Biological Activities and Emerging Roles of Lignin and Lignin-Based Products─A Review

Abstract

Bioactive substances, displaying excellent biocompatibility, chemical stability, and processability, could be extensively applied in biomedicine and tissue engineering. In recent years, plant-based bioactive substances such as flavonoids, vitamins, terpenes, and lignin have received considerable attention due to their human health benefits and pharmaceutical/medical applications. Among them is lignin, an amorphous biomacromolecule mainly derived from the combinatorial radical coupling of three phenylpropane units (p-hydroxypenyl, guaiacyl, and syringyl) during lignification. Lignin possesses intrinsic bioactivities (antioxidative, antibacterial, anti-UV activities, etc.) against phytopathogens. Lignin also enhances the plant resistance (adaptability) against environmental stresses. The abundant structural features of lignin offer other significant bioactivities including antitumor and antivirus bioactivities, regulation of plant growth, and enzymatic hydrolysis of cellulose. This Review reports the latest research results on the bioactive potential of lignin and lignin-based substances in biomedicine, agriculture, and biomass conversion. Moreover, the interfacial reactions and bonding mechanisms of lignin with biotissue/ cells and other constituents were also discussed, aiming at promoting the conversion or evolution of lignin from industrial wastes to value-added bioactive materials.

High-Molecular-Weight Fractions of Spruce and Eucalyptus Lignin as a Perspective Nanoparticle-Based Platform for a Therapy Delivery in Liver Cancer

“…Very few publications relate the biological behavior of lignin to certain biological processes (Gordobil et al, 2019). The biological activity and emerging role of lignin have been summarized in a review of Shu et al (2021). Antitumor properties of eucalyptusderived phytochemicals were related to the phenolic constituents and were summarized in a review (Abiri et al, 2021).…”

A tunable deep eutectic solvent-based processing for valorization of chestnut wood fiber as a source of ellagic acid and lignin

“…The possibility to recover a lignin-rich fraction endowed with potent antioxidant properties is an important outcome of this work, since lignin is finding increasing applications also in the health sector, e.g. in diabetes treatment, obesity control, and tissue therapy, and most of these therapeutic effects seem to be dependent on its antioxidant activity [72,73].…”

Research Progress on Lignocellulosic Biomass Degradation Catalyzed by Enzymatic Nanomaterials

“…and carbon‐carbon bonds ( β ‐5, β ‐1, and 5‐5, etc. ), accounting for 50–80% and 20–35%, respectively [35] . The composition of lignin units depends on the type of biological raw materials and other factors.…”