A Test to Differentiate Ergosterol From Cholesterol.

Abstract

When sulphuric acid or a mixture of selenious and sulphuric acids is used as a reagent for cholesterol dissolved in chloroform, the two layers, that is the chloroform and the acid layer, assume different colorations. With sulphuric acid alone the chloroform layer is cherry red and the acid layer shows green fluorescence. With the selenious-sulphuric acid mixture, the chloroform layer assumes a deep beautiful purple, while the lower layer is red brown but does not display green fluorescence.When, however, ergosterol is used with either reagent, the acid layer is colored but the chloroform layer remains free from color. With concentrated sulphuric acid and an equal volume of chloroform solution, the acid layer ranges in color from a brownish red in a 1%, to cherry red in a 0.5%, to light cherry red in a 0.1%, to orange in a 0.04%, and to yellowish orange in a 0.025% solution of ergosterol. In all these concentrations the typical green fluorescence is also observed in the acid layer.With concentrated sulphur...