Sample records for estranes
-
Lindemann, Peter
2015-11-01
In plants androstanes, estranes, pregnanes and corticoids have been described. Sometimes 17β-estradiol, androsterone, testosterone or progesterone were summarized as sex hormones. These steroids influence plant development: cell divisions, root and shoot growth, embryo growth, flowering, pollen tube growth and callus proliferation. First reports on the effect of applicated substances and of their endogenous occurrence date from the early twenties of the last century. This caused later on doubts on the identity of the compounds. Best investigated is the effect of progesterone. Main steps of the progesterone biosynthetic pathway have been analyzed in Digitalis. Cholesterol-side-chain-cleavage, pregnenolone and progesterone formation as well as the stereospecific reduction of progesterone are described and the corresponding enzymes are presented. Biosynthesis of androstanes, estranes and corticoids is discussed. Possible progesterone receptors and physiological reactions on progesterone application are reviewed. Copyright © 2015 Elsevier Inc. All rights reserved.
-
Metabolism of norethisterone in the greyhound.
Biddle, S T B; O'Donnell, A; Houghton, E; Creaser, C S
2013-10-30
Norethisterone has been used as a successful oral contraceptive in humans for many years. It was recently permitted for use as an oestrus suppressant in racing greyhounds. To monitor the use of norethisterone as part of a routine drug surveillance programme, knowledge of its metabolism was required to enable detection. Gas chromatography/mass spectrometry and selective derivatisation techniques have been used to identify urinary metabolites of norethisterone following oral administration to the greyhound. Metabolites were extracted using solid-phase and liquid-liquid extraction techniques. Several metabolites were identified, including reduced, mono-, di- and trihydroxylated steroids. The major metabolites observed were 17α-ethynyl-5β-estrane-3α,17β-diol, 17α-ethynyl-5α-estrane-3β,17β-diol, three 17α-ethynylestranetriol stereoisomers and two 17α-ethynylestranetetrol stereoisomers. The major metabolites were predominantly excreted as glucuronic acid conjugates and detection of the administration of norethisterone was possible for up to 8 days post-dose using the methods described. The nandrolone metabolites, 19-norepiandrosterone, estranediol and 19-noretiocholanolone, were also identified in the post-administration samples collected up to 8 h after dosing the treated animals. The urinary metabolites identified in this study have further increased the knowledge of steroid metabolism in the greyhound, providing information to support routine drug testing programmes for greyhound racing. Copyright © 2013 John Wiley & Sons, Ltd.
-
Andriushina, V A; Iaderets, V V; Stytsenko, T S; Druzhinina, A V; Voĭshvillo, N E
2013-01-01
The main and side products of hydroxylation by the C. lunata VKPM F-981 mycelium of fourteen delta(4)-3-ketosteroids of the estrane, androstane, and pregnane series and six of their delta(5)-3beta-hydroxy analogues were identified by H1 PMR spectroscopy and comparison with standard samples. The obtained experimental data are considered in terms of the triangular model of the enzyme-substrate interaction. The dependence of the direction of hydroxylation of steroid molecules and the orientation of hydroxy groups on the structure of the initial substrate was revealed.
-
Modélisation morphodynamique cross-shore d'un estran vaseux
NASA Astrophysics Data System (ADS)
Waeles, Benoı̂t; Le Hir, Pierre; Silva Jacinto, Ricardo
2004-08-01
Numerical experiments were performed to simulate the profile evolution of an intertidal mudflat with a 1D cross-shore morphodynamical model. First, the hydrodynamical forcing is a cross-shore tidal current due to semi-diurnal variations of the free surface elevation at the open boundary. Further, considering the conservation of the action density of surface gravity waves, a wave height (and resulting bottom shear stress) calculation is added to the morphodynamical model. Results of the numerical experiments show that the shape of the profile reaches equilibrium. The mudflat progrades continually when the forcing is tide only, whereas it can be steady under the simultaneous action of tide and waves. To cite this article: B. Waeles et al., C. R. Geoscience 336 (2004).
-
Erukainure, O L; Ajiboye, J A; Abbah, U A; Asieba, G O; Mamuru, S; Zaruwa, M Z; Manhas, N; Singh, P; Islam, M S
2018-05-01
The antioxidative effect of Monodora myristica seed acetone extract and its effect on chemical functional groups were investigated in sickled erythrocytes as well as molecular modeling of the antisickling potentials of its secondary metabolites. The extract was subjected to gas chromatography-mass spectrometry to identify the compounds present, which were then docked into the allosteric-binding site of deoxy-hemoglobin. The extract was incubated with sickled erythrocytes at 37°C for 6, 12, and 24 h and were subjected to antioxidative analysis for reduced glutathione (GSH), superoxide dismutase (SOD), catalase, and lipid peroxidation (LPO). Chemical functional group of the treated cells was analyzed via Fourier transform infrared spectroscopy (FTIR). The predominant compounds identified were 17-octadecynoic acid; oleic acid, androstan-3-one, 17-hydroxy-2-methyl- (2.beta.,5.beta.,17.beta.)-; estran-3-one, 17-(acetyloxy)-2-methyl-, (2.alpha., 5.alpha., 17.beta.), and (+)-3-carene, 10-(acetylmethyl)-. They all fitted well within the active site of Hb with good binding affinity, as evidenced by the negative CDocker interaction energies of their complexes ranging between -54.4 and -26.7 kcal/mol. Treatment with the extract exacerbated SOD and catalase activities as well as GSH level, while LPO was suppressed. This antioxidative activity was time and/or dose dependent, with 6 and 12 h incubation showing the optimum activity. FTIR analysis of the treated cells showed the presence of hydrophobic functional groups. The synergetic molecular interaction of the major compounds of the extract with the α-dimer of Hb depicts an antisickling effect of M. myristica acetone extract. This is accompanied by exacerbation of endogenous antioxidant enzymes activity and modification of the functional chemistry of the cells.
-
Dutour, Raphael; Maltais, Rene; Perreault, Martin; Roy, Jenny; Poirier, Donald
2018-03-07
RM-133 belongs to a new family of aminosteroid derivatives demonstrating interesting anticancer properties, as confirmed in vivo in four mouse cancer xenograft models. However, the metabolic stability of RM-133 needs to be improved. After investigation, the replacement of its androstane scaffold by a more stable estrane scaffold led to the development of the mestranol derivative RM-581. Using solid-phase strategy involving five steps, we quickly synthesized a series of RM-581 analogs using the recently-developed diethylsilyl acetylenic linker. To establish structure-activity relationships, we then investigated their antiproliferative potency on a panel of cancer cell lines from various cancers (breast, prostate, ovarian and pancreatic). Some of the mestranol derivatives have shown in vitro anticancer activities that are close to, or better than those observed for RM-581. Compound 23, a mestranol derivative having a ((3,5-dimethylbenzoyl)-L-prolyl)piperazine side chain at position C2, was found to be active as an antiproliferative agent (IC50 = 0.38 ± 0.34 to 3.17 ± 0.10 µM) and to be twice as active as RM-581 on LNCaP, PC-3, MCF-7, PANC-1 and OVCAR-3 cancer cells (IC50 = 0.56 ± 0.30, 0.89 ± 0.63, 1.36 ± 0.31, 2.47 ± 0.91 and 3.17 ± 0.10 µM, respectively). Easily synthesized in good yields by both solid-phase organic synthesis and classic solution-phase chemistry, this promising candidate could be used as an antiproliferative agent on a variety of cancers, notably pancreatic and ovarian cancers, both having very bad prognoses. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
-
Kaabia, Z; Dervilly-Pinel, G; Popot, M A; Bailly-Chouriberry, L; Plou, P; Bonnaire, Y; Le Bizec, B
2014-04-01
Nandrolone (17β-hydroxy-4-estren-3-one) is amongst the most misused endogenous steroid hormones in entire male horses. The detection of such a substance is challenging with regard to its endogenous presence. The current international threshold level for nandrolone misuse is based on the urinary concentration ratio of 5α-estrane-3β,17α-diol (EAD) to 5(10)-estrene-3β,17α-diol (EED). This ratio, however, can be influenced by a number of factors due to existing intra- and inter-variability standing, respectively, for the variation occurring in endogenous steroids concentration levels in a single subject and the variation in those same concentration levels observed between different subjects. Targeting an efficient detection of nandrolone misuse in entire male horses, an analytical strategy was set up in order to profile a group of endogenous steroids in nandrolone-treated and non-treated equines. Experiment plasma and urine samples were steadily collected over more than three months from a stallion administered with nandrolone laurate (1 mg/kg). Control plasma and urine samples were collected monthly from seven non-treated stallions over a one-year period. A large panel of steroids of interest (n = 23) were extracted from equine urine and plasma samples using a C18 cartridge. Following a methanolysis step, liquid-liquid and solid-phase extractions purifications were performed before derivatization and analysis on gas chromatography-tandem mass spectrometry (GC-MS/MS) for quantification. Statistical processing of the collected data permitted to establish statistical models capable of discriminating control samples from those collected during the three months following administration. Furthermore, these statistical models succeeded in predicting the compliance status of additional samples collected from racing horses. Copyright © 2013 John Wiley & Sons, Ltd.
-
NASA Astrophysics Data System (ADS)
Van-Wierts, Stefanie
Au Québec maritime, l'érosion côtière est une problématique d'envergure, notamment sur les côtes de formations meubles. Les plages ont un rôle de zone tampon ayant comme fonction naturelle d'absorber l'énergie des vagues et donc d'assurer l'équilibre de certains écosystèmes et le maintien de l'écoumène en réduisant l'érosion de la côte. Les méthodes d'acquisition conventionnelles ne permettent pas de quantifier convenablement les changements morphosédimentaires d'une plage à l'échelle des cellules hydrosédimentaires. Le manque de méthode d'acquisition fiable et de données quantitatives mène à une surestimation ou à une sous-estimation de la disponibilité sédimentaire d'un système côtier. Pour contrer ces lacunes et afin de minimiser les coûts d'acquisition, un nouveau système mobile de LiDAR terrestre a été mis en place, permettant d'acquérir des données topographiques de l'estran, de la haute plage et des falaises. Le système multicapteurs comprend un LiDAR, un système de navigation à haute précision (IMU et D-GPS) et une caméra. L'ensemble des instruments et capteurs sont montés sur un véhicule de type tout-terrain. Le système a été évalué sur la zone côtière de la péninsule de Manicouagan. La comparaison des données LiDAR avec 1 050 points de référence géopositionnés au D-GPS montre une erreur verticale moyenne de 0,1 m sur les secteurs de plage. Les résultats montrent que le volume sédimentaire moyen des plages devant les zones où la ligne de rivage présente un ouvrage de protection en enrochement (12 m 3/m) est plus de trois fois plus faible que devant les secteurs à l'état naturel (35,5 m3/m). La moyenne des secteurs en transition, constituant les segments où une zone artificielle et une zone naturelle se chevauchent présentent un volume moyen de 28 m3/m. Aussi, les plages devant les secteurs anthropisés sont en moyenne près de 2 fois plus étroites (12,7 m) que devant les secteurs naturels (25,4 m). Un indice de bilan sédimentaire des plages a été testé et il constitue un excellent proxy pour évaluer la disponibilité sédimentaire des plages ainsi qu'identifier les secteurs déficitaires. La réalisation d'une couverture complète au LiDAR a permis de constater que des profils de plage réalisés à un intervalle de plus de 200 m sur des côtes diversifiées mènent à des résultats significativement différents de la réalité. Par contre, il semble que l'intervalle des profils à peu d'impact sur de longs secteurs de plages uniformes.