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Glycosaminoglycans (GAGs) are important sulfated carbohydrates prevalently found in the extracellular matrix that serve many biological functions. The synthesis of structurally diverse but defined GAGs is extremely challenging as one has to account for the various sulfation patterns. Described is the automated synthesis of two chondroitin sulfate hexasaccharides. The oligosaccharides are prepared on a solid support that is equipped with a photolabile linker. The linker cleavage from the resin is performed in a continuous-flow photoreactor under chemically mild conditions. The described approach will serve as a general scheme to systematically access oligosaccharides of all GAG families.

Various aniline and phenol derivatives bearing an N-tosyl-1,2,3-triazole side chain are investigated with a view to preparing the title heterocycles under metal-free conditions at an elevated temperature.

The selective synthesis of substituted 3-methylene-2,3-dihydrobenzofurans and 3-methylbenzofurans has developed through Rh(II)-catalyzed denitrogenative annulation of N-sulfonyl-1,2,3-triazole at ambient to mild heating condition, respectively. Further, a one-pot strategy is also developed by using substituted O-propargylphenols through Cu/Rh-catalyzed method to rapidly construct 3-methylene-2,3-dihydrobenzofuran derivatives.

Two new sarsolenane diterpenes, dihydrosarsolenone (2), methyl dihydrosarsolenoneate (3), and two new capnosane diterpenes, sarsolilides B (5) and C (6), were isolated together with the known analogue, sarsolilide A (4), from the Hainan soft coral Sarcophyton trocheliophorum Marenzeller. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data, leading to a structure revision of sarsolenone (1). The absolute configurations of 2 and 5 were determined by TDDFT ECD calculations, and they could be used as ECD reference compounds in the determination of the absolute configuration of their related derivatives. Compounds 4 and 5 exhibited inhibitory activity in vitro against protein tyrosine phosphatases 1B (PTP1B), representing the first report of PTP1B inhibitory activity for capnosane diterpenes.

This review covers structural diversity and biological activities of terpenes from soft corals of the genus of Sarcophyton, reported from 1995 to July, 2011. During this period, besides undefined species, 16 species of the genus Sarcophyton, from different geographical areas, had been chemically examined. Two hundred and five terpenes had been isolated from this genus, including eleven sesquiterpenes, 165 diterpenes, 29 biscembranoids, some of which had novel skeletons. They exhibited various biological features, such as antifeedant, anti-inflammatory, antiviral, and antifouling activities.

Sialic acids are a diverse family of negatively charged monosaccharides with a shared nine-carbon carboxylated backbone, and they often serve as the terminal positions of cell surface glycoproteins and glycolipids. Sialic acids play essential roles in mediating or modulating numerous pathological, biological, and immunological recognition events. Advances in synthesis have provided chemically well-defined and structurally homogeneous sialic acid-containing carbohydrates that are crucial for studying glycobiology. This review highlights recent innovations in the chemical and chemoenzymatic synthesis of difficult α-sialosides, with a particular focus on methods developed for α-selective sialylation in the synthesis of O-linked and S-linked oligosialic acids.

isolation, structural determination and antibacterial activity of two new steroids (I) and (II) together with 13 known analogues

A new class of novel chiral Schiff base ligands has been developed using a stepwise approach. The key feature of these new ligands is that they possess two different donor units, one of them is aromatic while the other is non-aromatic.