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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]

Abstract: Two major polysaccharide fractions, CDA-1A and CDA-3B, were isolated from the cold-water extract of Cistanche deserticola Y. C. Ma, a holoparasitic plant and a valuable traditional Chinese medicine, using anion-exchange chromatography on DEAE-cellulose and gel-permeation chromatography on Sephacryl S-300 and Sephadex G-150. Their major structural features were elucidated using component and linkage analyses, periodate oxidation, Smith degradation, partial acid hydrolysis, and NMR spectroscopy. The results indicated that CDA-1A is an α-(1→4)-d-glucan with α-(1→6)-linked branches attached to the O-6 of branch points and that CDA-3B is an RG-I polysaccharide containing a typical rhamnogalacturonan backbone and arabinogalactan or arabinan branches. Bioactivity tests showed that CDA-1A is inert for T-cell proliferation stimulation but active for B-cell proliferation, while CDA-3B is potent for the stimulation of both T- and B-cell proliferation. [Copyright &y& Elsevier]

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]

Abstract: Potentilla anserina L. polysaccharide had been selenizingly modified by nitric acid–selenious acid method with microwave-assistant. The optimal reaction parameters on selenylation modification were time 116min, temperature 63°C, microwave power 190W and the actual value of selenium content was 2690.1±7.2μg/g. The scavenging ability of DPPH, OH and superoxide radicals, the metal chelating ability and reducing power in vitro were compared by antioxidant assay taking the non-modified PAP as a control. The results showed that selenylation modification could significantly enhance the antioxidant activity of SePAP and SePAP could be used as a potential antioxidant. [Copyright &y& Elsevier]

Abstract: A polysaccharide fraction, J6, was isolated from the hot-water extract of flowers of oleander Nerium indicum Mill., using ethanol precipitation, cetyltrimethylammonium bromide (CTAB) complexing, anion-exchange chromatography and gel permeation chromatography. J6 was found to contain l-rhamnose, l-arabinose, d-galactose, and d-galacturonic acid, in the ratio of 10.1:49.8:30.1:10.0. Its structure was investigated by methylation analysis, periodate oxidation, Smith degradation, partial acid hydrolysis, electrospray ionization mass spectrometry and NMR spectroscopic methods. It was found that J6 is an RG-I type polysaccharide, which contains a rhamnogalacturonan backbone, with various branches attached to O-4 of l-rhamnose. The branches probably involve (1→4)-β-d-galactan, branched l-arabino-(1→3)(1→6)-β-d-galactan, and (1→5)-α-l-arabinan. J6 stimulated NO production of macrophage RAW264.7 cells in a preliminary test. [Copyright &y& Elsevier]

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]

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]

In the present study, sulfated derivatives of Artemisia sphaerocephala polysaccharide (SASP) with high degree of substitution (DS) were synthesized by using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. It was found that DMAP/DCC showed marked improvement in DS of sulfated samples. Compared to sulfated derivatives without catalyst, the DS of SASP increased from 0.91 to 1.28 with an increment in dosage of DMAP from 0 to 10 mg. The influence of DMAP/DCC on the DS of sulfated derivatives was depended on the content of DMAP. The effect of DMAP might be due to its strong coordination to the hydroxy group. The results of FT-IR and X-ray photoelectron spectroscopy (XPS) indicated that SO 3 − group (S 6+ , binding energy of 172.3 eV) was widely present in sulfated polysaccharide molecules. 13 C NMR results indicated that C-6 substitution was predominant for sulfated polysaccharide when compared with other positions. In the sulfation reaction, a sharp decrease in M W was observed. DMAP/DCC was an effective catalyst system in sulfated modification of polysaccharide. [ABSTRACT FROM AUTHOR]

Abstract: Selenium (Se) is an essential trace element for human beings and many other forms of life. Organic Se from natural foods has higher bioavailability and is safer than inorganic Se species. In the present study, selenium-containing derivatives of Artemisia sphaerocephala polysaccharide with the highest Se content of 1703μg/g were synthesized using H2SeO3/HNO3 and BaCl2 as a catalyst. The effects of the ratio of HNO3 concentration and reaction temperature were investigated. Results of Raman and 13C NMR spectroscopy indicated that C-6 substitution was predominant in selenized polysaccharide. A sharp decrease in M w was observed in the selenized reaction due to the acid environment. The in vitro antioxidant results suggest that selenium-containing polysaccharide should be applied as a novel selenium source in dietary supplements, with potent antioxidant properties. [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: It was essential to understand the chemical structure of polysaccharides for further research and biochemical or medical application of this natural biopolymer. In the present study, sulfated derivatives of guar gum with high degree of sulfation (DS) were synthesized using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. The effects of the ratio of chlorosulfuric acid to pyridine, the content of catalyst and reaction temperature were investigated. Results of FT-IR, 1H and 13C NMR indicated that C-6 substitution was predominant in sulfated polysaccharide. In the sulfation reaction, a sharp decrease in M W was observed. The enhanced antioxidant activities of sulfated polysaccharides were not a function of a single factor but a combination of high DS and low molecule weight. [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]

Abstract: Sulfated polysaccharides exerted potential biological property which was relative to degree of sulfation (DS), M w, substitution position and chain conformation. In the present study, commercial guar gum was purified and its sulfated derivates with different DS and M w were synthesized. FT-IR and 13C NMR analysis indicated that C-6 substitution was predominant in sulfated samples compared with other positions. In the sulfation reaction, a sharp decrease in M w was observed. The d f values from 1.92 to 2.85 indicated that the –SO3H groups led to the relatively expanded conformation of sulfated polysaccharides. Antioxidant assays showed that sulfated polysaccharides had better antioxidant activities. The data obtained in in vitro models indicated that high DS and low 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 Artemisia sphaerocephala polysaccharides (ASP), which is a traditional Chinese food. The extracting parameters were optimized by Box-Behnken design. In microwave heating process, a decrease in molecular weight (M w) was detected in SEC-LLS measurement. A d f value of 2.85 indicated ASP using MAE exhibited as a sphere conformation of branched clusters in aqueous solution. Furthermore, it showed stronger antioxidant activities compared with hot water extraction. The data obtained showed that the molecular weights played a more important role in antioxidant activities. [Copyright &y& Elsevier]