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https://www.readbyqxmd.com/read/24213656/baeyer-villiger-oxidation-of-some-c-19-steroids-by-penicillium-lanosocoeruleum
#1
Alina Świzdor
The biotransformation of androsterone (1), epiandrosterone (2), androstanedione (3) and DHEA (dehydroepiandrosterone) (4) by Penicillium lanosocoeruleum-a fungal species not used in biotransformations so far-were described. All the substrates were converted in high yield (70%-99%) into D ring δ-lactones. The oxidation of 1 produced 3α-hydroxy-17a-oxa-D-homo-5α-androstan-17-one (5). The oxidation of 2 led to 3β-hydroxy-17a-oxa-D-homo-5α-androstan-17-one (6). The biotransformation of 3 resulted in the formation of 3α-hydroxy-17a-oxa-D-homo-5α-androstan-17-one (5) and 17a-oxa-D-homo-5α-androstan-3,17-dione (7)...
2013: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/22640920/bovine-liver-slices-a-multifunctional-in-vitro-model-to-study-the-prohormone-dehydroepiandrosterone-dhea
#2
Jeroen C W Rijk, Toine F H Bovee, Ad A C M Peijnenburg, Maria J Groot, Ivonne M C M Rietjens, Michel W F Nielen
Biotransformation of inactive prohormones like dehydroepiandrosterone (DHEA) can lead to the formation of potent androgens and subsequent androgenic responses in target tissues. In the present study, precision-cut bovine liver slices were used to study the effects of DHEA on the metabolite, transcript and androgenic activity level. Bovine liver slices were exposed for 6h to various concentrations of DHEA. Changes in androgenic activity of the DHEA containing cell culture media were measured using a yeast androgen bioassay and metabolites were identified using ultra performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOFMS), while gene expression in the DHEA-treated liver slices was examined using bovine microarrays and compared with the profile as obtained with 17ß-testosterone (17ß-T)...
September 2012: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/22473025/a-comparison-of-dehydroepiandrosterone-and-7-keto-dehydroepiandrosterone-with-other-drugs-that-modulate-ethanol-intake-in-rats-responding-under-a-multiple-schedule
#3
COMPARATIVE STUDY
Russell Joseph Amato, Mary Worrel Hulin, Peter John Winsauer
Dehydroepiandrosterone (DHEA), 7-keto DHEA, and several comparison drugs (ethanol, chlordiazepoxide, rauwolscine, and RO15-4513) were administered to male rats responding under a multiple schedule of food and ethanol presentation to determine their selectivity for decreasing ethanol-maintained responding. DHEA and 7-keto DHEA significantly decreased both ethanol-maintained and food-maintained responding, compared with the control, while also decreasing the blood ethanol concentration (BEC). Acute ethanol administration also decreased responding for both food and ethanol; however, ethanol-maintained responding was more potently decreased than food-maintained responding...
June 2012: Behavioural Pharmacology
https://www.readbyqxmd.com/read/21051179/effects-of-7-keto-dehydroepiandrosterone-on-voluntary-ethanol-intake-in-male-rats
#4
Mary E Worrel, Olga V Gurkovskaya, Stuart T Leonard, Peter B Lewis, Peter J Winsauer
Administration of dehydroepiandrosterone (DHEA), a neurosteroid that can negatively modulate the GABA A receptor, has been shown to decrease voluntary intake of ethanol in rats. In vivo, DHEA can be metabolized to a variety of metabolites, including 3β-acetoxyandrost-5-ene-7,17-dione (7-keto DHEA), a metabolite without the prohormonal effects of DHEA. This study compared the effectiveness of 7-keto DHEA with DHEA for reducing ethanol intake in the same group of rats. The subjects, previously trained to drink ethanol using a saccharin-fading procedure, had access to ethanol for 30 min daily and the amount consumed was recorded...
June 2011: Alcohol
https://www.readbyqxmd.com/read/19578835/gradient-hplc-separation-of-dehydroepiandrosterone-dhea-from-its-metabolites-and-biological-congeners-role-of-tetrahydrofuran-in-the-chromatographic-mechanism
#5
András Gergely, Péter Horváth, György Szász, Gábor Veress
A three-step gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the separation of dehydroepiandrosterone (DHEA), its sulfate ester (DHEA-S), its three C7-oxidized metabolites (7alphaOH-DHEA, 7betaOH-DHEA, 7-keto-DHEA), and its biosynthetic congeners (androstenedione, testosterone, estradiol, pregnenolone). This new method allows the quantitative characterization of DHEA metabolism and biosynthetic transformation under given physiological, pathological, or therapeutically influenced circumstances...
August 2009: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/19010388/hexose-6-phosphate-dehydrogenase-modulates-the-effect-of-inhibitors-and-alternative-substrates-of-11beta-hydroxysteroid-dehydrogenase-1
#6
Zoltán Balázs, Lyubomir G Nashev, Charlie Chandsawangbhuwana, Michael E Baker, Alex Odermatt
Intracellular glucocorticoid reactivation is catalyzed by 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1), which functions predominantly as a reductase in cells expressing hexose-6-phosphate dehydrogenase (H6PDH). We recently showed that the ratios of cortisone to cortisol and 7-keto- to 7-hydroxy-neurosteroids are regulated by 11beta-HSD1 and very much depend on coexpression with H6PDH, providing cosubstrate NADPH. Here, we investigated the impact of H6PDH on the modulation of 11beta-HSD1-dependent interconversion of cortisone and cortisol by inhibitors and alternative substrates...
March 25, 2009: Molecular and Cellular Endocrinology
https://www.readbyqxmd.com/read/17593962/hexose-6-phosphate-dehydrogenase-modulates-11beta-hydroxysteroid-dehydrogenase-type-1-dependent-metabolism-of-7-keto-and-7beta-hydroxy-neurosteroids
#7
Lyubomir G Nashev, Charlie Chandsawangbhuwana, Zoltan Balazs, Atanas G Atanasov, Bernhard Dick, Felix J Frey, Michael E Baker, Alex Odermatt
BACKGROUND: The role of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in the regulation of energy metabolism and immune system by locally reactivating glucocorticoids has been extensively studied. Experiments determining initial rates of enzyme activity revealed that 11beta-HSD1 can catalyze both the reductase and the dehydrogenase reaction in cell lysates, whereas it predominantly catalyzes the reduction of cortisone to cortisol in intact cells that also express hexose-6-phosphate dehydrogenase (H6PDH), which provides cofactor NADPH...
2007: PloS One
https://www.readbyqxmd.com/read/16137639/interactions-between-dehydroepiandrosterone-and-glucocorticoid-metabolism-in-pig-kidney-nuclear-and-microsomal-11beta-hydroxysteroid-dehydrogenases
#8
Boaz Robinzon, Russell A Prough
The 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) activates glucocorticoids (GC) by reversibly converting 11-keto-GC to 11-hydroxy-GC, while 11betaHSD2 and 11betaHSD3 only catalyzes the reverse reaction. Recently, rat and human 11betaHSDs were shown to interconvert 7alpha- and 7beta-hydroxy-dehydroepiandrosterone (7alpha- or 7beta-OH-DHEA) with 7-oxo-DHEA. We report that pig kidney microsomes (PKMc) and nuclei (PKN) oxidize 7alpha-OH-DHEA to 7-oxo-DHEA at higher rates with NAD+, than with NADP+. Corticosterone (CS), dehydrocoticosterone (DHC), 11alpha- and 11beta-hydroxyprogesterone, and carbenoxolone completely inhibited these reactions, while 7-oxo-DHEA only inhibited the NAD+-dependent reaction...
October 1, 2005: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/16112271/c-19-5-ene-steroids-in-nature
#9
REVIEW
Henry Lardy, Ashok Marwah, Padma Marwah
Dehydroepiandrosterone (DHEA), produced from cholesterol in the adrenals, is the most abundant steroid in our circulation. It is present almost entirely as the sulfate ester, but the free steroid is the form that serves as a precursor of estrogens and androgens, as well as 7- and 16-oxygenated derivatives. Mammalian tissues reduce the 17-keto Group of DHEA to produce androstenediol-a weak estrogen and full-fledged androgen. Its androgen activity is not inhibited by the anti-androgens commonly used to treat prostate cancer...
2005: Vitamins and Hormones
https://www.readbyqxmd.com/read/12970085/interactions-of-androgens-green-tea-catechins-and-the-antiandrogen-flutamide-with-the-external-glucose-binding-site-of-the-human-erythrocyte-glucose-transporter-glut1
#10
Richard J Naftalin, Iram Afzal, Philip Cunningham, Mansur Halai, Clare Ross, Naguib Salleh, Stuart R Milligan
This study investigates the effects of androgens, the antiandrogen flutamide and green tea catechins on glucose transport inhibition in human erythrocytes. These effects may relate to the antidiabetogenic effects of green tea. Testosterone, 4-androstene-3,17-dione, dehydroepiandrosterone (DHEA) and DHEA-3-acetate inhibit glucose exit from human erythrocytes with half-maximal inhibitions (Ki) of 39.2+/-8.9, 29.6+/-3.7, 48.1+/-10.2 and 4.8+/-0.98 microM, respectively. The antiandrogen flutamide competitively relieves these inhibitions and of phloretin...
October 2003: British Journal of Pharmacology
https://www.readbyqxmd.com/read/12650722/prohormones-and-sport
#11
Frans T Delbeke, Peter Van Eenoo, Wim Van Thuyne, Noël Desmet
Several precursors of testosterone and nandrolone introduced on the nutritional supplement market as performance enhancing drugs are banned in sports. Until now they are legally sold without a prescription in the US. Results of excretion studies with related compounds including 7-keto-DHEA and 1-androstenediol are presented. The main metabolites of 7-keto-DHEA are 7-hydroxylated compounds. The commercial 1-androstenediol preparation was contaminated with several other anabolic steroids. Oxidation of 1-androstenediol to 1-androstenedione seems to be the major renal metabolic pathway...
December 2002: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/12581618/7-oxo-dhea-and-raynaud-s-phenomenon
#12
Garret Ihler, Hasna Chami-Stemmann
Patients with Raynaud's phenomenon have abnormal digital vasoconstriction in response to cold. The pathogenesis remains unknown but may involve a local neurovascular defect leading to vasoconstriction. Diagnosis of primary Raynaud's phenomenon is based on typical symptomatology coupled with normal physical examination, normal laboratory studies and lack of observable pathology by nail fold capillaroscopy. Secondary Raynaud's phenomenon is known to occur associated with several connective tissue diseases, vascular injury due to repeated vibrational trauma, and other causes which produce demonstrable vascular and microcirculatory damage...
March 2003: Medical Hypotheses
https://www.readbyqxmd.com/read/9691759/control-of-the-immune-response-by-dhea-and-its-metabolites
#13
R M Loria, D A Padgett
The 17 keto steroid, Dehydroepiandrosterone (5-androsten-3 beta-17-one, DHEA) has been shown to protect mice from a variety of lethal infections. This includes, but is not limited to, infection with viruses (herpesvirus type 2, coxsackievirus B4-CVB4),bacteria (Enterococcus faecalis, Pseudomonas aeruginosa), and a parasite (Cryptosporidium parvum). We have reported that androstenediol (5-androsten-3 beta-17 beta-diol, beta AED), which is derived from DHEA, is at least 100x more effective in up-regulating systemic resistance against CVB4-infection than its precursor...
June 1998: Rinsho Byori. the Japanese Journal of Clinical Pathology
https://www.readbyqxmd.com/read/6780718/delayed-puberty-in-males-with-chronic-renal-failure
#14
J Ferraris, P Saenger, L Levine, M New, S Pang, B B Saxena, J E Lewy
The effects of chronic renal failure on the pituitary-testicular axis of 31 males, aged 11.7 to 20.0 yr (mean, 16.0 yr) were studied. Nine patients not on hemodialysis (group I) had serum creatinines between 2.5 and 8.0 mg/dl, 10 patients were on hemodialysis (group II) and 12 patients had received a renal transplant (group III). The Tanner stage of pubertal development was delayed relative to chronologic age. Testosterone (T), delta 4-androstenedione (delta 4), and urinary 17-keto steroids were normal when related to pubertal stage in groups I and II; and dehydroepiandrosterone (DHEA) and DHEA sulfate (DS) were in the low normal range...
September 1980: Kidney International
https://www.readbyqxmd.com/read/2960467/delta-5-3-beta-hydroxysteroid-dehydrogenase-activity-of-the-rat-corpus-luteum-exhibits-positive-substrate-binding-co-operativity-a-continuous-monitoring-microdensitometric-study-with-unfixed-ovarian-tissue-sections
#15
M Gordon, W R Robertson
delta (5)3 beta hydroxysteroid dehydrogenase activity transforms biologically inactive delta (5)3 beta hydroxy steroids into the active delta (4)3-keto products (e.g. pregnenolone to progesterone). Using a cytochemical procedure which allows for the continuous microdensitometric monitoring of an enzyme reaction as it proceeds and a well described cytochemical assay for delta (5)3 beta HSD we have analysed the initial velocity rates (Vo) for dehydroepiandrosterone (DHEA) binding to this enzyme in regressing (i...
October 1987: Cell Biochemistry and Function
https://www.readbyqxmd.com/read/2531683/twenty-four-hour-urinary-free-cortisol-in-premenopausal-cigarette-smokers-and-nonsmokers
#16
J Yeh, R L Barbieri
Cigarette smoking has been reported to produce acute increases in plasma ACTH and cortisol, but the effect of chronic smoking on integrated adrenal steroid production has not been studied. The effects of chronic smoking on 24-hour urinary-free cortisol, 11-deoxycortisol, DHEAS, and 17-keto-steroids were studied in 10 premenopausal smokers, and their results were compared with 15 premenopausal nonsmokers. The 24-hour excretion of urinary-free cortisol (85.0 +/- 40.8 nmol/d in smokers versus 81.7 +/- 49.7 nmol/d in nonsmokers), 11-deoxycortisol (259 +/- 170 nmol/d in smokers versus 222 +/- 147 nmol/d in nonsmokers), DHEAS (3,140 +/- 2,909 nmol/d in smokers versus 2,890 +/- 1,960 nmol/d in nonsmokers), and 17-ketosteroids (17...
December 1989: Fertility and Sterility
https://www.readbyqxmd.com/read/125195/-steroid-metabolism-in-primates-xvi-secretion-of-corticosteroids-in-the-baboon-papio-hamadryas-during-chronic-administration-of-sodium-chloride
#17
N P Gontscharow, A J Simarina, S K Jefremova, R Schön, K Schubert
The adrenal steroid secretion was investigated in male baboons (Papio hamadryas) treated for a long time with sodium chloride, in comparison to an untreated control group. In animals treated with NaCl, the secretion of progesterone, 17alpha-hydroxyprogesterone, 11-deoxycortisol, aldosterone and corticosterone was decreased, while cortisone, pregnenolone, 7-keto-cholesterol, 7-keto-DHEA, DHEA and adrenosterone were increased.
January 1975: Endokrinologie
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