Colourning matters of Australian plants. IV. Haemocorin: A unique glycoside from Haemodorum corymbosum Vahl

Abstract

The bulbous roots of Haemodorum corymbosum Vahl. yield a red crystalline glycoside, haemocorin, which is readily hydrolysed to cellobiose and the purple-red aglycone, C₂₀H₁₄O₄. The latter contains one methoxyl group and gives a diacetate and isomeric mono- and dimethyl ethers. The absorption spectra and other properties of these compounds suggest a polycyclic tautomeric enolone structure. Oxidation of a dimethyl ether gives a compound C₂₂H₁₈O₇, believed to be a lactol ester, and a compound C₂₀H₁₄O₅, which is apparently a polycyclic aromatic anhydride. These results indicate that the aglycone is a polycyclic enolic α-diketone, possibly of the indandione type.