LABELING OF A LIGNIN FROM SUSPENSION-CULTURES OF PICEA-ABIES

The lignin released by suspension cultures of Picea abies into the cul ture medium was labelled with C-13 by adding uniformly-labelled glucos e to the culture. The successful labelling (the lignin contained ca 20 % C-13) greatly facilitates the acquisition of detailed and reliable s tructural information using NMR and makes it possible to carry out thr ee dimensional HMQC-HOHAHA experiments. These spectral data were compa red with similar data from lignin that had been isolated from cell wal ls of intact pine (Pinus sylvestris) and from a polymer that had been prepared in vitro by oxidation of labelled coniferyl alcohol. Differen ces in chemical structure have been found that are of importance for t he elucidation of the chemical processes involved in the deposition of lignin in the walls of lignifying tissues. (C) 1998 Elsevier Science Ltd. All rights reserved.