28893-44-9Relevant academic research and scientific papers
Synthesis and evaluation of new 6-hydroximinosteroid analogs as cytotoxic agents
Poza, Javier,Rega, Miriam,Paz, Vanessa,Alonso, Beatriz,Rodriguez, Jaime,Salvador, Nelida,Fernandez, Antonio,Jimenez, Carlos
, p. 4722 - 4740 (2008/03/13)
Taking into account the structural requirements for cytotoxicity, several new hydroximinosteroid derivatives have been prepared and evaluated for their cytotoxic activity against A-549, H116, PSN1, and T98G cultured tumor cell lines in order to obtain further information on the potential pharmacophoric core of this type of compound. The influence of the oxygenated position in the A ring, the presence of an additional oxygenated position at C-7 and C-16, and a fluorinated position at C-5 were considered in order to study the structure-activity relationships. The results reveal the importance of oxygenated positions in the A ring (e.g., 4,5-epoxide showed an IC50 value against HCT-116 under micromolar level) for an increase in cytotoxic activity in this type of compound. Furthermore, they showed an important selectivity toward colon tumor line (HCT-116).
Epoxidation and reduction of cholesterol, 1,4,6-cholestatrien-3-one and 4,6-cholestadien-3β-ol
Ma, Eunsook,Kim, Haksoon,Kim, Eunjeong
, p. 245 - 250 (2007/10/03)
Many naturally occurring polyhydroxylated sterols and oxysterols exhibit potent biologic activities. This paper describes reagent and position selectivity of epoxidation and reduction of cholesterol derivatives. Cholesterol was reacted with m-chloroperoxybenzoic acid (m-CPBA) to form 5α,6α-epoxycholestan-3β-ol, but in reaction with 30% H 2O2, it did not reacted. 1,4,6-Cholestatrien-3-one was obtained from cholesterol and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone in dioxane. 1,4,6-Cholestatrien-3-one was reacted with 30% H2O 2 and 5% NaOH in methanol to give 1α,2α-epoxy-4,6- cholestadien-3-one, which was stereoselectively reduced with NaBH4 to form 1α,2α-epoxy-4,6-cholestadien-3β-ol and reduced with Li metal in absolute ethanol to give 2-ethoxy-1,4,6-cholestatrien-3-one. And 1,4,6-cholestatrien-3-one was epoxidized with m-CPBA in dichloromethane to afford 6α,7α-epoxy-1,4-cholestadien-3-one, which was reacted with NaBH4 to synthesize 6α-hydroxy-4-cholesten-3-one and reduced Li metal in absolute ethanol to form 2-ethoxy-1,4,6-cholestatrien-3-one, respectively. 1,4,6-Cholestatrien-3-one was reduced with NaBH4 in absolute ethanol to form 4,6-cholestadien-3β-ol, which was reacted with 30% H2O2 to leave original compound, but was reacted with m-CPBA to give 4β,5β-epoxy-6-cholesten-3β-ol as the major product and 4β,5β-epoxy-6α,7α-epoxycholestan-3β-ol as the minor product.
1-α-hydroxy vitamin D compounds and process for preparing same
-
, (2008/06/13)
The invention provides novel 1α-hydroxy vitamin D compounds and a method for their preparation from 1α-hydroxy-25-hydrogen cholesta-5,7-dienes by irradiation and isomerization techniques. The invention also includes the said 1α-hydroxy-25-hydrogen-cholesta-5,7-dienes and the corresponding cholest-5-enes. The new compounds may be obtained in a crystalline form substantially free from isomeric or other impurities arising from manufacture.
Steroidal Allylic Epoxides
Glotter, Erwin,Zviely, Michael
, p. 321 - 326 (2007/10/02)
Two allylic epoxides, 4β,5β-epoxycholest-6-en-3β-ol and 4α,5α-epoxycholest-6-ene-1α,3α-diol, were obtained by reaction of the corresponding conjugated dienols with t-butyl hydroperoxide in the presence of bisacetylacetonato-oxovanadium as catalyst.The reductive opening of these epoxides and other related reactions are discussed.
Oxidation of Ketone and Aldehyde Hydrazones, Oximes, and Semicarbazones and of Hydroxylamines and Hydrazo-compounds, using Benzeneselenic Anhydride
Barton, Derek H. R.,Lester, David J.,Ley, Steven V.
, p. 1212 - 1217 (2007/10/02)
Benzeneseleninic anhydride (1; BSA) is an effective reagent for the mild regeneration of the carbonyl group from ketone phenylhydrazones, p-nitrophenylhydrazones, tosylhydrazones, oximes, and semicarbazones at 40-50 deg C.Tosylhydrazones and oximes of aldehydes are also readily converted into the parent aldehyde.The phenylhydrazone and p-nitrophenylhydrazone derivatives of aldehydes afford ketoazo-compounds.The ketoazo-species could also be prepared by oxidation of the corresponding hydrazide with compound (1).Both aromatic and aliphatic hydrazo-compounds and hydroxylamines can be oxidised to azo- and nitrozo-derivatives respectively.
Dehydrogenation of Steroidal and Triterpenoid Ketones using Benzeneseleninic Anhydride
Barton, Derek H. R.,Lester, David J.,Ley, Steven V.
, p. 2209 - 2212 (2007/10/02)
Steroid and triterpenoid ketones can by smoothly dehydrogenated in high yield with benzeneseleninic anhydride in chlorobenzene at 95-120 deg C.With the excess of benzeneseleninic anhydride and longer reaction times 4,4-dimethyl ketones give ring-A-contracted diketones in moderate yields.
