59694-37-0Relevant academic research and scientific papers
Glycosylation with ulosonates under Mitsunobu conditions: Scope and limitations
Kánya, Nándor,Kun, Sándor,Batta, Gyula,Somsák, László
supporting information, p. 14463 - 14476 (2020/10/02)
A systematic study was performed by using Mitsunobu conditions (diethyl azodicarboxylate, Ph3P or n-Bu3P in THF or CH3CN) for glycosylations with methyl 3,4,5,7-tetra-O-benzoyl-α-d-gluco-hept-2-ulopyranosonate. From a set of 47 O-, N-, S- and C-nucleophiles, phenols and N-hydroxy compounds with a pKa of 5-8, phthalimide, benzotriazole, 6-chloropurine, an oxazolidinedione and several tetrazoles with a pKa of 4-8, and thiophenol gave the corresponding products in moderate to very good yields, while C-nucleophiles were unreactive. Trihaloacetanilides underwent O-glycosylation to give O-glycosyl-N-aryl trihaloacetimidates which could not be made by conventional O-imidoylations. All reactions were highly stereoselective to produce the β(d) anomers only. With methyl (5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-d-glycero-d-galacto-2-nonulopyranose)onate phenols and benzotriazole resulted in the expected products, but all other nucleophiles failed to react. While these transformations gave anomeric mixtures in a ratio close to 1?:?1 at room temperature, the α-selectivity increased to 92?:?8 at -30 °C. An o-nitrophenyl sialoside was converted to a spiro-benzoxazinone derivative by reduction of the nitro group and subsequent spontaneous ring closure.
Synthesis of poly(aspartimide)-based bio-glycoconjugates
Carlescu, Irina,Osborn, Helen M.I.,Desbrieres, Jacques,Scutaru, Dan,Popa, Marcel
, p. 33 - 40 (2011/02/28)
The purpose of this programme was to synthesize and analyze new bioconjugates of interest for the potential inhibition of the influenza virus, using poly(aspartimide) as a polymer support. The macromolecular targets were obtained by attaching various sial
Syntheses of C-3-modified sialylglycosides as selective inhibitors of influenza hemagglutinin and neuraminidase
Sun, Xue-Long,Kanie, Yoshimi,Guo, Chao-Tan,Kanie, Osamu,Suzuki, Yasuo,Wong, Chi-Huey
, p. 2643 - 2653 (2007/10/03)
In an effort to develop new structures as inhibitors of both influenza virus proteins hemagglutinin and neuraminidase, a series of sialic acid derivatives, including those with one of the hydrogen atoms at the C-3 position replaced by either OH or F, were synthesized. The sialic acid derivative with a 3-eq-OH group was first synthesized by means of a new process and used as the key intermediate for further derivatization at the C- 3 position. The stability of these compounds under acid- and sialidase- catalyzed hydrolysis conditions was studied, and the results showed that these compounds exhibit stronger resistance towards both conditions than their parent p-nitrophenyl α-sialoside. Further inhibition assay indicated that the 3-ax-OH or F derivatives 4, 5, and 24, the 4-epimer of 4, are effective specific inhibitors of the sialidases from Clostridium perfringens, among other bacterial sialidases tested. The 3-eq-OH derivative 3, however, showed little inhibition. The same tendency was observed for the inhibition of human influenza sialidases N1 and N2. Compounds 3-5 and sialic acid were then converted into the distealoylphosphatidylethanolamine conjugates. Of these liposome-like compounds, the ones from 4 and 5 showed potent and selective inhibitory activities against the hemagglutinin H3 subtype, but displayed resistance to the influenza virus neuraminidases N1 and N2.
A facile access to aryl α-sialosides: The combination of a volatile amine base and acetonitrile in glycosidation of sialosyl chlorides
Kuboki, Atsuhito,Sekiguchi, Takahiro,Sugai, Takeshi,Ohta, Hiromichi
, p. 479 - 482 (2007/10/03)
We have succeeded in achieving a facile access to 4-nitrophenyl and 4-methylumbelliferyl-α-sialosides. To sialosyl chlorides which are fully protected with acetyl groups as glycosyl donors, the action of phenols with diisopropylethylamine in acetonitrile brought about high yield as well as facile product isolation.
PHASE-TRANSFER-CATALYZED SYNTHESIS OF ARYL α-KETOSIDES OF N-ACETYLNEURAMINIC ACID. A 2-METHYLFLUORAN-6-YL GLYCOSIDE OF N-ACETYLNEURAMINIC ACID, 2-METHYL-6-(5-ACETAMIDO-3,5-DIDEOXY-α-D-glycero-D-galacto-NONULOPYRANOSYLONIC ACID)XANTHENE-9-SPIRO-1'-ISOBENZOFURAN-3'-ONE, A NEW SUBSTRATE..
Rothermel, Joerg,Faillard, Hans
, p. 29 - 40 (2007/10/02)
Glycosidation of N-acetylneuraminic acid by phase-transfer catalysis in chloroform-aqueous alkali gave several known and some new aryl α-ketosides in a short reaction time and in good yields.The 4-methylumbelliferyl α-ketoside, the standard substrate for neuraminidase, was prepared in a yield of up to 70percent.New Neu5Ac ketosides were prepared with fluorescein and the fluorescein analog, 2-methyl-6-hydroxyfluoran (2-methyl-6-hydroxyxanthene-9-spiro-1'-isobenzofuran-3'-one) as aglycons, the latter being synthesized from 2-(2-hydroxy-5-methylbenzoyl) benzoic acid and 3-fluorophenol.The α configuration was ascertained by 400-MHz 1H-NMR spectroscopy and by cleavage of the ketosides with neuraminidases from Vibrio cholerae and Clostridium perfringens.The enzymic hydrolysis of the 2-methylfluoran-6-yl ketoside gave Km values of 82 μM (V. cholerae) and 96 μM (C. perfringens).
