53-16-7Relevant articles and documents
Mechanism of the hydrolysis of the sulfamate EMATE-an irreversible steroid sulfatase inhibitor
Spillane, William J.,Malaubier, Jean-Baptiste
, p. 2059 - 2062 (2010)
The kinetics of hydrolysis of the medicinally important sulfamate ester EMATE have been probed over a wide pH range and into moderately strong base (H_ region). Analysis of the pH/H_-rate profile, measurements of pKas, solvent-reactivity, kinetic isotope effects and determination of activation data reveal that in the pH range from ～1 to ～8 an SN2 (S) solvolytic mechanism is followed and after the pKa of EMATE (pKa ～9) is passed, a second pathway showing a first-order dependence on base operates and an E1cB mechanism is supported.
Characterization of 17β-hydroxysteroid dehydrogenase and regulators involved in estrogen degradation in Pseudomonas putida SJTE-1
Wang, Pingping,Zheng, Daning,Peng, Wanli,Wang, Yanqiu,Wang, Xiuli,Xiong, Weiliang,Liang, Rubing
, p. 2413 - 2425 (2019)
In bacteria, the enzyme catalyzing the transformation of 17β-estradiol is considered the key enzyme for its metabolism, whose enzymatic activity and regulatory network influence the biodegradation efficiency of this typical estrogen. In this work, a novel 17β-hydroxysteroid dehydrogenase (17β-HSD) was characterized from the estrogen-degrading strain Pseudomonas putida SJTE-1, and two regulators were identified. This 17β-HSD, a member of the short-chain dehydrogenase/reductase (SDR) superfamily, could be induced by 17β-estradiol and catalyzed the oxidization reaction at the C17 site of 17β-estradiol efficiently. Its Km value was 0.068?mM, and its Vmax value was 56.26?μmol/min/mg; over 98% of 17β-estradiol was oxidized into estrone in 5?min, indicating higher efficiency than other reported bacterial 17β-HSDs. Furthermore, two genes (crgA and oxyR) adjacent to 17β-hsd were studied which encoded the potential CrgA and OxyR regulators. Overexpression of crgA could enhance the transcription of 17β-hsd, while that of oxyR resulted in the opposite effect. They could bind to the specific and different sites in the promoter region of 17β-hsd gene directly, and binding of OxyR could be released by 17β-estradiol. OxyR repressed the expression of 17β-hsd by its specific binding to the conserved motif of GATA-N9-TATC, while CrgA activated the expression of this gene through its binding to the motif of T-N11-A. Therefore, this 17β-HSD transformed 17β-estradiol efficiently and the two regulators regulated its expression directly. This work could promote the study of the enzymatic mechanism and regulatory network of the estrogen biodegradation pathway in bacteria.
Synthetic approaches towards 4-functionalized estrone derivatives
Schoen, Uwe,Messinger, Josef,Solodenko, Wladimir,Kirschning, Andreas
, p. 3822 - 3828 (2012)
Directed ortho-lithiation of estrone carbamate followed by reaction with electrophiles afforded 2-substituted estrone derivatives. Reductive cleavage of the carbamate group followed by O-allylation and Claisen rearrangement led to new 4-functionalized est
The Status of Oxygen Atoms in the Removal of C-19 in Oestrogen Biosynthesis
Akhtar, Muhammed,Calder, Michael R.,Corina, David L.,Wright, J. Neville
, p. 129 - 130 (1981)
Three O2-dependent reactions are involved in the removal of C-19 as formate, in oestrogen biosynthesis; it is shown that the oxygen atoms introduced in steps 1 and 3 of the process are the ones which are found in the biosynthetic formate.
An efficient steroid pharmacophore-based strategy to identify new aromatase inhibitors
Neves, Marco A.C.,Dinis, Teresa C.P.,Colombo, Giorgio,Sa e Melo, M. Luisa
, p. 4121 - 4127 (2009)
Aromatase, an enzyme involved in the conversion of androgens into estrogens, is an important target for the endocrine treatment of breast cancer. Aromatase inhibition is usually achieved with steroids structurally related to the substrate of catalysis or,
Gold nanoparticles as dehydrogenase mimicking nanozymes for estradiol degradation
Zhang,Bragg, Leslie M.,Servos, Mark R.,Liu, Juewen
, p. 1655 - 1658 (2019)
Nanozyme catalysis has been mainly focused on a few chromogenic and fluorogenic substrates, while environmentally and biologically important compounds need to be tested to advance the field. In this work, we studied oxidation of estradiol (E2) in the presence of various nanomaterials including gold nanoparticles (AuNPs), nanoceria (CeO2), Fe3O4, Fe2O3, MnO2 and Mn2O3, and found that AuNPs had a dehydrogenase-mimicking activity to convert E2 to estrone (E1). This conversion was monitored using HPLC. The reaction was faster at higher pH and reached saturation at pH 8. Smaller AuNPs had a higher catalytic efficiency and 5 nm AuNPs were 4.8-fold faster than 13 nm at the same total surface area. Finally, we tried 17α-ethinylestradiol (EE2) as a substrate and found that 5 nm AuNPs can catalyze EE2 oxidation in the presence of H2O2. This work indicated that some nanomaterials can affect environmentally important hormones via oxidation reactions, and this study has expanded the scope of substrate of nanozymes.
Me3SI-promoted chemoselective deacetylation: a general and mild protocol
Gurawa, Aakanksha,Kashyap, Sudhir,Kumar, Manoj
, p. 19310 - 19315 (2021/06/03)
A Me3SI-mediated simple and efficient protocol for the chemoselective deprotection of acetyl groups has been developedviaemploying KMnO4as an additive. This chemoselective deacetylation is amenable to a wide range of substrates, tolerating diverse and sensitive functional groups in carbohydrates, amino acids, natural products, heterocycles, and general scaffolds. The protocol is attractive because it uses an environmentally benign reagent system to perform quantitative and clean transformations under ambient conditions.
Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information, p. 20391 - 20399 (2021/08/13)
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
PhIO-Mediated oxidative dethioacetalization/dethioketalization under water-free conditions
Du, Yunfei,Ouyang, Yaxin,Wang, Xi,Wang, Xiaofan,Yu, Zhenyang,Zhao, Bingyue,Zhao, Kang
, p. 48 - 65 (2021/06/16)
Treatment of thioacetals and thioketals with iodosobenzene in anhydrous DCM conveniently afforded the corresponding carbonyl compounds in high yields under water-free conditions. The mechanistic studies indicate that this dethioacetalization/dethioketalization process does not need water and the oxygen of the carbonyl products comes from the hypervalent iodine reagent.
Photochemical Behavior of Some Estrone Aryl and Methyl Sulfonates in Solution: Preparative and Mechanistic Studies
Quindt, Matías I.,Gola, Gabriel F.,Ramirez, Javier A.,Bonesi, Sergio M.
, p. 8 - 21 (2020/06/03)
Direct irradiation of estrone aryl and methyl sulfonates in different organic solvents under nitrogen atmosphere was investigated under steady-state conditions. The estrone derivatives reacted efficiently through the photo-Fries rearrangement reaction involving [1;3]-sulfonyl migration providing the ortho-sulfonyl estrone derivatives and estrone as the photoproducts. In addition, estrone and 2-arylsulfonyl estrone derivatives were epimerized involving a Norrish Type-I reaction. Chemical quenching and photosensitization experiments on the photoreaction have been also carried out to establish the photoreactive excited state. Likewise, the solvent effect and the nature of the sulfonyl group on the photoreactions have been also studied.
