3188-46-3Relevant academic research and scientific papers
Biosynthesis of Estrogens. Estr-5(10)-ene-3,17-dione: Isolation, Metabolism and Mechanistic Implications
Ranjith, H.,Dharmaratne, W.,Kilgore, James L.,Roitman, Esther,Shackleton, Cedric,Caspi, Eliahu
, p. 1529 - 1536 (2007/10/02)
The 16-2H2 title compound 5b constituted a significant amount of the non-aromatic metabolites recovered from incubations of 3,17-dioxo-2H3>androst-4-en-19-al 1 with placental aromatase.For the evaluation of the role of compound 5b in the elaboration of estrogens, its transformations at pH 6.5 and 7.2 in the presence and absence of microsomal placental aromatase were investigated.In the presence of the aromatase at pH 6.5, estrogens (6.8percent), products of isomerization of the double bond (Δ5(10) -> Δ4) and products of reduction of the carbonyl groups were formed.When the incubation was carried out at pH 7.2, products similar to those obtained above were isolated but in different yields.Noticeably more estrogens (22.7percent) and less of the reduced products were formed.Additionally, at pH 7.2, 10β-hydroxy-2H2>estr-4-ene-3,17-dione 4a was obtained.In the absence of the aromatase, which was replaced with bovine albumin at both pH 6.5 and 7.2, 2H2>estr-4-ene-3,17-dione 3a and its 10β-hydroxy derivative 4a were formed in large amounts and were the only products detected.The ramifications of our observations in the context of estrogen biosynthesis are discussed.
Mass Spectrometric Studies on 17β-Estradiol-17-fatty Acid Esters: Evidence for the Formation of Anion-Dipole Intermediates
Debrauwer, Laurent,Paris, Alain,Rao, Dinesh,Fournier, Francoise,Tabet, Jean-Claude
, p. 709 - 719 (2007/10/02)
The behaviour towards low collision energy processes (eV range) of (1-) prepared under negative ion chemical ionization (NICI) ammonia conditions from 17β-estradiol-17-fatty acid esters has been investigated.From such bifunctional compounds containing two acidic sites (i.e. phenol and ester groups), two isomeric forms (i.e. phenoxide and enolate forms) characterize the (1-) ion structures, whose distribution depends on the ion preparation mode.Here NICI (ammonia) provides both phenoxide and enolate forms as the (1-) species.This behaviour contrasts with the regioselectivity observed for proton abstraction from phenol under NICI (N2O) and fast atom bombardment conditions.Production of both phenoxide and enolate forms in NICI (ammonia) is demonstrated under NICI (ND3) conditions in which DO-labelled d - H>(1-) enolate ions are produced in a similar yield to unlabelled d - D>(1-) phenoxide ions.Collisionally activated dissociation (CAD) spectra of both isomeric deprotonated molecules differ strongly by the presence of two different pairs of complementary daughter ions, suggesting that these ionic species are unconvertible.This is due to a steric hindrance effect on the long-distance proton transfer.A mechanistic investigation on the formation of fragment ion pairs produced under CAD was performed with various deuterium-labelled molecules.From these experiments, evidence is provided for molecular isomerizations into ion-dipole complexes (prior to dissociation) which are structurally dependent on the initial charge location.Direct dissociation of these intermediates competes with the occurence of exothermic proton transfer(s) yielding the formation of other isomeric intermediate forms.The orientation of these proton transfers is dictated by the relative acidities of both moieties of the complex.
