Phosphotungstic acid as a novel acidic catalyst for carbohydrate protection and glycosylation

Utilizing Reusable Catalyst Phosphotungstic Acid for the Synthesis of Thioglycoside from Per-O-acetyl Saccharides with Microwave-Assisted and De-O-acetylation with Methanol

Traditional methods for synthesizing complex oligosaccharides currently developed are not efficient, requiring a new glycosylation methodology. Herein, using phosphotungstic acid (PTA) as a catalyst has demonstrated to be a simple possibility for carbohydrate synthesis. The methodology is engineered into a PTA-catalyzed thioglycoside preparation under microwave conditions and de-O-acetylation of carbohydrates. These easier operations and convenient protocols display a wide substrate scope. Moreover, both methods can be developed into a one-pot reaction for the efficient synthesis of carbohydrate analogues.

Phosphotungstate Acid Doped Polyanilines Nanorods for in situ NIR-II Photothermal Therapy of Orthotopic Hepatocellular Carcinoma in Rabbit

Introduction

Second near-infrared photothermal therapy (NIR-II PTT) has become a promising strategy for treating cancer in terms of safety and potency. However, the application of NIR-II PTT was limited in the treatment of deep-buried solid tumors due to the low dose of NIR-II absorption nanomaterials and the inadequate laser energy in the deep tumor.

Methods

Herein, the authors report the engineering of NIR-II absorbing polyaniline nanorods, termed HPW@PANI Nanorods, for in situ NIR-II PTT based on optical fibers transmission of laser power and transarterial infusion for the treatment of orthotopic hepatocellular carcinoma in the rabbit. HPW@PANI Nanorods were prepared via chemical oxidant polymerization of aniline under phosphotungstic acid, which exhibited effective NIR-II absorption for hyperthermia ablation cells.

Results

HPW@PANI Nanorods were fast and efficiently deposited into primary orthotopic transplantation VX2 tumor in rabbits via transarterial infusion. Furthermore, an optical fiber was interventionally inserted into the primary VX2 tumor to transmit 1064nm laser energy for in situ NIR-II PTT, which could ablate primary tumor, inhibit distant tumor, and suppress peritoneal metastasis.

Conclusion

This study provides new insights into the application of in situ NIR-II PTT based on optical fibers transmission of laser power and transarterial injection of NIR-II absorption nanomaterials to treat deep-buried tumors.

Trimethylsilyl Esters as Novel Dual-Purpose Protecting Reagents

Trimethylsilyl esters, AcOTMS, BzOTMS, TCAOTMS, etc., are inexpensive and chemically stable reagents that pose a negligible environmental hazard. Such compounds prove to serve as efficient dual-purpose reagents to respectively achieve acylation and trimethylsilylation of alcohols under acidic or basic conditions. Herein, a detailed study on protection of various substrates and new methodological investigations is described.

Amphiphilic Polyoxometalate-CNTs Nanohybrid as Highly Efficient Enzyme-free Electrocatalyst for H2O2 Sensing

Hybrid nanomaterials are emerging as a potential platform for the efficient detection of biomolecules, thus, the rational design of such materials has been widely explored. Polyoxometalates (POM) nanoclusters can serve...

Development of a Novel Method for Trimethylsilylation of Saccharides­

The trimethylsilyl (TMS) group is widely used in carbo­hydrate synthesis, although this protecting group is unstable and its post-synthetic purification challenging. The successful trimethylsilyl­ation of carbohydrates mediated by recyclable and efficient acidic catalyst PTA/HMDS and the novel reagent, TMSOAc (TEA/TMSOAc), under alkaline condition is reported. The advantages of these methods are that the reactions proceed in good to excellent yields without applying column chromatography for purification.