阅读说明：本技术 一种杆菌肽锌的制备方法 (Preparation method of bacitracin zinc ) 是由 徐强如 于 2021-08-19 设计创作，主要内容包括：本发明提供了一种杆菌肽锌的制备方法,步骤如下：(1)在杆菌肽滤液加入盐酸溶液调节pH2.5～6.0后加入锌盐溶液搅拌至溶液透明；(2)加入氢氧化钠溶液,调节pH至6.5～8.5,继续搅拌10～40min后,复测pH6.5～8.5,静置6h以上；(3)抽滤取滤饼,烘干,即得杆菌肽锌白色粉末。本发明解决了原有技术杆菌肽锌成盐收率不稳定的缺陷；在酸性条件下加入锌盐溶液,再通过缓慢调节pH至析晶,更容易观察反应现象和控制反应过程,较大的工业化生产、应用前景。(The invention provides a preparation method of bacitracin zinc, which comprises the following steps: (1) adding a hydrochloric acid solution into the bacitracin filtrate to adjust the pH to be 2.5-6.0, adding a zinc salt solution, and stirring until the solution is transparent; (2) adding a sodium hydroxide solution, adjusting the pH value to 6.5-8.5, continuously stirring for 10-40 min, measuring the pH value again to 6.5-8.5, and standing for more than 6 h; (3) and (4) filtering the filter cake, and drying to obtain the bacitracin zinc white powder. The invention solves the defect of unstable salification yield of zinc bacitracin in the prior art; the zinc salt solution is added under the acidic condition, and the pH is slowly adjusted to crystallize, so that the reaction phenomenon is easier to observe and the reaction process is easier to control, and the method has a wider industrial production and application prospect.)

1. A method for preparing bacitracin zinc, comprising the steps of:

(1) adding a hydrochloric acid solution into the bacitracin filtrate to adjust the pH to be 2.5-6.0, adding a zinc salt solution, and stirring until the solution is transparent;

(2) adding a sodium hydroxide solution, adjusting the pH value to 6.5-8.5, continuously stirring for 10-40 min, measuring the pH value again to 6.5-8.5, and standing for more than 6 h;

(3) and (4) filtering the filter cake, and drying to obtain the bacitracin zinc white powder.

2. The method of claim 1, wherein the step of preparing the bacitracin zinc comprises: the concentration of the hydrochloric acid solution in the step (1) is 10-30%.

3. The method of claim 1, wherein the step of preparing the bacitracin zinc comprises: the pH in step (1) was 4.0.

4. The method of claim 1, wherein the step of preparing the bacitracin zinc comprises: the concentration of the zinc salt solution in the step (2) is 30-60%, and the addition amount is 1.45 +/-0.30 kg/BOU.

5. The method of claim 1, wherein the step of preparing the bacitracin zinc comprises: the concentration of the sodium hydroxide solution in the step (2) is 5-20%.

6. The method of claim 1, wherein the step of preparing the bacitracin zinc comprises: and (4) drying at the temperature of 80-250 ℃ for 2-8 h in the step (3).

7. The method of claim 6, wherein the step of preparing the bacitracin zinc comprises: the drying temperature in the step (3) is 170 ℃.

8. The method of claim 1, wherein the step of preparing the bacitracin zinc comprises: the pH in step (2) was 7.5.

Technical Field

The invention belongs to the field of peptide drug preparation, and particularly relates to a preparation method of bacitracin zinc.

Background

Bacitracin zinc (abbreviated as BcZn, CAS1405-89-6) is a complex of Zn2+ with δ -N of the imidazolyl group of histidine of Bacitracin, the sulfur atom of the thiazoline ring and the carboxylate of glutamic acid. White or off-white powder, with special odor and bitter taste. The substance is almost insoluble in water, methanol, acetone, chloroform, easily soluble in pyridine, and slightly soluble in diethyl ether. The bacitracin zinc is an effective narrow-spectrum polypeptide antibiotic, has an antibacterial spectrum similar to that of penicillin, mainly aims at gram-positive cocci and bacilli, has a certain inhibition effect on a few gram-negative bacteria, spirochetes and actinomycetes, and has the advantages of high efficiency, low toxicity, small residual quantity and the like. Therefore, the bacitracin zinc is not only an important antibiotic drug, but also an antibiotic feed additive for livestock and poultry with good safety.

The existing bacitracin zinc production technology is mainly prepared by a microbial fermentation method, takes Bacillus subtilis and B-type Bacillus licheniformis fermentation liquor as raw materials, the fermentation liquor is mixed with zinc oxide or zinc chloride, and then is evaporated and concentrated in vacuum, so that the content of dry substances is increased from 4.5-5% to 17-20%, and then is spray-dried to obtain the bacitracin zinc. The product obtained by the method has complex components and can only be used as a feed additive.

Patent CN102161693A discloses a method for preparing bacitracin zinc, which comprises adding an alkaline solution into bacitracin solution, adjusting PH to 8-11, adding inorganic zinc to form salt, adjusting PH to 5-7 with inorganic acid, stirring for 1-2 hours, and standing for 5-10 hours. And then obtaining qualified bacitracin zinc through the production steps of separation, drying, crushing, screening, inspection, finished product packaging and the like. Although the method has been applied to a certain extent, the method has some defects: the inorganic zinc is directly added under the alkaline condition, a large amount of crystallization occurs, the control of reaction rate and impurities is not facilitated, and the yield is low.

Disclosure of Invention

In order to solve the above problems, the present invention provides a method for preparing bacitracin zinc, wherein a zinc salt solution is added under acidic conditions, and then pH is slowly adjusted until crystallization. The invention is easier to observe the reaction phenomenon and control the reaction process, is more beneficial to the crystallization of the product, reduces impurities and improves the yield. Has the advantages of high yield, easy control of reaction process, strong impurity removal capability and the like, and has great industrial production and application prospects.

The technical scheme provided by the invention is as follows:

a method for preparing bacitracin zinc, comprising the steps of:

(1) adding a hydrochloric acid solution into the bacitracin filtrate to adjust the pH to be 2.5-6.0, adding a zinc salt solution, and stirring until the solution is transparent;

(2) adding a sodium hydroxide solution, adjusting the pH value to 6.5-8.5, continuously stirring for 10-40 min, measuring the pH value again to 6.5-8.5, and standing for more than 6 h;

(3) and (4) filtering the filter cake, and drying to obtain the bacitracin zinc white powder.

Preferably, the concentration of the hydrochloric acid solution in the step (1) is 10-30%.

Preferably, the zinc salt solution in step (1) is zinc chloride or zinc sulfate.

Preferably, the pH in step (1) is 4.0.

More preferably, the concentration of the zinc salt solution in the step (2) is 30-60%, and the addition amount is 1.45 +/-0.30 kg/BOU.

Preferably, the concentration of the sodium hydroxide solution in the step (2) is 5-20%.

Preferably, the drying temperature in the step (3) is 80-250 ℃, and the drying time is 2-8 h.

More preferably, the drying temperature in step (3) is 170 ℃.

Preferably, the pH in step (2) is 7.5.

Compared with the prior art, the method has the following technical advantages:

(1) according to the invention, the bacitracin filtrate is adjusted to be acidic, and then the zinc salt solution is added, so that the reaction phenomenon is obvious. When the zinc salt is added under an acidic condition, the phenomenon that crystals are precipitated and dissolved again can be seen, and the salt forming process is easy to observe.

(2) The method adds the zinc salt solution instead of directly adding the zinc salt solid, can directly combine the zinc element with the bacitracin, reduces the loss of the zinc element and improves the yield. The zinc salt solid needs to dissolve ionized zinc ions first and then combine with the peptide solution, and the zinc bacitracin formed first may wrap the undissolved zinc salt solid, resulting in loss of zinc element, and thus leading to low yield and instable zinc content. The zinc element in the zinc salt solution is free zinc ion, and can be directly combined with the peptide solution to form bacitracin zinc, so that the loss of the zinc element is reduced, and the yield is improved.

(3) According to the invention, the zinc salt solution is added under acidic conditions, and then the product is slowly crystallized through pH adjustment, so that impurity precipitation can be effectively reduced, and the product quality is improved. Bacitracin zinc crystallizes rapidly under alkaline conditions, and addition of zinc salts under alkaline conditions results in excessive crystallization rate and inclusion of impurities. The zinc salt solution is added under acidic condition, and then pH adjustment is carried out, so that bacitracin zinc can be slowly crystallized, the crystallization rate is easy to control, the crystallization level is improved, and the impurity content of the product is reduced.

Drawings

FIG. 1 is an HPLC detection profile of zinc bacitracin prepared in example 1

FIG. 2 is an HPLC detection profile of zinc bacitracin prepared in example 2

FIG. 3 is an HPLC detection profile of zinc bacitracin prepared in example 3

FIG. 4 is an HPLC detection profile of zinc bacitracin prepared in comparative example 1

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention in any way.

Example 1

Taking 50L of secondary bacitracin filtrate (bacitracin content is 6400U/mL), preparing 10% hydrochloric acid solution to adjust pH to 6.0. 500.0g of zinc chloride was weighed to prepare a 30% zinc chloride solution, which was added to the bacitracin filtrate. After stirring for clarification, 5% sodium hydroxide solution was added to adjust the pH to 6.5. After stirring for 10min, the pH was determined again to be 6.5 and stirring was continued for 1 h. Stopping stirring, standing for 6h, performing suction filtration, taking a filter cake, drying for 2h, and drying at the temperature of 80 ℃. Collecting to obtain 4.55kg of white powdery dry product with the molar yield of 80.2 percent. Through HPLC detection (the map is shown in figure 1), the bacitracin A content is 58.17%, the total amount of bacitracin A, B1, B2 and B3 is 82.31%, the bacitracin F content is 1.38%, and the total amount of impurities separated out before bacitracin B1 is 10.33%. Meets USP standard. According to USP standard, bacitracin A content is not less than 40.0%, bacitracin A, B1, B2 and B3 total amount is not less than 70.0%, total impurity precipitation before bacitracin B1 is not more than 20.0%, and bacitracin F is not more than 6.0%.

Example 2

Taking 50L of secondary bacitracin filtrate (bacitracin content is 6400U/mL), preparing 20% hydrochloric acid solution to adjust pH to 4.0. 500.0g of zinc chloride was weighed to prepare a 50% zinc chloride solution, which was added to the bacitracin filtrate. After clarification by stirring, 10% sodium hydroxide solution was added and the pH was adjusted to 7.5. After stirring for 30min, the pH was determined again at 7.5 and stirring was continued for 1 h. Stopping stirring, standing for 6h, performing suction filtration, taking a filter cake, drying for 4h, and drying at the temperature of 170 ℃. Collecting to obtain 4.78kg of white powdery dry product with the molar yield of 84.3 percent. Through HPLC detection (the map is shown in figure 2), the bacitracin A content is 63.86%, the total amount of bacitracin A, B1, B2 and B3 is 81.88%, the bacitracin F content is 2.49%, and the total amount of impurities separated out before bacitracin B1 is 4.07%. Meets USP standard. According to USP standard, bacitracin A content is not less than 40.0%, bacitracin A, B1, B2 and B3 total amount is not less than 70.0%, total impurity precipitation before bacitracin B1 is not more than 20.0%, and bacitracin F is not more than 6.0%.

Example 3

Taking 50L of secondary bacitracin filtrate (bacitracin content is 6400U/mL), preparing 30% hydrochloric acid solution to adjust pH to 2.5. 500.0g of zinc chloride was weighed to prepare a 60% zinc chloride solution, which was added to the bacitracin filtrate. After clarification by stirring, 20% sodium hydroxide solution was added and the pH was adjusted to 8.5. After stirring for 40min, the pH was again measured at 8.5 and stirring was continued for 1 h. Stopping stirring, standing for 8h, performing suction filtration, taking a filter cake, drying for 8h, and drying at the temperature of 250 ℃. Collecting to obtain 4.51kg of white powdery dry product with the molar yield of 79.5 percent. Through HPLC detection (the map is shown in figure 3), the bacitracin A content is 64.15%, the total content of bacitracin A, B1, B2 and B3 is 82.54%, the bacitracin F content is 2.15%, and the total content of impurities separated out before bacitracin B1 is 5.18%. Meets USP standard. According to USP standard, bacitracin A content is not less than 40.0%, bacitracin A, B1, B2 and B3 total amount is not less than 70.0%, total impurity precipitation before bacitracin B1 is not more than 20.0%, and bacitracin F is not more than 6.0%.

Comparative example 1

Taking 100L of secondary bacitracin filtrate (the bacitracin content is 6400U/mL), adding 1.5M sodium hydroxide solution, adjusting the pH to be 8-11, adding 1.1Kg of 30% zinc chloride solution to form salt, adjusting the pH to be 5-7 by hydrochloric acid, stirring for 1-2 hours, and standing for 6-7 hours. And then 8.00kg of bacitracin zinc is obtained by centrifugal drying, and the molar yield is 70.5%. Through HPLC detection (the map is shown in figure 4), the bacitracin A content is 67.20%, the total amount of bacitracin A, B1, B2 and B3 is 86.37%, the bacitracin F content is 1.03%, and the total amount of impurities separated out before bacitracin B1 is 4.22%. Meets USP standard. According to USP standard, bacitracin A content is not less than 40.0%, bacitracin A, B1, B2 and B3 total amount is not less than 70.0%, total impurity precipitation before bacitracin B1 is not more than 20.0%, and bacitracin F is not more than 6.0%. Although the detection result is basically normal, the obvious yield is low, the phenomenon is not obvious in the whole reaction process, the reaction rate is not easy to control, and whether the crystallization state is finished or not is difficult to judge in time.