KR20010024028A - PROCEDE FOR RECOVERY OF A β-LACTAM ANTIBIOTIC - Google Patents

Abstract

The present invention relates to a method for recovering β-lactam antibiotics from a mixture containing β-lactam antibiotics and D-phenyl glycine in a solution.

At the concentration at which FG remains in solution, the pH of the mixture containing β-lactam antibiotics and D-phenyl glycine (FG) is brought to pH 3-8, the solid β-lactam antibiotics obtained are recovered, and solid β Forming a slurry with lactam antibiotic and solid FG, bringing the pH of the slurry to a pH at which the β-lactam antibiotic is dissolved, separating the FG as a solid, and using at least a portion of the β-lactam antibiotic present in the mother liquor Send the residual liquid to the concentration stage,

Corresponding β-lactam nuclei, in particular 6-aminophenicylanic acid, 7-aminodesacetoxycephalosporanic acid and 7-amino-3-chloro-cef-3-m-4-carboxylic acid, are D-phenyl glycine derivatives It is preferred to use an initial mixture which actually contains β-lactam antibiotics and FG derived from the enzyme acylation reaction which is acylated with.

Description

PROCESS FOR RECOVERY OF A β-LACTAM ANTIBIOTIC

The present invention relates to a method for recovering β-lactam antibiotics from a mixture containing β-lactam antibiotics and D-phenyl glycine (FG) in a solution, wherein the pH of the mixture is 3-8 at a concentration of FG remaining in the solution. Recover the solid β-lactam antibiotics obtained, and form a slurry with solid β-lactam antibiotics and solid FG, bring the pH of the slurry to the pH at which β-lactam antibiotics dissolve, And the residual liquid is sent to a concentration step using at least some of the β-lactam antibiotics present in the mother liquor.

Generally, in the preparation of δ-lactam antibiotics comprising acylating β-lactam nuclei with D-phenyl glycine derivatives, β-lactam antibiotics are difficult to recover and the reaction mixture is difficult to aggregate. . Often, useful components for aggregation, in particular β-lactam antibiotics, are considerably lost, some in the form of loss of solubility, and some of the limited stability of the β-lactam antibiotics due to degradation.

The present invention provides a method for recovering β-lactam antibiotics in which the loss of β-lactam antibiotics is greatly reduced in a simple manner applicable to an industrial scale, and in which useful D-phenyl glycine is recovered.

Acylation reaction of the lactam nucleus with a suitable acylating agent, in particular amide of D-phenyl glycine such as, for example, D-phenyl glycine amide (FGA), or D-phenyl such as methyl ester of D-phenyl glycine (FGM) During the enzymatic acylation reaction with the ester of glycine, the acylating agent is hydrolyzed with β-lactam antibiotics to form D-phenyl glycine (FG).

The mixture obtained after the acylation reaction contains, in addition to β-lactam antibiotics and FG, for example, β-lactam nuclei and / or acylating agents, such as FGA or FGM, which have not yet been converted. The precise composition of the mixture which can be used in the process according to the invention is not particularly important. Mixtures which can suitably be used in the process according to the invention include 10-1500 mM, in particular 50-1000 mM β-lactam antibiotics; Preference is given to mixtures containing 0-1500 mM, in particular 0-1000 mM FG, 0-1000 mM, especially 0-200 mM β-lactam nuclei and 0-1000 mM, especially 0-400 mM D-phenyl glycine derivatives.

If necessary, the mixture containing β-lactam antibiotics and FG is brought to a concentration and pH at which all components, in particular the abovementioned components, are optionally dissolved all without β-lactam antibiotics. For this reason, the pH is selected as high, for example 6.5 to 11, preferably 7 to 9.5, or as low as for example 0 to 3, in particular 0.3 to 2. If the method is carried out on a large scale, it is preferable to choose a rather continuous aggregation method. In continuous dissolution methods, the residence time is shorter at relatively high or low pH. If desired, certain solid components still present are separable, for example by filtration or ultrafiltration.

According to the present invention, the mixture containing the solid β-lactam antibiotics is still brought to pH 3-8, preferably 4-7, and the reactants, in particular the concentration of FG, is optionally supersaturated with the exception of the β-lactam antibiotics. Take measures such as adding water to remain in solution irrespective of whether The concentration is preferably selected so that after the pH of the solution is between 3 and 8, the FG is supersaturated in the solution. The temperature is not particularly important and is -5 to 45 ° C, in particular 0 to 25 ° C. If the FG concentration in the mixture is relatively high, the temperature is preferably maintained at 0 to 10 ° C. This is because under these conditions FG is very supersaturable without precipitation. This allows relatively high concentrations to be maintained, requiring only a small amount and little β-lactam antibiotic remains in solution. As a result, the β-lactam antibiotic can precipitate out as a solid and be recovered.

However, after recovering the solid β-lactam antibiotics, it was found that the amount of β-lactam antibiotics present in the mother liquor was still relatively high. Applicants have found a way to further aggregate the liquid and to further increase the yield of β-lactam antibiotics. According to the invention, the liquid is concentrated. In order to prevent degradation of β-lactam antibiotics and discoloration of β-lactam antibiotics and FG crystals, a relatively low temperature should be chosen, while the concentration step should last relatively short, while a relatively high temperature and a relatively long, gradual concentration process. Should be chosen to obtain inviscid slurry and large FG crystals that can be easily separated. It has been found that degradation of β-lactam antibiotics is drastically reduced and still the FG crystals are relatively large so that the concentration step can proceed under these conditions that can be easily separated.

The temperature at which the concentration is carried out is for example 10 to 80 ° C., preferably 20 to 60 ° C., in particular 25 to 55 ° C. The concentration lasts, for example, from 10 minutes to 24 hours, preferably from 0.5 hours to 10 hours, in particular from 1 hour to 5 hours. The temperature at which the concentration takes place and the duration of the concentration are generally chosen such that a relatively short duration is selected with high temperature and vice versa.

Concentration is carried out under reduced pressure, for example by evaporation or by nanofiltration. Evaporation is carried out, for example, in a thin film evaporator. The wall was easy to maintain, so it was found that little degradation of β-lactam antibiotics occurred. It has also been found that better FG crystals are obtained when evaporation is effected, for example, by evaporation by passing a liquid suspension through an evaporator at high flow rates, in which the composition of the liquid changes gradually. A second possible embodiment of concentration is an evaporator-crystallizer, for example a bypass evaporator or several cascaded bypass evaporators.

It has also been found that the concentration can also be done very well by nanofiltration. It was found that even though crystallization occurred during nanofiltration, the flow rate through the membrane was relatively high. Suitable membranes for concentration through nanofiltration are, for example, SeIRO MPT-10 (Membrane Products Kiryat Weizmann), WFN0505 (Stork Friesland) and Nanomax-50 (Millipore).

The concentration factor, ie, the volume ratio before and after concentration, is very widely defined, with 1 to 30 being preferred, particularly 3 to 20. The higher the concentration factor, the higher the efficiency will be. The concentration factor is preferably selected so that salts occurring throughout the process remain dissolved. Those skilled in the art will be able to readily determine the optimal concentration factor in their particular case.

The slurry obtained after the concentration step is first separated into a clear liquid stream and a concentrated slurry, or separated into a clear liquid stream and a solid. Separation is carried out with a specific separation apparatus, for example a centrifuge or filter. Since the solid does not need to be separated as a solid, it is preferable to use a decanter. The clear liquid stream is for example discharged; This is a simple way to prevent decomposition of the resulting product and salt. Since the discharge stream is relatively small, only a small amount of β-lactam antibiotics due to loss of solubility are lost.

During concentration, both FG and β-lactam antibiotics form as solids. It was found that the solid FG formed in the concentration step can be easily filtered. As a result, due to the fact that the concentration of the β-lactam antibiotics is relatively low, the pH of the slurry is dissolved in the β-lactam antibiotics and the FG is not dissolved, for example, pH 6.5 to 11, preferably pH 7 to 9.5. Or it was found that FG can be recovered by bringing it to pH 0-3, preferably pH 0.3-2, and separating FG as a solid by filtration or centrifugation. Since the solids can now be separated rapidly, little or no degradation of the β-lactam antibiotic occurs during the separation, despite the high or low pH. If desired, the filtrate may be returned continuously to the process or may be reused in other ways.

Β-lactam antibiotics in the filtrate can be recovered by crystallization through pH change. Another possible method is to return the filtrate as above with a mixture containing dissolved β-lactam antibiotics and FG.

The method according to the invention comprises, for example, cephaalexin, ampicillin, cefaclor, fivampicillin, becampillin, tamampicillin and cefaloglycine and cefaloglycine Likewise, it can be suitably used to prepare β-lactam antibiotics having a phenyl glycine side chain.

In general, any β-lactam nucleus may be used, in particular the β-lactam nucleus of the following formula (1) may be used.

Wherein R ₀ represents H or an alkoxy group having 1-3 C; Y represents CH ₂ , O, S or sulfur in oxidized form; Z represents the following:

(In the above, R ₁ is, for example, H, OH, halogen, an alkoxy group having 1-5 C atoms, an alkyl group having 1-5 C atoms, a cycloalkyl group having 4-8 C atoms, 1- Substituted or unsubstituted alkyl, aryl, carboxy or alkoxy groups having 8 C atoms and represent aryl groups or heteroaryl groups having 6-10 C atoms; and the carboxylic acid groups are ester groups if desired).)

Suitable examples of β-lactam nuclei that can be used in the process according to the invention are penicillin derivatives, such as 6-aminopenicilanic acid (6-APA), 7- with or without substituents on the 3-site. Cephalosporanic acid derivatives, such as 7-aminocephalosporanic acid, such as 7-aminocephalosporanic acid (7-ACA), 7-aminodesacetoxycephalosporanic acid (7- ADCA: 7-aminodesacetoxycephalosporanic acid) and 7-amino-3-chloro-sef-3-m-4-carboxylic acid (7-ACCA: 7-amino-3-chloro-cef-3-em-4-carboxylic acid) have.

In general, suitable enzymes as catalysts in the coupling reaction can be used as enzymes. Such enzymes include enzymes collectively referred to as penicillin amidase or penicillin acylase. The enzyme is for example J. G. J.G. Shewale et al., Process Biochemistry, August 1989, pages 146-154, and J. G. Schvaler et al., Process Biochemistry International, June 1990, pages 97-103. Suitable enzymes include Acetobacter, especially Acetobacter pasteurianum, Aeromonas, Alcaligenes, particularly Alcaligenes faecalis, and Apanocardiium. (Aphanocladium), Bacillus sp., In particular Bacillus megaterium, Cephalosporium, Escherichia, in particular Escherichia coli, Flavobacterium ( Flavobacterium, Fusarium, especially Fusarium oxysporum and Fusarium solani, Kluyvera, Mycoplana, Protaminobacter, Proteus In particular Proteus rettgari, Pseudomonas, and Xanthomonas, in particular Xanthomonas citrii.

Immobilized enzymes are preferably used because they are easily isolated and reusable. Suitable immobilization techniques are disclosed, for example, in EP-A-222462. Another suitable technique is to immobilize penicillin G acylase on a carrier containing a gelatinizing agent such as gelatin and a polymer having free amino groups such as arginate amine, chitosan or polyethylene imine. In addition, enzymes can also be used as crystals (CLEC's ™).

Particularly suitable enzymes among commercially available immobilized enzymes include Enzygel. Commercially available under the trade name Boehringer Mannheim GmbH, Escherichia coli enzyme, Recordati immobilized penicillin-G acylase and Palmer biotech Hannover immobilized Penicillin-G acylase.

In the (enzyme) acylation reaction, the acylating agent is an activated form of D-phenyl glycine, preferably (primary, secondary or tertiary) amide or salt thereof, or lower alkyl (1-4C) such as methyl ester. ) Esters.

In general, the temperature at which the enzyme acylation reaction is carried out is 40 ° C or lower, preferably -5 to 35 ° C. Generally the pH at which the enzyme acylation is carried out is from 5.5 to 9.5, preferably from 6.0 to 9.0.

When the maximum conversion is near, it is desirable to terminate the reaction almost completely. A suitable embodiment for terminating the reaction is to lower the pH preferably to 4.0 to 6.3, in particular 4.5 to 5.7. Another suitable embodiment is to lower the temperature of the reaction mixture when the maximum conversion is reached. It is also possible to combine the above two.

When the reaction is terminated as soon as the maximum conversion is reached, the reaction mixture is generally in the form of a suspension consisting of as many solids as antibiotics, D-phenyl glycine and possible immobilizing enzymes. Preferably, the immobilized enzyme is recovered in consideration of the economics of the method. This can be suitably achieved, for example, by selecting the rotational direction of the stirrer such that the suspension is pumped upwards from the center of the stirrer and filtering the reaction mixture with a sieve while stirring. Thus, useful components such as antibiotics and FG can be recovered by the process according to the invention, possibly by first dissolving the solid components except solid antibiotics, for example by changing the pH.

The pH can be lowered in various ways within the vessel of the invention, for example by adding acid to the mixture. Suitable acids are, for example, inorganic acids, in particular sulfuric acid, hydrochloric acid or nitric acid. Preference is given to using hydrochloric acid. The pH can be raised by adding a base to the mixture. Suitable bases are, for example, inorganic bases, in particular ammonium hydroxide, potassium hydroxide or sodium hydroxide. Preference is given to using ammonium hydroxide.

In practice, the enzyme acylation reaction and aggregation of the reaction mixture is usually carried out in water. If desired, the reaction mixture also preferably contains up to 30 vol.% Of an organic solvent or a mixture of organic solvents. Examples of suitable organic solvents that can be used include alcohols having 1-7 carbon atoms, for example monohydric alcohols, in particular methanol or ethanol; Diols, in particular ethylene glycol, or triols, in particular glycerol.

The process according to the invention is used to aggregate the reaction mixture obtained after the enzymatic acylation reaction in which 6-APA is acylated with an amide of D-phenyl glycine, for example FGA, or an ester of D-phenyl glycine, for example FGM. Particularly suitable for the following.

In a preferred embodiment of the method, the concentration of dissolved 6-APA in the reaction mixture is kept relatively low so that a higher conversion can be obtained than if the concentration of dissolved 6-APA is chosen as high as possible. In addition, it was found that the stirring ability of the reaction mixture was significantly higher than that of the dissolved 6-APA concentration.

As used herein, the term 'conversion' refers to the molar ratio of the amount of ampicillin formed and 6-APA used. The concentration of 6-APA dissolved is expressed as the mole of 6-APA per kg of reaction mixture; The total concentration of dissolved and undissolved 6-APA is expressed as the mole of the amount of 6-APA and ampicillin per kilogram of total reaction mixture; The whole reaction mixture contains, in addition to the solution, several solids, for example 6-APA, ampicillin, phenyl glycine and immobilized enzyme.

The molar ratio of the acylating agent to 6-APA, divided by the total amount of added phenyl glycine derivatives by the total mole of 6-APA added, is preferably 2.5 or less. The molar ratio is preferably 1.0 to 2.0, in particular 1.2 to 1.8.

The enzyme acylation reaction is preferably carried out in a batch process. If desired, the reaction can also be carried out continuously with inline control of the concentration of dissolved 6-APA.

The total concentration of 6-APA and ampicillin (dissolved and undissolved form) in the reaction mixture is preferably at least 250 mM, more preferably at least 300 mM, in particular at least 350 mM.

In this preferred embodiment, during the preparation of ampicillin due to the increased instability of 6-APA at high concentrations of dissolved 6-APA, the concentration of dissolved 6-APA is preferably maintained below 300 mM, in particular below 250 mM. At high concentrations of acylating agents, the concentration of dissolved 6-APA is optionally chosen higher than at low concentrations. This is because the reaction rate is higher when the concentration of acylating agent is higher and 6-APA is dissolved in high concentration for a relatively short time.

The concentration of 6-APA dissolved in the reaction mixture can be kept low by various methods. One way to keep the concentration of dissolved 6-APA low is to initially supply only a fraction of the total amount of 6-APA and meter while balancing during the reaction. A disadvantage of this method is that it presents a practical problem when 6-APA needs to be metered in solid form. Therefore, in a batch process, the total amount of 6-APA is preferably supplied at the beginning of the reaction, so that during the enzyme acylation reaction the concentration of 6-APA in the reaction mixture will decrease and the concentration of ampicillin will increase. A suitable method for obtaining low levels of dissolved 6-APA is to maintain the pH at a lower value than when the maximum solubility of the reactants is achieved. A particularly suitable method for keeping the concentration of dissolved 6-APA low is to keep the concentration of the phenyl glycine derivative low by some metering in the phenyl glycine derivative during the reaction.

Herein, it was found that only a slight 6-APA was dissolved if the concentration of the phenyl glycine derivative was kept low, so that the dissolved 6-APA concentration could be controlled by metering the phenyl glycine derivative.

Particularly suitable embodiments are obtained when FGA is added in the form of one of its salts, preferably in the form of salts of FGA and inorganic acids, for example FGA.HCl, FGA.1 / 2H ₂ SO ₄ and FGA.HNO ₃ . In this method, it is easy to optimize the FGA by keeping the pH constant. Preferably, FGA. 1 / 2H ₂ SO ₄ is used as much as possible because the salts have very high solubility.

Within the framework of the present invention, several components are present in the reaction mixture in free form or as salts. The pH values mentioned are in all cases the pH values measured at room temperature.

The present invention will be described with reference to the following examples without being limited thereto.

Abbreviation:

AMPI = Ampicillin

AMPI.3H ₂ O = ampicillin trihydrate

6-APA = 6-amino-phenicylic acid

FGA = D-phenyl glycine amide

FG = D-phenyl glycine

FGHM = D-p-hydroxyphenyl glycine methyl ester

Assemblase ^™ is an immobilized Escherichia coli penicillin acylase from E. coli ATCC 1105 described in WO-A-97 / 04086. Immobilization is carried out as defined in EP-A-222462, gelatin and chitosan are used as gelatinization and glutaraldehyde is used as crosslinking agent.

The final activity of Escherichia coli penicillin acylase is determined by the amount of enzyme added to the active globules, quantified in 3 ASU / dry weight (g), where 1 ASU (Amoxicillin Synthetic Unit) is 6-APA and Defined as the amount of enzyme that can produce 1 g of amoxicillin.3H ₂ O from FGHM (at 20 ° C .; 6.5% 6-APA and 6.5% FGHM)

Example 1

Preparation of FGA.1 / H ₂ SO ₄ Solution

301.6 g (2.00 mole) of FGA was suspended in 650 g of water at T = 5 ° C. While maintaining the temperature by cooling at T <25 ℃ and stirring was dropwise added to the _{96-% H 2 SO 4 102.1g (} 1.00mole) in one hour.

Example 2

Enzymatic Synthesis of Ampicillin

In the enzyme reactor (1.5 L, 11 cm diameter) with a 175 μm mesh sieve bottom, the net-wet assemblease ^TM (the term 'net-wet' is separated from the enzyme slurry by a glass filter. Means a mass of enzyme obtained).

The reactor (1.2 L) was charged with 131.6 g (0.600 mole) of 6-APA, 30.2 g (0.200 mole) of FGA and 400 ml of water (T = 10 ° C). The mixture was stirred at T = 10 ° C. for 15 minutes and transferred to the enzyme reactor with 100 mL of water at t = 0 (T = 10 ° C.).

The stirrer in the enzyme reactor was operated at t = 0. The temperature was kept at 10 ° C throughout. 423.7 g (0.800 mole) of FGA.½H ₂ SO ₄ solution was added at a constant rate for 233 minutes. The pH was kept constant at about 6.3 by titration with 6N H ₂ SO ₄ . At t = 570 minutes, the amount of AMPI was maximum and the pH was reduced to 5.0 by adding 6N H ₂ SO ₄ . The enzyme reactor now contains 575 mmole AMPI, 15 mmole 6-APA, 50 mmole FGA and 365 mmole FG.

Example 3

Separation of AMPI / FG Slurry from Enzyme Reactor

The AMPI / FG slurry prepared as described in Example 2 was removed from the enzyme reactor through the sieve bottom by stirring filtration. This was done using an inclined-blade stirrer located 0.5 cm above the sieve. Agitation was performed upwards at about 500 rpm. 10 parts of 250 ml of water were sent to the reactor (T = 10 degreeC). Washing water was also removed through the sieve bottom by stirring filtration.

Both AMPI / FG slurry and water separated in the reactor were combined (T = 10 ° C.). The resulting AMPI / FG slurry contained> 99.8% of the total amount of AMPI prepared in the enzyme reactor and> 99.5% of the total amount of FG prepared.

After the above stirring filtration,> 99.5% of the assemblease ^TM was present in the enzyme reactor.

Example 4

Concentration of Ampicillin Stock Solution by Evaporation by Thin Film Evaporator

The mother liquor from the AMPI crystallization step (amount: 6798 g, T = 5 ° C., pH = 6.0) was 0.06% 6-APA (17 mmoles), 0.10% FGA (45 mmoles), 0.53% AMPI (104 mmoles) and 0.96% FG (430 mmoles) It contained.

The mother liquor was concentrated by evaporation with a thin film evaporator. The feed was fed from the storage vessel to the thin film evaporator and the product from the thin film evaporator was returned to the same storage vessel. The storage vessel was stirred.

The wall temperature of the thin film evaporator was adjusted to t = 65 ° C. and the pressure in the thin film evaporator was adjusted to P = 80 mbar.

The circulation was started at t = o (storage ⇒ thin film evaporator ⇒ storage); flow rate = 41.6 kg / hour.

The temperature of the liquid in the storage vessel was maintained at T = 40 ℃.

Evaporation was stopped at t = 257 minutes. A total of 5655 g of condensate was collected. The contents of the thin film evaporator and reservoir were circulated for an additional 2 hours while linearly lowering the temperature from T = 40 ° C. to T = 3 ° C. Therefore, the concentrate (1084 g) was discharged. 250 ml of water was first flowed into the thin film evaporator and reservoir and then 2000 ml of water (T = 10 ° C.). The condensate and the first wash water were combined. The second wash water contained very small amounts of AMPI and FG.

Example 5

Return of concentrated ampicillin mother liquor to the ampicillin process upon regeneration; FG separation

The combined concentrate + first wash water (Example 4) was filtered over a glass filter (10 cm in diameter, filtration time 10 minutes). The solid product was rewashed with 25 mL of water (T = 5 ° C.). Yield: 210 g of AMPI / FG wet cake. The mother liquor (1155 g) was discarded.

AMPI / FG wet cake was quantitatively transferred to a stirred reactor with 400 g of water. The slurry was stirred at T = 5 ° C. for 1 hour. Subsequently, 33.0 g of 6N HCl was added within 4 minutes at T = 5 ° C. After stirring for 5 minutes, the slurry was filtered on a glass filter (13 cm in diameter, filtration time 5 minutes). The FG wet cake was washed with 120 mL of water (T = 5 ° C.) and dried. Yield = 36.7 g of FG. The mother liquor and wash water were combined (T = 5 ° C.) and added after 2 minutes to the acid solution of Example 4 (for 30 minutes).

Example 6

Recrystallization of Ampicillin, including regeneration of concentrated ampicillin mother liquor

Recrystallization was carried out in a rig consisting of a storage vessel (4 L), a dissolution vessel (0.25 L), a filter with a Seitz filter plate, and a crystallization vessel (7 L). All vessels were equipped with stirrers, pH electrodes and thermometers.

200 ml of water (T = 5 ° C.) containing 5.0 g of AMPI.3H ₂ O as nuclei were added to the crystallization vessel. The pH was adjusted to pH = 7 with 2N NaOH solution.

The separated AMPI / FG slurry, as described in Example 3, was transferred quantitatively to the reservoir and cooled to T = 2 ° C. with stirring. The entire loop was brought to T = 2 ° C. and then charged from the reservoir to the reservoir.

The pH in the dissolution vessel at t = 0 was adjusted to pH = 1.1 with 6N HCl and the pH was maintained at 1.1 (titrated with 6N HCl). Next, the contents of the storage vessel were added to the dissolution vessel within 1 hour, during which the contents of the dissolution vessel were metered into the crystallization vessel, and the level in the dissolution vessel was kept constant. The temperature in the crystallization vessel was maintained at T = 5 ° C. The pH in the vessel was titrated with 2N NaOH solution and maintained at pH = 7.0. In addition, the combined mother liquor and wash water, prepared as described in Example 5, were added to the dissolution vessel at a constant rate from t = 15 minutes to t = 45 minutes.

At t = 60 minutes, the reservoir was emptied and the entire 300 mL of 6N HCl solution was filled into the dissolution vessel. 450 g of water was sent from the storage vessel to the dissolution vessel (T = 5 ° C.). 6N HCl titration was stopped. 50 g of water was sent from the melting vessel to the crystallization vessel (T = 5 ° C.). The pH in the crystallization vessel was reduced to 6.0 with 6N HCl. After stirring for 1 hour, the slurry in the crystallization vessel was filtered over a glass filter, the wet cake was washed with 2 x 175 ml of water (T = 5 ° C) and dried. Yield: AMPI.3H ₂ O (containing nuclei) 227g, AMPI.3H ₂ O (excluding nuclear) 222g, i.e. 92% for the 6-APA 600mmoles AMPI.3H ₂ O.

Claims (17)

At the concentration at which FG remains in solution, the pH of the mixture containing β-lactam antibiotics and D-phenyl glycine (FG) is brought to pH 3-8, Recovering the obtained solid β-lactam antibiotics, and Forming a slurry having a solid β-lactam antibiotic and solid FG, bringing the pH of the slurry to a pH at which the β-lactam antibiotic is dissolved, separating the FG as a solid, and at least a portion of the β-lactam antibiotic present in the mother liquor Send residual liquid to the concentration step A method for recovering β-lactam antibiotics from a mixture containing β-lactam antibiotics and D-phenyl glycine. The method of claim 1, And the concentration of the mixture is selected such that the FG is supersaturated in solution after the pH of the mixture is brought to pH 3 to pH 8. The method according to claim 1 or 2, The β-lactam antibiotic present in the mother liquor is at least partially recovered. The method according to any one of claims 1 to 3, The mother liquor is returned and combined with the mixture. The method according to any one of claims 1 to 4, Concentration is carried out for 0.5 to 10 hours at a temperature of 20 to 60 ℃. The method of claim 5, The concentration is characterized in that carried out for 1 to 5 hours at a temperature of 25 to 55 ℃. The method according to any one of claims 1 to 6, The concentration is carried out in a thin film evaporator. The method according to any one of claims 1 to 7, The concentration factor during concentration is characterized in that 3 to 20. The method according to any one of claims 1 to 8, Wherein said slurry is first separated into a concentrated slurry or a solid and liquid stream. The method of claim 9, Said separation being carried out in a decanter. The method according to any one of claims 1 to 10, The initial mixture substantially containing β-lactam antibiotics and FG is derived from an enzyme acylation reaction in which the corresponding β-lactam nucleus is acylated with a D-phenyl glycine derivative. The method of claim 11, The mixture obtained after the acylation reaction is first characterized in that the pH is changed to pH 6.5 to 11 or pH 0 to 3. The method of claim 12, The pH of the mixture is reduced to pH 0.3-2. The method according to any one of claims 1 to 13, Wherein said mixture contains 10-1500 mM β-lactam antibiotics, 0-1500 mM FG, 0-1000 mM D-phenyl glycine derivatives and 0-1000 mM β-lactam nuclei. The method according to any one of claims 1 to 14, The β-lactam nucleus is 6-aminophenicylanic acid (6-APA) and the β-lactam antibiotic is ampicillin. The method according to any one of claims 1 to 14, the β-lactam nucleus is 7-aminodesacetoxycephalosporranic acid (7-ADCA) and the β-lactam antibiotic is cephalexin. The method according to any one of claims 1 to 14, the β-lactam nucleus is 7-amino-3-chloro-cef-3-em-4-carboxylic acid (7-ACCA) and the β-lactam antibiotic is cefachlor.