Houttuynia cordata polysaccharide, Ultrasonication, Structure characterization, Antioxidant activity, Hypoglycemic activity, Polyphenols, Chemistry, QD1-999, Acoustics. Sound, QC221-246

This study aimed to evaluate the influence of ultrasonic degradation on Houttuynia cordata polysaccharide (HCP) physicochemical properties, structure characterization, and bioactivities. The results indicated that the ultrasonic degradation could significantly decrease HCP’s molecular weight (MW). Total polysaccharide, uronic acid content, solubility, and thermal stability of HCP increased gradually with the increase in ultrasonication power. Fourier transform infrared (FTIR) and Nuclear magnetic resonance spectroscopy (NMR) spectra proved that the primary structure of HCP had not been changed via ultrasonic degradation. Antioxidant and hypoglycemic activity results confirmed that ultrasonication enhanced the ability to scavenge free radicals (DPPH, ABTS, and OH) and improved α-glycosidase and α-amylase inhibition with the increase of ultrasonic power, which was increased in order HCP