Hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid, particulate composition comprising the same, their preparation and uses
The present invention has objects to provide a novel crystalline 2-O-α-glucosyl-L-ascorbic acid and its production process and uses, and solves the above objects by providing hydrous crystalline 2-O-α-glucosyl-L-ascorbic acid, a particulate composition containing hydrous crystalline 2-O-α-glucosyl-L-ascorbic acid, and their production processes and uses.
1. A hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid comprising crystallization water.
2. The hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , which exhibits diffraction peaks at least at diffraction angles (2θ) of 6.1°, 9.2°, 10.6°, 11.4° and 12.1° in a powder X-ray diffraction pattern obtained by using a CuKα-ray as an X-ray source.
3. The hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , which contains about 2.7% by weight of crystallization water.
4. The hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , which exhibits an endothermic peak at around 156° C. when determined on differential scanning calorimetric analysis.
5. A particulate composition comprising hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid, which comprises the hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , wherein the purity of 2-O-α-D-glucosyl-L-ascorbic acid is at least 85% by weight, on a dry solid basis.
6. A process for producing the hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , which comprises a step of evaporating water from an aqueous solution comprising a supersaturated amount of 2-O-α-D-glucosyl-L-ascorbic acid and a coexisting anhydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid to crystallize the hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 .
7. A process for producing the hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , which comprises the steps of adding said hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 as a seed crystal to an aqueous solution comprising 2-O-α-D-glucosyl-L-ascorbic acid to precipitate hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid; and collecting the precipitated crystal.
8. A process for producing a hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , which comprises the steps of coexisting the hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid of claim 1 , as a seed crystal, with an amorphous 2-O-α-D-glucosyl-L-ascorbic acid powder; retaining the resulting mixture at a temperature of 25° C. and a relative humidity of 90% to precipitate hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid; and collecting the precipitated crystal.
9. A filler/diluent/excipient/vehicle/adjuvant, which consists of a member selected from the group consisting of hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid comprising crystallization water, and the particulate composition of claim 5 .
10. A base material for pulverizing oily substances, which consists of a member selected from the group consisting of hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid comprising crystallization water, and the particulate composition of claim 5 .
11. A process for producing a food product, cosmetic, quasi-drug, or pharmaceutical, which contains a step of incorporating a member selected from the group consisting of hydrous crystalline 2-O-α-D-glucosyl-L-ascorbic acid comprising crystallization water, and the particulate composition of claim 5 .