Sequential enzymatic hydrolysis enables isolation of bioactive functional group-enriched lignin-carbohydrate complex:...

Lignin-carbohydrate complex (LCC), natural plant cell wall macromolecules, has garnered increasing attention for multifunctional bioactivities attributed to a unique lignin-polysaccharide hybrid structure. However, conventional separation methods often compromise the structural integrity and biological function of LCC, limiting practical applications. Herein, a novel two-step xylanase-cellulase method was developed to efficiently isolate functional group-enriched LCC (XCE-LCC) with enhanced free radical scavenging and α-glucosidase inhibitory activities. Comparative analyses revealed that the two-step method partially removed cellulose and hemicellulose barriers while preserving the native LCC structure. Notably, XCE-LCC contained increased levels of bioactive functional groups (phenolic-OH: 0.93 mmol/g, -COOH: 0.23 mmol/g, and aliphatic-OH: 4.38 mmol/g) resulting in DPPH radical scavenging (58.7 %) and particularly high α-glucosidase inhibition (87.4 %). These findings demonstrate an effective enzymatic method for functional group-enriched LCC isolation and underscore the potential of LCC as a functional polymer for oxidative stress mitigation and natural α-glucosidase inhibition.