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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 (3-4h 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., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In this study, a sulfated Artemisia sphaerocephala polysaccharide (ASPs) was prepared and its antitumor activity was evaluated in tumor cells and Hepatoma 22 (H22) tumor-bearing mice. In vitro experiments, ASPs significantly inhibited the growth of HepG2 and Hela cells with the IC 50 values of 172.03 and 161.42μg/mL, respectively. Moreover, no direct cytotoxicity against mouse fibroblast L929 normal cells was observed in vitro. After oral administration for 12days, the tumor growth was significantly suppressed by ASPs at the doses of 200mg/kg (inhibition rate of 60.85%). Results of tumor histological morphology and cell cycle analysis showed that ASPs could arrest H22 cells at S phase and promote cell apoptosis. Additionally, immunohistochemical analysis demonstrated that ASPs caused the down-regulation of mutant p53 protein expression in a dose-dependent manner. Therefore, these findings proposed new insight into antitumor properties of sulfated polysaccharide as a promising agent in cancer treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this work, selenylation of Artemisia sphaerocephala polysaccharide (SeASP MW ) was studied by using H 2 SeO 3 /HNO 3 /BaCl 2 reaction system in microwave field. SeASP MW exhibited the Se content range of 111-264μg/g with high yields (72.1-94.9%). 13 C NMR results indicated that the weak C-6 substitution was occurred. The decrease (from 7.348×10 4 g/mol to 1.736-4.667×10 4 g/mol) in weight average molecular mass (M W ) of SeASP MW was observed in size exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS) analysis. SeASP MW exhibited a more rigid solution conformation which might be due to the degradation of polysaccharide chains in acidic reaction reagent. This was also supported by atomic force microscopy (AFM) result that SeASP MW showed short chains and island-like topography. In anti-tumor activity assays, SeASP MW6 exhibited the inhibition rates of 32.381% and 39.776% against human non-small cell lung cancer cell line (H1650) at the concentration of 100 and 200μg/mL, respectively. The relatively weak inhibition effect of SeASP MW was not related to cell apoptosis and cell cycle arrest, suggesting Se content might be a key factor to influence the anti-tumor activities of selenized polysaccharides in vitro., (Copyright © 2016 Elsevier B.V. All rights reserved.)

It has been reported in our previous work that selenized Artemisia sphaerocephala polysaccharides (SeASPs) with the Se content range of 168-1703μg/g were synthesized by using Na2SeO3/HNO3/BaCl2 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 df values indicated that SeASPs with different conformational features that were highly dependent on MW. SeASPs exhibited a more rigid conformation (df value of 1.29-1.52) in low molecular weight range (MW of 1.026-1.426×10(4)g/mol) and compact spherical conformation in high molecular weight range (MW of 2.268-4.363×10(4)g/mol). It could be due to the degradation of polysaccharide chains in HNO3, 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, SeASP2 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., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

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 (SRSASP) was prepared by using triphenylchloromethane (TrCl) as protecting precursor. The decrease in fractal dimension (df) values (1.56-2.04) of SRSASP was observed in size-exclusion chromatography combined with multi angle laser light scattering (SEC-MALLS) analysis. Compared to sample substituted at C-6, SRSASP 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. SRSASP 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., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The biological activities of sulfated polysaccharides are related to the substitution positions of functional groups. In this study, regioselective sulfation of Artemisia sphaerocephala polysaccharides (SRSASP) 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 168.7eV) 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 65ppm were not observed. The degree of substitution varied from 0.44 to 0.63 in SRSASP 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., (Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.)

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.

Objective: To analyse the chemical constituents of Artemisia dracunculus., Method: The essential oil from A. dracunculus was extracted by steam distillation and the chemical constituents were analysed by capillary GC-MS method. The relative content of each component was calculated by area normalization., Result: 36 peaks were separated and all of them were identified. The main chemical components were 3,7-dimethyl-1,3,7-octatriene (38.43%), 1S-alpha-pinene (36.96%), 1-methoxy-4-(2-Propenyl)-benzene (8.57%), limonene (6.33%), 1R-alpha-pinene (3.40%), etc., Conclusion: The study provided solid and scientific proof for the further exploitation and utilization of A. dracunculus.

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]

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: 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]