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Feasibility of using high performance liquid chromatographic input to the chemical reaction interface mass spectrometry system was assessed by measuring the profile of hydrolyzed urinary metabolites of [9,12,12- 2 H 3 ]cortisol in six human subjects with no preparation other than hydrolysis and solid phase extraction. Relative amounts of tetrahydrocortisol, tetrahydrocortisone, and...
26,26,26,27,27,27-Hexafluo-1,25(OH)2 vitamin D3, the hexafluorinated analog of 1,25(OH)2 vitamin D3, has been reported to be several times more potent than the parent compound regarding some vitamin D actions. The reason for enhanced biologic activity in the kidneys and small intestine appears to be related to F6-1,25(OH)2 vitamin D3 metabolism to ST-232, 26,26,26,27,27,27-hexafluoro-1α,23S,25-trihydroxyvitamin...
The 1α-hydroxylated metabolite of 25-hydroxyvitamin D 3 , 1,25-dihydroxyvitamin D 3 , is the biologically most active metabolite of vitamin D. The 24-hydroxylated metabolites were generally considered as degradation products of a catabolic pathway finally leading to excretion of calcitroic acid. Studies with analogues fluorinated at the C-24 position did not indicate a physiological...
The secosteroid hormone 1α,25-dihydroxyvitamin D 3 [1α,25(OH) 2 D 3 ] is metabolized in its target tissues through modifications of both the side chain and the A-ring. The C-24 oxidation pathway, the main side chain modification pathway is initiated by hydroxylation at C-24 of the side chain and leads to the formation of the end product, calcitroic acid. The C-23 and C-26 oxidation...
Dehydroepiandrosterone (DHEA) is a naturally occurring steroid synthesized in the adrenal cortex, gonads, brain, and gastrointestinal tract, and it is known to have chemopreventive and anti-proliferative actions on tumors. These effects are considered to be induced by the inhibition of glucose-6-phosphate dehydrogenase (G6PD) and/or HMG-CoA reductase (HMGR) activities. The present study was undertaken...
The estrogen metabolite 2-methoxyestradiol was synthesized from estradiol bis-THP-ether which was 2-hydroxylated using the superbase LIDAKOR, trimethyl borate, and H 2 O 2 , then methylated and deprotected to obtain 2-methoxyestradiol in three steps and 61% yield. 2-Hydroxyestradiol was obtained by deprotecting the 2-hydroxyestradiol bis-THP-ether from the first step.
7α-Methylthio-3β-hydroxy-17α-pregn-4-ene-21,17-carbolactone and 7α-methylthio-3α-hydroxy-17α-pregn-4-ene-21,17-carbolactone, the two major metabolites of spironolactone, were prepared stereoselectively by exploring different types of reduction reagents. For the 3β-hydroxyl isomer, the application of NaBH 4 /CeCl 3 ·7H 2 O gave the best result while for the 3α-hydroxyl isomer,...
Methyldrostanolone (2α,17α-dimethyl-17β-hydroxy-5α-androstan-3-one) was synthesized from drostanolone (17β-hydroxy-2α-methyl-5α-androstan-3-one) and identified in commercial products. Cultures of cryopreserved human hepatocytes were used to study the biotransformation of drostanolone and its 17-methylated derivative. For both steroids, the common 3α- (major) and 3β-reduced metabolites were identified...
The applicability of LC–MS/MS in precursor ion scan mode for the detection of urinary stanozolol metabolites has been studied. The product ion at m/z 81 has been selected as specific for stanozolol metabolites without a modification in A- or N-rings and the product ions at m/z 97 and 145 for the metabolites hydroxylated in the N-ring and 4-hydroxy-stanozolol metabolites, respectively. Under these...
The screening of testosterone misuse in the doping control field is normally performed by the measurement of the ratio between the concentrations of testosterone and epitestosterone excreted as glucuronides (T/E). Despite the satisfactory results obtained with this approach, the measurement of T/E presents some limitations like the long-term detection of oral testosterone administration. Recently,...
Desoxymethyltestosterone (DMT; 17β-hydroxy-17α-methyl-5α-androst-2-ene) is a designer steroid present in hormonal supplements distributed illegally as such or in combination with other steroids, for self-administration. It figures on the list of substances prohibited in sports and its detection in athlete’s urine samples is based upon the presence of the parent compound or the main urinary metabolite,...
Epidemiologic studies link several factors related to estrogen production in women to an increased risk of breast cancer. These include early menarche, late menopause, obesity, use of post-menopausal hormone therapy, and plasma estradiol levels. Two possible mechanisms have been proposed to explain the increased risk: (1) estrogen receptor (ER) mediated stimulation of breast cell proliferation with...
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