6911-95-1Relevant academic research and scientific papers
Disturbance in sex-steroid serum profiles of cattle in response to exogenous estradiol: A screening approach to detect forbidden treatments
Regal, Patricia,Nebot, Carolina,Díaz-Bao, Mónica,Barreiro, Rocio,Cepeda, Alberto,Fente, Cristina
experimental part, p. 365 - 375 (2011/04/15)
Estradiol benzoate (EB) has been one of the most widely used estrogenic agents in animal husbandry, as a way of exogenously introducing the natural hormone estradiol-17β into the animal organism. Estradiol was previously employed to induce anabolic effects or reproductive improvements in cattle. However, the employment of EB in European countries has been permanently forbidden by Directive 2008/97/EC to guarantee consumers' health. Despite this prohibition, the control of estradiol-17β and its esters continues to be a difficult task for residue-monitoring plans in European Communities because official analyses of natural thresholds for hormones in cattle have not yet been established, leading to a lack of confirmation for any exogenous administration of natural hormones. Several researchers have worked on excretion profiles of metabolites, variation in specific hormonal ratios and metabolomic fingerprints after hormonal treatments. This research focuses on the possible existence of disturbances in the serum profile of animals treated with EB in terms of steroid sex hormones (androgens, oestrogens and progestogens), by investigating the serum levels of several of these hormones. The serum samples were collected from three groups of cows: one treated with an intramuscular injection of EB, one treated with a combination of intravaginal EB and progesterone and a control (non-treated) group. The samples have been analysed by a validated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method, and 17 natural hormones were identified and quantified. Subsequently, data from the serum profiles were submitted for statistic and multivariate analysis, and it was possible to observe a manifest variation between animal groups. The obtained results can help in the development of a viable screening tool for monitoring purposes in cattle.
Convenient preparation of A-ring fused pyridines from steroidal enamides
Barthakur, Madan G.,Borthakur, Moyurima,Boruah, Romesh C.
, p. 1137 - 1142 (2008/12/22)
A facile strategy for the preparation of A-ring fused pyridosteroids has been accomplished in high yields by the reaction of Vilsmeier reagent (chloromethyleneiminium salt) with steroidal A-ring enamides (2- and 3-ene) under thermal conditions. The structure of 6′-chloro-5α-cholest [3,2-b]pyridine was determined by X-ray analysis.
Nucleosteroids: Carbocyclic nucleoside analogs of androst-4-en-17β-ol
Gelpi, Maria E,Cadenas, Raul A,Mosettig, Jorge,Zuazo, Beatriz N
, p. 263 - 267 (2007/10/03)
Steroidal nucleoside analogs were synthesized starting from testosterone. By reduction of the oxime of 17β-hydroxy-androst-4-en-3-one (testosterone), a mixture of the two amino epimers of C-3 were obtained. The 3α-amino-androst-4-en-17β-ol was crystallized in 73% yield and coupled with 5-amino-4,6-dichloropyrimidine to give 3α-(5′-amino-4′-chloro-pyrimidin-6′-yl)amino-androst-4-en-17β-ol. This compound was treated with triethyl orthoformate in acid media to give the corresponding purinyl steroid adduct 3α-(6′-chloro-purin-9′-yl)-androst-4-en-17β-ol in 98% yield. This substance, in turn, was converted with good yield into the 6′-thio, 6′-methylamino, and 6′-diethyl aminopurinyl derivatives through nucleophilic reactions at C-6 of the purine nucleus. Copyright
Prolonged release of antifertility drugs
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, (2008/06/13)
Antifertility drug complexes which have enhanced effectiveness and prolonged release of the antifertility drug. The complex includes an antifertility drug, a polybasic acid and a polyvalent metal ion. The antifertility drug is in the form of a basic amine derivative.
