1639-43-6Relevant academic research and scientific papers
Synthesis of novel C17 steroidal carbamates. Studies on CYP17 action, androgen receptor binding and function, and prostate cancer cell growth
Moreira, Vania M.A.,Vasaitis, Tadas S.,Guo, Zhiyong,Njar, Vincent C.O.,Salvador, Jorge A.R.
, p. 1217 - 1227 (2008)
We have exploited the reaction of 1,1′-carbonylbis(2-methylimidazole) (CBMI) with several 17β-hydroxy androstanes to synthesize a series of novel C17 steroidal carbamates. Structural elucidation features have been provided for the final compounds based on 1D and 2D NMR techniques, IR spectroscopy, and related literature. The new compounds were tested for inhibition of human cytochrome 17α-hydroxylase-C17,20-lyase (CYP17) and androgen receptor (AR) binding and function effects. Their inhibitory potential against PC-3 cell proliferation was also evaluated. Compounds 11 and 23 were found to inhibit CYP17 with IC50 values of 17.1 and 11.5 μM, respectively. The carbamate moiety at C17 allowed tight binding of the synthesized compounds to both wild-type (wt-) and mutated AR. When bound to the mutated AR, the compounds were found to have a dual effect, stimulating transcription at low concentrations while almost fully blocking it at the higher concentrations tested, in the presence of the natural androgen dihydrotestosterone (DHT). Compounds 8 and 12 were the most active against PC-3 cell proliferation with EC50 values of 2.2 and 0.2 μM, respectively.
Acetylenic Inhibitors of C-22 Hydroxylase of Ecdysone Biosynthesis
Mauvais, Antony,Burger, Alain,Roussel, Jean Pierre,Hetru, Charles,Luu, Bang
, p. 36 - 50 (1994)
Acetylenic derivatives of cholesterol designed to be inhibitors of ecdysteroid biosynthesis were prepared.The side chains of these compounds differ additionally from that of cholesterol by stereochemical modifications at C-17 and C-20.A bicyclic acetylenic compound containing the partial structure of the C and D rings of the cholesterol nucleus was also synthesized.These compounds were devised with the aim of inhibiting the C-22 hydroxylation of ecdysone biosynthesis by a suicide substrate mechanism.One of these molecules inhibits very efficiently the synthesis of ecdysone in prothoracic glands in vitro.
Reduction of steroidal ketones and enones by sodium dithionite in presence of phase transfer catalyst
Akamanchi,Patel,Meenakshi
, p. 1655 - 1660 (1992)
Sodium dithionite has been effectively used in the reduction of steroidal ketones and enones with remarkable selectivity and high yields under phase transfer catalysis (PTC) conditions to give alcohols and ketones respectively. An application of these selectivities is demonstrated by reducing an important steroid intermediate 16-dehydropregnenolone acetate to pregnenolone acetate in very high yields.
Epimerization of Tertiary Carbon Centers via Reversible Radical Cleavage of Unactivated C(sp3)-H Bonds
Wang, Yaxin,Hu, Xiafei,Morales-Rivera, Cristian A.,Li, Guo-Xing,Huang, Xin,He, Gang,Liu, Peng,Chen, Gong
supporting information, p. 9678 - 9684 (2018/07/21)
Reversible cleavage of C(sp3)-H bonds can enable racemization or epimerization, offering a valuable tool to edit the stereochemistry of organic compounds. While epimerization reactions operating via cleavage of acidic C(sp3)-H bonds, such as the Cα-H of carbonyl compounds, have been widely used in organic synthesis and enzyme-catalyzed biosynthesis, epimerization of tertiary carbons bearing a nonacidic C(sp3)-H bond is much more challenging with few practical methods available. Herein, we report the first synthetically useful protocol for the epimerization of tertiary carbons via reversible radical cleavage of unactivated C(sp3)-H bonds with hypervalent iodine reagent benziodoxole azide and H2O under mild conditions. These reactions exhibit excellent reactivity and selectivity for unactivated 3° C-H bonds of various cycloalkanes and offer a powerful strategy for editing the stereochemical configurations of carbon scaffolds intractable to conventional methods. Mechanistic study suggests that the unique ability of N3? to serve as a catalytic H atom shuttle is critical to reversibly break and reform 3° C-H bonds with high efficiency and selectivity.
Silver-mediated oxidative aliphatic C-H trifluoromethylthiolation
Guo, Shuo,Zhang, Xiaofei,Tang, Pingping
supporting information, p. 4065 - 4069 (2015/03/30)
The first example of a practical and direct trifluoromethylthiolation reaction of unactivated aliphatic C-H bonds employs a silver-based reagent. The reaction is operationally simple, scalable, and proceeds under aqueous conditions in air. Furthermore, its broad scope and good functional-group compatibility were demonstrated by applying this method to the selective trifluoromethylthiolation of natural products and natural-product derivatives.
Synthesis and antiproliferative activity of some androstene oximes and their O-Alkylated derivatives
Acharya, Pratap Chandra,Bansal, Ranju
, p. 193 - 199 (2014/03/21)
In order to study the structure-activity relationship with respect to the cytotoxicity of steroidal oximes, several 6E-hydroximino-4-ene steroids and their O-alkylated derivatives were synthesized. The oxime ethers were solidified and purified by preparing their corresponding oxalate salts. The new derivatives as well as some previously synthesized ones were evaluated for in vitro antineoplastic activity against a panel of 60 cancer cell lines at 10 μM. The oximes and oxime ethers were found to have moderate to good antiproliferative activity against various leukemia, colon, melanoma, and renal cancer cell lines. Several 6E-hydroximino-4-ene steroids and their O-alkylated derivatives were synthesized. Their structure-activity relationship with respect to the cytotoxicity of steroidal oximes was studied. The oximes and oxime ethers were found to have moderate-to-good antiproliferative activity against various leukemia, colon, melanoma, and renal cancer cell lines.
A practical solution for aqueous reactions of water-insoluble high-melting-point organic substrates
Cui, Xiaoxue,Li, Bo,Liu, Tianzhen,Li, Chunbao
supporting information; experimental part, p. 668 - 672 (2012/06/01)
A practical solution to the problem of performing aqueous reactions for very sparingly soluble high-melting-point (VSSHMP) organic substrates has been developed, which entails mechanically stirring a mixture of the substrate, the corresponding reagent(s), water, catalytic Aliquat 336 and sand. When the melting points of the substrates which include steroids, ketones, aldehydes, aromatics and alkaloids are around 200 °C, the reactions can be performed at 20 °C. The substrate solubility can be as low as 1 × 10-10 mol L-1. The Royal Society of Chemistry 2012.
Zinc(II) iodide-triethylsilane: A novel mild reduction system for direct deoxygenation of aryl aldehydes, ketones, and α,β-unsaturated enones
Li, Zheng,Deng, Gang,Li, Yuan-Chao
experimental part, p. 3053 - 3057 (2009/07/03)
ZnI2-TESH has been found to be a novel mild and efficient reduction system. This reagent, in contrast to the traditional ionic deoxygenation systems (TFA-R3SiH, BF3·OEt 2-R3SiH, etc.), could directly deoxygenate different kinds of carbonyl compounds such as aryl aldehydes, ketones, and αβ- unsaturated enones to the corresponding hydrocarbons in moderate to excellent yields. Georg Thieme Verlag Stuttgart.
Mild and efficient method for reduction of aldehydes and ketones with NaBH4 in the presence of Dowex1-x8
Zeynizadeh, Behzad,Shirini, Farhad
, p. 335 - 339 (2007/10/03)
Various aldehydes and ketones are reduced efficiently to alcohols with NaBH4/Dowex1-x8.
Regioselective esterification of polyhydroxylated steroids by Candida antarctica lipase B
Bertinotti, Anna,Carrea, Giacomo,Ottolina, Gianluca,Riva, Sergio
, p. 13165 - 13172 (2007/10/02)
The regioselectivity of Candida antarctica lipase B towards the acetylation of polyhydroxylated steroids has been systematically investigated. The enzyme showed a marked preference for the alcoholic moieties on the A ring and: on the steroidal side chain, making it possible the selective acylation at the positions 3 or 21 of polyhydroxy steroids. Acylation with the synthetically useful esters chloroacetate and levulinate was also accomplished, whereas esterification with benzoate and pivaloate was unsuccessful.
