- An efficient synthesis of 3-methoxy-19-norpregna-1,3,5(10),16-tetraen-20-one
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An efficient preparative method for the synthesis of 3-methoxy-19-norpregna-1,3,5(10), 16-tetraen-20-one was suggested. This compound is a key intermediate product in the preparation of 3,20-dihydroxy-19-norpregnatrienes, antagonists of estrogen receptor and cytotoxic agents. The reaction of 16-dehydro-17-carbonitrile (obtained in two steps from estrone methyl ether) with methyl magnesium halides gave the target product in high yield. While studying this reaction, we isolated and characterized an unusual steroid dimer, a fused 16,17-pyridinosteroid substituted in the hetero ring of the second steroid molecule. A mechanism of its formation was suggested.
- Kuznetsov, Yu. V.,Levina,Shashkov,Zavarzin
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- New estrogen receptor antagonists. 3,20-Dihydroxy-19-norpregna-1,3,5(10)-trienes: Synthesis, molecular modeling, and biological evaluation
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New estrogen receptor α (ERα) antagonists – 3,20-dihydroxy-19-norpregna-1,3,5(10)-trienes containing an additional carbocyclic ring D′ at the 16α,17α positions – were synthesized. The effects of the new compounds on the MCF-7 breast cancer cells and ERα activation were investigated. All the steroids studied were synthesized starting from estrone methyl ether. The scaffold of compounds containing the six-membered ring D′ was constructed via the Diels–Alder reaction of butadiene with 3-methoxy-19-norpregna-1,3,5(10),16-tetraen-20-one 5. The hydrogenation of primary 16α,17α-cyclohexeno-adduct 7 followed by 3-demethylation (by HBr–AcOH) and reduction of 20-oxo group (by LiAlH4) or in one step by DIBAH gave target mono- and dihydroxy steroids 9–11. The Corey–Chaykovsky reaction of the same 3-methoxy-19-norpregna-1,3,5(10),16-tetraen-20-one 5 gave 16α,17α-methylene-substituted compound. The reaction of the latter with DIBAH immediately yielded 3,20-dihydroxy-16α,17α-methyleno-19-norpregna-1,3,5(10)-triene 13. The same procedures using 3-methoxy-19-norpregna-1,3,5(10),16-tetraen-20-one 5 produced corresponding 3,20-dihydroxy-16,17-19-norpregna-1,3,5(10)-triene 16 and 3,20-dihydroxy-19-norpregna-1,3,5(10),16-tetraene 17. All compounds were fully characterized by 1D and 2D NMR, HRMS, and X-ray diffraction. The molecular docking showed that the target compounds can bind to ER, their binding mode being similar to that of natural estradiol. 16α,17α-Methylene- or unsubstituted compounds exhibit the highest cytotoxicity against MCF-7 cells, being simultaneously relatively weak ERα inhibitors. 3,20-Dihydroxy steroids containing the six-membered ring D′ proved to be the most effective ERα inhibitors. These compounds displayed moderate cytotoxicity comparable of that of tamoxifen and showed no toxic effect on MCF-10A normal, nontumorigenic epithelial cells. The new ER antagonists were found to be good candidates for further testing as agents for the treatment and prevention of ERα-positive breast cancers.
- Kuznetsov, Yury V.,Levina, Inna S.,Scherbakov, Alexander M.,Andreeva, Olga E.,Fedyushkina, Irina V.,Dmitrenok, Andrey S.,Shashkov, Alexander S.,Zavarzin, Igor V.
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p. 670 - 682
(2017/12/08)
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