Microwave-Assisted Heating Reactions of N -Acetylglucosamine (GlcNAc) in Sulfolane as a Method Generating 1,6-Anhydrosugars Consisting of Amino Monosaccharide Backbones

• Published in: Molecules (Basel, Switzerland) Vol. 25; no. 8; p. 1944
• Main Authors: Kaga, Harumi, Enomoto, Masaru, Shimizu, Hiroki, Nagashima, Izuru, Matsuda, Keigo, Kawaguchi, Seigou, Narumi, Atsushi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 22.04.2020; MDPI
• Subjects: Acetylation; Acetylglucosamine - chemistry; anhydro-furanose; anhydrosugar; Biomimetic materials; Chromatography; Chromatography, High Pressure Liquid; Communication; Conversion; Decomposition; Glucosamine; Heating; microwave; Microwaves; Molecular Structure; Monosaccharides; N-acetyl glucosamine (GlcNAc; N-Acetylglucosamine; NAG), anhydro-pyranose; Oligosaccharides; Oligosaccharides - chemistry; Polysaccharides; Raw materials; Saccharides; Sulfolane; Temperature; Thiophenes - chemistry; Yield; N-acetyl glucosamine (GlcNAc; biologically active building block; NAG), anhydro-pyranose; anhydrosugar; sulfolane; microwave; anhydro-furanose
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules25081944

The microwave-assisted heating reaction of -acetyl glucosamine (GlcNAc) in sulfolane is described. The reaction produces two major products that are assignable to 1,6-anhydro-2-acetamido-2-deoxy-β-d-glucopyranose (AGPNAc) and 1,6-anhydro-2-acetamido-2-deoxy-β-d-glucofuranose (AGFNAc). In order to reveal a general feature of the system, the 3, 5, and 10 min reactions were performed at 140, 160, 180, 200, and 220 °C to clarify the time course changes in the conversion of GlcNAc and the yields of the two produced 1,6-anhydrosugars. Temperature is a crucial factor that significantly affects the conversion of GlcNAc. The yields of AGPNAc and AGFNAc are also drastically changed depending on the reaction conditions. The 5-min reaction at 200 °C is shown to be the optimal condition to generate the 1,6-anhydrosugars with a high efficiency in which AGPNAc and AGFNAc are produced in the yields of 21% and 44%, respectively. Consequently, the microwave-assisted heating reaction of GlcNAc in sulfolane is shown to be a simple and promising pathway to generate 1,6-anhydrosugars consisting of amino monosaccharide backbones, which have high potentials as raw materials leading to biological oligosaccharides and biomimetic polysaccharides.