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A novel homogenous polysaccharide LPWF together with its three acid hydrolysis products LPWF1–3 were isolated and prepared from lotus plumule (germs of Nelumbo nucifera). LPWF was composed of rhamnose (Rha), arabinose (Ara), galactose (Gal), xylose (Xyl), and galacturonic acid (GalA) in the molar ratio of 7.3: 34.0: 7.0: 19.1: 32.6 with a molecular weight of 567.6 kDa. The structure of LPWF was elucidated by methylation and NMR analysis of LPWF1–3 and a follow-up structural assembling aided by high-resolution mass spectrometry mapping of oligosaccharides and ROSEY spectra. LPWF was characterized as an unusual pectin linked by rhamnogalacturonan I (RGI, composed of LPWF1–2) and xylogalacturonan (XGA, LPWF3). LPWF1 was an arabinan peeled from the RGI part with a 1,5-linked backbone branching on the O -2 position, while LPWF2 was the remaining part of RGI composed of Rha (36.1%), Gal (17.8%), and GalA (43.7%). LPWF3 was identified as the XGA part with a backbone of α-1,4-linked GalA and branches of mono-xylose substitutions on the O -3 of GalA. LPWF (25 μg/mL) demonstrated significant inhibitions on the expression of IL-1β, IL-6, and TNF-α in LPS-stimulated primary murine microglia cultures. LPWF1 and 2 showed selectively and significantly inhibitory activity against the expression of IL-1β. • Structure features of the pectin LPWF was determined by NMR and methylation. • Structural characterization of LPWF was elucidated by assembling three stepwise hydrolyzed fragments. • LPWF is speculated to be a linearly linked RGI and XGA pectin. • The pectin LPWF could significantly inhibit the expression of IL-1β, IL-6, and TNF-α. [ABSTRACT FROM AUTHOR]

An endo -β-1,3(4)-glucanase AnENG16A from Aspergillus nidulans shows distinctive catalytic features for hydrolysis of β-glucans. AnENG16A hydrolyzed Eisenia bicyclis laminarin to mainly generate 3-O-β-gentiobiosyl- d -glucose and hydrolyzed barley β-glucan to mainly produce 3-O-β-cellobiosyl- d -glucose. Using molecular exclusion chromatography, we isolated and purified 3-O-β-cellobiosyl- d -glucose and 3-O-β-gentiobiosyl- d -glucose, respectively, from AnENG16A-hydrolysate of barley β-glucan and E. bicyclis laminarin. Further study reveals that 3-O-β-cellobiosyl- d -glucose had 8.99-fold higher antioxidant activity than barley β-glucan and 3-O-β-gentiobiosyl- d -glucose exhibited 43.0% higher antioxidant activity than E. bicyclis laminarin. Notably, 3-O-β-cellobiosyl- d -glucose and 3-O-β-gentiobiosyl- d -glucose exhibited 148.9% and 116.0% higher antioxidant activity than laminaritriose, respectively, indicating that β-1,4-linkage or -1,6-linkage at non-reducing end of β-glucotrioses had enhancing effect on antioxidant activity compared to β-1,3-linkage. Furthermore, 3-O-β-cellobiosyl- d -glucose showed 237.9% higher antioxidant activity than cellotriose, and laminarin showed 5.06-fold higher antioxidant activity than barley β-glucan, indicating that β-1,4-linkage at reducing end of β-glucans or oligosaccharides resulted in decrease of antioxidant activity compared to β-1,3-linkage. • A distinctive β-glucanase for preparation of glucooligosaccharide from β-glucan • Superdex™ 30 open column can efficiently purification of glucooligosaccharides. • Antioxidant activity increases with increase of DP of glucooligosaccharides. • β-1,4/1,6-Linkage at non-reducing end enhance antioxidant activity of oligosaccharide. • β-1,4-Linkage at reducing end decreases antioxidant activity of glucooligosaccharide. [ABSTRACT FROM AUTHOR]

Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides, and in-source fragmented MS for analysis of oxidized polysaccharides. The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0. [ABSTRACT FROM AUTHOR]