Method for producing mixed crystal of disodium 5'-guanylate and disodium 5'-inosinate

Abstract

Disclosed herein are a process for producing mixed crystals of disodium 5'-guanylate and disodium 5'-inosinate which comprises precipitating mixed crystals of disodium 5'-guanylate and disodium 5'-inosinate (I+G mixed crystals) by adding an aqueous mixed solution of disodium 5'-guanylate and disodium 5'-inosinate and a hydrophilic organic solvent at the same time into a crystallization vessel in such manner that the ratio of the hydrophilic organic solvent to the liquid phase in the crystallization vessel is maintained in a range of 30 to 70 vol %, as well as such process for producing I+G mixed crystals wherein said producing of I+G mixed crystals is carried out by seeding crystallization wherein crystals of 5'-IMP2Na or / and I+G mixed crystals are used as seed crystals. According to these production processes, the by-production of amorphous solids of 5'-GMP2Na which adversely affect separability of the crystals concerned, is inhibited, and therefore, such mixed crystals having a good separability without contamination of such amorphous solids, can be produced in a high productivity.

Description

technical field [0001] The present invention relates to disodium 5'-guanylate (hereinafter abbreviated as 5'-GMP2Na or GMP) and disodium 5'-inosinate (hereinafter abbreviated as 5'-IMP2Na or IMP) and both are produced not in their simple mixture but in their mixed crystal form. Background technique [0002] 5'-GMP2Na and 5'-IMP2Na, as described above, are important in the fields of condiments and pharmaceuticals, but if they need to be used together, simply mixing the crystals of the two into powder will cause It is extremely difficult to prepare a mixture having a predetermined mixing ratio due to differences in crystal properties and powder properties of each, and various difficulties are involved in handling such a mixture. [0003] As methods for producing 5'-GMP2Na and 5'-IMP2Na in a mixed crystal form, the following three methods can be roughly classified. That is, (1) 5'-GMP2Na and 5'-IMP2Na are dissolved in water, and then by cooling, concentrating and adding alcoh...

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Problems solved by technology

[0002] 5'-GMP2Na and 5'-IMP2Na, as described above, are important in the fields of condiments and pharmaceuticals, but if they need to be used together, simply mixing the crystals of the two into powder will cause It is extremely difficult to prepare a mixture with a predetermined mixing ratio due to differences in crystal properties and powder properties, etc., and handling of such a mixture is also accompanied by various difficulties.

[0005] When obtaining I+G mixed crystals, in the above (1) method, in order to obtain the ratio (weight ratio) with desired 5'-IMP2Na and 5'-GMP2Na (hereinafter the ratio (weight ratio) of the two is abbreviated as For products (mixed crystals) with a ratio of I / G), during concentration and crystallization, it is necessary to strictly manage the concentrated drainage (dren), the management of the supply liquid, and the setting conditions such as temperature and pressure, and during cooling and crystallization, due to crystallization The composition of the crystallization solution changes continuously, so the management of the composition of the crystallization solution becomes more stringent, and the management of the equipment and process is complicated, which is a problem.

(2) The method can be crystallized with a high recovery rate, but due to the use of an organic solvent, an expensive explosion-proof device is required industrially, and the manufacturing cost increases, and there is this shortcoming

In addition, it is difficult to control the crystallization conditions, and GMP is generated depending on the crystallization conditions, thereby reducing the crystal separability, which is a problem.

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