KR810000520B1 - Process for purifying 5'-guanilic acid - Google Patents

Abstract

High purity 5'-guanylic acid(I) crystals were prepd. by seed-crystallization of impurities-contg. I soln. at 0.5-1.0 pH, 3-5≰C, 5hr. Thus, 500 g INa was dissolved in 6L H2O and small amount of columnar seed was added to the soln. followed by stirring at pH 0.7, 5≰C, to grow crystal, which was sepd. to give 358 g free crystal I. The crystal I was obtained by pptn. and filtration of the free crystal in 2L H2O(pH 8.2), 60% MeOH.

Description

Purification of 5'-Guanylic Acid

1 is a graph showing the precipitation rate of 5'-guanylic acid according to the crystallization time.

2 is a micrograph (100 times magnification) showing 5'-guanylic acid free crystals separated by the present invention.

The present invention relates to a process for purifying 5'-Guang sine mono phosphate to free form of 5'-guanylic acid in a high yield within a specific pH range.

To date, 5'-guanylic acid has been prepared by extraction of biological tissues, hydrolysis of ribohexane, direct fermentation, and synthesis, and the like, and various purification methods for the 5'-guanylic acid-containing liquid thus prepared have been invented. For example, precipitated and fractionated as an aromatic carbonic acid and a poorly soluble compound, or by adding uridil acid to a solution containing 5'-guanylic acid, the compound is produced and purified to a 5'-guanylic acid compound at pH1-5, or 1.4-di It is sometimes used to produce and separate dioxane compounds.Also, strong acidic cation exchange resins, strong basic anion exchange resins, nonionic exchange resins, and activated carbon can be adsorbed in a single or a combination of various organic or inorganic substances. There has been a method of selectively purifying with a mixed solution.

To describe in more detail such a conventional method, there is a method in which the 5'-guanylic acid-containing solution is separated into free or monosodium salt of 5'-guanylic acid at pH 1.0-5.0, but such a method is 5 In the physical properties of '-guanylic acid, the gel is formed between pH 1.5-6.0 and crystallization is difficult, and there is an industrial discontinuity that cannot raise the concentration of the 5'-guanylic acid solution before crystallization. When the low concentration of 5'-guanylic acid-containing solution is formed in the form of free and mono sodium salt at .0-5.0, it is an isoelectric point region such as pigments and proteins, which are impurities, It was lowered and a crystal phase with good separability could not be obtained. In addition, the separation method of 5'-guanylic acid by the addition of organic solvent to the partially purified and concentrated solution is the degradation of product quality due to precipitation of pigments and proteins which are co-precipitated in hydrophilic organic solvents such as methanol, ethanol and acetone. There was a drawback that the rebleaching and recrystallization process must be performed.

In other words, the conventional method is not only able to facilitate the purification of the 5'-guanylic acid-containing liquid, but also has a disadvantage in that it cannot be fractionated and purified in high yield, such as a suitable method for mass production.

The present inventors have steadily solved the above-mentioned drawbacks of the prior art, and have continued to study economically advantageous 5'-guanylic acid purification methods. As a result, 5'-guanylic acid is present in the free form in the acidic region or monosodium (mono sodium). It can be seen that it can be separated into 5'-guanylic acid having a good crystallinity and easy separation by using the property that it exists as a salt and becomes less than pH 1 and becomes extremely poorly soluble. Could.

The present invention will be described in detail. The 5'-guanylic acid-containing solution is adsorbed through a strong acid cation exchange resin, eluted with water, and the eluent is adsorbed on a strong basic anion exchange resin, eluted with 1.5-1.0 N HCl, and eluted with 5'-. 5 L of guanilic acid 80 g / L was obtained.

To this solution, the pH was adjusted to 0.7 with 6N HCl solution to decrease the temperature, and then separately added allied particles (Seed) were added and stirred while maintaining at 3-5 ° C.

At this time, if the separated columnar particles (Seed) is not added, the diamond particles and needle-like particles are delayed crystallization, resulting in a decrease in purity and poor separability.

TABLE 1

Sedimentation Rate Changes According to Crystallization Time

As shown in Table 1, in the present invention, when the crystallization of the 5'-guanylic acid-containing solution is more than 1 hour, 70% or more of 5'-guanylic acid is formed into large, clean columnar particles, and the resulting precipitate is filtered after stirring for 4 hours. And washed with a small amount of water and dried to separate 283 g of 5'-guanylic acid into a free form.

At this time, other ions in the crystallization solution, impurities such as proteins and pigments can be removed with a crystal mother solution, which is one of the characteristics of the present invention.

TABLE 2

Stability of 5'-guanylic acid with pH and time (concentration: g / l)

In addition, as shown in Table 2, it was found that 5'-guanylic acid was stable without degradation in the solution containing pH 0.7 even at a temperature of 5 ° C. for up to 12 hours. It was suspended in water, adjusted to pH 8.0 with NaOH, dissolved, and added MeOH to 60% to produce crystals of 5'- sodium guanylate, which was separated and dried to obtain 352 g of 5'- sodium guanylate.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

500 g of 5'- sodium guanylate was dissolved in 6 l of water, adjusted to pH 0.7, and stirred for 5 hours by adding a small amount of previously separated columnar particles before natural particles were formed while maintaining the temperature at 5 ° C. At this time, the formed particles were separated to obtain a free 358 g of 5'-guanylic acid, and this wet tablet was dissolved in 2 L of water and adjusted to pH8.2 with 6N-NaOH to form 60% with MeOH. Sodium 5'-guanylate 441 g of crystals were obtained.

Example 2

Directly fermentation 5g of 5'-guanylic acid containing 19g / 6l of liquid containing 5'-guanylic acid to remove cells and insoluble matters was adsorbed on 4l strong acid cation exchange resin to adsorb 5'-guanylic acid to other nucleotides (Nucleotide) and Nucleoside and pigment impurities were removed, eluted with demineralized water, and the eluent was adsorbed on 0.45 L of strong basic anion exchange resin, eluted with 0.5 N-NaCl to obtain 1.25 L of 5'-guanylic acid 70 g / L. The pH of the liquid was 0.8. While cooling the eluent, a small amount of columnar particles (Seed) was added, and after stirring for 4 hours at 5 ° C, the formed particles were separated and dried to obtain 60.7 g of 5'-guanylic acid glass.

Claims (1)

The pH of the 5'-guanylic acid-containing solution and some of the impurities removed or concentrated is adjusted to 0.5-1.0, and the particles are separated by adding separated particles (Seed) while maintaining the temperature at 3-5 ° C for high purity with good separation. Purification of 5'-guanylic acid, characterized by selectively precipitated and purified 5'-guanylic acid free crystals.

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