The spin-lattice relaxation time (T1) for the aliph. C atoms in the C3 side chains of acetylated MWL from C. avellana was below 0.5 s, while C atoms of substituted arom. carbonyl and Me in methoxy and Ac groups lead to T1 values ranging between 1 and 3 s as detd. by the progressive satn. pulse Fourier transform technique. The 13C NMR spectroscopy off acetylated MWL from A. glutinosa, C. avellana and A. pseudoplatanus permitted tracing 5 interunite linkages in each lignin. [on SciFinder (R)]