Yanli Cui

Room-temperature ionic liquids enhanced green synthesis of β-glycosyl 1-ester

We herein report an efficient synthesis of β-glycosyl 1-ester in room-temperature ionic liquids (RTILs) promoted via silver salt and quaternary ammonium salt (PTC) with good or excellent yields. All products were isolated exclusively as the β-anomers. Four different RTILs, eight metal salts and four quaternary ammonium salts were screened in the glycosylation reaction. The synergistic effect of C6mim·OTf, Ag2O and tetrabutylammonium iodine gave the best results. Their promotion to the system was integral. Thorough study provided insight into the catalytic activity of ionic liquid structure, metal salts and quaternary ammonium salt to these reactions. It is worth mentioning that the yield of aliphatic compound 2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl butyrate (3l) was highly improved when using C6mim·OTf as solvent compared with the normal volatile solvents under the same catalysts. This green approach has been proved to be practical and compatible with a wide range from aliphatic to aromatic substrates.

Synthesis of berbamine acetyl glycosides and evaluation of antitumor activity

A series of berbamine glycosides was designed, synthesized and evaluated as a new class of antitumor agents. An efficient glycosylation route was developed for berbamide derivatives. The newly synthesized glycosides were evaluated for their cytotoxic activity in vitro against a human leukemia cell line K562, a human lung adenocarcinoma cell line A549 and mouse lymphocytic leukemia cells L1210. In contrast to berbamine most of its glycosides manifested potent cytotoxic activities. The acetyl glycosyl berbamine 5a, 5d caused distinct improvement against K562, A549 and L1210. It is suggested that the acetyl D-glucose residue has affinity to these cancer cells.

Synthesis of oligosaccharides using per-O-trimethylsilyl-glycosyl iodides as glycosyl donor.

Trimethylsilyl (TMS) protecting group has been found to be very useful for the simultaneous protection of both the glycosyl donor- and the acceptor-substrates in oligosaccharide synthesis. Thus, while the per-O-trimethylsilylated glycosyl iodides served as the glycosyl donor, those bearing selectively exposed primary hydroxyl groups were found suitable as the glycosyl acceptor for the reaction. The cheap and commercially available trialkylamine, triethylamine was found to be an effective promoter for the glycosylation. Importantly, the reaction was α-stereospecific and gave the products in 58%-78% yields.

4,5-Cis Unsaturated α-GalCer Analogues Distinctly Lead to CD1d-Mediated Th1-Biased NKT Cell Responses

The total synthesis of 4,5-cis unsaturated α-GalCer analogues was achieved, and their immune-response altering activity was assessed in vitro as well as in vivo in mice. Using glycosyl iodide as a glycosyl donor, construction of the sphingosine unit was shortened by four steps and single α-stereoselectivity was achieved in good yield (67%). With regard to the therapeutic use of α-GalCer, the novel analogues (1b and 1c) distinctly induced a Th1-biased cytokine response, avoiding induction of a contradictory response and overstimulation.

Correction to: One-pot synthesis of hexias (6-O-acryl) cyclodextrin derivatives at room temperature

In the original publication of the article, one of the co-author names Weirong Yao was missed in the author group. And the order of the author group was also changed. These have been updated in this correction article.

2-Acetyl-amino-1,3,4,6-tetra-O-(tri-methyl-silyl)-2-de-oxy-α-d-gluco-pyran-ose.

The title compound, C20H47NO6Si4, was synthesized by per-O-trimethylsilylation of N-acetyl-d-glucosamine using chlorotrimethylsilane in the presence of hexamethyldisiloxane. The trimethylsilyl group and acetamido group are located on the same side of the pyran ring, showing an α-configuration glycoside. One of the trimethylsilyl groups is disordered over two orientations, with site-occupancy factors of 0.625 (9) and 0.375 (9). In the crystal, N—H⋯O hydrogen bonds link the molecules into supramolecular chains along the a-axis direction.

2,3,4,6-Tetra-O-acetyl-β-d-galacto­pyrano­syl butyrate

The title compound, C18H26O11, was synthesized by a condensation reaction of 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide and butyric acid. The acetoxymethyl and butyrate groups are located on the same side of the pyran ring, showing the β configuration for the d-glycosyl ester; the butyl group adopts an extend conformation, the C—C—C—C torsion angle being 179.1 (7)°. In the crystal, the molecules are linked by weak C—H⋯O hydrogen bonds.

The Difference of the Gaseous Fractions by Copyrolysis of Biomass and Polyolefin

The copyrolysis of biomass/polyolefin mixture was performed to obtain gaseous hydrocarbons. The difference of the gaseous fractions was analyzed by gas chromatography (GC). The optimum condition for C3-C4 gases production was temperature 410???, the biomass/ polyolefin (in mass) mixtures ratio 1:1. At 410???, the copyrolysis leaded to the production of more than 30% (in mass) of gases. It should be noted that for the composition of C1-C2 hydrocarbons close to 30% (in all gaseous hydrocarbons), the composition of C3-C4 hydrocarbons 67% (in all gaseous hydrocarbons), and the distillable liquids fraction represents close 30% in mass of the final products.

Characterizations of the gaseous fractions by catalytic copyrolysis of biomass and polypropylene

Catalytic copyrolysis of biomass/ polypropylene( pp) mixture was performed in airfree atmospheres. The gases were analyzed with GC. The optimum condition for C3–C4 gases production was temperature 410 °C, the biomass/ pp (in mass) mixtures ratio 1∶1. At 410°C, the copyrolysis leaded to the production of more than 30% (in mass) of gases. It should be noted that for the composition of C1–C2 hydrocarbons close to 30% (in all gaseous hydrocarbons), the composition of C3–C4 hydrocarbons 67% (in all gaseous hydrocarbons), and the distillable liquids fraction represents close 30% in mass of the final products.