Structural Characteristics of Compound Middle Lamella Lignin

Abstract
One of the most important targets of current lignin chemistry is to visualize the inhomogeneities of lignin in the wood cell wall. The soft xylem fraction was separated from birch wood at the end of May, 1983. Cell walls of the soft xylem fraction were extremely thin and were mainly composed of compound middle lamella. Degradation products from the soft xylem by alkaline nitrobenzene oxidation and permanganate oxidation strongly indicated that compound middle lamella lignin in hardwood must be rich in guaiacyl units and highly condensed.