title: Structural, thermal, and anti-inflammatory properties of a novel pectic polysaccharide from alfalfa (Medicago sativa L.) stem.
abstract: A pectic polysaccharide (APPS) was purified from the cold alkali extract of alfalfa stem and characterized to be a rhamnogalacturonan I (RG-I) type pectin with the molecular weight of 2.38 × 10(3) kDa and a radius of 123 nm. The primary structural analysis indicated that APPS composed of a →2)-α-l-Rhap-(1→4)-α-d-GalpA-(1→ backbone with 12% branching point at C-4 of Rhap forming side chains by l-arabinosyl and d-galactosyl oligosaccharide units. Transmission electron microscopy (TEM) analysis revealed a primary linear-shaped structure with a few branches in its assembly microstructures. The thermal decomposition evaluation revealed the stability of APPS with an apparent activation energy (Ea) of 226.5 kJ/mol and a pre-exponential factor (A) of 2.10 × 10(25)/s, whereas its primary degradation occurred in the temperature range from 215.6 to 328.0 °C. In addition, APPS showed significant anti-inflammatory effect against mRNA expressions of the pro-inflammatory cytokine genes, especially for IL-1β, suggesting its potential utilization in functional foods and dietary supplement products.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Yaqiong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Bona
authors.initials: B
authors.lastname: Dai
authors.forename: Yuan
authors.initials: Y
authors.lastname: An
authors.affiliation: §Department of Nutrition and Food Science, University of Maryland, College Park, Maryland 20742, United States.
authors.forename: Liangli Lucy
authors.initials: LL
authors.lastname: Yu
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry* / Q000494:pharmacology; D002460:Cell Line; D016207:Cytokines / Q000235:genetics; D006358:Hot Temperature; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D000455:Medicago sativa / Q000737:chemistry*; D051379:Mice; D008970:Molecular Weight; D010368:Pectins / Q000737:chemistry* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D018547:Plant Stems / Q000737:chemistry
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D010936:Plant Extracts; D010368:Pectins
keywords: alfalfa pectic polysaccharide; anti-inflammatory effect; rhamnogalacturonan I; thermal analysis