Preparation and Anti-Lung Cancer Activity Analysis of Guaiacyl-Type Dehydrogenation Polymer

Abstract

In this paper, guaiacyl dehydrogenated lignin polymer (G-DHP) was synthesized using coniferin as a substrate in the presence of β-glucosidase and laccase. Carbon-13 nuclear magnetic resonance (13C-NMR) determination revealed that the structure of G-DHP was relatively similar to that of ginkgo milled wood lignin (MWL), with both containing β-O-4, β-5, β-1, β-β, and 5-5 substructures. G-DHP fractions with different molecular weights were obtained by classification with different polar solvents. The bioactivity assay indicated that the ether-soluble fraction (DC2) showed the strongest inhibition of A549 lung cancer cells, with an IC50 of 181.46 ± 28.01 μg/mL. The DC2 fraction was further purified using medium-pressure liquid chromatography. Anti-cancer analysis revealed that the D4 and D5 compounds from DC2 had better anti-tumor activity, with IC50 values of 61.54 ± 17.10 μg/mL and 28.61 ± 8.52 μg/mL, respectively. Heating electrospray ionization tandem mass spectrometry (HESI-MS) results showed that both the D4 and D5 were β-5-linked dimers of coniferyl aldehyde, and the 13C-NMR and 1H-NMR analyses confirmed the structure of the D5. Together, these results indicate that the presence of an aldehyde group on the side chain of the phenylpropane unit of G-DHP enhances its anticancer activity.

Keywords

• lignin
• dehydrogenation polymer
• classified fraction
• purified compound
• anti-tumor activity
• chemical structure