Fig. 4

2D ¹H–¹³C HSQC spectra of the long-chain ¹³C-labeled lignin oligomer models in the CSP experiment. a Superimposed 2D ¹H–¹³C HSQC spectra of the aromatic region in compound 4^(Arβ) (50 μM) in the presence (red) and absence (blue) of 350 μM TrCBM1. b A magnified image of the HSQC signals from the C 5 positions. c Superimposed 2D ¹H–¹³C HSQC spectra of aliphatic regions and methoxy groups in 4^(Arβ), 4^(α), and 4^(m) (50 μM) in the presence (red) and absence (blue) of 350 μM TrCBM1