REVISED STRUCTURES FOR NEOLIGNANS FROM ARUM-ITALICUM

On the basis of H-1 NMR spectral comparison with known dilignols, the neolignans isolated from Arum italicum, for which unusual 8-O-3'-structures were proposed, have been reassigned to those with the conventional 8-O-4'-structures, erythro and threo-guaiacylglycerol-beta-coniferyl ether respectively. In addition, the 8-O-4'-neolignan glucoside with a 1,3,5-trisubstitution pattern for ring A has been reassigned to threo-guaiacylglycerol-beta-coniferyl ether-4-beta-D-glucopyranoside, with the conventional 1,3,4-trisubstituted ring A. Thus far there is no evidence for the existence of 8-O-3'-neolignans in nature.