- Total Synthesis of a Partial Structure from Arabinogalactan and Its Application for Allergy Prevention
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Arabinogalactan, a microheterogeneous polysaccharide occurring in plants, is known for its allergy-protective activity, which could potentially be used for preventive allergy treatment. New treatment options are highly desirable, especially in a preventive manner, due to the constant rise of atopic diseases worldwide. The structural origin of the allergy-protective activity of arabinogalactan is, however, still unclear and isolation of the polysaccharide is not feasible for pharmaceutical applications due to a variation of the activity of the natural product and contaminations with endotoxins. Therefore, a pentasaccharide partial structure was selected for total synthesis and subsequently coupled to a carrier protein to form a neoglycoconjugate. The allergy-protective activity of arabinogalactan could be reproduced with the partial structure in subsequent in vivo experiments. This is the first example of a successful simplification of arabinogalactan with a single partial structure while retaining its allergy-preventive potential.
- Krumb, Matthias,J?ger, Maximilian,Voss, Alice,Immig, Loreen,Peters, Karin,Kowalczyk, Danuta,Bufe, Albrecht,Opatz, Till,Holst, Otto,Vogel, Christian,Peters, Marcus
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p. 928 - 933
(2020/10/29)
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- Glycosylation of Glaucocalyxin a and Evaluation of Its Cytotoxic Activity
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The 7,14-diglucoside of glaucocalyxin A was prepared by a five-step reaction. Its structure was confirmed by spectroscopic methods, and its cytotoxic activity was tested by the MTT method.
- Xiang, Zhaobao,Zhang, Yan,Jin, Yongsheng,Sun, Bin,Chen, Gang
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p. 861 - 864
(2020/09/21)
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- Urea–hydrogen peroxide prompted the selective and controlled oxidation of thioglycosides into sulfoxides and sulfones
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A practical method for the selective and controlled oxidation of thioglycosides to corresponding glycosyl sulfoxides and sulfones is reported using urea–hydrogen peroxide (UHP). A wide range of glycosyl sulfoxides are selectively achieved using 1.5 equiv of UHP at 60 °C while corresponding sulfones are achieved using 2.5 equiv of UHP at 80 °C in acetic acid. Remarkably, oxidation susceptible olefin functional groups were found to be stable during the oxidation of sulfide.
- Singh, Adesh Kumar,Tiwari, Varsha,Mishra, Kunj Bihari,Gupta, Surabhi,Kandasamy, Jeyakumar
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supporting information
p. 1139 - 1144
(2017/06/20)
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- In(III) triflate-mediated solvent-free synthesis and activation of thioglycosides by ball milling and structural analysis of long chain alkyl thioglycosides by TEM and quantum chemical methods
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Conventional solution-phase synthesis of thioglycosides from glycosyl acetates and thiols in the presence of In(III) triflate as reported for benzyl thioglucoside failed when applied to the synthesis of phenolic and alkyl thioglycosides. But, it was achieved in high efficiency and diastereospecificity with ease by solvent-free grinding in a ball mill. The acetates in turn were also obtained by the homogenization of free sugars with stoichiometric amounts of acetic anhydride and catalytic In(OTf)3 in the mill as neat products. Per-O-benzylated thioglycosides on grinding with an acceptor sugar in the presence of In(OTf)3 yield the corresponding O-glycosides efficiently. The latter in the case of a difficult secondary alcohol was nearly exclusive (>98%) in 1,2-cis-selectivity. In contrast, the conventional methods for this purpose require use of a coreagent such as NIS along with the Lewis acid to help generate the electrophilic species that actually is responsible for the activation of the thioglycoside donor in situ. The distinctly different self-assembling features of the peracetylated octadecyl 1-thio-α- and β-d-galactopyranosides observed by TEM could be rationalized by molecular modeling.
- Kumar, Vajinder,Taxak, Nikhil,Jangir, Ramniwas,Bharatam, Prasad V.,Kartha, K. P. Ravindranathan
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p. 3427 - 3439
(2014/05/06)
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- Synthesis of 3,6-branched arabinogalactan-type tetra- and hexasaccharides for characterization of monoclonal antibodies
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Synthesis of tetra- and hexasaccharides built up from a β-(1→6)-linked galactopyranosyl backbone with arabinofuranosyl side chains at position 3 and with a 3-aminopropyl spacer related to arabinogalactans is described. These oligosaccharides were prepared
- Fekete, Aniko,Borbas, Aniko,Antus, Sandor,Liptak, Andras
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experimental part
p. 1434 - 1441
(2009/12/09)
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- Design, synthesis, and evaluation of β-galactosylceramide mimics promoting β-glucocerebrosidase activity in keratinocytes
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We have established an efficient synthesis of mimics of β-galactosylceramide (β-GalCer) increasing a β-glucocerebrosidase (β-GlcCer'ase) activity that associates with the skin barrier function. Among the synthetic β-GalCer analogues (6a-6e) described herein, compound 6e exhibited a potent effect on the activation of β-GlcCer'ase function in vitro and reduced the transepidermal water loss (TEWL) level in a UVB-induced barrier disrupted mice model. These findings indicated that compound 6e could be useful for cosmetics and medicines to improve skin barrier function.
- Fukunaga, Kyoko,Yoshida, Masahiro,Nakajima, Fumio,Uematsu, Rie,Hara, Mariko,Inoue, Shintaro,Kondo, Hirosato,Nishimura, Shin-Ichiro
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p. 813 - 815
(2007/10/03)
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- Scope and applications of "active and latent" thioglycosyl donors. Part 4
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The relative reactivity of various thioglycosyl donors having ethyl, phenyl, or parasubstituted phenyl groups with electron donating (N-Ac) or electron withdrawing (NO2) substituents were compared using 1,2:3,4-di-O-isopropylidene-α-D-galactopy
- Cao, Suoding,Hernandez-Mateo, Fernando,Roy, Rene
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p. 609 - 631
(2007/10/03)
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- Reaction of sugar thiocyanates with Grignard reagents. New synthesis of thioglycosides
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Glycosyl thiocyanates having hydroxyl groups protected with acetyl or benzoyl groups react readily at -40°C with Grignard reagents to afford the corresponding alkyl or aryl thioglycosides in good yields. Monosaccharide derivatives having the SCN grouping at other positions form under similar conditions thioethers. Axial thiocyanates do not react. Elevated temperatures induce side reactions leading to mercaptans.
- Pakulski, Zbigniew,Pierozynski, Donat,Zamojski, Aleksander
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p. 2975 - 2992
(2007/10/02)
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- Electrosyntheses of disaccharides from phenyl or ethyl 1-thioglycosides
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Constant current electrolyses of the glycosyl donors phenyl and ethyl 2,3,4,6-tetra-O-benzyl-1-thio-β-D-glucopyranoside in dry acetonitrile in the presence of various primary and secondary sugar alcohols, performed in an undivided cell, gave β-linked disaccharide derivatives selectively in good yields.Phenyl 2,3,4,6-tetra-O-benzoyl-1-thio-β-D-glucopyranoside gave the β-glucosides exclusively in good to moderate yields.
- Mallet, Jean-Maurice,Meyer, Gilbert,Yvelin, Frederic,Jutand, Anny,Amatore, Christian,Sinay, Pierre
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p. 237 - 246
(2007/10/02)
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