaces. The developed procedures are based on the esterification of hydroxyl groups of anabolic steroids with picolinic acid, followed by conversion of carbonyl groups to Schiff bases by either Girard’s reagent T or 2-hydrazino pyridin. Results: Ionization efficiency for the model derivatized compounds 19-norandrosterone (nandrolone main metabolite) and methasterone was higher by almost two orders of magnitude compared with the respective efficiency of the underivatized compounds. Conclusion: The obtained derivatives provided a significant improvement in the ESI sensitivity, compared with those of underivatized molecules in positive LC–ESI-ion trap-MS full-scan mode.
12 citations
TL;DR: The studies of the in vitro and in vivo metabolism of methylstenbolone in horses using LC/HRMS, GC/MS andGC/MS/MS are described and the proposed in vivo metabolites included 16α/β-hydroxymethylstenbolones, which have never been reported before.
11 citations
TL;DR: In this study human liver microsomes and an uPA(+/+) -SCID chimeric mouse model were used to elucidate the metabolism of a steroid product called 'Xtreme DMZ', which contains the designer steroid dimethazine (DMZ).
Abstract: The use of anabolic steroids is prohibited in sports. Effective control is done by monitoring their metabolites in urine samples collected from athletes. Ethical objections however restrict the use of designer steroids in human administration studies. To overcome these problems alternative in vitro and in vivo models were developed to identify metabolites and to assure a fast response by anti-doping laboratories to evolutions on the steroid market. In this study human liver microsomes and an uPA(+/+) -SCID chimeric mouse model were used to elucidate the metabolism of a steroid product called 'Xtreme DMZ'. This product contains the designer steroid dimethazine (DMZ), which consists of two methasterone molecules linked by an azine group. In the performed stability study, degradation from dimethazine to methasterone was observed. By a combination of LC-High Resolution Mass Spectrometry (HRMS) and GC-MS(/MS) analysis methasterone and six other dimethazine metabolites (M1-M6), which are all methasterone metabolites, could be detected besides the parent compound in both models. The phase II metabolism of dimethazine was also investigated in the mouse urine samples. Only metabolites M1 and M2 were exclusively detected in the glucuro-conjugated fraction; all other compounds were also found in the free fraction. For effective control of DMZ misuse in doping control samples, screening for methasterone and methasterone metabolites should be sufficient. Copyright © 2016 John Wiley & Sons, Ltd.
5 citations
1 Jan 2014
TL;DR: In this study human liver microsomes and an uPA+/+-SCID chimeric mouse model were used to elucidate the metabolism of a steroid product called ‘Xtreme DMZ’, which contains the designer steroid dimethazine (DMZ), which consists of two methasterone molecules linked by an azine group.
Abstract: Studies on steroid metabolism are essential to target the best markers for an effective control by anti-doping laboratories. However, ethical objections restrict the use of designer steroids in human administration studies. To overcome these problems alternative in vitro and in vivo models were developed to identify metabolites of new substances and to assure a fast response to evolutions on the steroid market. In this study human liver microsomes and an uPA+/+-SCID chimeric mouse model were used to elucidate the metabolism of a steroid product called ‘Xtreme DMZ’. This product contains the designer steroid dimethazine (DMZ), which consists of two methasterone molecules linked by an azine group. In the performed stability study degradation from dimethazine to methasterone was observed. This degradation was accelerated at a lower pH, with a t1/2 of 23.7 min at 37°C. The high degradation rate at pH 0.5 suggests that an oral administration of dimethazine would lead to a complete degradation of the compound to methasterone in the acidic conditions in the stomach. By a combination of LC-HRMS and GC-MS(/MS) analysis methasterone and six other dimethazine metabolites (M1-M6), which are also methasterone metabolites, could be detected. For an effective control of dimethazine in doping control samples the screening for methasterone and methasterone metabolites should be sufficient. The results of this study will be published elsewhere.
1 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2019 | 1 |
| 2018 | 1 |
| 2016 | 1 |
| 2014 | 2 |
| 2012 | 1 |
| 2008 | 1 |