Chemical constituents from the tuber of Curcuma longa

Eight compounds were isolated from the tuber of Curcuma longa, and identified as curcumin( 1 ), demethoxycurcumin( 2 ), bisdemethoxycurcumin( 3 ), 4-hydroxybenzaldehyde( 4 ), vanillin( 5 ), 4-(4-hydroxyphenyl)butan-2-one( 6 ), (+)-rhododendrol( 7 ), and(2R, 4R)-6-(4′-hydroxyphenyl)-hexane-2, 4-diol( 8 ). Among them, compounds 4 - 7 were isolated from this plant for the first time, and compound 8 was a novel compound.