The Chemical Structure, Extraction Method, and Biological Activity of Lignin–Carbohydrate Complexes

Lignin–carbohydrate complexes (LCCs) represent a new type of compound in plants that have a complex interplay between lignin and carbohydrates, with their formation varying significantly among different plant species. Researchers have investigated different isolation methods for LCCs, but inconsistencies in the structures obtained highlight the complexity of these compounds. In woody plants, lignin and carbohydrates are typically formed through the covalent ether and ester or hydrogen bonds, while in gramineous plants, indirect linkages such as benzyl ether, phenyl glycosidic, and ester bonds are prevalent. Despite this, LCCs show a wide range of biological activities, including antioxidant, immunomodulatory, anti-UV, antitumor, etc., which renders them intriguing for biomedical applications. Given the significant biomedical potential of LCCs, understanding the relationship between their structure and bioactivities is crucial. This Perspective delves into the extraction methods, complex chemistry structure, and various biological features of LCCs to provide a comprehensive understanding of their biomedical potential. By establishing this knowledge base, the Perspective sets the stage for the development of LCCs as innovative biomedical materials with promising applications.