Effects of pure non-ionic and mixed non-ionic-cationic surfactants on the rates of hydrolysis of phenyl salicylate and phenyl benzoate in alkaline medium

2001 ◽  
Vol 14 (10) ◽  
pp. 669-676 ◽  
Author(s):  
M. Niyaz Khan ◽  
Emran Ismail ◽  
M. Rapandy Yusoff
Keyword(s):  
Alkaline Medium ◽  
Cationic Surfactants ◽  
Phenyl Benzoate ◽  
Phenyl Salicylate ◽  
Hydrolysis Of

ESTIMATION OF CORTICOSTEROIDS BY THE REDUCTION OF FERRICYANIDE

1959 ◽  
Vol 37 (1) ◽  
pp. 391-398 ◽  
Author(s):  
N. R. Stephenson
Keyword(s):  
Prussian Blue ◽  
Blood Sugar ◽  
Alkaline Medium ◽  
Alkaline Solution ◽  
Reducing Power ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Inhibiting Effect ◽  
Reducing Activity ◽  
Hydrolysis Of

A procedure based on a modification of Folin's micromethod for blood sugar (1, 2) was used to investigate the reducing activity of various corticosteroids. The ferrocyanide produced as a result of the reduction of ferricyanide in alkaline solution was measured photometrically as Prussian blue. With a filter transmitting light at 620 mμ, the relation between the absorbance of the chromogen and the amount of the reducing steroid obeyed Beer's law over the range from 0.005 to 0.050 mg. The oxygen function at C-3 accounted for most of the reducing power of the non-alpha ketolic steroids studied. An oxygen function at C-11 did not affect significantly the reduction of ferricyanide by 17-desoxycorticosteroids. Although the presence of a hydroxyl at C-17 depressed the reducing activity of the alpha-ketol side chain, a fluorine at C-9 and an hydroxyl at C-11 appeared to overcome this inhibiting effect. Evidence was obtained to suggest that a C-16 hydroxyl group was able to increase the reducing action of the alpha-ketolic side chain. Esterification of the C-21 hydroxyl influenced the reduction of ferricyanide only when interference with hydrolysis of the ester in the alkaline medium was experienced.

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