Extraction, structural features, and <i>in vitro</i> bioactivities of polysaccharides from <i>Prunus padus</i> L. berries

This study established an ultrasound-assisted hot-water extraction protocol optimised <i>via</i> Box–Behnken response surface methodology (RSM-BBD), achieving a crude polysaccharide yield of 13.46%. Two homogeneous polysaccharide fractions (PPLP2, PPLP3) were isolated using DEAE anion-exchange chromatography.

Multi-spectroscopic and chromatographic characterisation revealed distinct backbone architectures: PPLP2 (4.6 kDa) is a neutral β-linked arabinogalactan, while PPLP3(4.4 kDa) is an acidic α-type pectic polysaccharide rich in galacturonic acid, as confirmed by FT-IR spectral analysis. <i>In vitro</i> tests revealed dose-dependent radical-scavenging and anti-carbohydrase effects for both fractions. PPLP3 exhibited superior antioxidant activity (IC₅₀: DPPH<b>^·</b> = 1.25 mg mL⁻¹, ABTS⁺<b>^·</b> = 0.98 mg mL⁻¹, hydroxyl radical = 1.42 mg mL⁻¹).