Figure 1.

Release of hydroxystilbenes from the lignin of Norway spruce bark by reductive cleavage. Top: Total-ion chromatogram of the DFRC degradation products released from the MWL lignin isolated from Norway spruce bark, showing the presence of the hydroxystilbenes resveratrol 1, isorhapontigenin 2, and piceatannol 3, as their acetate derivatives. cG and tG are the cis- and transconiferyl alcohol monomers (as their acetate derivatives). Note the occurrence of a peak from glucose Glc (as its peracetylated derivative). Bottom: Electron-impact mass spectrum of isorhapontigenin acetate 2.