Purification, structural identification, antioxidant activity, and inhibitory effects on digestive enzymes of α-glucan from Chuanminshen violaceum

Abstract

Chuanminshen violaceum, as a food and folk medicine, is cultivated and grown only in China. Its polysaccharides play an important role in medicinal benefits. Herein, crude C. violaceum polysaccharides (CVPs) were purified to yield two polysaccharide fractions (CVPs-1-G and CVPs-2-G) using DEAE Cellulose-52 and Sephadex G-100 column chromatography. Structural analyses indicated that both CVPs-1-G and CVPs-2-G were glucans with average molecular weights of 8.1 kDa and 187.5 kDa, respectively. The main chain of the major component (CVPs-1-G) might be composed of (1 → 4)-linked α-Glcp, and the branched-chain might be an α-Glcp → 4)-α-D-Glcp-(1 → 6)-α-D-Glcp-(1 → 4)-α-D-Glcp, which connected to the main chain through the O-6 position of → 3,6)-α-D-Glcp-(1 →. In addition, CVPs-1-G displayed ABTS, DPPH, and hydroxyl radical scavenging activity, as well as competitive inhibitory activities of α-amylase and non-competitive inhibitory activities of lipase and pepsin. According to molecular docking, its inhibitory activity on digestive enzyme might be caused by hydrogen bond and hydrophobic interaction between them. Thus, CVPs exhibit strong potential for use in functional foods and pharmaceuticals.

Keywords

• Chuanminshen violaceum
• α-glucan
• Structural identification
• Digestive enzyme activity
• Kinetics of digestive enzyme