28398-76-7Relevant articles and documents
Synthesis and acetylcholinesterase inhibitory activity of polyhydroxylated sulfated steroids: Structure/activity studies
Richmond, Victoria,Murray, Ana P.,Maier, Marta S.
, p. 1141 - 1147 (2013)
Disulfated and trisulfated steroids have been synthesized from cholesterol and their acetylcholinesterase inhibitory activity has been evaluated. In our studies we have found that the activity was not only dependent on the location of the sulfate groups but on their configurations. 2β,3α,6α- trihydroxy-5α-cholestan-6-one trisulfate (18) was the most active steroid with an IC50 value of 15.48 μM comparable to that of 2β,3α-dihydroxy-5α-cholestan-6-one disulfate (1). Both compounds were found to be less active than the reference compound eserine. The butyrylcholinesterase activity of 1 and 18 was one magnitude lower than that against acetylcholinesterase revealing a selective inhibitor profile.
Potassium borohydride reductions of immobilised ketosteroids
Briggs, Josie C.,Hodge, Philip,Zhengpu, Zhang
, p. 3943 - 3956 (2007/10/03)
Ketosteroids absorbed into various insoluble supports (powdered polyethylene, microporous 2% crosslinked polystyrene beads, macroporous highly crosslinked polystyrene beads, silica gel and alumina) call be reduced using aqueous potassium barohydride. The use of phase transfer catalysts generally raises yields. In the case of 6-ketosteriods the supported reactions often follow a stereochemical course significantly different from that of analogous reactions in solution. This is attributed to the adsorbtion of the steroid onto the inner surfaces of the supports. In these cases reduction of (he ketosteroid by alkoxyborohydrides is substantially suppressed and thus most of the reduction is brought about by BH4- itself, a relatively sterically undemanding reductant. The net result is that whilst reductions of 6-ketosteroids in solution by potassium borohydride typically gives the 69α- and 6β-alcohols in the ratio 15:85, with the supported steroid the ratios can be as high as 90:10.
Potassium Borohydride Reductions of Ketones absorbed into Polymer Supports: Stereochemical Effects
Briggs, Josie C.,Hodge, Philip
, p. 310 - 311 (2007/10/02)
The proportions of 6α-alcohol obtained from aqueous potassium borohydride reductions of 3β-cholestan-6-one (1) absorbed into various polymers varied from 0 to 90percent depending on the polymer used and whether or not a phase transfer catalyst was added; some other ketones show similar streochemical effects, the greatest effects probably arising when the substrates are adsorbed to the inner surfaces of appropriate polymers.
