Studies on the Constituents of Digitalis purpurea L. XII. New Cardiotonic Glycosides, Gitorocellobioside, Glucogitoroside, and Gitoxin-cellobioside.

Abstract

The structures of substance B-III and B-III', newly isolated from digitalis seeds, were examined. It was found that enzymatic hydrolysis of substance B-III afforded gitoroside, and a mild acid hydrolysis afforded gitoxigenin and new trisaccharide which consists of cellobiose and digitoxose. This sugar was named digilanidotriose. Therefore, substance B-III is formulated as gitoxigenin cellobiosido-digitoxoside, and was designated as gitorocellobioside. The partial decomposition of gitorocellobioside with a snail enzyme afforded a new diglycoside which is gitoxigenin glucosido-digitoxoside and this was designated as glucogitoroside. Substance B-III' was examined by the same method and was shown to be a new cardiotonic pentaglycoside which has a structure of gitoxigenin cellobiosido-tridigitoxoside, and was named gitoxin cellobioside.