The Heterogeneity of Natural Lignin

The results of investigations of the molecular-weight distribution of lignin in the delignification of wood by various methods, modern ideas on the distribution of lignin in cell walls of plant tissues, and the presence of bonding between the lignin and the carbohydrate components are critically examined. The results obtained in the course of these investigations show that natural lignin evidently consists of two main components which differ in molecular weight, in their localisation in the cell walls of the plant tissues, in the nature and number of the bonds with the carbohydrate components of the wood, and also in the topochemical models at the time of delignification.
The present review is the first attempt to survey the results relating to the problem of the heterogeneity of natural lignin.
There is a bibliography of 143 references.