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Polysaccharide from seeds of Plantago asiatica L. is rich in calcium, which is important for keeping viscous and weak gelling properties of the polysaccharide. However, few studies reported effect of calcium on solution and conformational characteristics of the polysaccharide. In this study, polysaccharide was prepared from seeds of P. asiatica L. and named as PLCP. PLCP was treated with EDTA to remove calcium ion to get PLCP-E. PLCP and PLCP-E were characterized by Ubbelohde capillary viscometer, light scattering and HPSEC with refractive index, light scattering and viscometric detectors. The results showed that PLCP had much higher intrinsic viscosity, hydrodynamic radius ( R h ), radius of gyration ( R g ) and molecular weight than that of PLCP-E when measured in the same solvent. PLCP and PLCP-E were in random coil conformation in aqueous solutions according to light scattering and HPSEC measurements. HPSEC data showed PLCP-E had lower intrinsic viscosity than that of PLCP with the same molecular weight. Persistence length of L p was 2.5 nm for PLCP and 2.3 nm for PLCP-E, respectively. In conclusion, PLCP exhibited higher intrinsic viscosity and molecular weight, and stiffer conformation than that of PLCP-E, which could explain the reason of higher viscosity of PLCP. [ABSTRACT FROM AUTHOR]

Abstract: A water-soluble heterogalactan, designated as PSG-2 was isolated and purified from the fruiting bodies of Ganoderma atrum. The molecular weight of PSG-2 was 6.9 × 104 Da by HPSEC determination. Its structure was analyzed using monosaccharide composition, partial acid hydrolysis, methylation analysis, combined with FT-IR spectra and 1D/2D NMR spectroscopy. PSG-2 was composed of galactose, fucose and glucose with molar percentage of 75.87%, 11.83% and 6.02%, respectively. Low content of mannose was also detected. Acetyl group was found in PSG-2 by FT-IR and NMR spectra. The backbone of PSG-2 consisted of 1,6-Galp (55.29%), and the short branched chains were attached to its O-2 position (1,2,6-Galp, 15.76%). The terminal residues contained T-Fucp (8.71%), T-Galp (5.97%) and T-Manp (1.83%). Three sugar residues, 1,2-Galp, 1,4-Glcp and 1,3-Glcp were also found to be with comparable amounts. Based on these results and NMR spectroscopy, a structure of PSG-2 was proposed as follows: ▪ where R would be one of the following fragments: T-α-D-Galp(1 → 6)-2-OAc-α-D-Galp-(1→, T-α-D-Galp(1 → 6)-α-D-Galp-(1 → 4)-β-D-Glcp-(1→, T-α-D-Galp or T-α-D-Manp. [Copyright &y& Elsevier]

Highlights: [•] The C. paliurus polysaccharides could be effectively separated by ultrafiltration. [•] Four polysaccharide fractions were isolated by ultrafiltration membranes. [•] Its molecular weight distribution properties were elucidated by HPGPC. [•] The method is easy to scale up for polysaccharides preparation. [ABSTRACT FROM AUTHOR]

This study explored the physicochemical properties and structural characteristics of Agrocybe cylindracea polysaccharides at four developmental stages, as well as their dynamic evolution during maturation. Results showed that the polysaccharides from A. cylindracea water extract exhibited similar structural characteristics across all four maturity stages, despite a significant reduction in yields. Four water-soluble heteroglycans, including one high molecular weight (ACPM-Et50-I) and three low molecular weight (ACPM-Et50-II, ACPM-Et60, ACPM-Et80), were isolated from A. cylindracea at each maturity stage. ACPM-Et50-I was identified as branched heterogalactans, while ACPM-Et60 and ACPM-Et80 were branched heteroglucans. However, ACPM-Et50-II was characterized as a branched glucuronofucogalactoglucan at the tide-turning stage but a glucuronofucoglucogalactan at the pileus expansion stage due to the increase of its α-(1 → 6)-D-Gal p. In general, although the structural skeletons of most A. cylindracea heteroglycans were similar during maturation as shown by their highly consistent glycosyl linkages, there were still differences in the distribution of some heteroglucans. This work has for the first time reported a glucuronofucogalactoglucan in A. cylindracea and its dynamic evolution during maturation, which may facilitate the potential application of A. cylindracea in food and biomedicine industries. [Display omitted] • The polysaccharides from A. cylindracea water extract exhibited similar structural characteristics across four maturity stages. • Four water-soluble heteroglycans with different molecular weights were obtained at each stage. • ACPM-Et50-I was identified as branched heterogalactans, while ACPM-Et60 and ACPM-Et80 were branched heteroglucans. • ACPM-Et50-II was identified as a glucuronofucogalactoglucan at the tide-turning stage but a glucuronofucoglucogalactan at the pileus expansion stage. [ABSTRACT FROM AUTHOR]

Abstract: A water-soluble polysaccharide was isolated from the water extract of Cyclocarya paliurus (Batal.) Iljinskaja, which is a well-known native health tea in China. This polysaccharide was named as CPP-1. The molecular weight of CPP-1 was determined by high-performance gel permeation chromatography, with an average molecular weight of about 1167kDa. The analysis of monosaccharide composition in the polysaccharide by gas chromatography revealed that it was a heteropolysaccharide and consisted of d-xylose, l-arabinose, d-glucose, d-galactose, l-rhamnose and d-mannose in a molar ratio of 1.00:9.67:9.65:4.96:3.29:2.70. Furthermore, CPP-1 contains 8.44% of protein and 17 general amino acids, and it is rich in glutamic acid, asparagic acid, leucine, glycine, arginine, tyrosine and alanine. The antioxidant activity of CPP-1 was also evaluated. It was found that CPP-1 exerted significant scavenging effects on DPPH radicals with a value of around 91.4%, compared to the reference controls of BHT (91.2%) and ascorbic acid (98.9%) at a concentration of 400μg/ml, and with EC50 values of 52.3μg/ml. [Copyright &y& Elsevier]

Three water-soluble pectic polysaccharides (WKBP-P2, P3 and P4) were isolated from white kidney bean by ion exchange combined with size-exclusion methods. The structural features were characterized by GC–MS, NMR spectroscopy and HPSEC-MALLS-RI. It was found that three pectic polysaccharides were the major water-extracted polysaccharides in white kidney bean. All the WKBP-P2, P3 and P4 were probably composed of various structural regions including homogalacturonan (HG), xylogalacturonan (XGA), rhamnogalacturonan I (RG-I) regions in backbone, and arabinan region mainly as side chain. However, these pectic polysaccharides were significantly different in molar ratios of these structural regions and molecular size. WKBP-P2 was HG-predominant pectin (partially methyl-esterified) with weight-average molecular weight (M w) of 1.2 × 104 g/mol, and contained minor RG-I, arabinan and probable XGA regions. WKBP-P3 (M w of 4.0 × 104 g/mol) primarily embraced XGA, HG, arabinan regions and minor RG-I region. WKBP-4 with highest M w (4.5 × 105 g/mol) had the most arabinan region (51.3%), which was probably the side chain linked to the backbone composed of RG-I, HG and slight XGA regions. These findings provided a structural basis for study on polysaccharides from white kidney bean, which was benefit for development of functional food. [Display omitted] • Pectic polysaccharides (WKBP-P2, P3 and P4) were isolated from white kidney bean. • WKBP-P2 (M w of 1.2 × 104 g/mol) was characterized by the predominance of HG. • WKBP-P3 (M w of 4.0 × 104 g/mol) probably consisted of XGA, HG and minor RG-I. • WKBP-P4 (M w of 4.5 × 105 g/mol) had 51.3% arabinan, certain HG, RG-I and slight XGA. [ABSTRACT FROM AUTHOR]

Polysaccharides were extracted by hot water and alkali in sequence from Dolichos lablab L. hull, and further purified by ion-exchange and gel columns. Hot water extracted D. lablab hull polysaccharide (DLHP) was rich in glucuronoxylan and pectin, and alkali extracted polysaccharide (DLHAP) mostly embraced glucuronoxylan. The structures of purified glucuronoxylans from DLHP and DLHAP were mainly analyzed by HPAEC-PAD, methylation combined with GC–MS, NMR and SEC-MALLS. DLHP-1 was identified as acetylated glucuronoxylan containing →4)-β-Xyl p- (1→ backbone with substitution at O -2 site by α-Glc p A/4- O -methyl-α-Glc p A. The molar ratio of β-Xyl p to α-Glc p A was 6.9:1, and acetylation was mainly at O -3 site of β-Xyl p with acetylation degree of 21.5%. DLHP-1 and DLHP-2 had similar physicochemical properties, except for molecular weight (M w). DLHAP-1 was the non-methylated glucuronoxylan almost without acetylation, and it had the molar ratio of β-Xyl p to α-Glc p A of 5.6:1. Besides, DLHP-1 (M w of 20.0 × 103 g mol−1) adopted semi-flexible chain, while DLHAP-1 (M w of 15.4 × 103 g mol−1) showed flexible chain. These results provided a structural basis for study on polysaccharides from D. lablab hull, which was benefit for understanding biological activities and developing functional food or pharmaceuticals of D. lablab. • Water and alkali isolated glucuronoxylans of Dolichos lablab L. hull were obtained. • Water extracted DLHP-1 was acetylated glucuronoxylan with Xyl/GlcA ratio of 6.9:1. • Alkali extracted DLHAP-1 was glucuronoxylan with Xyl/GlcA ratio of 5.6:1 in non-methylated form. • DLHP-1 and DLHAP-1 adopted the semi-flexible and flexible chain, respectively. [ABSTRACT FROM AUTHOR]

Glucomannans (GMs) from abundant natural resources have excellent processing properties and plentiful bioactivities. In current study, functional properties of GMs with different structural characteristics, including KGM from konjac, DOP from dendrobium, AGP 40 , ASP-4N, ASP-6N, & ASP-8N from aloe were determined. Results suggested that molecular weights (M w) of GMs were positively correlated with their water absorption capacity, fat absorption capacity, and viscosity, while ratio of mannose/glucose showed negative effect. Higher degree of acetylation (DA) mainly corresponded to higher values of solubility and ζ -potential. Then, effects of the six GMs on general health status, serum biochemicals, and intestinal SCFAs production in mice were evaluated in vivo. Analysis of general health status and levels of serum biochemicals revealed that mice with consecutive supplementation of GMs for 14 days performed normally compared with those in control group. Interestingly, the productions of SCFAs (mainly acetate and butyrate) in the cecal and colonic contents were significantly promoted. Generally, higher concentrations of SCFAs were produced when mice were treated with GMs having higher M w , ratio of glucose, and DA. The current investigation suggested that both functional and intestinal fermentation property of GMs were jointly determined by the monosaccharide composition, molecular weight, and degree of acetylation. • Functional properties of GMs with different structures were compared. • The M w positively influenced viscosity and water absorption capacity of GMs. • Degree of acetylation (DA) mainly affected zeta potential and solubility of GMs. • Effects of GMs on serum biochemical and intestinal SCFAs production were evaluated. • The M w , DA, and M/G ratio were all related to production of intestinal SCFAs. [ABSTRACT FROM AUTHOR]

• Water-extracted pomelo albedo pectin (PAP) was high methoxyl pectin. • PAP was composed of arabinose, glucose and galacturonic acid. • Apparent viscosity of PAP was concentration-dependently increased. • Interaction between PAP and konjac glucomannan was occurred. Pomelo albedo was extracted with water to obtain the high methoxyl pectin, labeled as PAP. The physicochemical and rheological properties of PAP were determined. The effects of PAP addition on rheological property and thermal stability of konjac glucomannan (KGM) were evaluated. Results indicated that PAP was composed of arabinose, glucose and galacturonic acid with a relative mass percentage of 7.2%: 9.5%: 83.3%, and exhibited an average molecular weight of 56.6 kDa. The degree of esterification of PAP was 65.5%, showing PAP was a kind of high methoxyl pectin. Apparent viscosity of PAP was concentration-dependently increased, while it was slightly enhanced with salt (NaCl or CaCl 2) addition. Moreover, the addition of PAP declined the apparent viscosity, elastic property and thermal stability of KGM. It can be concluded that interaction was occurred between KGM and PAP. Meanwhile, the interaction mechanism between KGM and PAP has been preliminarily proposed. The present study can provide some references for the application of PAP and support the combination usage of this pectin and KGM in food and other industries. [ABSTRACT FROM AUTHOR]

Glucomannans (GMs) are a group of hydrophilic polysaccharides, which have been produced from different parts of natural plants. Studies on plant-derived GMs contribute to wide applications of GMs or GMs-added products that have desirable quality and health characteristics. Among those popular GMs, konjac glucomannan (KGM) and acemannan are the most famous ones that have been widely reviewed from various points in recent years. However, there is a lack of a comprehensive review to introduce the sources, extraction and purification methods, structural features, and other aspects of GMs from common natural plants such as Aloe, Dendrobium, Bletilla, and so on. This review firstly presents the extraction and purification technologies of GMs from different plant sources, aiming at optimizing more effective production methods with specific treatments for special plant origins. After that, structural features, biological properties, as well as structure-function relationship are summarized. GMs have been widely isolated from different sectors (leaf, stem, and roots) of many plant resources. A general extraction and purification procedure together with several suggestions is put forward to prepare GMs. Although the β-(1 → 4)-linked main chain has been confirmed, detailed structural characteristics of GMs such as side chain and functional group related properties need further studies. Molecular weights, monosaccharide composition, and acetyl group of GMs are key factors that have been identified to affect plentiful biological properties such as immunomodulatory, anti-tumor, anti-diabetic activities. However, the inherent action mechanisms remain unclear. Several research interests in the future are recommended. Image 1 • Sources, methods for extraction and isolation of glucomannans are outlined. • Chemical features of glucomannans are discussed. • Glucomannans have assorted potential, but remains underdeveloped. • Structure–activity relationships of glucomannans are discussed. [ABSTRACT FROM AUTHOR]

Abstract Aloe barbadensis Miller (Aloe vera) has long been used in food, cosmetic and pharmaceutical industries. The solid wastes such as the spikes and the outer green skins are usually separated from the inner gel and discarded during the process of Aloe vera leaves. Three kinds of polysaccharides (designated as ASP-4N, ASP-6N and ASP-8N) were successfully purified from the leaf skin of Aloe vera in our previous work. The present study aimed to analyze the structural and molecular features of ASP-6N and ASP-8N using methylation and GC-MS, NMR, high performance size-exclusion chromatography coupled with multi-angle laser light scattering (HPSEC-MALLS) and scanning electron microscopy (SEM) techniques. Results showed that ASP-6N and ASP-8N were β-(1→4)-glucomannans with acetyl groups, which may attach to O -2, O -3 or O -6 of mannopyranosyl residues in the backbone as mono-, di-, or tri-acetylated forms. HPSEC-MALLS analysis indicated that the polysaccharide fractions from Aloe leaf skin adopted various conformations in the aqueous solution depending on their molecular mass. The polysaccharides had fibrous, ribbon-like and spherical morphology by SEM observation. Graphical abstract Image 1 Highlights • Two polysaccharides from leaf skin of Aloe vera were identified to be O -acetyl-β-(1→4)-glucomannans. • The acetyl groups attached at O -2, O -3 and/or O -6 positions. • HPSEC-MALLS analysis showed that they adopted various conformations in aqueous NaNO 3 solution. [ABSTRACT FROM AUTHOR]

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-Gal p A-(1 → and →4)-α-Gal p A-6- O -methyl-(1 →, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides. • Two pectic polysaccharides (FWP-60 and FHWP-50) were purified from Fructus aurantii. • Both FWP-60 and FHWP-50 were composed of HG and RG-I regions. • FWP-60 and FHWP-50 emulsions exhibited the different stability behaviors. • The effect of structures on emulsifying properties of FWP-60 and FHWP-50 were discussed. [ABSTRACT FROM AUTHOR]

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-Gal p A-(1 → and →4)-α-Gal p A-6- O -methyl-(1 →, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides. • Two pectic polysaccharides (FWP-60 and FHWP-50) were purified from Fructus aurantii. • Both FWP-60 and FHWP-50 were composed of HG and RG-I regions. • FWP-60 and FHWP-50 emulsions exhibited the different stability behaviors. • The effect of structures on emulsifying properties of FWP-60 and FHWP-50 were discussed. [ABSTRACT FROM AUTHOR]

In this study, three chemically carboxymethyl polysaccharides (CM-CPs) were derived from Cyclocarya paliurus polysaccharides. The physicochemical properties and antioxidant activity in vitro of carboxymethyl derivatives were determined. The results of degree of substitution and FT-IR analysis showed the carboxymethylation of polysaccharides were successful. Compared with unmodified polysaccharides, the contents of carbohydrate and protein were decreased while CM-CP 3 with highest DS value had more uronic acid. The carboxymethyl derivatives was mainly composed of Ara, Gal, Glc, Man, GalA, with a molecular weight ( Mw ) of 1.03–1.08 × 10 6 Da. Compared with the native polysaccharide, the CM-CP 3 with highest DS and Mw exhibited the highest antioxidant activity in β-carotene–linoleic acid assay. However, the superoxide radical and hydroxyl radical scavenging activity were decreased by CM-CPs. These results demonstrated appropriate carboxymethylation modification could enhance the potential of C. paliurus polysaccharide as oxidation inhibitor. [ABSTRACT FROM AUTHOR]

In this study, polysaccharides extracted from Cyclocarya paliurus leaves were modified to obtain its three acetylated derivatives, Ac-CP 1 , Ac-CP 2 , and Ac-CP 3 . The physicochemical characteristics and antioxidant activities of acetylated derivatives were investigated. The results of chemical and FT-IR spectrum analysis showed differences between acetylated derivatives and native C. paliurus polysaccharide, which revealed that the acetylation were successful. Relative to unmodified polysaccharide, the protein contents of acetylated derivatives decreased, while carbohydrate values increased. The molecular weight (Mw) of acetylated derivatives were approximately 1.05–1.09 × 10 6 Da and were mainly composed of Ara, Gal, Glc, Man, GalA. Ac-CP 1 with relatively low degree of substitution (0.13 ± 0.01) exhibited excellent antioxidant activity in DPPH radical assay (95.21 ± 0.89%), and also had strong chelating activity on β-carotene–linoleic acid assay (34.64 ± 2.07%) at 0.5 mg/ml. In addition, scanning electron microscope (SEM) observations suggested that acetylation could change the morphology and structure of polysaccharides from C. paliurus leaves. [ABSTRACT FROM AUTHOR]

Abstract: Black-bone silky fowl (Gallus gallus domesticus Brisson) (BSF) muscle was hydrolyzed by papain, and the hydrolysate was separated by preparative high performance liquid chromatography (HPLC). The amino acid composition of the BSF hydrolysate (BSFH) and its fractions was determined by HPLC precolumn derivation with 2,4-dinitrofluorobenzene. The molecular weight (MW) distribution of the BSFH and its fractions was measured by a peptide column on an HPLC system. Antioxidant activities of the BSFH and its fractions were studied by testing the reducing power and four radical scavenging systems: superoxide anion (O2 −), hydroxyl (·OH), 1,1-diphenyl-2-picrylhydrazyl (DPPH''-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS +) radicals. The results demonstrated that the BSFH had strong antioxidant capacity to scavenge O2 −, DPPH +, and displayed strong reducing power, but revealed less powerful ability to scavenge ·OH. Fraction II of the BSFH exhibited the highest activity in scavenging O2 − and DPPHucing power, whereas fraction I displayed the strongest ·OH scavenging ability. Besides Glu, Asp and Gly, the rich amino acids of Ala and Leu played an important role in antioxidant activity. The small-size peptides with MW ranging from approximately 200–6000Da probably contributed to higher antioxidant activity. Results from this study indicated that BSFH and its fractions could be used as food additives and diet nutrients. [Copyright &y& Elsevier]

[Display omitted] • Water-extracted polysaccharides from M. albuminosa (MAWP) were purified into three sub-fractions. • Three purified fractions exhibited significant polysaccharide structural heterogeneity. • MAWP contained glucomannogalactans and galactoglucans with different viscosity. • Three fractions adapted random coil conformation in aqueous solution. Macrolepiota albuminosa (Berk.) Pegler is abundant in active polysaccharides, but little is known about their structures and solution properties. In this study, water-extracted polysaccharides from M. albuminosa (MAWP) were purified into three fractions with structural heterogeneity, which was attributed to the diversity in molecular weight, monosaccharide composition and linkage patterns, further affecting their solution properties. Methylation and NMR analysis revealed MAWP-60p and MAWP-70 were a 3- O -methylated glucomannogalactan and a previously unreported glucomannogalactan, whereas MAWP-80 was elucidated as a branched galactoglucan. Besides, three fractions exhibited random coil conformation in aqueous solution, while MAWP-60p had the highest viscosity due to its highest molecular weight, mean square radius of gyration (R g) and O -methyl group attached to the backbone. The molecular weight, monosaccharide composition and glycosidic linkages might be the major contributors to the flexibility, molecular size and stereochemistry of mushroom polysaccharide chains. [ABSTRACT FROM AUTHOR]

[Display omitted] • A branched galactoglucan was purified from alkali-extracted polysaccharides from M. albuminosa. • It exhibited a random coil conformation with a molecular weight of 210 kDa. • Its steady flow behavior was highly dependent on concentration. • The structure of alkali-extracted polysaccharides from M. albuminosa was given for the first time. A homogeneous galactoglucan was purified from the alkali-extracted polysaccharides from the basidioma of Macrolepiota albuminosa by gradient ethanol precipitation, whose proposed structure was given for the first time. Results showed it had a molecular weight of 210 kDa, and mainly consisted of glucose and galactose. There were abundant filaments, randomly distributed sheet-like and flaky appearance in its surface by SEM observation. Its backbone comprised β-(1 → 6)-Glc p , α-(1 → 6)-Gal p and β-(1 → 3,6)-Glc p residues at 4:1:1, terminated by β-(1 → 3)-Glc p and T -Glc p residues. Rheological measurements suggested its steady flow behavior was highly dependent on concentrations. Newtonian behavior was evident at low concentrations, whereas pseudoplastic behavior was observed at high concentrations. Besides, the X-ray diffraction patterns proved the presence of amorphous structure. The conformational parameters were detected by HPSEC-MALLS-RI, revealing a random coil conformation in NaNO 3 aqueous solution. This work provides a theoretical basis for the application of polysaccharides from M. albuminosa in food- and drug-based therapies. [ABSTRACT FROM AUTHOR]

The water-extracted polysaccharide from Portulaca oleracea L. mainly consisted of two pectic polysaccharides designated as POWP-H and POWP-L. The POWP-L was rich in linear homogalacturonan with GalA content of 77.6%, while POWP-H might be a rhamnogalacturonan I (RG-I) pectin composed of Rha (15.7%), Ara (31.7%), Gal (42.5%) and GalA (10.1%). The structure of POWP-H was elucidated by partial degradation, methylation analysis combined with GC-MS method and NMR spectroscopy. It had a weight-average molecular weight of 1.2 × 106 g/mol and high degree of branch of 0.57. The presence of abundant arabinogalactan-II and certain galactan side chains in POWP-H was verified by the T-Ara f (17.4%), 1,3,6-Gal p (11.8%), 1,3-Gal p (8.1%), T-Gal p (13.4%) and 1,4-Gal p (14.3%). The evidence for the RG-I backbone of POWP-H was demonstrated by the structure analysis of its degraded product POWP-H-H, which had the backbone of →4)-α-Gal p A-(1 → 2)-α-Rha p -(1 → 4)-α-Gal p A-(1 → 2,4)-α-Rha p -(1→ substituted by short side chain of β-Gal p -(1 → 4)-β-Gal p -(1→ at O -4 position of →2,4)-α-Rha p -(1 →. Moreover, the POWP-H-H was mainly O -acetylated at O -3 position of α-Rha p with 24.8% acetylation degree. In conclusion, POWP-H was mainly the highly branched and acetylated RG-I pectin with relative short RG-I backbone and abundant arabinogalactan II and certain galactan side chains. Besides, it adopted a flexible chain conformation in 0.1 M NaNO 3 solution. Image 1 • Pectic polysaccharides (POWP-H and POWP-L) were isolated from Portulaca oleracea. • POWP-L was rich in homogalacturonan with 79.8% GalA. • POWP-H (M w of 1.2 × 106 g/mol) was rich in highly branched and acetylated RG-I. • Arabinogalactan II, galactan as main side chain probably linked to RG-I in POWP-H. [ABSTRACT FROM AUTHOR]

While polysaccharides are the most abundant biomacromolecules widely distributed in nature, little is known in their chemical structures and functional mechanism. Compared with DNA and protein, polysaccharides possess more complex structures and composition with various molecular size, conformational shape and charge characteristic. Currently, the lack of a uniform and clear consensus of polysaccharide purity leads to low accuracy of structural analysis. In the present study, a new theory on polysaccharide purification named as "relative ordered structure" was proposed, which was used to purify the water-extracted polysaccharides from Hypsizygus marmoreus (SHMP), successfully giving five purified sub-fractions. Results showed that their major chemicals were similar, while molecular weights, monosaccharide compositions, surface morphology, solution properties as well as their structural features enormously varied. Methylation and 1D/2D NMR analysis indicated the presence of α-glucans, fucomannogalactans and galactoglucan in SHMP, further confirming the feasibility of this theory in isolation and purification of natural polysaccharides. Based on the results and previous reports, this work aims to introduce and generalize the "relative ordered structure" theory. Altogether, structural characterization of polysaccharides cannot simply "copy" the techniques on protein, more theories and methodology applicable to polysaccharide itself should be established. Image 1 •"Relative ordered structure" effectively guides the purification of complex polysaccharide. •Five fractions were successfully purified from the water-extracted polysaccharides from H. marmoreus (SHMP). •They presented different viscosities and structures with high sugar content and narrow M w distribution. •SHMP contained α-(1→ 4)-glucans, fucomannogalactans and galactoglucans. [ABSTRACT FROM AUTHOR]

Polysaccharide from Agrocybe cylindracea has been demonstrated to exhibit excellently biological functions, but insufficient understanding of its physicochemical property and fine structure limits its wide application and development. In the present study, two water-soluble heteroglycans, a high molecular weight (SACP-40) and a low molecular weight (SACP-80), were isolated from the fruit bodies of A. cylindracea by hot water extraction and gradient ethanol precipitation. There was little difference in their physicochemical properties, including major chemicals and monosaccharide compositions. Rheological measurements revealed SACP-80 was a typical pseudoplastic fluid with shear thinning behavior at the concentration of 3.0%, whereas exhibited a near-Newtonian fluid at lower concentration. SEM observation suggested SACP-80 showed micro-spherical shapes loosely attached to fibrous filament in its surface. Besides, methylation and 1D/2D NMR analysis indicated that SACP-80 was a branched heteroglycan with a backbone composed of β-(1 → 6)-glucopyranosyl, α-(1 → 6)-galactopyranosyl and α-(1 → 2,6)-glucopyranosyl residue at a ratio of 3:1:1. This work provides a theoretical basis for gaining insight into the relationship between the fine structure and viscosity of polysaccharide from A. cylindracea , which could further guide its functional studies and advance the potential application in food and biomedicine industries. Image 1 • Two water-soluble heteroglycans with different molecular weights were obtained. • Glucose, galactose and fucose with different ratios were found in SACP-40 and SACP-80. • SACP-80 exhibited low viscosity and weak gel property at higher concentration. • The backbone of SACP-80 was elucidated. [ABSTRACT FROM AUTHOR]

• Four fractions were successfully purified from the alkaline extract of A. cylindracea. • Their morphology, solution properties and structural features enormously varied. • The four sub-fractions contained fucoglucogalactans and β-glucans. • JACP-30 exhibited the highest apparent viscosity with shear thinning behavior. Agrocybe cylindracea is a common source of active polysaccharides, but their fine structures are not clearly elucidated. In the present study, four fractions were purified from the alkaline extract of A. cylindracea (JACP), and their chemical components and structures were compared by HPAEC-PAD, methylation combined with GC–MS, and 1D/2D NMR analysis. Results showed the purified fractions' physicochemical properties, including monosaccharide compositions, molecular weights, viscosities and surface morphology considerably varied. JACP-30 was identified as a fucoglucogalactan with a α-(1 → 6)-galactopyranosyl as main chain. JACP-50p and JACP-80r were characterized as β-(1 → 6)-glucans with side chains composed of terminal and 3-substituted β-glucopyranosyl residues attached at O -3 for every three residues. Similarly, the backbone of JACP-80 was β-(1 → 6)-linked glucopyranosyl and β-(1 → 3,6)-linked glucopyranosyl residues at a ratio of 4:1. This work provides more information to the understanding of polysaccharides from A. cylindracea , further guiding its biological researches and developing the application in food and biomedicine industries. [ABSTRACT FROM AUTHOR]

Previous studies have suggested that water-soluble polysaccharides from fermented carrot pulp (WSP-p) have stronger anti-diabetic effects than those from un-fermented carrot pulp (WSP-n). This study aimed to improve understanding of these functional differences by comparing their molecular structures. Weight-average molecular weights of WSP-p fractions were lower than those of the corresponding WSP-n fractions. While both WSPs had similar functional groups, more fragmented particles were observed on the surface of large particles of WSP-n than WSP-p. Monosaccharide composition and methylation analysis confirmed that both WSP-p and WSP-n were pectic polysaccharides, containing rhamnogalacturonan-I-type polysaccharides with 1,4-linked α- d -galacturonic acid residues and homogalacturonan regions with 1,4-Gal p A linkages. 1H and 13C NMR showed that they had similar linkage patterns. These findings suggested that probiotic fermentation of WSP mainly cleaved the linkages between repeating units, and resulted in less polydisperse molecular size distributions. [ABSTRACT FROM AUTHOR]

Arabinoxylan (BIF-60) was isolated from barley water-insoluble fiber (BIF) by ethanol precipitation at 60 % (v/v). BIF-60 was composed of xylose (48.5 %) and arabinose (30.3 %). Its average molecular weight was 1360 kDa. Methylation and 1D/2D NMR analysis showed that BIF-60 possessed β-(l→4)-xylan as backbone, comprised of un-substituted (1,4-linked β-Xyl p , 56.9 %), mono-substituted (1,2,4-linked and 1,3,4-linked β-Xyl p , 22.1 %) and di-substituted (1,2,3,4-lin4ked β-Xyl p , 18.4 %) xylose units, as well as other residues (T-Ara f -(1→, T-Xyl p -(1→, →5)-Ara f -(1→, →2)-Ara f -(1→, →3)-Ara f -(1→ and →4)-Glc p -(1→). BIF-60 exhibited shear-thinning behaviour, low gel stability and weak gelling ability at high concentrations. This work provides a theoretical and experimental basis for molecular structure and properties of the alkali-extracted arabinoxylan from barley kernel, which could guide further functional research and application of barley-derived arabinoxylan. [ABSTRACT FROM AUTHOR]

• Konjac glucomannan (KGM) of 823.4 kDa was partially degraded by β-mannanase. • The two degraded products (147.2 kDa and 21.5 kDa) had similar structure to KGM. • The degraded products could be more rapidly fermented than native KGM in the colon. • Moderate degradation of KGM may improve its effects on intestinal functions. Konjac glucomannan (KGM) with a molecular weight (MW) of 823.4 kDa was partially degraded by endo-1,4-β-mannanase. Two hydrolyzed KGM fractions (KGM-M-1: 147.2 kDa and KGM-M-2: 21.5 kDa) were characterized and applied to the animal tests in comparison with the native KGM. After oral feeding to the mice, KGM-M-1 and KGM-M-2 significantly increased the levels of short chain fatty acids (SCFAs) in the colonic contents and the native KGM increased the SCFAs in the cecum. The more significant effect of the native KGM in the cecum may be attributable to its high viscosity, slowing down the movement of intestinal microflora through the cecum, while the lower MW KGM-M-1 and KGM-M-2 could move more easily through the colon to be fermented by colonic bacteria. This new finding may be useful for future research and development of low-MW KGM polysaccharides through enzyme hydrolysis for the desired gut health benefits. [ABSTRACT FROM AUTHOR]

The present study mainly elucidated fine structural information of four O -acetyl-glucomannans (Ac GMs) from Amorphophallus rivirei (konjac), A. albus , and two local types of A. bulbifer (wild type M and wild type B), which were named as KGM, AGM, MGM, and BGM, respectively. Distributions of sugar units and acetyl groups along the main chain were examined by NMR spectroscopy and MALDI-TOF-MS methods in combination with partial degradations. Results of 2D NMR suggested that the basic building blocks of backbones were almost the same for all fractions regardless of their sources. Mono-acetylation at O -2 and O -3 of mannoses were the dominant substitution forms of the four samples. Data from HMBC and NOESY spectra showed that the partially acetylated mannosyl residues linked to both non-acetylated sugar residues and acetylated mannosyl residues. The high relative percentage of oligosaccharides with lower molecular weights in MALDI-TOF-MS spectra of KGM indicated that it had more M4-M4 disaccharide units in the polymer chain compared with AGM, MGM, and BGM. In addition, KGM had O -2,3 di-acetylated mannosyl residues deduced from the trimers with five acetyl groups. Monosaccharide compositions of the products after partial acid hydrolysis suggested that non-random repeating units consisting of mannose and glucose existed in AGM. However, such regularity of distribution of sugar residues was not found in KGM, MGM, and BGM. Glucoses in these fractions presented at the periphery of polymer chain with different random patterns. Image 1 • Distribution of sugar units of four glucomannans from konjac tubers was elucidated. • All GMs had various acetylated and/or non-acetylated disaccharide units. • Sugar residues at outside of GMs chains were in random distribution patterns. • KGM from A. rivirei had O -2,3-di-acetylated mannosyl residues. • The distribution of sugar residues was more regular for AGM from A. albus. [ABSTRACT FROM AUTHOR]

Viscous polysaccharide is one kind of main bioactive components in Plantago asiatica L. seeds. This study aims to investigate effects of various monosaccharides, disaccharides, especially ascorbic acid (VC), on apparent viscosity and physicochemical properties of crude water soluble polysaccharide from the seeds of P. asiatica L. (PLWEP-C), as well as its stability and degradation mechanism. Results showed that small molecules such as glucose, sucrose, maltose, and lactose had little effects on apparent viscosity of PLWEP-C, while VC could significantly reduce the viscosity. There was no obvious change in FT-IR spectra and monosaccharide composition of PLWEP-C after VC addition. Hydroxyl radicals were probably involved in the degradation of polysaccharide induced by VC, which was confirmed by glucose inhibition test. SEM observation showed that PLWEP-C was mainly in lamellar and filamentous appearance, and no great change was generated by VC. The solution stability of PLWEP-C can only be kept well, when VC was at low concentration and low temperature. In conclusion, VC could significantly reduce the viscosity of polysaccharide from the seeds of P. asiatica L., which was probably attributed to the reduction of molecular weight. Hydroxyl radicals participation were probably one of main reasons in the degradation process. Image 100055 • Polysaccharide from the seeds of Plantago asiatica L. (PLWEP-C) was interacted with ascorbic acid (VC). • Apparent viscosity and molecular weight of PLWEP-C decreased after the interaction. • The morphology appearance, FT-IR spectra and monosaccharide composition of PLWEP-C was not changed a lot after the interaction. [ABSTRACT FROM AUTHOR]

An alkali-extracted polysaccharide (HEAEP-0.5) was prepared from the water insoluble residue of Hericium erinaceus fruiting body. Effects of concentration, temperature, pH and salts on its rheological property were systematically evaluated. Its physicochemical property, structural characteristic and intrinsic viscosity were also determined. Results revealed that HEAEP-0.5 was a β-D-glucan polymer, which contained a →3)-Glc p -(1→ backbone branched with Glc units at O -6 position. HEAEP-0.5 was a high molecular weight (5400 kDa and 290 kDa) polysaccharide showing high viscosity with an intrinsic viscosity value as 1.43 L/g, and revealing a triple helix conformation. It exhibited strong shear-thinning behavior and could form weak gels as concentration increased. Increase in concentration and addition of NaCl or CaCl 2 elevated the apparent viscosity and gel strength of HEAEP-0.5 solution, while reverse was the case as temperature increased. The gel formed by this polysaccharide at the concentration of 2.0 g/dL was a thermally irreversible gel and was not highly sensitive to temperature changes (5–45 °C). Its apparent viscosity and gel strength were higher under neutral addition (pH 7.0) than those under alkaline (pH 8.0 & pH 9.0) and acidic additions (pH 5.0 & pH 6.0). This study indicates HEAEP-0.5 is a novel hydrocolloid in food and other industries. Image 1 • Polysaccharide HEAEP-0.5 was obtained from Hericium erinaceus fruiting body. • HEAEP-0.5 was β-D-glucan polymer contained a →3)-Glc p -(1→ backbone. • HEAEP-0.5 had high molecular weight and behaved as triple helix conformation. • HEAEP-0.5 showed high viscosity and could form a weak gel. • Concentration, temperature, pH and salts affected rheological property of HEAEP-0.5. [ABSTRACT FROM AUTHOR]