Figure 3.

¹³C MAS NMR spectra obtained for the cutin-enriched materials upon extraction. Spectra of the reference cutin sample and cutin-enriched materials derived from reactions with cholinium hexanoate or BMIM acetate for 2, 15, and 170 h (A) and the corresponding calculated reticulation (B and C) and esterification (D) ratios. The regions assigned to the long methylene chains, oxygenated aliphatics, aromatics, and carboxyl groups are marked. The imidazolium-based cation contributes to the signal assigned to the CH₃ groups at 15 ppm (**), whereas the cholinium cation is seen in the signal at 54 ppm (*); both contaminants can be washed out.