Methods for controlled synthesis and chemical recycling of stereoregular polysaccharides via polymerization of biomass-derived anhydrosugars are provided. The anhydrosugars react with an initiator in the presence of a synergy of a catalyst and the initiator providing the polysaccharides with high chain end fidelity and an excellent molecular weight distribution in a controlled manner, which allows for the preparation of polymeric systems with well-defined architectures. The polysaccharides obtained by such methods can be substantially converted to the start monomers in the present of a catalyst and can be used for biomedicine.

Methods for controlled synthesis and chemical recycling of stereoregular polysaccharides via polymerization of biomass-derived anhydrosugars are provided. The anhydrosugars react with an initiator in the presence of a synergy of a catalyst and the initiator providing the polysaccharides with high chain end fidelity and an excellent molecular weight distribution in a controlled manner, which allows for the preparation of polymeric systems with well-defined architectures. The polysaccharides obtained by such methods can be substantially converted to the start monomers in the present of a catalyst and can be used for biomedicine.

The present invention identifies moisturizing and physiological activities of agarobiose and provides a novel substance alkyl-agarobioside for maintaining moisturization activity of agarbiose and securing both pH and temperature stability, and a preparation method therefor. According to the present invention, alkyl-agarobioside can be produced in a cost-efficient manner as a moisturizing material for foods, medicinal products, and cosmetic products.

The present invention identifies moisturizing and physiological activities of agarobiose and provides a novel substance alkyl-agarobioside for maintaining moisturization activity of agarbiose and securing both pH and temperature stability, and a preparation method therefor. According to the present invention, alkyl-agarobioside can be produced in a cost-efficient manner as a moisturizing material for foods, medicinal products, and cosmetic products.

The present invention relates to a method for preparing 3,6-anhydro-L-galactose, and use thereof. More specifically, 3,6-anhydro-L-galactose, which is a monosaccharide constituting agar, is produced in a high yield through chemical and enzymatic methods, and the physiological activities thereof such as whitening, moisturizing, antioxidant, antiinflammatory activities and the like are displayed, thereby enabling industrial use thereof.

The present invention relates to a method for preparing 3,6-anhydro-L-galactose, and use thereof. More specifically, 3,6-anhydro-L-galactose, which is a monosaccharide constituting agar, is produced in a high yield through chemical and enzymatic methods, and the physiological activities thereof such as whitening, moisturizing, antioxidant, antiinflammatory activities and the like are displayed, thereby enabling industrial use thereof.

The present invention relates to a method for preparing 3,6-anhydro-L-galactose, and use thereof. More specifically, 3,6-anhydro-L-galactose, which is a monosaccharide constituting agar, is produced in a high yield through chemical and enzymatic methods, and the physiological activities thereof such as whitening, moisturizing, antioxidant, anti-inflammatory activities and the like are displayed, thereby enabling industrial use thereof.

The present invention relates to a method for preparing 3,6-anhydro-L-galactose, and use thereof. More specifically, 3,6-anhydro-L-galactose, which is a monosaccharide constituting agar, is produced in a high yield through chemical and enzymatic methods, and the physiological activities thereof such as whitening, moisturizing, antioxidant, anti-inflammatory activities and the like are displayed, thereby enabling industrial use thereof.

Provided is a labeling method having a step of labeling a substrate having a carbon-hydrogen bond with an oxygen isotope by using a catalyst and an oxidant produced from a hypervalent iodine compound having an ester structure and labeled water labeled with at least one oxygen isotope selected from the group consisting of .sup.17O and .sup.18O. Also provided is an oxidant for labeling that is produced from a hypervalent iodine compound having an ester structure and labeled water labeled with at least one oxygen isotope selected from the group consisting of .sup.17O and .sup.18O and labels a substrate having a carbon-hydrogen bond with an oxygen isotope in the co-presence of a catalyst.

The present invention relates to a method for preparing 3,6-anhydro-L-galactose, and use thereof. More specifically, 3,6-anhydro-L-galactose, which is a monosaccharide constituting agar, is produced in a high yield through chemical and enzymatic methods, and the physiological activities thereof such as whitening, moisturizing, antioxidant, anti-inflammatory activities and the like are displayed, thereby enabling industrial use thereof.