1164-91-6Relevant articles and documents
The Cephalostatins. 22. Synthesis of bis-steroidal pyrazine pyrones
Pettit, George R.,Moser, Bryan R.,Mendonca, Ricardo F.,Knight, John C.,Hogan, Fiona
, p. 1063 - 1069 (2012)
Cephalostatin 1 (1), a remarkably strong cancer cell growth inhibitory trisdecacyclic, bis-steroidal pyrazine isolated from the marine tube worm Cephalodiscus gilchristi, continues to be an important target for practical total syntheses and a model for the discovery of less complex structural modifications with promising antineoplastic activity. In the present study, the cephalostatin E and F rings were greatly simplified by replacement at C-17 with an α-pyrone (in 12), typical of the steroidal bufodienolides, and by a dihydro-γ- pyrone (in 16). The synthesis of pyrazine 12 from 5α- dihydrotestosterone (nine steps, 8% overall yield) provided the first route to a bis-bufadienolide pyrazine. Dihydro-γ-pyrone 16 was synthesized in eight steps from ketone 13. While only insignificant cancer cell growth inhibitory activity was found for pyrones 12 and 16, the results provided further support for the necessity of more closely approximating the natural D-F ring system of cephalostatin 1 in order to obtain potent antineoplastic activity.
Long-range effect of 17-substituents in 3-oxo steroids on 4,5-double bond hydrogenation
Sidova, Romana,Stransky, Karel,Kasal, Alexander,Slavikova, Barbora,Kohout, Ladislav
, p. 1528 - 1542 (1998)
The long-range effect of substituents in the 17-position on the hydrogenation of double bond of the steroidal Δ4-3-ketones in acetic acid on a platinum catalyst is described in a series of testosterone (1) and epitestosterone (5) esters with carboxylic acids of varying alkyl chain length. The ratio 5α-to 5β-products is affected by the nature of substituents in the position 17.
Synthesis of high affinity fluorine-substituted ligands for the androgen receptor. Potential agents for imaging prostatic cancer by positron emission tomography
Liu,Carlson,Katzenellenbogen
, p. 2113 - 2129 (1992)
We have prepared nine androgens substituted with fluorine at C-16 or C-20 to evaluate their potential, as positron emission tomographic (PET) imaging agents for prostatic cancer when labeled with the positron emitting radionuclide fluorine-18 (t( 1/2 ) = 110 min). These compounds represent members from the following classes of androgens: testosterone (T), 5α- dihydrotestosterone (DHT), 7α-methyl-19-nortestosterone (MNT), mibolerone (Mib), and metribolone (R1881). All of these compounds were prepared by functionalization of suitable androgen precursors, and the synthetic routes were developed to allow the introduction of fluorine by a fluoride ion displacement reaction late in the synthesis, as is required for the preparation of these compounds in fluorine-18 labeled form. We have also prepared four androgens in which the C-3 carbonyl or 17β-hydroxyl groups are replaced by fluorine. Most of the fluorine-substituted androgens show high affinity for the androgen receptor (AR), although fluorine substitution lowers their affinity by a small factor. None of the androgens where fluorine replaces oxygen functions at C-3 or C-17 have substantial affinity for AR. Derivatives of the natural androgens (T and DHT) as well as MNT have little affinity for other steroid hormone receptors (progesterone and mineralocorticoid receptors), whereas the Mib and R1881 derivatives have somewhat greater heterologous binding. With sex steroid binding protein, a human serum binding protein, the pattern of binding affinities is nearly the reverse, with derivatives of Mib, R1881 and MNT having low affinity, and DHT and T, high affinity. From these fluorine-substituted compounds, we can select several whose preparation in fluorine-18 labeled form for further tissue distribution studies is merited.
Direct Synthesis of α-Amino Nitriles from Sulfonamides via Base-Mediated C-H Cyanation
Shi, Shasha,Yang, Xianyu,Tang, Man,Hu, Jiefeng,Loh, Teck-Peng
supporting information, p. 4018 - 4022 (2021/05/26)
Herein, we disclose a transition-metal-free reaction system that enables α-cyanation of sulfonamides through C-H bond cleavage for the preparation of α-amino nitriles, including difficult-to-access all-alkyl α-tertiary scaffolds. More than 50 substrate examples prove a wide functional group tolerance. Additionally, its synthetic practicality is highlighted by gram-scalability and the late-stage modification of natural compounds. Mechanistic experiments suggest that this process involves in situ formation of an imine intermediate via base-promoted elimination of HF.
ANTI-CANCER NUCLEAR HORMONE RECEPTOR-TARGETING COMPOUNDS
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Page/Page column 147-148, (2021/05/21)
The disclosure relates to anti-cancer compounds which are anti-cancer PARP inhibitors of formula Al, A2, A3 or A4 conjugated by a linker to a steroid, whereby the steroid targets the conjugate to the nucleus, as well as to methods for their preparation and use. (I)
Chemical synthesis of 2β-amino-5α-androstane-3α,17β-diol N-derivatives and their antiproliferative effect on HL-60 human leukemia cells
Thibeault, Dominic,Roy, Jenny,DeRoy, Patrick,Poirier, Donald
, p. 5062 - 5077 (2008/12/22)
Even though few steroids are used for the treatment of leukemia, 2β-(4-methylpiperazinyl)-5α-androstane-3α,17β-diol (1) was recently reported for its ability to inhibit the proliferation of human leukemia HL-60 cells. With an efficient procedure that we had developed for the aminolysis of hindered steroidal epoxides, we synthesized a series of 2β-amino-5α-androstane-3α,17β-diol N-derivatives structurally similar to 1. Hence, the opening of 2,3α-epoxy-5α-androstan-17β-diol with primary and secondary amines allowed the synthesis of aminosteroids with diverse length, ramification, and functionalization of the 2β-side chain. Sixty-four steroid derivatives were tested for their capacity to inhibit the proliferation of HL-60 cells; thus obtaining first structure-activity relationship results. Ten aminosteroids with long alkyl chains (7-16 carbons) or bulky groups (diphenyl or adamantyl) have shown antiproliferative activity over 78% at 10 μM and superior to that of the lead compound. The 3,3-diphenylpropylamino, 4-nonylpiperazinyl and octylamino derivatives of 5α-androstane-3α,17β-diol inhibited the HL-60 cell growth with IC50 of 3.1, 4.2 and 6.4 μM, respectively. They were also found to induce the HL-60 cell differentiation.
Controlling the reactive state through cation binding: Photochemistry of enones within zeolites
Uppili, Sundararajan,Takagi, Shinsuke,Sunoj,Lakshminarasimhan,Chandrasekhar,Ramamurthy
, p. 2079 - 2083 (2007/10/03)
The nature of the lowest triplet state of enones is altered by the cations present within Y zeolites. Alkali metal ions, such as Li+, are predicted to interact with the carbonyl unit of enones in a collinear fashion and significantly lower both the p-type n and π-2 orbitals. Excited state energies, estimated at the CIS(D)/6-31+G* level, show that the lowest triplet is n-π* in character for the enones, but switch to π-π* on coordination with Li+. Observed product distribution within zeolite is consistent with this theoretical prediction.
Synthesis of α,β-unsaturated ketone from α-iodo ketone using photoirradiation
Ji, Shun-Jun,Takahashi, Eiji,Takahashi, T. Tomoyoshi,Horiuchi, C. Akira
, p. 9263 - 9266 (2007/10/03)
Irradiation of α-iodo ketone in hexane under a nitrogen atmosphere with a high-pressure mercury lamp (λ>300nm) at room temperature afforded the corresponding α,β-unsaturated ketones in good yield. This reaction affords a new, clean and convenient synthetic method for the α,β-unsaturated ketone.
Formation of 5α steroids by biotranformation involving the 5 α-reductase activity of Penicillium decumbens
Holland, Herbert L.,Dore, Sophia,Xu, Weili,Brown, Frances M.
, p. 642 - 647 (2007/10/02)
The biotransformation of a series of Δ4-3-ketosteroids by the Penicillium decumbens ATCC 10436 has been investigated. Conversion to the 5α-dihydrosteroid was observed substrates of the androsterone and pregne series: the reaction is tolerant of non-polar substituents (Cl and CH3) at C-4 of the substrate, but does not occur in the presence of a 4-hydroxyl group, or with additional unsaturation at the Δ1 or Δ6 positions. A-nor, B-nor, 3-deoxy-, and 3,5-cycloandrostanes are not reduced, but 6-methylenestestosterone is converted to a 6-methylene-5α-dihydro derivative. Several biotransformations are reported which involve oxidoreductase activity at C-3 and/or C-17, either concomitant or independent of Δ4 reduction: the substrate specificity of the oxidoreductase processes has been examined and defined by the use of 3α-hydroxy, 3β-hydroxy, 3-keto, 17β-keto substituted steroids. In this way, the existence in P. decumbens of 3β-hydroxy-3-keto and 17β-hydroxy-17-keto oxidoreductases has been demonstrated.
THE BIOTRANSFORMATION OF SOME STEROIDS BY CEPHALOSPORIUM APHIDICOLA
Hanson, James R.,Nasir, Habib
, p. 831 - 834 (2007/10/02)
Hydroxylation of 5α-androstane-3-one and 3,6-dione by C. aphidicla takes place at C-17β and, in the case of the latter, at C-5α.The fungus reduces 5α-androstan-17-one and the 3,17-dione to the 17β-alcohols. Key Word Index - Cephalosporium aphidicola; fungus; microbiological hydroxylation; steroids.
