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Though the retrogradation property as affected by starch fine molecular structures has been widely investigated, it remains largely unexplored how concurrent starch structures and storage conditions e.g. temperature tailor the starch retrogradation property. The amylopectin long-term retrogradation for 8 different rice starches with a broad range of amylose content was thus investigated under different storage temperatures. Results showed that gelatinized starch stored at −20 °C generally had a narrower melting temperature range from differential scanning calorimetry, while larger cells and thicker cell walls in the gel matrix than that stored at 4 °C. Different linear correlations were found between starch fine molecular structures and amylopectin retrogradation parameters when starch was stored under different temperatures. For example, the melting enthalpy of retrograded starch double helices was negatively correlated with the amount of amylose intermediate chains at 4 °C, while positively correlated with the relative length of amylopectin short chains at −20 °C. Under both temperatures, rice starch R250 had the highest retrogradation enthalpy. These results could help the rice industry improve both the nutritional and textural attributes of cooked rice by selecting starch with desirable molecular structures and optimizing the storage conditions for rice after cooking. [ABSTRACT FROM AUTHOR]

This study isolated and characterized a novel polysaccharide (PNPS-0.3) from the residue of Panax notoginseng by gradient elution. PNPS-0.3 mainly consisted of a backbone of →4)- α-D-GalAp-(1 → 4-β-L-Rhap-1 → 4)-β-D-Galp-(1 → residues, with an α-L-Araf-1 → 5)-α-L-Araf-(1 → branch connecting to the backbone at O-3 of →4-β-L-Rhap-1 → and a molecular weight of 76,655 Da. Furthermore, the adjuvant potential of PNPS-0.3 with bone marrow dendritic cells (BMDCs) was investigated. The results suggested that PNPS-0.3 could induce maturation of BMDCs by reshaping the morphology, upregulating the CD40, CD80, CD86 and MHC II membrane phenotypic markers, and by promoting the secretion of TNF-α and IL-12 proinflammatory cytokines. Moreover, PNPS-0.3 can trigger the DC-induced T-cell immune response, as indicated by the higher expressions of CD4, CD8, CD69, and MHC II in T cells with increased secretion of INF-β. Furthermore, PNPS-0.3 can bind to the pattern recognition receptors (PRR) of Toll-like receptor 4 (TLR 4), Toll-like receptor 2 (TLR 2), and mannose receptor (MR) on BMDCs. PNPS-0.3 also upregulated the expressions of Myd88, IKKβ, P P65, T-P65, and NF - κB, suggesting that the TLR4/TLR2-NF-κB signaling pathway was involved in the immunomodulatory mechanism. In conclusion, the immunoadjuvant potential of novel PNPS-0.3 was characterized, which is beneficial for the future utilization and development of P. notoginseng. [ABSTRACT FROM AUTHOR]

The anti-aging activities on Caenorhabditis elegans of a polysaccharide, O -acetyl glucomannan (LPR), purified from roots of Lilium davidii var. unicolor Cotton, were assessed by observing the mean lifespan, reproduction, pharyngeal pumping and stress response on nematodes. Additionally, the fluorescence intensity of lipofuscin and the level of reactive oxygen species (ROS) were detected. Also the activities of superoxide dismutase (SOD), catalase (CAT) and contents of malondialdehyde (MDA) were determined by the kit method. The results showed that LPR effectively delayed the aging of C. elegans in a dose-dependent manner. When the concentration reached 4 mg/mL, LPR extended the mean lifespan of C. elegans by up to 40%, 61% (P < 0.01) and 50% (P < 0.05) under normal, thermal and oxidative stress culture conditions, respectively. Moreover, LPR remarkably increased the reproduction duration of the nematodes at a concentration of 1 mg/L, and significantly decreased the ROS and lipofuscin level of C. elegans in three dosage groups. Further study illustrated that LPR at 4 mg/mL strongly increased the activity of SOD and CAT by 39.03% (P < 0.01) and 41.89% (P < 0.05), and decreased the lipid peroxidation of MDA level in C. elegans by 52.59% (P < 0.005) compared to a control. It was inferred that LPR provided stress resistance to heat and oxidation, and prolonged the lifespan of wild type N2 C. elegans mainly by elevating the function of nematode antioxidant defense systems and by scavenging free radicals. These findings provided evidence for the anti-aging properties of this polysaccharide from L. davidii. Unlabelled Image [ABSTRACT FROM AUTHOR]

A polysaccharide (LPR) was separated from the roots of Lilium davidii var. unicolor Cotton with hot water extraction, ethanol precipitation, and purification by anion-exchange and gel-permeation chromatography. LPR was characterized. The weight-average molecular weight (M W) of LPR was 5.12 × 104 g/moL. Glucose and mannose comprised LPR with a molar ratio of 2.9:3.3. IR, NMR and methylation analysis showed that LPR was a natural O -acetyl glucomannan, the backbone mainly contained β-(1 → 4)-linked d -glucopyranosyl and β-(1 → 4)-linked D-mannopyanosyl, and the branches probably linked at O-2 and/or O-3 of the mannosyl and glucosyl residues. The acetyl groups mainly attached at O-2 or O-3 of mannosyl residues. X-ray diffractometric (XRD) analysis and scanning electron microscopy (SEM) analysis revealed that LPR was a semi-crystalline substance with porous lamellar structure. Bioassays in vitro indicated that LPR had distinct scavenging activities on hydroxyl radical and DPPH radical. These findings provided a reference for functional underutilization roots of L. davidii as natural antioxidant in food and pharmaceutical industry. Unlabelled Image • First report structure and bioactivities of polysaccharide (LPR) purified from the roots of L. davidii. • LPR was a glucomannan with O -acetyl group attached. • LPR was a semi-crystalline substance with porous lamellar structure. • LPR to scavenge hydroxyl radical stronger than that of Vc (especially the concentration < 0.3 mg/mL). [ABSTRACT FROM AUTHOR]

Two heteropolysaccharides, BHP-1 and BHP-2, were separated and purified from the edible bulbs of Lilium davidii var. unicolor Cotton by anion-exchange and gel-permeation chromatography. The primary structural characteristics of BHP-1 and BHP-2 were investigated by Congo red test, X-ray diffractometry (XRD) analysis, IR, GC and NMR. The results showed that the weight-average molecular weight (M W) and number-average molecular weight (Mn) of BHP-1 and BHP-2 were nearly 1.93 × 105 g/moL, 8.86 × 104 g/moL and 3.52 × 104 g/moL, 2.95 × 104 g/moL, respectively. Glucose and mannose comprised BHP-1 in a relative molar ratio of 5.9:2.0, and BHP-2 was consisted of glucose, galactose, mannose and arabinose with approximate molar ratios of 8.3:1.5:1.0:1.1. Their backbone mainly contained α-(1 → 4)-linked d -glucopyranosyl. In addition, the C-6 of the glucose and C-2 of mannose residue of BHP-1 and BHP-2 were substituted. The two polysaccharides were semi-crystalline substance with multi-branching structure and triple helix conformation. Bioassays showed that BHP-1 and BHP-2 had effective antioxidant activities evaluated by DPPH, scavenging superoxide radical and OH radical in a dose-dependent manner. The two heteropolysaccharides also displayed distinct and selective antibacterial activity against B. cereus , P. putida , M. luteus and K. pneumonia with inhibition zones of 13 mm, 16 mm, 17 mm, 23 mm and 12 mm, 17 mm, 19 mm, 20 mm, respectively. These findings provided a reference for potential applications of the polysaccharides from L. davidii as natural antioxidants and antibacterial agents in food and pharmaceuticals. Unlabelled Image • First report on the structure and activity of the polysaccharide by the 70% ethanol precipitation from Lanzhou lily. • Two polysaccharides purified with anion-exchange and gel-permeation chromatography from Lanzhou lily. • Two polysaccharides had effective antioxidant activities in vitro. • Two polysaccharides had distinct and selective antibacterial activity against test bacteria. [ABSTRACT FROM AUTHOR]