KR20050085876A - Method for purification of milbemycins - Google Patents

Abstract

A method for the purification of milbemycins which comprises washing a milbemycin with a base. According to the method, impurities can be easily removed without using an industrially troublesome technique such as chromatography.

Description

Purification of Milvemicin {METHOD FOR PURIFICATION OF MILBEMYCINS}

The present invention relates to a purification method on an industrial scale of milbamycins.

Milbemycins, which are 16-membered cyclic macrolide compounds obtained from microbial metabolites, are known to have insecticidal, tick insecticidal activity, or antiparasitic activity, and examples thereof include compounds shown in Table 1 below.

In the preparation of these compounds, usually, as with all microbial metabolites, they contain a lot of soft bodies and impurities. Therefore, when manufacturing these compounds industrially, it is necessary to refine | purify by the method which can be used by an industrial manufacturing method.

As a general method for purifying the compound, after extracting the compound from the fermentation culture using an organic solvent, silica gel, alumina, dextran gel, ion exchange resin, synthetic adsorbent, molecular sieve, C ₈ H ₁₇ , C ₁₈ H ₃₇ A method of concentrating and drying a fraction containing a target compound obtained by applying to a chromatography using a carrier such as chemically bonded silica gel such as C ₆ H ₅ or the like (for example, Patent Document 1, Patent Document 2, See Patent Document 3 or Patent Document 4.). However, in the method using these chromatographs, since the load of the carrier is low, a large amount of eluting solvents, such as a chromate carrier and an organic solvent, must be used, the productivity is low, and the obtained refined product is expensive and industrially necessarily. It is not a satisfactory purification method.

Disclosure of the Invention

It is an object of the present invention to provide a purification method for milbamycin that can be easily removed without using industrially complicated purification methods, for example, chromatography.

MEANS TO SOLVE THE PROBLEM As a result of earnest effort in order to solve the said subject, the present inventors discovered that unnecessary material can be removed simply by wash | cleaning Milbemycin with a base, and completed this invention.

The present invention,

(1) Purification of Milbemycins by washing Milbemycins with a base,

(2) the purification method according to (1), wherein the milbemicins are one or two or more mixtures of a compound selected from milbemycin A ₃ , milbamycin A ₄ , milbemycin D, milbamycin α _11, or milbamycin α ₁₄ ,

(3) the purification method according to (1) or (2), wherein the milbemicins are milbemycin A ₃ , milbamycin A _4, or a mixture thereof;

(4) The purification method according to any one of (1) to (3), which is carried out in a solvent.

(5) The purification method in any one of (1)-(4) characterized by wash | cleaning the ethyl acetate solution of Milvemycin with a base.

(6) The purification method in any one of (1)-(5) whose base is a solution of amines.

(7) It is the purification method in any one selected from (1)-(6) whose base is an aqueous ammonia solution.

As the "milbemycins" in the present invention, for example, one or two or more mixtures of compounds selected from Milbemycin A ₃ , Milbemycin A ₄ , Milbemycin D, Milbemycin α ₁₁ or Milbemycin α ₁₄ can be mentioned. And preferably one or two or more mixtures of compounds selected from Milbemycin A ₃ , Milbemycin A ₄ or Milbemycin D, and more preferably Milbemycin A ₃ , Milbemycin A ₄ or mixtures thereof. Can be mentioned.

Examples of the "solvent" in the present invention include water; alcohols such as methanol, ethanol or t-butanol; Ketones such as acetone or methyl isobutyl ketone; Nitriles such as acetonitrile; Esters such as ethyl acetate; Halogenated hydrocarbons such as methylene chloride, chloroform or dichloroethane; Ethers such as diethyl ether, tetrahydrofuran or dioxane; Aromatic hydrocarbons such as benzene or toluene; Amides such as dimethylformamide or dimethylacetamide; Sulfoxides such as dimethyl sulfoxide or aliphatic hydrocarbons such as hexane or octane, and mixed solvents thereof.

The "base" in the present invention is not particularly limited as long as it does not decompose milbamycins, but includes, for example, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide or lithium hydroxide; Alkaline earth metal hydroxides such as calcium hydroxide or magnesium hydroxide; Inorganic bases such as alkali metal carbonates such as sodium carbonate, potassium carbonate, sodium bicarbonate or cesium carbonate or alkaline earth metal carbonates such as calcium carbonate or ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, tri Ethylamine, trin-butylamine, diisopropylethylamine, 1,4-diazabicyclo [2.2.2] octane (DABCO), 1,8-diazabicyclo [5.4.0] undec-7-ene Amines such as (DBU), pyridine, collidine or 4- (N, N-dimethylamino) pyridine, and the like, preferably amines, preferably ammonia, methylamine, dimethylamine, trimethyl Amine, ethylamine, diethylamine, triethylamine, and particularly preferred are ammonia, methylamine, dimethylamine, ethylamine and diethylamine, more preferably ammonia, methylamine and ethylamine. Preferably ammo It can be ah.

Best Mode for Carrying Out the Invention

The present invention is a method for purifying Milbemycin by washing Milbemycin with a base.

Here, "washing Milbemycins with a base",

(A) dissolving milbamycins in a solvent, adding a base which does not dissolve in the solvent, and performing stirring and the like,

(B) dissolving milbamycin in a solvent, dissolving a base in a solvent which is not mixed with the solvent, and performing stirring and the like,

(C) dissolving the base in a solvent in which the milbemycins are insoluble, adding milbemycins, and performing stirring,

(D) Milbemycin is added to the base which is a liquid at the temperature which wash | cleans, stirring, etc. are shown.

Among these, preferably,

(1) Said (A)-(C) is mentioned, More preferably,

(2) Said (A) or (B) is mentioned, More preferably,

(3) The said (A) or (B) WHEREIN: The case where the solvent which melt | dissolves a mildew mycin is ethyl acetate is mentioned, Especially preferably,

(4) The said (A) or (B) WHEREIN: The solvent which melt | dissolves a mildew mycin is ethyl acetate, and a base is amines, Most preferably,

(5) In said (B), the case where the solvent which melt | dissolves a mildew mycin is ethyl acetate, a base is ammonia, and the solvent is water is mentioned.

Milbemycins are known compounds which are known to have insecticidal, tick insecticidal activity, or antiparasitic activity as described above. Milbemycin A ₃ and Milbemycin A ₄ are disclosed in JP-A-55-131398, Milbemycin D can be manufactured by the method of Unexamined-Japanese-Patent No. 56-32481, and Milbemycin (alpha) ₁₁ and Milbemycin (alpha) ₁₄ are respectively described by Unexamined-Japanese-Patent No. 1-93,270.

Although the time when the milbamycins are washed with a base is not particularly limited, it is usually 15 minutes to 2 days, and preferably 30 minutes to 3 hours. The temperature at that time is 0-80 degreeC normally, Preferably it is 20-40 degreeC.

The amount of the base to be used may vary greatly depending on the purity of the milbemycins, but is usually 20% to 10 times by weight, preferably 50% to 5 times the weight of milbemycin.

After the washing process ends, the

In the case of (A), purity is improved by filtering the base according to a conventional method, and then washing the filtrate with an acidic solution such as aqueous sulfuric acid solution, if necessary, and then concentrating it under reduced pressure or normal pressure. Milbemycins can be obtained,

In the case of (B), milbamycin improved in purity by extracting a solution in which the milbamycins are dissolved and, if necessary, washing with an acidic solution such as an aqueous sulfuric acid solution and then concentrating it under reduced pressure or normal pressure. Get Ryu,

In the case of (C) and (D), the mildew mycins with improved purity can be obtained by filtering the mildew mycins and washing with a suitable solvent.

In addition, when a higher purity compound is required as needed, a method such as a recrystallization method, a liquid-liquid distribution method, or a derivatization method may be combined.

In order to demonstrate this invention further more concretely, an Example etc. are shown below, but this invention is not limited to this.

(Example 1)

From a cake of milbe erythromycin A ₃ and A ₄ milbe hygromycin fermentation broth derived from the ethyl acetate solution it was prepared. Concentration of a portion under reduced pressure showed that the purity of the concentrated residue was 28% (Milbemycin A ₃ : 4.2%; Milbemycin A ₄ : 23.8%). The ethyl acetate solution (130 ml) was washed sequentially with 63 ml of 5% aqueous ammonia and 39 ml of 5% aqueous sulfuric acid solution. 300 ml of methanol and 300 ml of water were sequentially added to the residue obtained by concentrating this ethyl acetate solution, and then, with Isoper E (hydrocarbon solvents made by Exxon Mobil: 60-70% octane, 30-40% nonane) Extracted. The obtained isoper E solution was concentrated under reduced pressure to recrystallize, followed by filtration to obtain 3.06 g (yield 75%) of crystals of milbamycin A ₃ and milbamycin A ₄ . The purity was 95% (Milbemycin A ₃ : 15.2%; Milbemycin A ₄ : 79.8%).

The content and purity of Milbemycin A ₃ and Milbemycin A ₄ were determined using high performance liquid chromatography under the following conditions. Also in the reference example 1, it determined similarly.

High Speed Liquid Chromatography Conditions

Column: Wakosil-II 5C18 HG φ4.6 × 250mm

Solvent: Acetonitrile / water = 80/20

Flow rate: 1.Oml / min

Detection: UV240nm

(Reference Example 1)

1 L of methanol solution prepared from the cake derived from the fermentation broth of Milbemycin A ₃ and Milbemycin A ₄ was concentrated, and the residue obtained was subjected to silica gel (using Wacogel C-100, 400 g) column chromatography. Ethyl acetate-hexane mixed solvent to deployment, and concentrated and the resulting milbe erythromycin A ₃ and A ₄ milbe azithromycin-containing fraction. After giving the obtained residue to recrystallization, 2.69 g (yield 78%) of milbemectin crystals were obtained by filtering. The purity was 95% (Milbemycin A ₃ : 14.3%; Milbemycin A ₄ : 80.7%).

According to the present invention, there is provided a method for purifying Milbemycins which is simple, inexpensive, and highly purified, without using chromatography.

Claims (7)

Purification method of Milbemycin by wash | cleaning Milbemycin with a base. The purification method according to claim 1, wherein the Milbemycins are one or two or more mixtures of substances selected from Milbemycin A ₃ , Milbemycin A ₄ , Milbemycin D, Milbemycin α _11, or Milbemycin α ₁₄ . The purification method according to claim 1 or 2, wherein the millibemycins are Milbemycin A ₃ , Milbemycin A _4, or a mixture thereof. The purification method according to any one of claims 1 to 3, which is carried out in a solvent. The purification method according to any one of claims 1 to 4, wherein an ethyl acetate solution of milbamycin is washed with a base. The purification method according to any one of claims 1 to 5, wherein the base is a solution of amines. The purification method according to any one of claims 1 to 6, wherein the base is an aqueous ammonia solution.