Quantitative1H and13C NMR spectroscopy of lignins from an aqueous ethanolic cook of aspen wood

General and comparative characteristics obtained by¹H and¹³C NMR spectroscopy of the lignins from aqueous ethanolic cooks are presented. It is shown that degradation of the lignin macromolecule takes place during the digestion of aspen wood. The mean length of the lignin side chains decreases and ether bonds are cleaved, while the degree of condensation of the substances increases.Irkutsk State University. Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 277–285, March–April, 1993.