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Highlights • An arabinogalactan, HH1-1 was purified and characterized from Carthamus tinctorius. • The backbone of HH1-1 was composed of 1,6-linked Gal p branched at its C-3. • The branches contained 1,5-linked/1,3,5-linked, T-arabinose and T-galactose. • HH1-1 had immune-enhancing activity by activating NF-κB signaling. • HH1-1 could also induce TNF-α, IL-1β and iNOS expressions. Abstract Previous studies showed that polysaccharides from flowers of Carthamus tinctorius L. had immunomodulating activities. However, their structures were little known. Here, an arabinogalactan, named as HH1-1 with a relative molecular weight of 70.9 kDa, was isolated from flowers of Carthamus tinctorius L. by hot water extraction, followed by purification of a DEAE-Cellulose 32 column and a Sephacryl S-200HR column, subsequently. The structure of HH1-1 was evaluated to have a backbone of 1,6-linked Gal p branched at C-3 by side chain of 1,3-linked Gal p , with sub-branches attached at its C-3 position. The branches mainly contained 1,5-linked, 1,3,5 linked, terminal arabinose and terminal galactose. Biological activity assays showed that this polysaccharide had immune-enhancing activity by multiple ways, including promoting immune responses by activation of NF-κB signaling and increasing TNF-α, IL-1β and iNOS expressions in lymphocytes and macrophages. [ABSTRACT FROM AUTHOR]

The crude polysaccharide SSa, obtained from the roots of Sophora subprostrata by boiling-water extraction and ethanol precipitation, was fractionated by anion-exchange and gel permeation chromatography, giving four polysaccharide fractions termed SSa1, SSa2, SSa3, and SSa4. Their structural features were investigated by sugar analysis, methylation analysis, partial hydrolysis, and NMR spectroscopy. SSa1 and SSa2 were both characterized as highly branched amylopectins with small average unit chain length of 8–10 except that SSa2 was contaminated with small amount of arabinogalactan. SSa3 was mainly an arabinogalactan, attached to a rhamnogalacturonan core. SSa4 was a rhamnogalacturonan I (RG-I) pectic polysaccharide having a backbone consisting of 1,4-linked α-d-galacturonic acid and 1,2-linked α-l-rhamnose, with various branches attached to O-4 of l-rhamnose. [Copyright &y& Elsevier]

Angiogenesis plays an essential role in tumor development. Blocking angiogenesis in tumor has become a promising tactic in limiting cancer progression. Here, an arabinogalactan polysaccharide, RN1 was isolated from flowers of Panax notoginseng . Its structure was determined to possess a backbone of 1,6-linked Gal p branched at C3 by side 1,3-linked Gal p , with branches attached at position O-3 of it. The branches mainly contained 1,5-linked, 1,3,5-linked, terminal Arabinose and terminal Galactose. RN1 could inhibit microvessel formation in the BxPC-3 pancreatic cancer cell xenograft tumor in nude mice. The antiangiogenesis assay showed that RN1 could reduce the migratory activity of endothelial cells and their ability of tube formation on matrigel, but no effect on endothelial cells growth. Further studies revealed that RN1 could inhibit BMP2/Smad1/5/8/Id1 signaling. All those data indicated the RN1 had an antiangiogenic effect via BMP2 signaling and could be a potential novel inhibitor of angiogenesis. [ABSTRACT FROM AUTHOR]

Highlights • The acidic ionic liquids could promote the selenylation of polysaccharides. • Acidity of the ionic liquids played an important role in increase of Se content. • Regulating the M W could be achieved by adjusting anions of ionic liquids. Abstract Exploring new solvents or catalysts has great prospect for the derivatization of poorly soluble natural polysaccharides as bio-resources which were extracted from food or industrial waste residue, as compared to traditional reaction system. In this work, selenized Artemisia sphaerocephala polysaccharide (SePAS) was synthesized by using imidazolium-based acidic ionic liquids (AILs) as catalyst. The results showed the highest Se content increased to 20438 μg/g compared to conventional method (1703 μg/g), indicating AILs could enhance selenylation reactivity and Se content was controlled by the acidity due to the protonation effect of H 2 SeO 3 by AILs. FT-IR, X-ray photo-electron spectroscopy (XPS) and 13C NMR results exhibited that seleno-group exists in SePAS and the substitution position was at C-6. The hydrogen bonding effect and acidity of AILs showed regulation on weight average molecular mass of SePAS. Therefore, AILs with excellent catalytic efficiency could be as potential catalyst for full use of polysaccharide-rich resources. [ABSTRACT FROM AUTHOR]

Use of microwave radiation is one of the most potential techniques in polysaccharide derivatives synthesis due to its advantages such as higher yields, milder reaction conditions and shorter reaction times. This study was aimed at producing sulfated polysaccharides by microwave irradiation using polar reagents and solvent. Six sulfated Artemisia sphaerocephala polysaccharide derivatives (SPAS) were obtained by using chlorosulfuric acid/pyridine method in the reaction duration range of 15–300 min at a fixed microwave power of 100W. Synthesis of SPAS under microwave filed was highly effective and characterized by time saving and high degrees of substitution (DS). The chemical structure of SPAS was confirmed by FT-IR and 13 C NMR that sulfation had occurred and the substitution position was mainly at C-6. Size-exclusion chromatograph combined with multi-angle laser photometer (SEC-MALLS) data indicated that short reaction time minimized acid-catalyzed degradation of polysaccharide chains. AFM observation demonstrated that low- M W derivative exhibited aggregation of polysaccharide chain as irregular spherical lumps. In anti-tumor activity assays, sulfation of PAS significantly improved the capacity to inhibit tumor cells growth by arresting the cell cycle progress in specific phases. It could be concluded that M W and molecular mass distribution had much greater influence on anti-tumor activities of SPAS against human non-small cell lung cancer A549 cells, human hepatocellular carcinoma HepG2 cells and human cervical cancer Hela cells. Microwave-assisted synthesis might possess widespread application in preparation of new polysaccharide derivatives with rich variety of structural features and bioactivities. [ABSTRACT FROM AUTHOR]

Phosphorylation is a key route to achieve varieties of biological activities for polysaccharides. Currently, conventional phosphorylation reagents are characterized by long processing times and high reaction temperatures. Here, we reported phosphorylation of Artemisia sphaerocephala polysaccharides (PASP) with the degrees of substitution (DS) of 0.34-0.54 in mild reaction conditions (3–4 h and 25 °C) by employing POCl 3 /pyridine technique. FT-IR spectroscopy and X-ray photoelectron spectroscopy (XPS) analysis confirmed the appearance of phosphate ester (P 5+ ) groups in PASP. Size exclusion chromatography combined with multi-angle laser light scattering (SEC-MALLS) result clearly showed temperature-dependent increment of weight average molecular mass ( M W ). High temperature facilitated the reaction of phosphoryl chloride with primary and secondary hydroxyl groups, favoring the crosslinking of polysaccharide chains by phosphate di-esters as further confirmed in 13 C NMR determination. Our results provide insight into the relationship between the structure and reaction conditions of phosphorylated polysaccharide, which is important for understanding and exploiting these derivatives in a wide range of applications. [ABSTRACT FROM AUTHOR]

It has been reported in our previous work that selenized Artemisia sphaerocephala polysaccharides (SeASPs) with the Se content range of 168–1703 μg/g were synthesized by using Na 2 SeO 3 /HNO 3 /BaCl 2 system. In the present work, the solution property of SeASP was studied by using size exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS). A decrease in d f values indicated that SeASPs with different conformational features that were highly dependent on M W . SeASPs exhibited a more rigid conformation ( d f value of 1.29–1.52) in low molecular weight range ( M W of 1.026–1.426 × 10 4 g/mol) and compact spherical conformation in high molecular weight range ( M W of 2.268–4.363 × 10 4 g/mol). It could be due to the degradation of polysaccharide chains in HNO 3 , which was supported in monosaccharide composition analysis. Congo red (CR) spectrophotometric method and atomic force microscopy (AFM) results also confirmed the conformational transition and the evidence on the shape of the rigid chains. In vitro anti-tumor assays, SeASP 2 displayed greater anti-proliferative effects against three tumor cell lines (hepatocellular carcinoma HepG-2 cells, lung adenocarcinom A549 cells and cervical squamous carcinoma Hela cells) in a dose-dependent manner. This suggested that selenylation could significantly enhance the anti-tumor activities of polysaccharide derivatives in vitro. [ABSTRACT FROM AUTHOR]

Regioselective modification is an effective approach to synthesize polysaccharides with different structure features and improved properties. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharide (S RS ASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. The decrease in fractal dimension ( d f ) values (1.56–2.04) of S RS ASP was observed in size-exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS) analysis. Compared to sample substituted at C-6, S RS ASP showed a more expanded conformation of random coil, which was attributed to the breakup of hydrogen bonds and elastic contributions. Circular dichroism (CD), methylene blue (MB) and congo red (CR) spectrophotometric method and atomic force microscopy (AFM) results confirmed the conformational transition and stiffness of the chains after sulfation. S RS ASP exhibited enhanced antioxidant activities in the DPPH, superoxide and hydroxyl radical scavenging assay. Sulfation at C-2 or C-3 was favorable for the chelation which might prevent the generation of hydroxyl radicals. It concluded that the degree of substitution and substitution position were the factors influencing biological activities of sulfated polysaccharides. [ABSTRACT FROM AUTHOR]

The biological activities of sulfated polysaccharides are related to the substitution positions of functional groups. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharides (S RS ASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. FT-IR spectra and X-ray photoelectron spectroscopy (XPS) showed that SO 3− group (S 6+ , high binding energy of 168.7 eV) was widely present in sulfated polysaccharides. 13 C NMR spectroscopy showed that C-2 and C-3 substitution was occurred but not fully sulfation. Meanwhile, C-6 substituted signals near 65 ppm were not observed. The degree of substitution varied from 0.44 to 0.63 in S RS ASP which could be attributed to the low reactivity at secondary hydroxyl. Monosaccharide composition result showed a decrease in the ratio of mannose/glucose, indicating the change of chemical composition in sulfated polysaccharides. In size-exclusion chromatograph analysis, a decrease in molecular weight and broadening of molecular weight distribution of sulfated polysaccharides was also observed. It could be attributed to the hydrolysis of polysaccharide in the sulfated reaction. [ABSTRACT FROM AUTHOR]

Sulfated derivatives of galactomannan from locust bean gum (LBG) with the degree of substitution (DS) of 0.34–1.07 were synthesized using chlorosulfonic acid/pyridine (CSA/Py) method. Box–Behnken design (BBD) of response surface methodology (RSM) was employed to optimize the reaction conditions. Results of FT-IR and X-ray photoelectron spectroscopy (XPS) indicated that SO 3 H groups were widely present in sulfated LBG (SLBG). 13 C NMR result revealed that sulfation had occurred and C-6 substitution was predominant in SLBG. All sulfated samples showed a decrease in M w and more broad molar mass distribution in size exclusion chromatography combined with laser light scattering (SEC-LLS) analysis. Results of M W – 〈 S 2 〉 z 1 / 2 showed a decrease in fractal dimension ( d f ) value. Laser light scattering results also showed a conformation transition from a compact chain conformation of branched clusters to a random coil conformation of SLBG. Compared to LBG and SLBG with low DS and molecular weight, SLBG 2 exhibited an internal structure of random coil with a DS of 1.07. DS and molecular weight had great influence on its conformation in aqueous solution. Our results confirmed that the degradation of polysaccharide and SO 3 H groups improved significantly the stiffness of the chains due to the electrostatic effect. [ABSTRACT FROM AUTHOR]

Highlight: [•] A neutral glucan LJW0F2 was isolated and purified from flowers of Lonicera japonica Thunb. [•] The structure of LJW0F2 was elucidated as to an α-d-(1→4)-glucan with an α-(1→4) linked branch attached to C-6 position. [•] The polysaccharide LJW0F2 could block Aβ 42 aggregation directly and attenuated its cytotoxicity in SH-SY5Y cells. [Copyright &y& Elsevier]

Abstract: The seed of Cassia obtusifolia is a food or herbal medicine used for improving eyesight, treating constipation and other disorders, and polysaccharides have been implicated in these pharmacological activities. The endosperm of the seeds, Cassia gum, is a commercial thickening or gelling agent, composed mainly of galactomannans. However, the whole seeds of C. obtusifolia, rather than the endosperm, are used in folk medicine or food, which might contain more complex constituents of polysaccharides. In this study, the whole seeds of C. obtusifolia were extracted with boiling water, and from the water extract, three homogeneous fractions were isolated, designated CFAA-1, CFAA-3, and CFBB2, respectively, after treatment with Fehling solution followed by anion-exchange and gel permeation chromatography. Using chemical and spectroscopic methods, CFAA-1, and CFAA-3 were elucidated to be both branched galactomannans with different molecular weights, consisting of 1,4-linked β-d-mannopyranosyl backbone with single-unit α-d-galactopyranosyl branches attached to O-6 of mannose, while CFBB2 was shown to be a linear (1→4)-α-polygalacturonic acid. [Copyright &y& Elsevier]

Abstract: To discover anti-pancreatic cancer cells growth inhibitor, a new water-soluble glucan, WTMA, was isolated from the rhizome of Gastrodia elata Bl. The mean molecular weight of the polysaccharide was estimated to be 7.0×105 Da by high performance gel permeation chromatography (HPGPC). The structure of WTMA was characterized by GC, GC–MS, NMR and MALDI-TOF. WTMA was deduced as an α-(1→4)-glucan with α-(1→4) linked branches attached to O-6 at branch points. Bioactivity tests in vitro indicated that WTMA and its partial acid hydrolysis-derived mixture product, WTMA-AD-O, could significantly inhibit the proliferation of pancreatic cancer cells. However, WTMA-DE, the degraded polysaccharide without branch chain by isoamylase, did not inhibit the proliferation of pancreatic cancer cells. Thus side chain on WTMA was deduced to be required for the anti-cancer cell activity. Further study demonstrated that WTMA and all of its hydrolysis products had no inhibition effect on liver LO2 cells. [Copyright &y& Elsevier]

Abstract: Sulfated polysaccharides exerted potent biological property which was relative to degree of sulfation (DS), M w, substitution position and chain conformation. In the present study, sulfated derivatives of Artemisia sphaerocephala polysaccharide (ASP) with different DS were synthesized by chlorosulfuric acid/pyridine method. FT-IR and 13C NMR analysis indicated that C-6 substitution was predominant in sulfated ASP (SASP) compared with other positions at C-2. In the sulfation reaction, a sharp decrease in M w was observed in SASP. The d f values from 1.96 to 2.77 indicated that the –SO3H groups leading to the relatively expanded conformation of SASP. Antioxidant assays showed that SASP had better antioxidant activities. The data obtained in vitro models indicated that high DS and moderate M w showed the best antioxidant capacities. [Copyright &y& Elsevier]

Abstract: The conventional extraction methods for polysaccharides were time-consuming, laborious and energy-consuming. Microwave-assisted extraction (MAE) technique was employed for the extraction of Potentilla anserina polysaccharides (PAPMAE), which is a traditional Chinese functional food. The extracting parameters of PAPMAE were optimized by Box–Behnken design. The optimum conditions were ratio of water to raw material 14.5:1, microwave power 369W, extraction temperature 63.3°C and extraction time 76.8min with an enhanced yield of 13.33%. In microwave heating process, a sharp decrease in M w was detected in SEC-LLS measurement. A d f value of 3.03 indicated that PAPMAE exhibited a compact hard sphere conformation in an aqueous solution. Furthermore, it showed stronger antioxidant activities compared with hot water extraction by evaluating in superoxide radical (), hydroxyl radical ( OH), 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, reducing power and metal chelating assay. The data obtained clearly showed that the molecular weights played a more important role in antioxidant activities. [Copyright &y& Elsevier]