Total synthesis of syringalide B, a phenylpropanoid glycoside.

The first total synthesis of syringalide B, 2-(4-hydroxyphenyl)ethyl 4-O-[(E)-feruloyl]-beta-D-glucopyranoside, is described. The hydroxyl groups were protected with allyloxycarbonyl (Aoc) and allyl groups, which successfully prevent the migration of the feruloyl group during the deblocking procedure.

Synthesis and bioactivities of two multiple antigen peptides as potential vaccine against schistosoma.

Based on the two antigenic peptides, 26-43 (P26) and 116-131 (P116), derived from 28 kDa glutathione S-transferase of Schistosoma mansoni (Sm28GST), two multiple antigenic peptides (MAPs), (P26)4-MAP and (P116)4-MAP with the same oligomeric lysine core, were synthesized by stepwise solid-phase peptide synthesis method. The antigenicities and protective effects of these two MAPs were examined on experimental animals. As shown in the dot-ELISA result, the synthetic MAPs could be recognized and bound by immunoglobins in both patient's and infected-rabbit's sera. After Kunming mice were immunized with (P26)4-MAP, the worm burden reduction rate and the liver egg reduction rate were 59.9% and 61.1%. In (P26)4-MAP or (P116)4-MAP immunized BALB/c mice, the worm burden reduction rates were 37.5% and 62.5%, respectively, and the liver egg reduction rates were 35.1% and 54.0%, respectively.

Synthesis of N-sugar-substituted phthalimides and their derivatives from sugar azides and phthalic anhydride.

N-Sugar-substituted phthalimides and tetrachlorophthalimide derivatives can be prepared in good yields under essentially neutral conditions. Mixing a sugar azide, NaI, Me3SiCl, phthalic or substituted phthalic anhydride and tetrabutylammonium iodide as catalyst in acetonitrile at rt or 60 degrees C, afforded 12 imides in 83-95% yields.

Unexpected reductions of glycosyl spacer-armed phthalimides.

An unusual reductive ring-opening reaction in the title compounds, of the phthalimide group with sodium hydride in anhydrous DMF is observed for the first time and the presumed mechanism is described in detail. An unexpected hydrogenation of the phthalimide group was also observed.

Synthesis and potential antimetastatic activity of monovalent and divalent beta-D-galactopyranosyl-(1-->4)-2-acetamido-2-deoxy-D-glucopyranosides.

Anomers of monovalent and divalent beta-D-galactopyranosyl-(1-->4)-2-acetamido-2-deoxy-D-gluco-pyranosides were synthesized under different glycosylation conditions, and evaluated for in vitro antimetastatic activity. Three compounds showed promising inhibitory effects on cancer cell attachment, spreading, migration, and invasion.

Synthesis of a spacer-armed disulfated tetrasaccharide of SB1a, a carbohydrate hapten associated with human hepatocellular carcinoma.

A disulfated tetrasaccharide fragment with a spacer arm of human hepatocellular carcinoma carbohydrate antigen SB(1a), namely, 2-aminoethyl 3-O-sulfo-beta-D-galactopyranosyl-(1 --> 3)-2-acetamido-2-deoxy-beta-D-galactopyranosyl-(1 --> 4)-3-O-sulfo-beta-D-galactopyranosyl-(1 --> 4)-beta-D-glucopyranoside was synthesized via a [2 + 1 + 1] block building mode. In the last coupling step toward the trisaccharide acceptor 8, benzoyl protected galactosyl bromide donor 14 was found to be much more reactive than the acetyl-protected donors.

Facile synthesis of 1-thio-beta-lactoside clusters scaffolded onto p-methoxyphenyl, beta-D-galactopyranoside, beta-D-glucopyranoside, and lactoside.

The free-radical addition of 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl-(1-->4)-2,3,6-tri-O-acetyl-1-thio-beta-D-glucopyranose to the allyl ether functions of p-methoxyphenyl per-O-allyl-D-galactopyranoside, D-glucopyranoside, and lactoside provides a concise and effective route for synthesis of glycoside clusters, of use for exploring anti-metastatic activity.

Synthesis of a potential tetrasaccharide ligand for E-selectin.

A potential tetrasaccharide ligand for E-selectin, (Na(+-)O(3)SO-3)Galbeta-(1-->4)[Fucalpha-(1-->3)]Glcbeta-(1-->6)Gal, an analogue of the ovarian cystadenoma glycoprotein tetrasaccharide fragment, was synthesized in a highly practical way.

Bromonium ion-promoted glycosidic bond formation and simultaneous bromination of an activated aryl aglycon.

N-Bromosuccinimide (NBS) together with a catalytic amount of Me(3)SiOTf was found to be effective for the activation of thioglycosides. Concurrently with formation of the glycosidic bond, bromination took place on the activated aromatic ring of a 4-methoxyphenyl aglycon.