- Total Synthesis of the Repeating Unit of Bacteroides fragilis Zwitterionic Polysaccharide A1
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Zwitterionic polysaccharides isolated from commensal bacteria are endowed with unique immunological properties and are emerging as immunotherapeutic agents as well as vaccine carriers. Reported herein is a total synthesis of the repeating unit of Bacteroides fragilis zwitterionic polysaccharide A1 (PS A1). The structurally complex tetrasaccharide unit contains a rare sugar 2-acetamido-4-amino-2,4,6-trideoxy-d-galactose (AAT) and two consecutive 1,2-cis glycosidic linkages. The repeating unit was efficiently assembled by rapid synthesis of d-galactosamine and AAT building blocks from cheap and abundant d-mannose via a one-pot SN2 displacement of 2,4-bistriflates and installation of all of the glycosidic bonds in a highly stereoselective manner. The total synthesis involves a longest linear sequence of 17 steps with 3.47% overall yield.
- Pathan, Ennus K.,Ghosh, Bhaswati,Podilapu, Ananda Rao,Kulkarni, Suvarn S.
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p. 6090 - 6099
(2021/05/06)
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- Improvement of the versatility of an arabinofuranosidase against galactofuranose for the synthesis of galactofuranoconjugates
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Galactofuranoconjugates are rare compounds with interesting biological properties. Their syntheses by traditional approaches are however tedious. Glycosidases are nowadays often used to simplify such syntheses but the use of galactofuranosidase has not be
- Pavic, Quentin,Pillot, Aline,Tasseau, Olivier,Legentil, Laurent,Tranchimand, Sylvain
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p. 6799 - 6808
(2019/07/22)
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- NEW ANTIBACTERIAL COMPOUNDS AND BIOLOGICAL APPLICATIONS THEREOF
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The invention relates to compounds of formulae (Ia), (Ib) or (Ic) wherein, - A1 and A2, identical or different, are H, (C1-C6) alkyl, (C1-C6) fluoroalkyl, (C2-C6) alkenyl, (C2-C6) alkynyl, (C1-C6) alkyl-ORa, (C1-C6) alkyl-SRa, (C1-C6) alkyl-NRaRb, ORa, SRa, NRaRb, or CORa; - A3 is H, OH or form a carbonyl with A4; - A4 is H, OH or form a carbonyl with A3; - A5 is H, CRaRbOH, F, OH or forms a double bond with X in the case where X is CH; - A6 is H or F; - X is CH2, CHF, CF2, CHOH, O, S, NRa or a simple bond, or X is CH in the case where A5 forms with X a double bond; - Y is P(O) (ORa) (ORb) or P (O) (ORa) (NRaRb); - V is O or S; - A7 is H, (C1-C6) alkyl, (C1-C6) fluoroalkyl, (C2-C6) alkenyl, (C2-C6) alkynyl or (C1-C6) alkyl-ORa; - A8 is OH or H, - Ra and Rb, identical or different, are H, (C1-C6) alkyl, (C1-C6) fluoroalkyl, (C1-C6) alkyl-OH or (C1-C6) alkyl-O- (C1- C6) alkyl; and their addition salts thereof with acids and bases, their preparation and their use in the antibacterial prevention and therapy, used alone or in association with antibacterials, antivirulence agents or drugs reinforcing the host innate immunity.
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- New antibacterial compounds and biological applications thereof
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The invention relates to compounds of formula (I) wherein, - A1 and A2, identical or different, are H, (C1-C6) alkyl, (C1-C6) fluoroalkyl, (C2-C6) alkenyl, (C2-C6) alkynyl, (C1-C6) alkyl-ORa, (C1-C6) alkyl-SRa, (C1-C6) alkyl-NRaRb, ORa, SRa, NRaRb, or CORa; - A3 is H, OH or form a carbonyl with A4; - A4 is H, OH or form a carbonyl with A3; - A5 is H, OH, CRaRbOH or F; - A6 is H or F; - X is CH2, CHF, CF2, CHOH, O, S, NRa or a simple bond; - Y is P(O) (ORa) (ORb) or P(O) (ORa) (NRaRb) ; - V is O or S; - A7 is H, (C1-C6) alkyl, (C1-C6) fluoroalkyl, (C2-C6) alkenyl, (C2-C6) alkynyl or (C1-C6) alkyl-ORa; - Ra and Rb, identical or different, are selected from the group consisting of H, (C1-C6) alkyl, (C1-C6) fluoroalkyl, (C1-C6) alkyl-OH and (C1-C6) alkyl-O-(C1-C6) alkyl; and their addition salts thereof with acids and bases, their preparation and their use in the antibacterial prevention and therapy, used alone or in association with antibacterials, antivirulence agents or drugs reinforcing the host innate immunity.
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Paragraph 0063
(2014/05/20)
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- Glucofuranoses
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A β-D-glucofuranose compound which is 1,2,3,5,6-penta-O-propanoyl-β-D-glucofuranose, preferably in crystalline form, is prepared from D-glucose. The compound is prepared by reacting D-glucose with boric acid, or an equivalent thereof, followed by treatment with a propanoylating reagent, preferably propanoic anhydride. The compound is useful for the preparation of other compounds, such as glucofuranosides.
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- Glucofuranosylation with penta-O-propanoyl-β-D-glucofuranose
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Readily available, crystalline penta-O-propanoyl-β-D-glucofuranose is shown to be a suitable glycosylating agent for the acid-catalysed, direct synthesis of O-, S- and N-glucofuranosyl compounds. β-Linked products are formed with good selectivity. Reactio
- Furneaux, Richard H.,Martin, Benedicte,Rendle, Phillip M.,Taylor, Carol M.
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p. 1999 - 2004
(2007/10/03)
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- A general and diastereoselective synthesis of 1,2-cis-hexofuranosides from 1,2-trans-thiofuranosyl donors
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The general formation of 1,2-trans-thioglycofuranosides derived from D- galactose, D-glucose and D-mannose was readily accomplished starting from the corresponding alkyl glycofuranosides via per-O-acetyl-hexofuranoses as key synthons. Glycosidation of ethyl or phenyl perbenzylated 1,2-trans- thiofuranosides afforded disaccharides containing a nonreducing 1,2-cis- hexofuranosyl unit, i.e. α-D-galactosyl, α-D-glucosyl or β-D-mannosyl, with interesting diastereoselectivities. Activation of the thiofuranosyl donors was performed by N-iodosuccinimide and a catalytic amount of tin(II) trifluoromethanesulfonate.
- Gelin, Muriel,Ferrieres, Vincent,Plusquellec, Daniel
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p. 1423 - 1431
(2007/10/03)
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- Anomeric Configuration Analysis-Extension of the Ring Oxygen Helicity Rule to Aromatic Glycofuranosides
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A strong Cotton effect associated with the ring oxygen was studied in aromatic glucofuranosides.Phenyl and phenyl 1-thioglycofuranosides gave a strong band at 180 nm and 200 - 210 nm respectively, similar to the corresponding glycopyranosides, suggesting
- Kohata, Katsunori,Meguro, Hiroshi
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p. 2077 - 2086
(2007/10/02)
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