Chitosan, a polyaminosaccharide, has been investigated for its use in the field of drug-delivery and biomaterial applications because of its natural biocompatibility and polycationic properties. Chemical modifications of chitosan have been attempted in an effort to increase the transfection efficiency with respect to gene delivery applications; however, it is unknown how these modifications affect the formation of the condensates. This study attempts to determine the effects of modification of the cationic center of chitosan on the ability to condense DNA. Specifically, electron-donating or -withdrawing groups were used as modifiers of the cationic charge on the chitosan backbone to stabilize the protonated form of chitosan, which is necessary to form condensates and increase the efficiency of the polymer to condense DNA by yielding condensates at a lower nitrogen to phosphorous (N : P) ratio. While an N : P ratio of 7 is needed to condense DNA with unmodified chitosan, phthalate-modified chitosan yielded condensates were obtained at an N : P ratio of 1.0.
{"title":"Selective Modification of Chitosan to Enable the Formation of Chitosan-DNA Condensates by Electron Donator Stabilization","authors":"K. E. Kador, A. Subramanian","doi":"10.1155/2011/146419","DOIUrl":"https://doi.org/10.1155/2011/146419","url":null,"abstract":"Chitosan, a polyaminosaccharide, has been investigated for its use in the field of drug-delivery and biomaterial applications because of its natural biocompatibility and polycationic properties. Chemical modifications of chitosan have been attempted in an effort to increase the transfection efficiency with respect to gene delivery applications; however, it is unknown how these modifications affect the formation of the condensates. This study attempts to determine the effects of modification of the cationic center of chitosan on the ability to condense DNA. Specifically, electron-donating or -withdrawing groups were used as modifiers of the cationic charge on the chitosan backbone to stabilize the protonated form of chitosan, which is necessary to form condensates and increase the efficiency of the polymer to condense DNA by yielding condensates at a lower nitrogen to phosphorous (N : P) ratio. While an N : P ratio of 7 is needed to condense DNA with unmodified chitosan, phthalate-modified chitosan yielded condensates were obtained at an N : P ratio of 1.0.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"42 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2011-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74479237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, increasing attention has been paid to water-soluble derivatives of chitosan at its applications. The chemical characteristics and the antimicrobial properties of these salts can play significant role in pharmacological and food areas mainly as carriers for drug delivery systems and as antimicrobial packaging materials. In the current paper, a historical sequence of the main preparative methods, physical chemistry aspects, and antimicrobial activity of chitosan quaternized derivatives are presented and briefly discussed. In general, the results indicated that the quaternary derivatives had better inhibitory effects than the unmodified chitosan.
{"title":"Quaternary Salts of Chitosan: History, Antimicrobial Features, and Prospects","authors":"D. Britto, R. Goy, S. Filho, O. Assis","doi":"10.1155/2011/312539","DOIUrl":"https://doi.org/10.1155/2011/312539","url":null,"abstract":"Recently, increasing attention has been paid to water-soluble derivatives of chitosan at its applications. The chemical characteristics and the antimicrobial properties of these salts can play significant role in pharmacological and food areas mainly as carriers for drug delivery systems and as antimicrobial packaging materials. In the current paper, a historical sequence of the main preparative methods, physical chemistry aspects, and antimicrobial activity of chitosan quaternized derivatives are presented and briefly discussed. In general, the results indicated that the quaternary derivatives had better inhibitory effects than the unmodified chitosan.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"24 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2011-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76910944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. D. Guerra, N. Barbani, M. Gagliardi, E. Rosellini, C. Cristallini
The use of materials, containing the biocompatible and bioresorbable biopolymer poly()-2-amino-2-deoxy--D-glucan, containing some N-acetyl-glucosamine units (chitosan, CHI) and/or its derivatives, to fabricate devices for the regeneration of bone, cartilage and nerve tissue, was reviewed. The CHI-containing devices, to be used for bone and cartilage regeneration and healing, were tested mainly for in vitro cell adhesion and proliferation and for insertion into animals; only the use of CHI in dental surgery has reached the clinical application. Regarding the nerve tissue, only a surgical repair of a 35 mm-long nerve defect in the median nerve of the right arm at elbow level with an artificial nerve graft, comprising an outer microporous conduit of CHI and internal oriented filaments of poly(glycolic acid), was reported. As a consequence, although many positive results have been obtained, much work must still be made, especially for the passage from the experimentation of the CHI-based devices, in vitro and in animals, to their clinical application.
{"title":"Chitosan-Based Macromolecular Biomaterials for the Regeneration of Chondroskeletal and Nerve Tissue","authors":"G. D. Guerra, N. Barbani, M. Gagliardi, E. Rosellini, C. Cristallini","doi":"10.1155/2011/303708","DOIUrl":"https://doi.org/10.1155/2011/303708","url":null,"abstract":"The use of materials, containing the biocompatible and bioresorbable biopolymer poly()-2-amino-2-deoxy--D-glucan, containing some N-acetyl-glucosamine units (chitosan, CHI) and/or its derivatives, to fabricate devices for the regeneration of bone, cartilage and nerve tissue, was reviewed. The CHI-containing devices, to be used for bone and cartilage regeneration and healing, were tested mainly for in vitro cell adhesion and proliferation and for insertion into animals; only the use of CHI in dental surgery has reached the clinical application. Regarding the nerve tissue, only a surgical repair of a 35 mm-long nerve defect in the median nerve of the right arm at elbow level with an artificial nerve graft, comprising an outer microporous conduit of CHI and internal oriented filaments of poly(glycolic acid), was reported. As a consequence, although many positive results have been obtained, much work must still be made, especially for the passage from the experimentation of the CHI-based devices, in vitro and in animals, to their clinical application.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"249 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2011-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77167729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, much attention has been paid to chitosan as a potential polysaccharide resource. Although several efforts have been reported to prepare functional derivatives of chitosan by chemical modifications, few attained their antimicrobial activity against plant pathogens. The present paper aims to present an overview of the antimicrobial effects, mechanisms, and applications of a biopolymer chitosan and its derivatives in crop protection. In addition, this paper takes a closer look at the physiochemical properties and chemical modifications of chitosan molecule. The recent growth in this field and the latest research papers published will be introduced and discussed.
{"title":"A Biopolymer Chitosan and Its Derivatives as Promising Antimicrobial Agents against Plant Pathogens and Their Applications in Crop Protection","authors":"M. Badawy, E. Rabea","doi":"10.1155/2011/460381","DOIUrl":"https://doi.org/10.1155/2011/460381","url":null,"abstract":"Recently, much attention has been paid to chitosan as a potential polysaccharide resource. Although several efforts have been reported to prepare functional derivatives of chitosan by chemical modifications, few attained their antimicrobial activity against plant pathogens. The present paper aims to present an overview of the antimicrobial effects, mechanisms, and applications of a biopolymer chitosan and its derivatives in crop protection. In addition, this paper takes a closer look at the physiochemical properties and chemical modifications of chitosan molecule. The recent growth in this field and the latest research papers published will be introduced and discussed.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"20 1","pages":"1-29"},"PeriodicalIF":0.0,"publicationDate":"2011-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85100150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glycolipids are important constituents of biological membranes, and understanding their structure and dynamics in lipid bilayers provides insights into their physiological and pathological roles. Experimental techniques have provided details into their behavior at model and biological membranes; however, computer simulations are needed to gain atomic level insights. This paper summarizes the insights obtained from MD simulations into the conformational and orientational dynamics of glycosphingolipids and their exposure, hydration, and hydrogen-bonding interactions in membrane environment. The organization of glycosphingolipids in raft-like membranes and their modulation of lipid membrane structure are also reviewed.
{"title":"Structure and Dynamics of Glycosphingolipids in Lipid Bilayers: Insights from Molecular Dynamics Simulations","authors":"Ronak Y. Patel, P. V. Balaji","doi":"10.1155/2011/950256","DOIUrl":"https://doi.org/10.1155/2011/950256","url":null,"abstract":"Glycolipids are important constituents of biological membranes, and understanding their structure and dynamics in lipid bilayers provides insights into their physiological and pathological roles. Experimental techniques have provided details into their behavior at model and biological membranes; however, computer simulations are needed to gain atomic level insights. This paper summarizes the insights obtained from MD simulations into the conformational and orientational dynamics of glycosphingolipids and their exposure, hydration, and hydrogen-bonding interactions in membrane environment. The organization of glycosphingolipids in raft-like membranes and their modulation of lipid membrane structure are also reviewed.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"40 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2011-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80055836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Janice M. H. Cheng, A. A. Khan, Mattie S. M. Timmer, B. L. Stocker
In the same way that peptide antigens are presented by major histocompatibility complex (MHC) molecules, glycolipid antigens can also activate the immune response via binding to CD1 proteins on antigen-presenting cells (APCs) and stimulate CD1-restricted T cells. In humans, there are five members of the CD1 family, termed CD1a–e, of which CD1a–d are involved in glycolipid presentation at the cell surface, while CD1e is involved in the intracellular trafficking of glycolipid antigens. Both endogenous (self-derived) and exogenous (non-self-derived) glycolipids have been shown to bind to members of the CD1 family with varying degrees of specificity. In this paper we focus on the key glycolipids that bind to the different members of the CD1 family.
{"title":"Endogenous and Exogenous CD1-Binding Glycolipids","authors":"Janice M. H. Cheng, A. A. Khan, Mattie S. M. Timmer, B. L. Stocker","doi":"10.1155/2011/749591","DOIUrl":"https://doi.org/10.1155/2011/749591","url":null,"abstract":"In the same way that peptide antigens are presented by major histocompatibility complex (MHC) molecules, glycolipid antigens can also activate the immune response via binding to CD1 proteins on antigen-presenting cells (APCs) and stimulate CD1-restricted T cells. In humans, there are five members of the CD1 family, termed CD1a–e, of which CD1a–d are involved in glycolipid presentation at the cell surface, while CD1e is involved in the intracellular trafficking of glycolipid antigens. Both endogenous (self-derived) and exogenous (non-self-derived) glycolipids have been shown to bind to members of the CD1 family with varying degrees of specificity. In this paper we focus on the key glycolipids that bind to the different members of the CD1 family.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"93 1","pages":"1-13"},"PeriodicalIF":0.0,"publicationDate":"2011-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90697936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Various glycolipids were synthesized using thiolactosides as scaffolds for glycosylation in animal cells. The basic building blocks, n-dodecyl β-D-thiolactoside (β-LacSC12) and n-dodecyl α-D-thiolactoside (α-LacSC12), were chemically synthesized in 2 steps: glycosylation followed by deacylation. The thiolactosides were administered to animal cells in culture and served as substrates for cellular enzyme-catalyzed glycosylation. Incubation of mouse melanoma B16 cells in the presence of β-LacSC12 or α-LacSC12 resulted in sialylation of the terminal galactose residue and gave a GM3-type ganglioside. Administration of β-Lac SC12 in Madin-Darby canine kidney (MDCK) cells likewise gave a GM3-type ganglioside. On the other hand, introduction of β-LacSC12 in African green monkey kidney (Vero) cells gave Gb3- and Gb4-type glycolipids aside from GM3-type ganglioside. In the course of the study, significant changes in B16 cell morphology and elevated secretion of melanin were also observed.
以硫代乳糖苷为支架,在动物细胞中进行糖基化,合成了多种糖脂。通过糖基化和去酰化两个步骤合成了n-十二烷基β- d -硫代乳糖苷(β-LacSC12)和n-十二烷基α- d -硫代乳糖苷(α-LacSC12)。硫代乳糖苷被施用于培养的动物细胞,并作为细胞酶催化糖基化的底物。小鼠黑色素瘤B16细胞在β-LacSC12或α-LacSC12存在下孵育,导致末端半乳糖残基的唾液酰化,产生gm3型神经节苷脂。在Madin-Darby犬肾(MDCK)细胞中给予β-Lac SC12同样给予gm3型神经节苷脂。另一方面,在非洲绿猴肾(Vero)细胞中引入β-LacSC12,除了gm3型神经节苷脂外,还产生Gb3-和gb4型糖脂。在研究过程中,还观察到B16细胞形态的显著变化和黑色素分泌的升高。
{"title":"Thiolactosides: Scaffolds for the Synthesis of Glycolipids in Animal Cells","authors":"Masako Mori, M. Kasuya, M. Mizuno, K. Hatanaka","doi":"10.1155/2011/267208","DOIUrl":"https://doi.org/10.1155/2011/267208","url":null,"abstract":"Various glycolipids were synthesized using thiolactosides as scaffolds for glycosylation in animal cells. The basic building blocks, n-dodecyl β-D-thiolactoside (β-LacSC12) and n-dodecyl α-D-thiolactoside (α-LacSC12), were chemically synthesized in 2 steps: glycosylation followed by deacylation. The thiolactosides were administered to animal cells in culture and served as substrates for cellular enzyme-catalyzed glycosylation. Incubation of mouse melanoma B16 cells in the presence of β-LacSC12 or α-LacSC12 resulted in sialylation of the terminal galactose residue and gave a GM3-type ganglioside. Administration of β-Lac SC12 in Madin-Darby canine kidney (MDCK) cells likewise gave a GM3-type ganglioside. On the other hand, introduction of β-LacSC12 in African green monkey kidney (Vero) cells gave Gb3- and Gb4-type glycolipids aside from GM3-type ganglioside. In the course of the study, significant changes in B16 cell morphology and elevated secretion of melanin were also observed.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"46 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2011-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73585448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Somnath Ghosh, Tasneem Kausar Ranebennur, H. Vasan
Antibacterial efficacy of silver nanoparticles (Ag NPs) deposited alternatively layer by layer (LBL) on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip has been studied. An eight-bilayer chitosan/silver (Cs/Ag)8 hybrid was prepared having a known concentration of silver. Techniques such as UV-visible spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), and atomic force microscopy (AFM) were carried out to understand and elucidate the physical nature of the film. Gram-negative bacteria, Escherichia coli (E. coli), were used as a test sample in saline solution for antibacterial studies. The growth inhibition at different intervals of contact time and, more importantly, the antibacterial properties of the hybrid film on repeated cycling in saline solution have been demonstrated. AFM studies are carried out for the first time on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months) are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. The hybrid can be a promising bioactive material for the prevention of biofilms specific to E. coli and in purification of water for safe drinking.
{"title":"Study of Antibacterial Efficacy of Hybrid Chitosan-Silver Nanoparticles for Prevention of Specific Biofilm and Water Purification","authors":"Somnath Ghosh, Tasneem Kausar Ranebennur, H. Vasan","doi":"10.1155/2011/693759","DOIUrl":"https://doi.org/10.1155/2011/693759","url":null,"abstract":"Antibacterial efficacy of silver nanoparticles (Ag NPs) deposited alternatively layer by layer (LBL) on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip has been studied. An eight-bilayer chitosan/silver (Cs/Ag)8 hybrid was prepared having a known concentration of silver. Techniques such as UV-visible spectroscopy, inductively coupled plasma optical emission spectroscopy (ICP-OES), and atomic force microscopy (AFM) were carried out to understand and elucidate the physical nature of the film. Gram-negative bacteria, Escherichia coli (E. coli), were used as a test sample in saline solution for antibacterial studies. The growth inhibition at different intervals of contact time and, more importantly, the antibacterial properties of the hybrid film on repeated cycling in saline solution have been demonstrated. AFM studies are carried out for the first time on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months) are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. The hybrid can be a promising bioactive material for the prevention of biofilms specific to E. coli and in purification of water for safe drinking.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"6 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81131769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Pazynina, V. Nasonov, I. Belyanchikov, R. Brossmer, Maxim Maisel, A. Tuzikov, N. Bovin
Earlier we reported a convenient and efficient method of preparing α2-6 sialooligosaccharides in conditions of Koenigs-Knorr reaction. The use of Ag2CO3 allowed carrying out α2-6 sialylation of galacto-4,6-diol of mono- and disaccharides with chloride of acetylated N-acetylneuraminic acid methyl ester as glycosyl donor. In this study we applied this approach to other derivatives of neuraminic acid, namely, Neu5Gc, 9-deoxy-9-NAc-Neu5Ac, Neu5Acα2-8Neu5Ac, and Neu5Acα2-8Neu5Acα2-8Neu5Ac as glycosyl donors; eight compounds were synthesized: Neu5Gcα-O(CH2)3NH2 (8), Neu5Gcα2-6Galβ1-4GlcNAcβ-O(CH2)3NH2 (10), 9-deoxy-9-NAc-Neu5Ac-O(CH2)3NH2 (15), 9-deoxy-9-NAc-Neu5Acα2-6Galβ1-4GlcNAcβ-O(CH2)3NH2 (17), Neu5Acα2-8Neu5Acα-O(CH2)3NH2(23) Neu5Acα2-8Neu5Acα-OCH3 (24), Neu5Acα2-8Neu5Acα-OCH2(p-C6H4)NHCOCH2NH2 (25), and Neu5Acα2-8Neu5Acα2-8Neu5Acα-O(CH2)3NH2 (32). These sialosides were used for characterization of siglecs and other carbohydrate-binding proteins.
此前我们报道了一种在Koenigs-Knorr反应条件下制备α2-6低聚唾液糖的简便高效方法。使用Ag2CO3可以用乙酰化n -乙酰神经氨酸甲酯氯作为糖基供体对单糖和双糖的半乳糖-4,6-二醇进行α2-6唾液化。在本研究中,我们将该方法应用于神经氨酸的其他衍生物,即Neu5Gc、9-脱氧-9- nac - neu5ac、Neu5Acα2-8Neu5Ac和Neu5Acα2-8Neu5Ac作为糖基供体;合成了neu5ac α- o (CH2)3NH2(8)、neu5ac α- 2- 6galβ 1- 4glcnac β- o (CH2)3NH2(10)、9-脱氧-9- nac - neu5ac - o (CH2)3NH2(15)、9-脱氧-9- nac - neu5ac α- 2- 6galβ 1- 4glcnac β- o (CH2)3NH2(17)、neu5ac α- 2- 8neu5ac α- o (CH2)3NH2(23)、neu5ac α- 2- 8neu5ac α- och2 (p-C6H4)NHCOCH2NH2(25)、neu5ac α- 2- 8neu5ac α- och2 (p-C6H4)NHCOCH2NH2和neu5ac α- 2- 8neu5ac α- o (CH2)3NH2(32)。这些硅皂苷被用于siglecs和其他碳水化合物结合蛋白的表征。
{"title":"Koenigs-Knorr Glycosylation with Neuraminic Acid Derivatives","authors":"G. Pazynina, V. Nasonov, I. Belyanchikov, R. Brossmer, Maxim Maisel, A. Tuzikov, N. Bovin","doi":"10.1155/2010/594247","DOIUrl":"https://doi.org/10.1155/2010/594247","url":null,"abstract":"Earlier we reported a convenient and efficient method of preparing α2-6 sialooligosaccharides in conditions of Koenigs-Knorr reaction. The use of Ag2CO3 allowed carrying out α2-6 sialylation of galacto-4,6-diol of mono- and disaccharides with chloride of acetylated N-acetylneuraminic acid methyl ester as glycosyl donor. In this study we applied this approach to other derivatives of neuraminic acid, namely, Neu5Gc, 9-deoxy-9-NAc-Neu5Ac, Neu5Acα2-8Neu5Ac, and Neu5Acα2-8Neu5Acα2-8Neu5Ac as glycosyl donors; eight compounds were synthesized: Neu5Gcα-O(CH2)3NH2 (8), Neu5Gcα2-6Galβ1-4GlcNAcβ-O(CH2)3NH2 (10), 9-deoxy-9-NAc-Neu5Ac-O(CH2)3NH2 (15), 9-deoxy-9-NAc-Neu5Acα2-6Galβ1-4GlcNAcβ-O(CH2)3NH2 (17), Neu5Acα2-8Neu5Acα-O(CH2)3NH2(23) Neu5Acα2-8Neu5Acα-OCH3 (24), Neu5Acα2-8Neu5Acα-OCH2(p-C6H4)NHCOCH2NH2 (25), and Neu5Acα2-8Neu5Acα2-8Neu5Acα-O(CH2)3NH2 (32). These sialosides were used for characterization of siglecs and other carbohydrate-binding proteins.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"11 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2010-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74339018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Easy, quantitative, and one-pot introduction of eight -lactoside-modules onto a porphyrin-core was achieved through -catalyzed chemoselective coupling (click chemistry) between a porphyrin carrying eight alkyne-terminals and -lactosyl azides. The obtained porphyrin-based glycocluster shows not only good water-solubility but also strong/specific lectin-affinity.
{"title":"Convenient Approach to Access Octa-Glycosylated Porphyrins via “Click Chemistry”","authors":"Misako Okada, Yuko Kishibe, Kanako Ide, Toshiyuki Takahashi, Teruaki Hasegawa","doi":"10.1155/2009/305276","DOIUrl":"https://doi.org/10.1155/2009/305276","url":null,"abstract":"Easy, quantitative, and one-pot introduction of eight -lactoside-modules onto a porphyrin-core was achieved through -catalyzed chemoselective coupling (click chemistry) between a porphyrin carrying eight alkyne-terminals and -lactosyl azides. The obtained porphyrin-based glycocluster shows not only good water-solubility but also strong/specific lectin-affinity.","PeriodicalId":13788,"journal":{"name":"International Journal of Carbohydrate Chemistry","volume":"116 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2009-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87773307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}