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Artigos de revistas sobre o tema "Anomeric position"

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Autor: Grafiati

Publicado: 25 de maio de 2024

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1

Filho, João Rufino de Freitas, Jucleiton José Rufino de Freitas, Pedro Ramos de Souza Neto, Fabrícia Aparecida Marques de Souza, Adiel Soares Ferreira, Anne Gabrielle Marques da Silva, Francisco Antonio Mabson Henrique Lopes, Marcilio Martins de Moraes, Clécio Souza Ramos e Ronaldo Nascimentos de Oliveira. "Recent Advances Related to Anomeric and Exo-anomeric Effects in Carbohydrate Chemistry". International Research Journal of Pure and Applied Chemistry 24, n.º 5 (22 de setembro de 2023): 95–110. http://dx.doi.org/10.9734/irjpac/2023/v24i5830.

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The anomeric effect in carbohydrate chemistry is known as the interaction between the OHd substituent at the anomeric position to favor an axial orientation rather than an equatorial one, despite the increased 1,3-diaxial interactions. In the anomeric effect, a sugar ring is stabilized by an electronegative substituent at the C1 carbon, also known as the anomeric carbon. The stabilization is thought to result from interactions between lone electron pairs on oxygen and a C1 antibonding orbital. On the other hand, the anomeric effect can be of two types: endo-anomeric and exo-anomeric. The effect is called endo-anomeric when the lone pair comes from the oxygen atom in the sugar ring and exo-anomeric when the lone pair comes from oxygen in a substituent on C1. Several factors influence the anomeric effect. In this way, this review aims to describe the recent advances in main theories, observations, and advances achieved in the last decades related to the anomeric effect. GRAPHICAL ABSTRACT

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2

Jabbari, Hadi. "Selective Anomeric Deacetylation of Per-Acetylated Carbohydrates Using (i-Pr)3Sn(OEt) and Synthesis of New Derivatives". Journal of Molecular Biology Research 10, n.º 1 (30 de novembro de 2020): 166. http://dx.doi.org/10.5539/jmbr.v10n1p166.

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In this study natural carbohydrates such as glucose, galactose, xylose, fructose andlactose, are acetylated by acetic anhydride and sodium acetate catalyst. Anomeric configuration is deacetylated by (i-Pr)3Sn(OEt)as a catalyst, an easy synthetic regioselective deacetylation of full acetylated carbohydrates using (i--Pr)3Sn(OEt) is described. The acetylated carbohydrates reacted with HBr (solution in AcOH, 32 wt.%) for the bromination of anomeric position. The synthesis oxazaphosphorine, and bromo hexa alkyl Methylsulfonate derivatives from anomeric position of carbohydrates was reacted. FT IR, 1H, 13C NMR, 31PNMR spectroscopy techniques were employed to examine the synthesized compounds.

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3

Lee, Sang Jun, Dale E. A. Lewis e Sankar Adhya. "Induction of the Galactose Enzymes in Escherichia coli Is Independent of the C-1-Hydroxyl Optical Configuration of the Inducer d-Galactose". Journal of Bacteriology 190, n.º 24 (17 de outubro de 2008): 7932–38. http://dx.doi.org/10.1128/jb.01008-08.

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ABSTRACT The two optical forms of aldohexose galactose differing at the C-1 position, α-d-galactose and β-d-galactose, are widespread in nature. The two anomers also occur in di- and polysaccharides, as well as in glycoconjugates. The anomeric form of d-galactose, when present in complex carbohydrates, e.g., cell wall, glycoproteins, and glycolipids, is specific. Their interconversion occurs as monomers and is effected by the enzyme mutarotase (aldose-1-epimerase). Mutarotase and other d-galactose-metabolizing enzymes are coded by genes that constitute an operon in Escherichia coli. The operon is repressed by the repressor GalR and induced by d-galactose. Since, depending on the carbon source during growth, the cell can make only one of the two anomers of d-galactose, the cell must also convert one anomer to the other for use in specific biosynthetic pathways. Thus, it is imperative that induction of the gal operon, specifically the mutarotase, be achievable by either anomer of d-galactose. Here we report in vivo and in vitro experiments showing that both α-d-galactose and β-d-galactose are capable of inducing transcription of the gal operon with equal efficiency and kinetics. Whereas all substitutions at the C-1 position in the α configuration inactivate the induction capacity of the sugar, the effect of substitutions in the β configuration varies depending upon the nature of the substitution; methyl and phenyl derivatives induce weakly, but the glucosyl derivative does not.

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4

Ölgen, Süreyya, e Chung K. Chu. "Synthesis And Antiviral Activity Of 2'-Deoxy-2'-Fluoro-L-Arabinofuranosyl 1,2,3-Triazole Derivatives". Zeitschrift für Naturforschung B 56, n.º 8 (1 de agosto de 2001): 804–11. http://dx.doi.org/10.1515/znb-2001-0814.

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The title compounds were prepared by building up the triazole ring at the anomeric position via the glycosyl azides 5 a,b. The anomeric configurations of these nucleosides were assigned by using 1H, 13C and NOESY NMR spectroscopy. The synthesized nucleosides were evaluated against HIV-1 and HBV

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5

Estevez, Juan C., Helen Ardron, Mark R. Wormald, David Brown e George W. J. Fleet. "Spirocyclic peptides at the anomeric position of mannofuranose". Tetrahedron Letters 35, n.º 47 (novembro de 1994): 8889–90. http://dx.doi.org/10.1016/s0040-4039(00)78526-1.

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6

Tanzi, Lisa, Marina Simona Robescu, Sara Marzatico, Teresa Recca, Yongmin Zhang, Marco Terreni e Teodora Bavaro. "Developing a Library of Mannose-Based Mono- and Disaccharides: A General Chemoenzymatic Approach to Monohydroxylated Building Blocks". Molecules 25, n.º 23 (7 de dezembro de 2020): 5764. http://dx.doi.org/10.3390/molecules25235764.

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Regioselective deprotection of acetylated mannose-based mono- and disaccharides differently functionalized in anomeric position was achieved by enzymatic hydrolysis. Candida rugosa lipase (CRL) and Bacillus pumilus acetyl xylan esterase (AXE) were immobilized on octyl-Sepharose and glyoxyl-agarose, respectively. The regioselectivity of the biocatalysts was affected by the sugar structure and functionalization in anomeric position. Generally, CRL was able to catalyze regioselective deprotection of acetylated monosaccharides in C6 position. When acetylated disaccharides were used as substrates, AXE exhibited a marked preference for the C2, or C6 position when C2 was involved in the glycosidic bond. By selecting the best enzyme for each substrate in terms of activity and regioselectivity, we prepared a small library of differently monohydroxylated building blocks that could be used as intermediates for the synthesis of mannosylated glycoconjugate vaccines targeting mannose receptors of antigen presenting cells.

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7

Hain, Julia, Patrick Rollin, Werner Klaffke e Thisbe K. Lindhorst. "Anomeric modification of carbohydrates using the Mitsunobu reaction". Beilstein Journal of Organic Chemistry 14 (29 de junho de 2018): 1619–36. http://dx.doi.org/10.3762/bjoc.14.138.

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The Mitsunobu reaction basically consists in the conversion of an alcohol into an ester under inversion of configuration, employing a carboxylic acid and a pair of two auxiliary reagents, mostly triphenylphosphine and a dialkyl azodicarboxylate. This reaction has been frequently used in carbohydrate chemistry for the modification of sugar hydroxy groups. Modification at the anomeric position, leading mainly to anomeric esters or glycosides, is of particular importance in the glycosciences. Therefore, this review focuses on the use of the Mitsunobu reaction for modifications of sugar hemiacetals. Strikingly, unprotected sugars can often be converted regioselectively at the anomeric center, whereas in other cases, the other hydroxy groups in reducing sugars have to be protected to achieve good results in the Mitsunobu procedure. We have reviewed on the one hand the literature on anomeric esterification, including glycosyl phosphates, and on the other hand glycoside synthesis, including S- and N-glycosides. The mechanistic details of the Mitsunobu reaction are discussed as well as this is important to explain and predict the stereoselectivity of anomeric modifications under Mitsunobu conditions. Though the Mitsunobu reaction is often not the first choice for the anomeric modification of carbohydrates, this review shows the high value of the reaction in many different circumstances.

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8

Wang, Ruibo, Kaimin Cai, Hua Wang, Chen Yin e Jianjun Cheng. "A caged metabolic precursor for DT-diaphorase-responsive cell labeling". Chemical Communications 54, n.º 38 (2018): 4878–81. http://dx.doi.org/10.1039/c8cc01715h.

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9

de Robichon, Morgane, Andrea Bordessa, Maciej Malinowski, Jacques Uziel, Nadège Lubin-Germain e Angélique Ferry. "Access to C-aryl/alkenylglycosides by directed Pd-catalyzed C–H functionalisation of the anomeric position in glycal-type substrates". Chemical Communications 55, n.º 78 (2019): 11806–8. http://dx.doi.org/10.1039/c9cc05993h.

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10

Sandoval, M., P. Hoyos, A. Cortés, T. Bavaro, M. Terreni e M. J. Hernáiz. "Development of regioselective deacylation of peracetylated β-d-monosaccharides using lipase from Pseudomonas stutzeri under sustainable conditions". RSC Adv. 4, n.º 98 (2014): 55495–502. http://dx.doi.org/10.1039/c4ra10401c.

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An efficient deacylation of peracetylated pyranosides has been developed in different biosolvents, catalyzed by Pseudomonas stutzeri lipase, which displayed regiospecific activity towards the anomeric position.

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11

Zhu, Feng, Sloane O'Neill, Jacob Rodriguez e Maciej A. Walczak. "Stereoretentive Reactions at the Anomeric Position: Synthesis of Selenoglycosides". Angewandte Chemie 130, n.º 24 (14 de maio de 2018): 7209–13. http://dx.doi.org/10.1002/ange.201802847.

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12

Zhu, Feng, Sloane O'Neill, Jacob Rodriguez e Maciej A. Walczak. "Stereoretentive Reactions at the Anomeric Position: Synthesis of Selenoglycosides". Angewandte Chemie International Edition 57, n.º 24 (14 de maio de 2018): 7091–95. http://dx.doi.org/10.1002/anie.201802847.

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13

Estevez, J. "Spirodiketopiperazines at the Anomeric position of Mannopyranose: Novel N-Linked Glycopeptides Incorporating an α-amino acid at the Anomeric Position of Mannopyranose". Tetrahedron Letters 36, n.º 45 (6 de novembro de 1995): 8287–90. http://dx.doi.org/10.1016/00404-0399(50)1732w-.

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14

Estevez, Juan C., Daniel D. Long, Mark R. Wormald, Raymond A. Dwek e George W. J. Fleet. "Spirodiketopiperazines at the anomeric position of mannopyranose: Novel N- linked glycopeptides incorporating an α- amino acid at the anomeric position of mannopyranose". Tetrahedron Letters 36, n.º 45 (novembro de 1995): 8287–90. http://dx.doi.org/10.1016/0040-4039(95)01732-w.

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15

Wróblewski, Andrzej E. "Analogues of Methyl D̲-Ribo-and D̲-Arabino-furanosides Having Phosphorus in the Anomeric Position+". Zeitschrift für Naturforschung B 41, n.º 6 (1 de junho de 1986): 791–92. http://dx.doi.org/10.1515/znb-1986-0622.

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Abstract Acid-catalysed cyclisation of (1S̲J-and (1R̲)-1-C̲-(dimethoxyphosphinyl)-D-erythritols gave exclusively P-epimeric analogues of methyl D-ribo- and D-arabino-furanosides with phosphorus in the anomeric position.

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16

Sierocki, Pierre, Krystal Gaillard, Ruben Arturo Arellano Reyes, Chloé Donnart, Emilie Lambert, Sandrine Grosse, Laurence Arzel et al. "Synthesis of novel C-nucleoside analogues bearing an anomeric cyano and a 1,2,3-triazole nucleobase as potential antiviral agents". Organic & Biomolecular Chemistry 20, n.º 13 (2022): 2715–28. http://dx.doi.org/10.1039/d1ob02451e.

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We report the synthesis of C-nucleosides with a quaternary carbon at the anomeric position tethered to a 4-substituted 1,2,3-triazole ring and a cyano group, which were developed as potential antiviral agents.

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17

Lioux, Thierry, Roger Busson, Jef Rozenski, Martine Nguyen-Distèche, Jean-Marie Frère e Piet Herdewijn. "Synthesis of Peptidoglycan Units with UDP at the Anomeric Position". Collection of Czechoslovak Chemical Communications 70, n.º 10 (2005): 1615–41. http://dx.doi.org/10.1135/cccc20051615.

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A series of UDP-disaccharide peptide compounds were synthesized as synthetic substrate analogues or potential inhibitors of glycosyl transferase. Fluorescent compounds have been prepared with the aim of developing a screening method for selecting transglycosylase inhibitors.

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18

Lubin-Germain, Nadège, Jean-Pierre Baltaze, Alexis Coste, Agnès Hallonet, Hugo Lauréano, Grégory Legrave, Jacques Uziel e Jacques Augé. "DirectC-Glycosylation by Indium-Mediated Alkynylation on Sugar Anomeric Position". Organic Letters 10, n.º 5 (março de 2008): 725–28. http://dx.doi.org/10.1021/ol7029257.

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19

Koumanov, Françoise, Christelle Henry, Catherine Ghezzi, Jean-Paul Mathieu, Christophe Morin, Michel Vidal, Joël de Leiris, Michel Comet e Daniel Fagret. "Biological evaluation of two anomeric glucose analogues iodinated in position". Nuclear Medicine and Biology 24, n.º 6 (agosto de 1997): 519–25. http://dx.doi.org/10.1016/s0969-8051(97)00022-x.

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20

ESTEVEZ, J. C., H. ARDRON, M. R. WORMALD, D. BROWN e G. W. J. FLEET. "ChemInform Abstract: Spirocyclic Peptides at the Anomeric Position of Mannofuranose." ChemInform 26, n.º 16 (18 de abril de 1995): no. http://dx.doi.org/10.1002/chin.199516243.

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21

ESTEVEZ, J. C., D. D. LONG, M. R. WORMALD, R. A. DWEK e G. W. J. FLEET. "ChemInform Abstract: Spirodiketopiperazines at the Anomeric Position of Mannopyranose: Novel N-Linked Glycopeptides Incorporating an α-Amino Acid at the Anomeric Position of Mannopyranose." ChemInform 27, n.º 8 (12 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199608232.

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22

Désilets, S., e M. St-Jacques. "The anomeric effect in thio derivatives of benzocycloheptene". Canadian Journal of Chemistry 70, n.º 10 (1 de outubro de 1992): 2650–58. http://dx.doi.org/10.1139/v92-334.

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The conformational properties of six thio derivatives of benzocycloheptene were studied by 1H and 13C high-field NMR spectroscopy in solution at low temperature. Both parent compounds 2 and 6, with sulfur at positions 3 and 1, respectively, were found to exist in the chair conformation. The 2-substituted derivatives of 2 (3: Y = OCH3 and 4: Y = Cl) revealed the presence of the Ca form only. In contrast, the 2-substituted derivatives of 6 (7: Y = OCH3 and 8: Y = Cl), with sulfur at position 1, showed mixtures of three conformers, namely Ca:Ce:TB (Ca = axial chair, Ce = equatorial chair, and TB = twist-boat), whose populations in CHF2Cl were, respectively, 93:5:2 and 85:12:3. The predominance of the Ca form in both series argues in favour of a strong anomeric effect in spite of the large departure from coplanarity (~35°) in the:—S—C—Y fragment of both 7 and 8. This noncoplanarity appears to weaken only slightly the n–σ* overlap characteristic of the endo-anomeric effect, contrary to earlier observations for the:—O—C—Y fragment in 5. The differences between the effects of O and S are discussed.

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23

Cattaneo, Vittorio, Davide Oldrini, Alessio Corrado, Francesco Berti e Roberto Adamo. "Orthogonal cleavage of the 2-naphthylmethyl group in the presence of the p-methoxy phenyl-protected anomeric position and its use in carbohydrate synthesis". Organic Chemistry Frontiers 3, n.º 6 (2016): 753–58. http://dx.doi.org/10.1039/c6qo00144k.

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24

Wróblewski, Andrzej E. "Analogues of branched-chain tetrafuranosides having phosphorus in the anomeric position". Tetrahedron 42, n.º 13 (janeiro de 1986): 3595–606. http://dx.doi.org/10.1016/s0040-4020(01)87326-9.

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25

Downey, A. Michael, e Michal Hocek. "Strategies toward protecting group-free glycosylation through selective activation of the anomeric center". Beilstein Journal of Organic Chemistry 13 (27 de junho de 2017): 1239–79. http://dx.doi.org/10.3762/bjoc.13.123.

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Glycosylation is an immensely important biological process and one that is highly controlled and very efficient in nature. However, in a chemical laboratory the process is much more challenging and usually requires the extensive use of protecting groups to squelch reactivity at undesired reactive moieties. Nonetheless, by taking advantage of the differential reactivity of the anomeric center, a selective activation at this position is possible. As a result, protecting group-free strategies to effect glycosylations are available thanks to the tremendous efforts of many research groups. In this review, we showcase the methods available for the selective activation of the anomeric center on the glycosyl donor and the mechanisms by which the glycosylation reactions take place to illustrate the power these techniques.

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26

Saeed, Muhammad, Muhammad Abbas, Khalid Mohammad Khan e Wolfgang Voelter. "Total Synthesis of S-(+)-Argentilactone". Zeitschrift für Naturforschung B 56, n.º 3 (1 de março de 2001): 325–28. http://dx.doi.org/10.1515/znb-2001-0318.

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Abstract Asymmetrie Total Synthesis Asymmetrie total synthesis of S-(+)-argentilactone (2) was accomplished, using methyl-a-D-glucopyranoside (3) as carbohydrate template. Benzylidene acetal 5 was hydrolysed with tBuOOH/AlCl3 and further manipulated to produce the aldehyde 10. A Wittig reaction and subsequent oxidation of the anomeric position yielded the target argentilactone.

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27

Lundt, Inge, e Robert Madsen. "ChemInform Abstract: Isoimino Sugars: Glycosidase Inhibitors with Nitrogen at the Anomeric Position". ChemInform 31, n.º 32 (3 de junho de 2010): no. http://dx.doi.org/10.1002/chin.200032259.

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28

Moccia, Maria, Linda Piras, Gea Bellini, Michele Saviano e Mauro F. A. Adamo. "Synthesis and Characterization of Abasic β-Diol-C-Nucleosides". Chemistry 5, n.º 2 (31 de maio de 2023): 1343–56. http://dx.doi.org/10.3390/chemistry5020091.

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Modified nucleobases are potentially useful building blocks when containing catalytically active functionalities and could be introduced in chiral tridimensional molecules such as nucleic acids, which creates the premises for the development of novel catalytic species. Herein, we describe the synthesis of a novel β-C-nucleoside bearing a diol group at anomeric position, amenable as a metal ligand or organocatalyst. An abasic ligand was successfully prepared and inserted into a complementary DNA strand.

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29

Chittaboina, Srinivas, Blake Hodges e Qian Wang. "A Facile Route for the Regioselective Deacetylation of Peracetylated Carbohydrates at Anomeric Position". Letters in Organic Chemistry 3, n.º 1 (1 de janeiro de 2006): 35–38. http://dx.doi.org/10.2174/157017806774964521.

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30

Cumpstey, Ian, Jens Frigell, Elias Pershagen, Tashfeen Akhtar, Elena Moreno-Clavijo, Inmaculada Robina, Dominic S. Alonzi e Terry D. Butters. "Amine-linked diglycosides: Synthesis facilitated by the enhanced reactivity of allylic electrophiles, and glycosidase inhibition assays". Beilstein Journal of Organic Chemistry 7 (16 de agosto de 2011): 1115–23. http://dx.doi.org/10.3762/bjoc.7.128.

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Diglycose derivatives, consisting of two monosaccharides linked at non-anomeric positions by a bridging nitrogen atom, have been synthesised. Conversion of one of the precursor monosaccharide coupling components into an unsaturated derivative enhances its electrophilicity at the allylic position, facilitating coupling reactions. Mitsunobu coupling between nosylamides and 2,3-unsaturated-4-alcohols gave the 4-amino-pseudodisaccharides with inversion of configuration as single regio- and diastereoisomers. A palladium-catalysed coupling between an amine and a 2,3-unsaturated 4-trichloroacetimidate gave a 2-amino-pseudodisaccharide as the major product, along with other minor products. Derivatisation of the C=C double bond in pseudodisaccharides allowed the formation of Man(N4–6)Glc and Man(N4–6)Man diglycosides. The amine-linked diglycosides were found to show weak glycosidase inhibitory activity.

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31

Singh, Adesh Kumar, Rapelly Venkatesh e Jeyakumar Kandasamy. "Palladium-Catalyzed One-Pot Stereospecific Synthesis of 2-Deoxy Aryl C-Glycosides from Glycals and Anilines in the Presence of tert-Butyl Nitrite". Synthesis 51, n.º 22 (26 de agosto de 2019): 4215–30. http://dx.doi.org/10.1055/s-0037-1611916.

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The palladium-catalyzed one-pot synthesis of 2,3-deoxy-3-keto aryl C-glycosides is achieved from glycals and anilines in the presence of tert-butyl nitrite and aqueous HBF4 under mild conditions. This one-pot method stereospecifically provides α- and β-aryl glycosides (≥19:1 by NMR) in good yields at room temperature. The configuration at the C-3 position in the glycal determines the anomeric selectivity (i.e., α or β) of the desired products.

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Sánchez-Fernández, Elena M., Raquel García-Hernández, Francisco Gamarro, Ana I. Arroba, Manuel Aguilar-Diosdado, José M. Padrón, José M. García Fernández e Carmen Ortiz Mellet. "Synthesis of sp2-Iminosugar Selenoglycolipids as Multitarget Drug Candidates with Antiproliferative, Leishmanicidal and Anti-Inflammatory Properties". Molecules 26, n.º 24 (11 de dezembro de 2021): 7501. http://dx.doi.org/10.3390/molecules26247501.

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sp2-Iminosugar glycolipids (sp2-IGLs) represent a consolidated family of glycoconjugate mimetics encompassing a monosaccharide-like glycone moiety with a pseudoamide-type nitrogen replacing the endocyclic oxygen atom of carbohydrates and an axially-oriented lipid chain anchored at the pseudoanomeric position. The combination of these structural features makes them promising candidates for the treatment of a variety of conditions, spanning from cancer and inflammatory disorders to parasite infections. The exacerbated anomeric effect associated to the putative sp2-hybridized N-atom imparts chemical and enzymatic stability to sp2-IGLs and warrants total α-anomeric stereoselectivity in the key glycoconjugation step. A variety of O-, N-, C- and S-pseudoglycosides, differing in glycone configurational patterns and lipid nature, have been previously prepared and evaluated. Here we expand the chemical space of sp2-IGLs by reporting the synthesis of α-d-gluco-configured analogs with a bicyclic (5N,6O-oxomethylidene)nojirimycin (ONJ) core incorporating selenium at the glycosidic position. Structure–activity relationship studies in three different scenarios, namely cancer, Leishmaniasis and inflammation, convey that the therapeutic potential of the sp2-IGLs is highly dependent, not only on the length of the lipid chain (linear aliphatic C12 vs. C8), but also on the nature of the glycosidic atom (nitrogen vs. sulfur vs. selenium). The ensemble of results highlights the α-dodecylseleno-ONJ-glycoside as a promising multitarget drug candidate.

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Imperio, Daniela, Erika Del Grosso, Silvia Fallarini, Grazia Lombardi e Luigi Panza. "Anomeric sugar boronic acid analogues as potential agents for boron neutron capture therapy". Beilstein Journal of Organic Chemistry 15 (19 de junho de 2019): 1355–59. http://dx.doi.org/10.3762/bjoc.15.135.

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After the development of accelerators as neutron source, the access to new suitable agents for boron neutron capture therapy (BNCT) became a major need. Among many others, sugar boronic acids have recently attracted attention as boron carriers. Herein we report the synthesis and preliminary biological studies of two new sugar analogues containing a boronic acid at the anomeric position. The analogues were obtained by hydroboration of proper open-chain terminal alkenes that, after quenching with water, spontaneously afforded cyclic boronic acids with hemiacetal-like structures.

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Chu, Fengting, Quhao Wei, Ping Wang, Dan Lu, Siyao Wang e Hongli Yin. "Rapid Assembly of Oligosaccharides by Using a Hydrophobic Tag-Assisted Liquid-Phase Method". Synlett 31, n.º 12 (7 de maio de 2020): 1163–66. http://dx.doi.org/10.1055/s-0040-1707965.

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A 3,5-didocosyloxybenzyl alcohol tag that was introduced at the anomeric position of the carbohydrate acceptor was applied in the assembly of a pentasaccharide. The intrinsic high solubility in nonpolar solvent and precipitation properties in polar solvent are crucial features of this tag. Thus, rapid and simple precipitation-centrifugation can be conducted throughout the synthetic route at each step to ease work-up and purification processes, and reduce the amount of solvent required. This method provides an efficient, environmental-friendly, and economical approach to synthesize complex oligosaccharides.

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Saaidi, Pierre-Loïc, Mathieu Guyonnet, Erwann Jeanneau, Paul Fleurat-Lessard e Jens Hasserodt. "Trimerization Products of Trifluoroacetone: Critical Solvent Effect on Position and Kinetics of Anomeric Equilibria". Journal of Organic Chemistry 73, n.º 4 (fevereiro de 2008): 1209–16. http://dx.doi.org/10.1021/jo701669p.

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36

Estevez, Juan C., Jonathan W. Burton, Ramon J. Estevez, Helen Ardron, Mark R. Wormald, Raymond A. Dwek, David Brown e George W. J. Fleet. "Spirodiketopiperazines of mannofuranose: carbopeptoid α-amino acid esters at the anomeric position of mannofuranose". Tetrahedron: Asymmetry 9, n.º 12 (junho de 1998): 2137–54. http://dx.doi.org/10.1016/s0957-4166(98)00206-7.

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37

Krülle, T. "Specific Inhibition of Glycogen Phosphorylase by a Spirodiketopiperazine at the Anomeric position of Glucopyranose". Tetrahedron Letters 36, n.º 45 (6 de novembro de 1995): 8291–94. http://dx.doi.org/10.1016/00404-0399(50)1733x-.

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38

Park, Simon, Hsiao-Wu Hsieh e Jacquelyn Gervay-Hague. "Anomeric O-Functionalization of Carbohydrates for Chemical Conjugation to Vaccine Constructs". Molecules 23, n.º 7 (17 de julho de 2018): 1742. http://dx.doi.org/10.3390/molecules23071742.

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Carbohydrates mediate a wide range of biological interactions, and understanding these processes benefits the development of new therapeutics. Isolating sufficient quantities of glycoconjugates from biological samples remains a significant challenge. With advances in chemical and enzymatic carbohydrate synthesis, the availability of complex carbohydrates is increasing and developing methods for stereoselective conjugation these polar head groups to proteins and lipids is critically important for pharmaceutical applications. The aim of this review is to provide an overview of commonly employed strategies for installing a functionalized linker at the anomeric position as well as examples of further transformations that have successfully led to glycoconjugation to vaccine constructs for biological evaluation as carbohydrate-based therapeutics.

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39

Alhassid, Anat, Alon Ben-David, Orly Tabachnikov, Dima Libster, Einat Naveh, Gennady Zolotnitsky, Yuval Shoham e Gil Shoham. "Crystal structure of an inverting GH 43 1,5-α-L-arabinanase from Geobacillus stearothermophilus complexed with its substrate". Biochemical Journal 422, n.º 1 (29 de julho de 2009): 73–82. http://dx.doi.org/10.1042/bj20090180.

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Arabinanases are glycosidases that hydrolyse α-(1→5)- arabinofuranosidic linkages found in the backbone of the pectic polysaccharide arabinan. Here we describe the biochemical characterization and the enzyme–substrate crystal structure of an inverting family 43 arabinanase from Geobacillus stearothermophilus T-6 (AbnB). Based on viscosity and reducing power measurements, and based on product analysis for the hydrolysis of linear arabinan by AbnB, the enzyme works in an endo mode of action. Isothermal titration calorimetry studies of a catalytic mutant with various arabino-oligosaccharides suggested that the enzyme active site can accommodate at least five arabinose units. The crystal structure of AbnB was determined at 1.06 Å (1 Å=0.1 nm) resolution, revealing a single five-bladed-β-propeller fold domain. Co-crystallization of catalytic mutants of the enzyme with different substrates allowed us to obtain complex structures of AbnBE201A with arabinotriose and AbnBD147A with arabinobiose. Based on the crystal structures of AbnB together with its substrates, the position of the three catalytic carboxylates: Asp27, the general base; Glu201, the general acid; and Asp147, the pKa modulator, is in agreement with their putative catalytic roles. In the complex structure of AbnBE201A with arabinotriose, a single water molecule is located 2.8 Å from Asp27 and 3.7 Å from the anomeric carbon. The position of this water molecule is kept via hydrogen bonding with a conserved tyrosine (Tyr229) that is 2.6 Å distant from it. The location of this molecule suggests that it can function as the catalytic water molecule in the hydrolysis reaction, resulting in the inversion of the anomeric configuration of the product.

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40

Virtanen, Valtteri, e Maarit Karonen. "Partition Coefficients (logP) of Hydrolysable Tannins". Molecules 25, n.º 16 (13 de agosto de 2020): 3691. http://dx.doi.org/10.3390/molecules25163691.

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The partition coefficients (logP) between n-octanol and water of 47 purified and characterized hydrolysable tannins were measured with the shake flask method utilizing UPLC and HPLC with UV detection. Results show that galloyl glucoses and gallotannins are clearly more hydrophobic than ellagitannins but the differences in hydrophobicity within ellagitannins are more varied than within galloyl glucoses or gallotannins. Most notable structural features that were found to influence the hydrophobicity of ellagitannins were the number of free galloyl groups, acyclic versus cyclic polyol, substitution of the anomeric position of glucose and 4C1 versus 1C4 conformation of the glucopyranose core.

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Caravano, Audrey, Diane Baillieul, Christophe Ansiaux, Weidong Pan, José Kovensky, Pierre Sinaÿ e Stéphane P. Vincent. "Synthesis of galactosides locked in a 1,4B boat conformation and functionalized at the anomeric position". Tetrahedron 63, n.º 9 (fevereiro de 2007): 2070–77. http://dx.doi.org/10.1016/j.tet.2006.12.028.

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42

Estevez, Juan C., Ramon J. Estevez, Helen Ardron, Mark R. Wormald, David Brown e George W. J. Fleet. "Tri- and tetra-peptides incorporating an α-amino acid at the anomeric position of mannofuranose". Tetrahedron Letters 35, n.º 47 (novembro de 1994): 8885–88. http://dx.doi.org/10.1016/s0040-4039(00)78525-x.

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43

Kinfe, Henok H., Felix L. Makolo, Paseka T. Moshapo e Zanele H. Phasha. "New Carbohydrate-DerivedS,S-Dioxothiochroman Derivatives and Their Unexpected Easy Epimerization at the Anomeric Position". Journal of Carbohydrate Chemistry 32, n.º 3 (24 de março de 2013): 193–204. http://dx.doi.org/10.1080/07328303.2013.789106.

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44

Itoh, Yoshiharu, Kazuhiro Haraguchi, Hiromichi Tanaka, Eisen Gen e Tadashi Miyasaka. "Divergent and Stereocontrolled Approach to the Synthesis of Uracil Nucleosides Branched at the Anomeric Position". Journal of Organic Chemistry 60, n.º 3 (fevereiro de 1995): 656–62. http://dx.doi.org/10.1021/jo00108a031.

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45

LAKHRISSI, M., A. CHAOUCH e Y. CHAPLEUR. "ChemInform Abstract: Dichlorocyclopropanation of Sugar Dichloroolefins: A New Route to Spirocyclopropanes at the Anomeric Position." ChemInform 27, n.º 48 (4 de agosto de 2010): no. http://dx.doi.org/10.1002/chin.199648225.

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46

Abdullayev, Shuay, Priyanka Kadav, Purnima Bandyopadhyay, Francisco Javier Medrano, Gabriel A. Rabinovich, Tarun K. Dam, Antonio Romero e René Roy. "Selectively Modified Lactose and N-Acetyllactosamine Analogs at Three Key Positions to Afford Effective Galectin-3 Ligands". International Journal of Molecular Sciences 24, n.º 4 (13 de fevereiro de 2023): 3718. http://dx.doi.org/10.3390/ijms24043718.

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Galectins constitute a family of galactose-binding lectins overly expressed in the tumor microenvironment as well as in innate and adaptive immune cells, in inflammatory diseases. Lactose ((β-D-galactopyranosyl)-(1→4)-β-D-glucopyranose, Lac) and N-Acetyllactosamine (2-acetamido-2-deoxy-4-O-β-D-galactopyranosyl-D-glucopyranose, LacNAc) have been widely exploited as ligands for a wide range of galectins, sometimes with modest selectivity. Even though several chemical modifications at single positions of the sugar rings have been applied to these ligands, very few examples combined the simultaneous modifications at key positions known to increase both affinity and selectivity. We report herein combined modifications at the anomeric position, C-2, and O-3′ of each of the two sugars, resulting in a 3′-O-sulfated LacNAc analog having a Kd of 14.7 µM against human Gal-3 as measured by isothermal titration calorimetry (ITC). This represents a six-fold increase in affinity when compared to methyl β-D-lactoside having a Kd of 91 µM. The three best compounds contained sulfate groups at the O-3′ position of the galactoside moieties, which were perfectly in line with the observed highly cationic character of the human Gal-3 binding site shown by the co-crystal of one of the best candidates of the LacNAc series.

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47

Nishida, Yoshihiro, Torsten Wiemann e Joachim Thiem. "Transfer of galactose to the anomeric position of N-acetyl gentosamine by galactosyltransferase from bovine milk". Tetrahedron Letters 33, n.º 52 (dezembro de 1992): 8043–46. http://dx.doi.org/10.1016/s0040-4039(00)74712-5.

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48

Nishida, Yoshihiro, Torsten Wiemann, Volker Sinnwell e Joachim Thiem. "A new type of galactosyltransferase reaction: transfer of galactose to the anomeric position of N-acetylkanosamine". Journal of the American Chemical Society 115, n.º 6 (março de 1993): 2536–37. http://dx.doi.org/10.1021/ja00059a074.

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49

Campbell, Matthew T., Dazhe Chen e Gary L. Glish. "Distinguishing Linkage Position and Anomeric Configuration of Glucose–Glucose Disaccharides by Water Adduction to Lithiated Molecules". Analytical Chemistry 90, n.º 3 (16 de janeiro de 2018): 2048–54. http://dx.doi.org/10.1021/acs.analchem.7b04162.

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50

Gauffeny, Françoise, Alberto Marra, Lian Kiow Shi Shun, Pierre Sinaÿ e Christine Tabeur. "A novel and convenient method for the removal of a nitrate group at the anomeric position". Carbohydrate Research 219 (outubro de 1991): 237–40. http://dx.doi.org/10.1016/0008-6215(91)89056-l.

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