Molecules Manuscript ID: polysaccharides-20071113-Lauriemzo-it
Type of the paper: Review
Title: Marine Derived Polysaccharides For Biomedical Applications: Chemical Modification Approaches
Abstract: Giovanna Gomez d’Ayala, Mario Malinconico, Paola Laurienzo*
Istituto di Chimica e Tecnologia dei Polimeri, C.N.R.-Via Campi Flegrei, 34- 80078 Pozzuoli (Naples), Italy
Abstract: Polysaccharides-based biomaterials are an emerging class in several biomedical fields such as tissue regeneration, particularly for cartilage, drug delivery devices and gel-entrapment systems for the immobilization of cells. Important properties of the polysaccharides include controllable biological activity, biodegradability, and their ability to form hydrogels. Most of polysaccharides derive from natural sources; particularly, alginate and chitosan, two polysaccharides which have an extensive history of use in medicine, pharmacy and basic sciences, can be easily extracted from marine plants (algae kelp) and crab shells, respectively. Recent re-discovery of polysaccharide-based materials is also attributable to new synthetic routes for their chemical modification, with the aim to promote new biological activities and to modify the final properties of the biomaterial for specific purposes. These synthetic strategies involve also the combination of polysaccharides with other polymers. A review of the more recent research in the field of chemical modification of alginate and chitosan is here presented. Moreover, we report as case studies the results of our recent work concerning various different approaches and applications of polysaccharide-based biomaterials, such as the realization of novel composites based on calcium sulphate and a blend of alginate with a chemically modified chitosan, the synthesis of novel alginate-poly (ethylene glycol) copolymers, and the development of a family of materials based on alginate and acrylic polymers of potential interest as drug delivery systems.

Molecules Manuscript ID: polyssacharides-20071114-Kadokawa-jp
Type of the paper: Review
Tentative Title: Chemoenzymatic Synthesis of Amylose-grafted Polymers
Authors: Yoshiro Kaneko and Jun-ichi Kadokawa*
Affiliation: Department of Nanostructured and Advanced Materials, Graduate School of Science and Engineering, Kagoshima University, Kagoshima 890-0065, Japan
Fax: +81-99-285-3253, E-mail: kadokawa@eng.kagoshima-u.ac.jp
E-mails: kadokawa@eng.kagoshima-u.ac.jp, ykaneko@eng.kagoshima-u.ac.jp
Abstract: Amylose, a natural linear polysaccharide linked through alpha(1,4)-glycosidic bonds, is one component of starch, which has been studied for many years in the materials research field because of its low cost, biodegradability, and renewability. Amylose can be prepared by phosphorylase-catalyzed enzymatic polymerization method using glucose-1-phosphate as a monomer. The polymerization is initiated from a maltooligosaccharide as a primer and the propagation proceeds by the reversible reaction to produce amylose. Because of the natural polysaccharides such as amylose are recycled carbon resources and considered to be eco-friendly substances, it is expected that use of the polysaccharides as one component of hybrid polymers will lead to the production of environmentally benign materials. On the basis of the above view points, in this review, we describe the chemoenzymatic synthesis of amylose-grafted polymers with well-defined structures. The synthesis of amylose-grafted heteropolysaccharides is disclosed. We also mention the preparation of amylose-grafted polymers having the synthetic main-chains such as polystyrene and polysiloxane.

Molecules Manuscript ID: polyssacharides-20071121-Verli-br
Type of the paper: Review
Tentative Title: From Conformation to Function: Current Status of Polysaccharides Analysis through Molecular Modeling
Author: Hugo Verli
E-mail: hverli@cbiot.ufrgs.br
Abstract: The rapid undergoing development of glycomics is progressively unraveling the intimate evolvement of carbohydrates and polysaccharides, as obtained from different sources in nature, within several biological events, such as
cell differentiation, adhesion and recognition, as well as the modulation of a broad spectrum of target receptors, resulting in numerous biological activities. Such properties of glycans derive from its chemical properties and interaction with the surrounding environment, resulting in a complex spectrum of three-dimensional arrangements governing its interactions with specific receptors. The obtaining of data about the structure and/or dynamics of such recognition events may be supported by techniques as X-ray crystallography, NMR spectroscopy and molecular modeling. While each technique has its own limitations, the continuous advances in hardware and software has been switching the paradigm that computer simulations necessarily lies on a trade-off between accuracy and efficiency. In this context, the current review focus on the recent advances of glycans analysis based on computational description of its structure and dynamics, from carbohydrate-aromatic interactions to the conformational sampling of molecules in time scales closer to those relevant to biological phenomena, passing through description of solvent effects on conformer populations, ultimately relying on its capabilities to contribute and support the description and prediction of important aspects related to polysaccharides structure, conformation and biological properties.

Molecules Manuscript ID: polysaccharides-20071122-Hamman-za
Type of the paper: Review
Tentative Title: Composition and Applications of Aloe vera Leaf Gel
Author: Josias H Hamman* and Alvaro M Viljoen
E-mails: HammanJH@tut.ac.za, ViljoenAM@tut.ac.za
Abstract: Many of the health benefits associated with Aloe vera have been attributed to the polysaccharides contained in the gel of the leaves. These biological activities include; promotion of wound healing, anti-inflammatory properties, antifungal activity, hypoglycemic or antidiabetic effects, anticancer, immunomodulatory and gastroprotective properties. While the known biological activities of Aloe vera will be briefly discussed, it is the aim of this review to further highlight recently discovered effects and applications of the leaf gel. These effects include the potential of whole leaf or inner fillet gel liquid preparations of Aloe vera to enhance the intestinal absorption and bioavailability of co-administered compounds as well as enhancement of skin permeation. In addition, important applications such as the use of the dried Aloe vera gel powder as an excipient in sustained release pharmaceutical dosage forms will be outlined.

Molecules Manuscript ID: polysaccharides-20071124-Teramoto-jp
Type of the paper: Review
Tentative Title: Synthetic Strategies Towards Trehalose-based Polymers for Environmentally Bbenign, Biocompatible and Bioactive Materials
Authors: Naozumi Teramoto* and Mitsuhiro Shibata
Affiliation: Department of Life and Environmental Sciences, Faculty of Engineering, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan; Fax: +81-47-478-0439, E-mail: teramoto-n@sea.it-chiba.ac.jp
Abstract: Trehalose is a non-reducing disaccharide found in yeast, fungi, sea algae and many insects. Trehalose is referred to as an amazing sugar, because it plays important roles for the cryptobiosis of selaginella mosses and tardigrades (water bears), which can revive with water from the dried out state. The interesting properties of trehalose is due to the unique structure, in which two glucose units are joined face-to-face by a 1→1 glucoside bond (acetal bond). Since Hayashibara Co. Ltd. developed an inexpensive and environmentally benign manufacturing process of a,a-D-trehalose by the enzymatic conversion of starch, the vision of its use has been expanded widely. Polymer synthesis for environmentally benign, biocompatible and bioactive materials from trehalose is one of the application fields emerging recently. The most discriminating properties of trehalose, compared with other sugars, are biocompatibility, chemical stability, and symmetrical properties for regio-selective reactions. Synthesis of sugar-based network polymer is straightforward because sugar has many hydroxyl groups, while synthesis of sugar-based linear polymer is challenging theme often involving many chemical reaction steps of protection and deprotection of hydroxyl groups. In this review, we overview the synthesis techniques for trehalose-based polymers and properties of the products. The reactions used for polymerization of trehalose or its derivatives are acetalization, enzymatic ester exchange, hydrosilylation, polyaddition, Diels-Alder cycloaddition, azide-alkyne Huisgen cycloaddition (click reaction), radical polymerization and photopolymerization.

Molecules Manuscript ID: polysaccharides-20071127-Mourao-br
Type of the paper: Review
Title: Sulfated Polysacharides from Marine Organisms
Authors: Vitor H. Pomin and Paulo A.S. Mourão
E-mail: pmourao@hucff.ufrj.br, vhpomin@gmail.com
Abstract: Sulfated fucans and sulfated galactans from marine algae have complex and heterogeneous structures but recent studies revealed the occurrence of repeat units in these polysaccharides from several species. Even in this case, the presence of highly branched portions and the complex distributions of sulfate and acetyl groups highlight the heterogeneity of algal polysaccharides. Another source of sulfated polysaccharides is marine invertebrates. The invertebrate polysaccharides have simple, ordered structures, which differ in the specific patterns of sulfation and/or position of the glycosidic linkages within their repeating units. The algal and invertebrate sulfated fucans and sulfated galactans have potent anticoagulant activity, mediated by antithrombin and/or heparin cofactor II. As most of the studies were carried out with algal polysaccharides it was not easy to trace a structure-activity relationship. This aspect was clarified as studies were extended to invertebrate polysaccharides. These definitively established that regular, linear sulfated a-L-fucans and sulfated a-L-galactans express anticoagulant activity, which is not simply a function of charge density, but depends critically on the pattern of sulfation and monosaccharide composition. NMR was an essential technique to determine the structure of the algal and invertebrate polysaccharides. But even more, investigation of NMR parameters may give important information about conformation of these polysaccharides in solution and their complexes with proteins. Novel NMR methods, such as Residual Dipolar Coupling and Saturation Transfer Experiments, may be used to elucidate structural features of the extended polysaccharides in solution. Furthermore, we predict that NMR may be used to study the interaction of sulfated polysaccharides with their target proteins of the coagulation system. These polysaccharides constitute potential therapeutic compounds, alternative to heparin. The complete understanding of their mechanism of action may help to design structure-based drugs with specific activity on each type of thrombosis episode and few side effects. They can also serve as research reagents to investigate and distinguish among a variety of interrelated events, such as coagulation, bleeding, thrombosis and platelet aggregation.

Molecules Manuscript ID: polysaccharides-20071127-Zdorovenko-ru
Type of the paper: Review
Title: Structure of the Lipopolysaccharides of Phytopathogenic Gram-negative Bacteria
Authors: Yuriy A. Knirel and Evelina L. Zdorovenko
E-mail: evelina@ioc.ac.ru
Abstract: The review summarizes data on the lipopolysaccharide structures of phytopathogenic Gram-negative bacteria from different families, including the structures of the lipid moiety (lipid A), core oligosaccharide, and O-specific polysaccharide (O-antigen). The main attention is paid to the O-antigens of Pseudomonas syringae, which by now are studied in most detail. The nature of structural heterogeneity of the O-antigens and correlation between the O-antigen structure, the immunospecificity of bacterial strains, and their specificity to the host plant are discussed.

Molecules Manuscript ID: polysaccharides-20071203-Kovacik-sk
Type of the paper: Review
Title: MS Methodology of Carbohydrates
Author: Vladimir Kovacik
E-mail: chemvkov@savba.sk
Abstract: The content of the review may include MS in the synthesis of carbohydrate derivatives, structure elucidation of oligosaccharides, glycoconjugates, MS methods of structure elucidation of polysaccharides, biomolecules up to glycoproteins.

Zhenlin Xu ¹, Youhui Yang ¹, Yueming Jiang ², Yuanming Sun ^1,*, Yudong Shen ¹ and Jie Pang ^1,3
1 College of Food Science, South China Agricultural University, Guangzhou 510642, P. R. China; E-mails: jallent@163.com; yhyang@scau.edu.cn; shenyudong@scau.edu.cn
2 South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, P. R. China; E-mail: ymjiang@scbg.ac.cn
3 College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, R. China; E-mail: pang3721941@163.com
* Author to whom correspondence should be addressed; E-mail: ymsun@scau.edu.cn
Received: 16 January 2008; in revised form: 20 February 2008 / Accepted: 20 February 2008 / Published: 1 March 2008
Full Paper: Synthesis and Characterization of Konjac Glucomannan-Graft-Polyacrylamide via γ-Irradiation
Molecules 2008, 13, 490-500 (PDF format 301 K)

Aleš Mráček ^1,*, Júlia Varhaníková ¹, Marián Lehocký ², Lenka Gřundělová ¹, Alena Pokopcová ¹ and Vladimír Velebný ³
1 Department of Physics and Materials Engineering, Faculty of Technology, Tomas Bata University in Zlín, Nad Stráněmi 4511, 76005 Zlín, Czech Republic; E-mails: juliavarhanikova@seznam.cz; Grundy.L@seznam.cz; salinka.p@azet.sk
2 Medical Materials Research Centre, Technology park, University Institute, Tomas Bata University in Zlín, Nad Ovcirnou III 3685, Zlín, 76001 Czech Republic; E-mail: lehocky@post.cz
3 CPN Ltd., Dolní Dobrouč 401, 561 02 Dolní Dobrouč, Czech Republic; E-mail: velebny@contipro.cz
* Author to whom correspondence should be addressed. E-mail: mracek@ft.utb.cz; Fax: +420576035141; Tel: +420576035102
Received: 28 February 2008; in revised form: 17 April 2008 / Accepted: 30 April 2008 / Published: 1 May 2008
Full Research Paper: The Influence of Hofmeister Series Ions on Hyaluronan Swelling and Viscosity
Molecules 2008, 13, 1025-1034 (PDF format 161 K) DOI: 10.3390/molecules13051025

Molecules Manuscript ID: polysaccharides-20071125-Chen-tw
Type of the paper: Full paper
Title: Fast Determination of Polysaccharides from Ganoderma lucidum Used Matrix-assisted Laser Desorption/ionization (MALDI) Mass
Wen-Bin Yang ¹, Wei-Ting Hung ¹, Shwu-Huey Wang ²and Chung-Hsuan Chen ¹^,*
¹ Genomics Research Center, Academia Sinica, No. 128, Academia Road Section 2, Nan-Kang, Taipei 11529, Taiwan; E-mail: winschen@gate.sinica.edu.tw
² Instrument Center, Taipei Medical University, Taipei 11031, Taiwan; E-mail: shwu@tmu.edu.tw
* Author to whom correspondence should be addressed; E-mail: winschen@gate.sinica.edu.tw; Tel.: +886-2-27899930 ext. 327; Fax: +886-2-27898771
Abstract: We have found that matrix-assisted laser desorption/ionization (MALDI) mass spectrometry is a good method to analyze the size of polysaccharide. Here, b-glucan isolated from fruiting bodies of Ganoderma lucidum was analyzed using MALDI in a direct and fast way. Permethylated polysaccharides of Ganoderma lucidum were measured to determine the linkage of G. lucidum polysaccharides to give sequencing information as a b-(1→3)/(1→6)-glucan.
Keywords: matrix-assisted laser desorption/ionization (MALDI); Ganoderma lucidum; b-glucan.

Molecules Manuscript ID: polysaccharides-20080109-Vicente-es
Type of the paper: Review
Title: Structure and biosynthesis of a xanthan-like polysaccharide produced by Xanthomonas albilineans
Authors: Laura Arribas, María Blanch, María-Estrella Legaz and Carlos Vicente*
E-mail: cvicente@bio.ucm.es
Abstract: Leaf scald is a vascular disease of sugarcane plants caused by Xanthomonas albilineans. Scalded leaves show white-yellowish streaks alternating with green zones in parallel to the main veins. The white-yellowish streaks show both phloem and xylem completely occluded by the gum and the overall mesophyll appears to be full of this bacterial secretion, as revealed by scanning electron microscopy. The gum in conducting tissues has been purified from juices obtained from scalded stalks by precipitation with isopropyl alcohol and size-exclusion chromatography. It was identified as a xanthan-like polysaccharide and found to be composed by glucose, mannose and glucuronic acid by acidic hydrolysis and capillary electrophoresis. Depending on the time of hydrolysis, cellobiose can also be identified as well as traces of glucose-1-P. The ratio of free glucose or cellobiose to mannose and glucuronic acid was calculated as 2.1 and 2.04, respectively-On these bases, it can be proposed that X. albilineans gum is composed by repeated tetrameric units containing two rests of fructose, one of mannose and one of glucuronic acid. This composition differs from that of the xanthan produced by X. campestris, formed by repeated pentameric units consisting of two glucose, two mannose and one glucuronic acid rests. Hydrolysis of xanthan with selective mannosidases and b-1,4-glucanases reveals that the macromolecule consists of a linear, b-1,4-backbone of b-glucose units to which mannose in b-1,3 bonds is linked.
Since xanthans contain glucuronic acid, the ability of Xanthomonas to produce an active UDP glucose dehydrogenase is often seen as a virulence factor. X. albilineans produces a UDP-glucose dehydrogenase growing on sucrose. The enzyme oxidizes UDP-glucose to UDP-glucuronic acid by using molecular oxygen and NADPH. Kinetics of enzymatic oxidation of NADPH is linearly dependent on the amount of oxygen supplied. The enzyme has been purified at homogeneity. The value of pI of the purified enzyme is 8.98 and its molecular mass has been estimated as about 14 kDa. The enzyme shows a michaelian kinetics for UDP-glucose concentrations. The value of K_m for UDP-glucose is 0.87mM and 0.26mM for NADPH, although the enzyme has three different sites to interact with NADPH. The enzyme is inhibited by UDP-glucose concentrations higher than 1.3 mM. N-Terminal sequence has been determined as IQPYNH.
X. albilineans axenically cultured did not secrete xanthans to Willbrink liquid media. Thus, the use of inoculated sugarcane tissues for producing and characterizing xanthans has been required. This host-dependence can be explained on the basis of the action of bacterial proteases upon the dehydrogenase. In vitro enzymatic assay of UDP-glucose dehydrogenase from X. albilineans requires the addition of a protease-inhibitors cocktail to cell-free extracts, since bacterial proteases rapidly hydrolyses the enzyme in solution. The addition of low amounts of 8-azaguanine and chloramphenicol to the culture medium do not impede the production of the dehydrogenase that requires concentrations higher than 0.3 mM of both antimetabolites to inhibit its synthesis, concentration that is sufficient to inhibit the production of proteases. Glycoproteins from sugarcane, the natural host of the bacterium, also assure the production of the active enzyme by inhibiting bacterial proteases.

Manuscript ID: molecules-20071203-Liu-cn
Type of the paper: Full Paper
Title: Effects of An Oil Soluble O-chitosan Derivative on Blood Serum Lipoprotein in Vitro
Authors: Xiaofei Liu* Tao Song Lin Li Yiyan Xiong
E-mail: liuxf@tju.edu.cn
Received: 3 December 2007
Abstract: Chitosan, the deacetylated derivative of chitin, is extracted from the shells of crustaceans. The strong positive charges on chitosan molecules enable it to bind with negatively charged substrates such as lipids. In this paper, an oil soluble chitosan derivative—O-C9OACs was prepared through introducing oleic acid group onto the C6- hydroxyl of chitosan with the locational protection of amino groups. By Fourier transform infrared (FTIR) spectrum, it was confirmed that MeSO3H had succeeded in protecting the amino groups and O-C9OACs was prepared. The solubility of O-C9OACs is much better than chitosan in common organic solvents. Furthermore, O-C9OACs has selective adsorption on lipoprotein by commercial test kits and circular dichroism spectrum (CD). Especially, O-C9OACs has good adsorption performance (63.3%) on selectively removing low density lipoprotein cholesterol (LDL-C) without affecting high density lipoprotein (HDL-C) in human serum in vitro.
Keywords: chitosan, derivatives, adsorption, lipoprotein, circular dichroism spectrum