Journal of Carbohydrate Chemistry最新文献

Carbohydrates are the most abundant natural products and a major component on the cell surface of living beings. They are useful building blocks of various natural products and organic synthesis due to their presence of multiple chiral centers and hydroxy groups. The recent outbreak of COVID-19 and other life-threatening viral infections necessitates the development of potent antiviral drugs. In this review, we focused on the synthesis of antiviral drugs to treat influenza, HIV, herpes, hepatitis, and other diseases, from different monosaccharides such as D-glucose, D-mannose, D-xylose, N-acetyl-D-glucosamine, D-gluconolactone, etc., such as anti-influenza drugs remdesivir, Tamiflu, zanamivir, and so on.

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A series of new macrocycles based on alkyl glycosides derived from D-glucose and D-galactose was synthesized. The macrocycles were easily obtained by the reaction of dialkynyl derivatives with diazides via copper-catlyzed 1,3-cycloaddition reaction. Simple protecting group strategies were applied to obtain the vicinal dihydroxy derivatives, followed by Williamson etherification with propargyl bromides to get the dialkynyl derivatives. These derivatives were subjected to 1,3-Hüisgen triazole coupling with diazides furnishing the macrocycles in good yields. The 1,3-Hüisgen reaction used to build these macrocycles was investigated thoroughly with respect to reaction time, catalysts, solvents, and temperature for optimum macrocyclisation.

The highly stereoselective synthesis of complex carbohydrates containing 1,2-cis-quinovosamine is an on-going challenge. Here, we report a synergistic strategy of merging reagent modulation and acyl remote participation for highly stereoselective construction of 1,2-cis-D-quinovosamine linkages. The strategy is applied to the preparation of natural disaccharide present on the surface of Pseudomonas aeruginosa bacteria. The resulting disaccharide can be covalently bound to microarray surface or carrier via the aminopentyl linker at the reducing end, allowing for exploring its antigenic and immunogenic properties.

Glycosphingolipids (GSLs) are a subclass of glycolipids made of a glycan and a ceramide that, in turn, is composed of a sphingoid base moiety and a fatty acyl group. GSLs represent the vast majority of glycolipids in eukaryotes, and as an essential component of the cell membrane, they play an important role in many biological and pathological processes. Therefore, they are useful targets for the development of novel diagnostic and therapeutic methods for human diseases. Since sphingosine was first described by J. L. Thudichum in 1884, several hundred GSL species, not including their diverse lipid forms that can further amplify the number of individual GSLs by many folds, have been isolated from natural sources and structurally characterized. This review tries to provide a comprehensive survey of the major GSL species, especially those with distinct glycan structures and modification patterns, and the ceramides with unique modifications of the lipid chains, that have been discovered to date. In particular, this review is focused on GSLs from eukaryotic species. This review has listed 251 GSL glycans with different linkages, 127 glycans with unique modifications, 46 sphingoids, and 43 fatty acyl groups. It should be helpful for scientists who are interested in GSLs, from isolation and structural analyses to chemical and enzymatic syntheses, as well as their biological studies and applications.

A diacyl phosphatidylinositol (PI) derivative with an azide linked to its inositol C4-position was effectively synthesized in 19 steps for the longest linear sequence and in a ca. 1% overall yield from 1,2-distearoyl-sn-glycerol and D-glucose. This compound was designed as a biosynthetic precursor of glycosylphosphatidylinositol (GPI) anchors. Its azide would enable further modification to introduce other molecular tags by a biocompatible click reaction. Therefore, it can be a useful probe for metabolic engineering of cell surface GPI anchors and GPI-anchored proteins.

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Arabinogalactan (ICPA) was isolated from the medicinal plant Ixeris chinensis (Thunb.) Nakai, and was used as the reducing agent to stabilize selenium nanoparticles (SeNPs). ICPA-decorated SeNPs (ICPA-SeNPs) were synthesized with Na₂SeO₃ and ICPA, and their average diameter was 82.6 ± 2.5 nm. ICPA-SeNPs had good dispersity in phosphate-buffered saline (PBS) with a hydrodynamic size of 156.2 ± 2.8 nm. They were stable in PBS solution with a zeta potential of −24.8 ± 0.6 mV. The anti-hepatoma activity of ICPA-SeNPs was investigated in vitro. ICPA-SeNPs significantly suppressed the growth of SMMC-7721 and HepG2 hepatoma cells. They entered SMMC-7721 cells via energy- and caveolae-dependent endocytosis. ICPA-SeNPs were able to increase reactive oxygen species levels, reduce mitochondrial membrane potential, and increase caspase-3 expression in SMMC-7721 cells, which led to the apoptosis of SMMC-7721 cells. They also arrested the cell cycle of SMMC-7721 cells in the S phase. These findings indicate that ICPA could enhance the stability of SeNPs and inhibit SMMC-7721 cell proliferation via the mitochondrial pathway. ICPA-SeNPs could be developed as an antitumor agent for hepatocellular carcinoma treatment.