CHEMICAL AND SPECTRAL STUDIES OF NODOSOSIDE A NEW ANTHRAQUINONE GLYCOSIDE FROM THE FLOWERS OF CASSIA NODOSA

Abstract

Chemical investigation of the flowers of Cassia nodosa has led to the isolation of a new anthraquinone glycoside, provisionally named as nodososide, from the alcoholic extract. Acid hydrolysis of the compound gave D–glucose (one mole) and an aglycone, named nodosin. From the studies based on the elemental analysis, IR and UV spectra, acetylation, colour reactions, oxidation with nitric acid and alkaline potassium permanganate, caustic potash fusion, zinc dust distillation and bromination the structure of nodosin has been derived to be 1,3,5,8–tetrahydroxy–2,7–dimethylanthraquinone. Periodate oxidation followed by the determination of formic acid liberated and periodate consumed and enzymic hydrolysis showed the presence of one α–linked D–glucopyranose moiety in nodososide. Spectral studies and colour reactions suggested the glycoside to be 8–O–α–D–glucopyranoside of 1,3,5,8–tetrahydroxy–2,7–dimethylanthraquinone.

Zusammenfassung

Aus dem alkoholischen Extrakt der Blüten von Cassia nodosa wurde ein neues Anthrachinon–Glykosid, vorläufig Nodososid genannt, isoliert. Säure–Hydrolyse ergab ein Mol D–Glukose und ein Nodosin genanntes Aglukon. Seine Struktur wurde als 1,3,5,8–Tetrahydroxy–2,7–dimethylanthrachinon ermittelt. Auf Grund der Spektralanalyse und von Farbreaktionen wird vermutet, daß das Glykosid ein 8–O–α–D–Glukopyranosid des 1,3,5,8–Tetrahydroxy–2,7–dimethylanthrachinons ist.