15342-09-3Relevant articles and documents
Thiol-Containing Androgens as Suicide Substrates of Aromatase
Bednarski, Patrick J.,Porubek, David J.,Nelson, Sidney D.
, p. 775 - 779 (1985)
The thiol-containing androgens 17β-hydroxy-10β-mercaptoestr-4-en-3-one (1) and 19-mercaptoandrost-4-ene-3,17-dione (2) were synthesized and tested in human placental microsomes for their ability to suicide inhibit aromatase.Both compounds showed time-dependent, pseudo-first-order rates of inactivation of aromatase with Ki's of 106 and 34 nM and kcat's of 3.2E-3 and 1.2E-3 s-1 respectively for 1 and 2 at 30 deg C.Diffusion dialysis failed to reactivate aromatase previously inactivated by either compound, and both compounds required that NaDPH and O2 be present for time -dependent inactivation of the enzyme.The presence of the substrate, androst-4-ene-3,17-dione (5.0 μM), protected the enzyme from inactivation while cysteine (1.0 mM) failed to protect aromatase from inactivation by either compound.The above evidence demonstrates that both compounds are potent suicide inhibitors of aromatase.
Synthesis of C-6 fluoroandrogens: Evaluation of ligands for tumor receptor imaging
Choe, Yearn Seong,Katzenellenbogen, John A.
, p. 414 - 422 (2007/10/02)
Seven androgens, substituted with fluorine at C-6, were prepared as potential imaging agents for androgen receptor-positive prostate tumors and were evaluated in vitro in terms of their lipophilicity and their relative binding affinities (RBA, relative to R1881 = 100) for the androgen receptor and for sex steroid binding protein.Introduction of a fluorine atom into the C-6 position of an androgen generally decreases binding affinity to the androgen receptor, except in the two cases: 6α-fluoro-19-nor-testosterone RBA = 41.6 versus 30.6 for the unsubstituted steroid) and 6α-fluorotestosterone (RBA = 8.9 versus 6.6).Receptor binding of the C-6 fluoro-androgens is also stereospecific, showing higher binding affinities for the α-epimers compared to the corresponding β-epimers (4:1 - 15:1).Binding affinity to sex steroid binding protein is the lowest with 19-nor-testosterone, which is also the least lipophilic androgen studied.Based on the binding properties of compounds in this series, 6α-fluoro-19-nor-testosterone appears to have the most promise as a tumor imaging agent. - Keywords: C-6-fluoroandrogens; fluorine substitution; relative binding affinity; 6α- and 6β-epimers; log Po/w; prostate tumors
Ketalization of steroidal ketones using chlorotrimethylsilane as a catalyst
Tandon, Amita,Ray, Suprabhat
, p. 58 - 59 (2007/10/02)
Chlorotrimethylsilane (CTMS) was found to be an effective catalyst in the ketalization reaction of various steroidal ketones.A comparative study of the pTSA catalyzed and CTMS-catalyzed ketalization reactions of some steroidal ketones showed the superiority of CTMS as a catalyst in ketal formation.
