HU193761B - Industrial process for recovering raw vinblastin-sulfate from vinca rosea l - Google Patents

Abstract

The present invention relates to a process for recovering crude vinblastine sulfate from Vinca rosea L. drug extraction, treating, concentrating, degreasing, reacting the resulting alkaloid base with sulfuric acid. According to the present invention, 1 part by weight of drug is present in an amount of from 5 to 10 parts by weight of 0.5 to 3.0% by weight of water containing from 2 to 5 carbon atoms of mono- or dicarboxylic acid and from 1 to 5% by weight of alkali metal or alkaline earth metal sulphate. and extracting the resulting aqueous alkaloid extract at pH 2.5-3.6 with chloroform, concentrating the resulting solution, dissolving the grease-type impurities with a C 6-12 hydrocarbon or a mixture thereof; base is converted into the sulfate salt in a manner known per se from 1 to 5 carbon atoms. -1-

Description

The present invention relates to a novel process for the recovery of crude vinblastine sulfate from a drug of Vinca rosea L. by extracting the drug, treating the extract, concentrating, degreasing, separating the obtained alkaloid base in the form of a sulfuric acid addition salt.

It is known that vinblastine (hereinafter VLB) has been used for decades as a dostatic agent which is effective, inter alia, in the treatment of acute leukemia. It is also known that, in addition to vinblastine, almost 100 other structural analogs of alkaloids are found in the plant called rosemaryg (Vinca rosea L.). Due to the high degree of structural similarity and relatively low concentration, obtaining either vinblastine or vincristine from the drug is not an easy task.

In the last two decades, several methods have been developed for the effective isolation of VLB, both by acidic or basic pretreatment of the dried drug and extraction using an organic solvent, transferring the aqueous alkaloids to one or two different ρΗ values in an organic solvent, based on the chromatographic fraction of the total alkali mixture dissolved in a solvent.

For example, U.S. Patent No. 3,097,137. and U.S. Pat. According to U.S. Pat. No. 5,123, the drug is extracted with ethanol-water-acetic acid (9: 1: 1) and, after desired concentration, the alkaloids are dissolved in 2% aqueous hydrochloric acid. The pH of the hydrochloric acid solution is then reduced to 4 with alkali. The weakly acidic solution is extracted with benzene, thereby removing most of the impurities accompanying the alkaloids and some of the unwanted alkaloids. The acidic phase, which now contains the alkaloids in a purer form, is brought to pH 7, the alkaloid bases are dissolved in benzene and the benzene solution is evaporated to dryness. In this way, the alkaloids are recovered in the form of a base and, after dissolution, separated by chromatography.

No. 3,225,030. According to US patent, the drug is first treated with aqueous alcohol, followed by benzene extraction, concentration of the extract and extraction of alkaloids with 2% tartaric acid. The pH of the solution is then reduced to 3.2 by the addition of alkali and the solution is extracted with dichloroethane or benzene. The two phases are separated, the organic phase contains some of the unwanted alkaloids and impurities accompanying the alkaloids, and the aqueous phase contains the desired alkaloids along with a large amount of other alkaloids. The aqueous phase is made basic to pH 9, then extracted with dichloroethane or benzene, the organic phase is evaporated and the alkaloids are separated off using deactivated alumina in a known manner.

An obvious disadvantage of the above processes is that they obtain an extremely low VLB-containing alkaloid mixture even after the extraction operation involving multiple phase changes, as well as high levels of non-alkaloid impurities.

In order to eliminate the disadvantages Hungarian researchers developed the 160.967. in the Hungarian patent. According to the method, the milled Vinca rosea L. drug is extracted with methanol containing 10% water in several portions and the filtered and combined methanolic extracts are concentrated under reduced pressure to practically methanol free. The aqueous residue is then acidified with dilute sulfuric acid to remove non-alkaloid type additives and the precipitate formed is filtered off. The aqueous-acidic solution is extracted several times with benzene, then the separated aqueous-acidic phase is made alkaline and the alkaline-aqueous solution is also extracted several times with benzene until alkaloid-free. The combined benzene solutions obtained by extraction of the alkaline-aqueous solution are evaporated to dryness under reduced pressure to give a loose, amorphous brown alkaline mixture. The alkaline mixture is dissolved in dilute ethanol containing up to 10% sulfuric acid while adjusting the pH of the solution to 4.0-5.0. The solution was inoculated with vinblastine sulfate crystals and the crystallization continued at room temperature for two days. The crystalline mixture of precipitated, filtered, sulfates of vinblastine, vinleurosin, vincristine and accompanying alkaloids is dissolved and directly chromatographed. The vinblastine and vinleurosin-containing fractions are then evaporated to dryness, dissolved in ethanol, and after crystallization of vinleurosin, the vinblastine is separated from the mother liquor in dilute ethanol containing up to 10% sulfuric acid, filtered and then crystallized for purification.

The main disadvantage of the above process is that the drug extraction is relatively low and it is almost impossible to obtain good yields of VLB sulfate in a further very high number of technological steps.

The disadvantages of the above method are disclosed in U.S. Patent No. 164,958. The process described in U.S. Patent No. 3,600,346 was attempted to eliminate the resulting crude alkaloid salt (which is still a mixture of various alkaloids) by converting the desmethyl VLB contained therein to vincristine. The production values achieved in the process are still below the required level and the production of pure VLB cannot be achieved in this way.

Nos. 150,019 and 150,024. U.S. Patent Nos. 4,109,121 to 5,101,125, discloses a new element that Vinca rosea L. is extracted with 2% tartaric acid after prior degreasing with n-hexane.

Although the authors of the process have recognized the chemical and economic benefits of extracting tartaric acid with water (selectivity can be increased and water is a cheap solvent), the industrial recovery of crude vinblastine cannot be achieved in this way. The main reason for this is that the drug must be degreased before being extracted with water using n-hexane or any other hydrocarbon (water immiscible) solvent. Between these two operations, the material must be dried to solvent-free (which is slow, costly, and unsuitable for continuous operation).

On the other hand, if drying is not perfect, the organic material impregnated with organic solvent has a hydrophobic property and creates unfavorable conditions for the acid-aqueous extractant.

It is therefore an object of the present invention to provide a process which, by improving the prior art techniques, provides a simple and excellent extraction.

In our experiments we found that the direct extraction of the drug was developed in a specific proportion

It can be excellently carried out by aqueous extraction containing C 2 -C 5 carboxylic acids and an alkali metal or alkaline earth metal sulfate.

It has also been found that pre-degreasing of the drug can be omitted during the above aqueous extraction provided that the temperature is maintained between 20 ° C and 50 ° C. In this case, a physical (consecutive) change in the fat-like substance results in a drug with a more hydrophilic property and the aqueous extraction (with a dilute acidic, sulfate-containing solution) is surprisingly effective for VLB but simultaneously with the inorganic salt dissolved in the extractant.

The water solubility of 193,761 greasy fats, all other impurities, is suppressed and, compared to any other prior art process, a purer vinblastine extract (30-40% pure in dry matter) can be obtained.

It has further been found that it is expedient to extract the aqueous extract with chloroform, and that fat-type impurities must be completely eliminated prior to salt formation, preferably by treatment with a hydrocarbon type solvent.

Accordingly, the present invention provides a process for recovering crude vinblastine sulfate from a drug of Vinca rosea L. by extracting the drug, treating the extract, concentrating, degreasing, reacting the resulting alkaloid base with sulfuric acid, comprising 5 parts to 10 parts by weight of drug powder. extracted with 0.5 to 3.0% by weight of water containing 2-5 carbon atoms of mono- or dicarboxylic acid and 1 to 5% by weight of alkali metal or alkaline earth metal sulphate at a temperature between 20 ° C and 50 ° C; The aqueous alkaloid extract at pH 6 is extracted with chloroform, the resulting solution is concentrated, the fat-like impurities are dissolved in 6 to 12 hydrocarbons or a mixture thereof, and the purified vinblastinase is converted to a sulfate salt in a C1 to 5 alkanol.

In the process according to the invention, the mono- or dicarboxylic acids having from 2 to 5 carbon atoms are used as tartaric acid, fumaric acid or acetic acid and the alkali metal or alkaline earth metal sulfate is sodium sulfate or calcium sulfate.

According to the present invention, the drug of Vinca rosea L. (also known as Catharantus roseus) is chopped into 8-10 mm ² pieces and subjected to aqueous extraction. The amount of water used for extraction is 5 to 10 times the weight of the drug. Preferably 7-7.5 times the amount of water is used. The water should contain from 0.5 to 3.0% by weight of carboxylic acid and from 1 to 5% by weight of alkaline or alkaline earth metal sulfate. As the carboxylic acid, tartaric acid, fumaric acid, succinic acid, acetic acid, malic acid can be used, while the sulfate salt gives calcium, sodium / ulfate.

The extraction may also be carried out in a batch, semi-continuous or continuous manner. The resulting dilute acidic aqueous extract is directly extracted with chloroform at room temperature. The combined chloroform phases are concentrated in vacuo at 40 ° C or less. After dehydration, the dense crude product is poured into hydrocarbons having from 6 to 12 carbon atoms, preferably gasoline. Petrol treatment can remove greasy impurities. The product obtained is dried (VB content is already 3-5%) and then dissolved in a lower alkanol, preferably ethanol, in a known manner and then mixed with concentrated sulfuric acid ethanol. The resulting VLB sulfate was crystallized, filtered, washed, and dried.

The crude VLB sulfate obtained in this manner already has a VLB content of 30 to 40%.

The main advantage of the process according to the invention is therefore that it provides the most efficient VLB extraction known to date. With the help of special equipment, known methods give a 20% higher yield and a reliable industrial process, which, regardless of the drug content and other quality of the drug, ensures a constant, high efficiency.

The product obtained by this process is easy to classify and store.

The process of the invention is illustrated by the following examples;

Example 1

The grinding

The dry leaf drug (containing up to 10% moisture content) of Vince rosea L. is ground.

B. Drug extraction

20 milligrams (containing 160 mg / kg of VLB) are then mixed with 140 liters of water containing 0.7 kg of tartaric acid and -1.4 kg of calcium sulphate for 1 hour and the extraction is carried out at 30 ° C. Extractions 2 and 3 were performed with a similar aqueous solution. In countercurrent (semi-continuous) extraction, extract 1 is always processed.

C. Extraction with chloroform

The extract from the first semi-continuous counter-current extraction process - that is 110 1 water extract (equivalent to 20 kg of drug) - filtered, clear solution was first extracted with stirring for 2-3 minutes, at a temperature from 20 to 30 ^b 25 1, and then twice with 12 1 of chloroform j5. The chloroform phases are combined or combined. in the case of continuous production, equilibrium extraction is performed, then only the chloroform extract 1 is processed, further, extracts 2 and 3 are used to extract the next batch 1.

D. Concentration, drying, degreasing of the chloroform solution

The chloroform extract to be processed, which has a capacity of 15 liters and has a max. At 40 ° C, it is concentrated to 1-2 liters. The solution - (if no phase boundary) - is mixed with 20-30 g of anhydrous sodium sulfate, dried and filtered. Concentration was then continued to a final volume of 0.1-OJ 1 to give a thick oil. The concentrate is then added to 2 to 4 liters (i.e. 10 times) of gasoline with vigorous stirring. After stirring for 3 to 4 hours, the material solidified, filtered through a vacuum filter and rinsed well with slurried petrol (2 L). The material is dried in the oven at 40 ° C or less to constant weight.

Yield: 85 g of product with VLB content

3-4%.

E. Isolation of Crude VLB Sulphate Dissolve g of dry petrol in 800 ml of ethanol (at room temperature) and adjust the pH of the solution to 4.5 with 60 ml of ethanol containing 2.5 ml of concentrated sulfuric acid, using a Stuphan indicator. The mixture was crystallized under slow stirring at 25-30 C for 2 days and then filtered through a glass filter. The crystal was washed with ethyl alcohol at room temperature without stirring until the effluent was colorless. After suction removal, the crystal is washed four times with 20 ml of petroleum ether to remove ethyl alcohol. The VLB sulfate is then dried in an oven at a temperature of up to 40 ° C to constant weight.

Yield: 8 g VLB sulfate (crude), 33% VLB.

Example 2

The pressed bales of Vinca rosea L. are rolled in a rotating drum roller and then rolled on a roller, thinned between the rotating rollers, to 5-10 mm pieces. 1000 kg drug powder containing 143 mg / kg VLB by analytical test, half-32

193 761

In addition, the extraction agent is added by preparing a 2% aqueous tartaric acid solution in a solution vessel in front of the dosing container.

After collecting the extract corresponding to a volume of 1 t of the drug, work-up was carried out as in Example 2.

Product: 325 g of crude VLB sulfate with a VLB content of 35%.

Example 4

In each case, the same procedure as in Example 2 was followed, except that 35 kg of fumaric acid was dissolved in the aqueous extraction solvent and 2201 n-hexane instead of gasoline was used for degreasing.

Product: 321 g of crude VLB sulfate with a VLB content of 33.5%.

Example 5

All proceed as in Example 4, except that 105 kg of acetic acid is used instead of fumaric acid.

Product: 313 g of crude VLB sulfate with a VLB content of 36.2%.

Claims (3)

A process for the recovery of crude vinblastine sulfate from a drug of Vinca rosea L. by extraction of the drug, treatment, concentration, degreasing of the extract, reacting the resulting alkaloid base with sulfuric acid, wherein 30 parts by weight of the drug powder are obtained. - 10 parts by weight of 0.5 to 3.0% by weight of water containing 2-5 carbon atoms of mono- or dicarboxylic acid and 1-5% by weight of alkali metal or alkaline earth metal sulphate at a temperature of 20 ° C to 50 ° C __. Extract the aqueous alkaloid extract at pH -3.6 with chloroform, concentrate the resulting solution, dissolve the fat-like impurities with 6 to 12 hydrocarbons or mixtures thereof, and purify the vinblastine base in C1 to 5 alkanol. 4Q is converted to the sulfate salt in a known manner. Process according to claim 1, characterized in that tartaric acid, fumaric acid or acetic acid is used as the C 2-5 mono or dicarboxylic acid. The process according to claims 1 and 2, wherein the alkali metal or alkaline earth metal sulfate is sodium sulfate or potassium sulfate. 4. A process according to any one of claims 1 to 3, wherein the carbon of the carbon number 6 to 12 is n-hexane or We use 50 zines. Extract in a continuous counter current extractor with 7000 L of water in which 140 kg of tartaric acid and 280 kg of crystalline sodium sulphate are dissolved. The system was heated to 540 ° C by jacket heating and extracted with stirring for 1 hour. The extract is then depressed from the drug and the extraction is repeated two more times in the same manner as the first. After the extraction equilibrium is reached, only extract 1 is further processed, extracts 2 and 3 are always used to extract fresh drug 10. 5500 L of extract corresponding to 1000 kg of drug are pressed through a decanter into an appropriately sized liquid-liquid extractor. Check the pH of the extract, which should be within the range 2.5 to 3.6. 1300 L of chloroform was then added, stirred for 2 minutes, and the phases were separated. Extraction is carried out at a temperature of 20-30 ° C. The aqueous phase is then extracted twice more with 700-700 liters of chloroform. The chloroform extracts are concentrated on a vacuum film evaporator to 100-150 L at a gentle temperature not exceeding 40 ° C. The concentrate is separated from the upper (aqueous) phase which may be present in a 300 L apparatus and mixed 4-5 kg anhydrous sodium sulfate. The mixture was filtered through a filter, and the filtered chloroform solution was evaporated in a 250 L stirrer under vacuum at a temperature of up to 40 ° C to a final volume of 10-15 L. The concentrate is allowed to cool to 20 ° C and then, in a 500-liter turbo-mixer, previously prepared with 200 L of gasoline, is added slowly with vigorous stirring. The reaction was carried out at 15 to -20 ° C, stirred for 3 hours and then placed in a suitable explosion-proof centrifuge, whereupon the precipitate was filtered off. The precipitate was dried in a tray oven (max. 40 ° C) to give 4200 g of petrol with a VLB content of 3%. The gasoline precipitate (4200 g) was dissolved in ethanol (42 L) at 20 ° C and the pH of the solution was adjusted to 4.5 with 3.2 l of ethanol containing 132 mL of concentrated sulfuric acid. The mixture was crystallized by thermostating at 25-30 ° C for 48 hours with constant stirring and then the crystals were filtered off with suction. The crystals were washed with ethanol and then dried at 30 ° C in an air oven. Yield: 320 g of vinblastine sulphate (crude) with a VLB content of 35% as determined by analytical method. Example 3 The Vinca rosea ground according to Example 2 is added to a continuous (U) -extractor by dry mixing 25 kg of crystalline calcium sulfate in the feed cyclone in increments of 500 kg. without figure