14 research outputs found
Cod Liver Oil as a Source of Vitamin A
In the course of experiments having for their object the study of the properties of vitamin A with a view to its isolation, certain observations were made concerning the behavior of animals on various rations containing cod liver oil. It was noted that different samples of cod liver oil apparently vary markedly in vitamin A potency. Xerophthalmia has been produced in rats on diets containing as much as 3 per cent of cod liver oil. Synthetic rations containing cod liver oil evolve a penetrating odor resembling acrolein. When the cod liver oil is replaced with butter fat, this odor is not observed. It is possible that the failure of rats on diets containing certain samples of cod liver oil may be due to one or more of the following factors. 1. A decreased consumption of the diet clue to this decomposition product. 2. A destruction of vitamin A which runs parallel with the destruction of the cod liver oil. 3. Certain samples of cod liver oil are not as rich in vitamin A as supposed heretofore
Synthesis of Spirocyclic Indolenines
This Review provides an in-depth account of the synthesis of spirocyclic indolenines. Over the last 77 years, a wide array of diverse synthetic methods has been developed in order to generate these synthetically useful and biologically important spirocyclic scaffolds. The main synthetic strategies discussed are grouped into three main categories, namely interrupted Fischer indolisations, dearomatisation reactions of indoles and condensation reactions. The historical background, common synthetic challenges, current state-of-the-art and future perspectives of this field are examined