VEGETABLE PURGATIVES CONTAINING ANTHRACENE DERIVATIVES
In Part I of this series of papers1 reference was made to a preliminary test on an extract of Senna pod which was found to contain only about 5 per cent. of its theoretical activity. Biological and chemical tests have since been carried out on a number of galenical preparations of senna pod and the results have confirmed that only a small proportion of the activity of the pod is present in these concentrated preparations. The ultimate aim of the work described in this paper has been to devise a method of preparing an extract representing the full activity of the pod from which it was made, and as a result, it has been possible to set out the principles underlying efficient extraction and concentration processes.
THE CHEMICAL ASSAY OF CASCARA
THE bark of cascara (Rhamnus purshiunus DC.) is believed to contain free emodin, aloe-emodin, and chrysophanol. The purgative activity of the drug is thought to be due not to these free anthraquinones, but to glycosides of the anthranols (or of the oxanthrones) corresponding to some or all of them. Little is known about the structure of such glycosides, except that Schindlerl has reported the isolation of a glycoside of emodin oxanthrone (I).
Sterol metabolism. XLI. Cholesterol A-ring autoxidations
Abstract Chromatographic and spectral evidence is adduced for the presence of cholest-5-en-3-one, cholest-4-en-3-one, and cholest-4-ene-3,6-dione in samples of cholesterol aged naturally in air or subjected to irradiation in air by 60 Co gamma radiation. These findings establish an additional mode of air oxidation of cholesterol to A-ring 3-ketones. Moreover, the oxidation by air of cholest-5-en-3-one induced by 60 Co gamma radiation yielded cholest-4-en-3-one, cholest-4-ene-3,6-dione, and the epimeric 3-oxocholest-4-ene-6-hydroperoxides. Cholest-4-en-3-one was not altered by irradiation in air, nor was cholesterol isomerized to cholest-4-en-3β-ol upon irradiation. From these observations it is deduced that the radiation-induced A-ring dehydrogenation of cholesterol yields initially cholest-5-en-3-one which upon isomerization yields cholest-4-en-3-one not further oxidized and which by a second oxidation yields the epimeric 3-oxocholest-4-ene-6-hydroperoxides which decompose to cholest-4-ene-3,6-dione.