Chemoenzymatic synthesis and immunological evaluation of sialyl-Thomsen-Friedenreich (sTF) antigen conjugate to CRM197.

sTF (sialyl-Thomsen-Friedenreich) is a type of tumor-associated carbohydrate antigens (TACAs) and is highly expressed in various human malignancies. To validate if sTF could be a valuable molecular target for future cancer vaccine development, in this work the sTF antigen was prepared by adopting a strategy combining chemical and enzymatic methods, and then was covalently conjugated to a carrier protein, CRM197. The preliminary immunological evaluation, performed on BALB/c mice, revealed that the sTF-CRM197 conjugate elicited high titers of specific IgG antibodies. FACS experiments showed that the antisera induced by sTF-CRM197 conjugate could specifically recognize and bind to sTF-positive cancer cells T-47D. Furthermore, the conjugate mediated effective and specific antibody-mediated complement-dependent cytotoxicity (CDC).

The Synthesis of Fluorinated Carbohydrates Using Sulfuryl Fluoride as the Deoxyfluorination Reagent.

Fluorination of carbohydrates has been one of the strategies to increase their enzymatic and chemical stabilities and reduce their hydrophilicities, making this modification attractive for drug discovery purposes. The synthesis of monofluorinated carbohydrates was achieved under mild conditions by using SO2F2 as the deoxyfluorination reagent in the presence of a base without extra fluoride additives. This method features low toxicity, easy availability, low cost, and high efficiency and can be subjected to diverse sugar units.

Advances in the chemistry, pharmacological diversity, and metabolism of 20(R)-ginseng saponins.

Ginseng has been used as a popular herbal medicine in East Asia for at least two millennia. However, 20(R)-ginseng saponins, one class of important rare ginsenosides, are rare in natural products. 20(R)-ginseng saponins are generally prepared by chemical epimerization and microbial transformation from 20(S)-isomers. The C20 configuration of 20(R)-ginseng saponins are usually determined by 13C NMR and X-ray single-crystal diffraction. 20(R)-ginseng saponins have antitumor, antioxidative, antifatigue, neuroprotective, and osteoclastogenesis inhibitory effects, among others. Owing to the chemical structure and pharmacological and stereoselective properties, 20(R)-ginseng saponins have attracted a great deal of attention in recent years. In this study, the discovery, identification, chemical epimerization, microbial transformation, pharmacological activities, and metabolism of 20(R)-ginseng saponins are summarized.

Oxidative C(sp3)-H functionalization of methyl-azaheteroarenes: a facile route to 1,2,4-triazolo[4,3-a]pyridines.

We herein describe an oxidative [4 + 1] annulation used to prepare 1,2,4-triazolo[4,3-a]pyridines in the presence of I2-DMSO. This protocol enables synthesis of triazolo[4,3-a]pyridine-quinoline linked diheterocycles via a direct oxidative functionalization of sp3 C-H bonds of 2-methyl-azaheteroarenes. The reaction shows a wide substrate scope and good functional group tolerance.