DE1954280C3 - Process for obtaining a germin adduct from germin values - Google Patents

Description

a low yield is obtained. An emulsion is obtained which contains an abundant amount of crystals in suspension. For the series display, it is therefore also necessary in this known process to repeat the extraction for about 100 " s. Therefore, in the known process, the yield of the desired product is significantly reduced, since low alkanols have a considerable disruptive effect in the production of germin adducts Thus, with the known method, only a relatively low yield of about 25% of the germin adduct can be achieved (134 g germin adduct from 750 g of a syrup with a solids content of 70% by volume ).

Another disadvantage of J? Cobs and Craig's approach is that To obtain a product in an administrable form it is necessary to carry out cumbersome and time-consuming cleaning steps perform. On page 55 of the work by Jacobs et al. It is stated that an emulsion ge ao which in suspension contains an abundant amount of crystals. A separation of the product in relatively pure form, a considerable number of extraction steps (100 or more) can only be carried out.

In contrast, the process according to the invention gives almost twice the yield of the desired one Germin adduct, the solid adduct being separated off easily, so that none There is a need for repeated extractions.

The method of the invention therefore envisions hydrolysis of germin levels, preferably in the absence of substantial amounts of other hydrolyzable alkaloid derivatives, but at least in the absence of substantial amounts of protoveratin, the treatment of the hydrolyzate with a liquid, water-immiscible haloe.enierten hydrocarbon in the presence of water to obtain a solid adduct of the germin and the ha-iogenated Hydrocarbon and then preferably treating the product with an alkanol, to split off the adduct. The germin is then obtained using known methods.

In practicing the method of the invention, the plant extract, germin levels contains and that essentially of other alkaloid esters, in particular of protoveratin and jervin is free, first treated with a hydrolyzing agent. A suitable source of the to be hydrosized Germin values represent the ether-soluble fraction of the plant extract. It was found that alkaloid ical derivatives and especially protoveratrine, which are insoluble in ethers, contribute after hydrolysis cause difficulties in separating the germin. For this reason, they are preferably made removed from the alkaloid mixture prior to hydrolysis. This can be done in a suitable manner by that the amorphous alkaloid mixture with diethyl ether at slightly elevated temperatures, in the area of 35 ° C. The germin values go into solution, and the parts that are insoluble in ether are then separated after cooling. Other solvents can be used, such as z. B. dimethyl ether or isopropyl ether. The term "ether-soluble fraction" as used herein relates to on the constitution of the material to be hydrolyzed and not on the use of a special solvent to separate the germin values from the other alkaloid esters. The germin values are after they are different from the others Alkaloidesters are separated, preferably isolated from the organic solution, for example by Evaporation of the solvent, and then hydrolyzed.

The hydrolysis is preferably carried out using a basic hydrolysis system. So you can 2. B. potassium hydroxide, sodium hydroxide or alkali metal alkoxides, preferably im alcoholic medium, such as in a lower alcohol, e.g. B. methanol, ethanol, propanol, isopropanol, Use butanol, t-butanol, and the like. Water can also be present in the system being. Aqueous potassium hydroxide in methanol is used as the preferred system. The quantities of Respondents are not particularly critical. For economic reasons, however, it is preferred to use an excess of the basic medium.

The hydrolysis time and temperature are somewhat related, with high temperatures the hydrolysis result in a relatively short time, while conversely lower temperatures require somewhat longer reaction times to achieve an essentially complete reaction. The hydrolysis conditions should be such that the formation of isogermin is tolerable Minimum remains. In this regard, the hydrolysis of germin values leads to reflux temperatures in the region of 65 to 70 ° C to substantially complete hydrolysis in 1/2 to about 2 hours.

Not inconsiderable amounts of the germin are produced upon reflux over periods of about 5 hours isomerized to isogermin. It is therefore preferred when working at reflux temperatures, reaction times that are shorter than about 5 hours. Reflux temperatures over a period of time from about 1/2 to 1 hour are suitable and are preferred, although one can if desired even at low temperatures, e.g. B. at 0 ° C, 24 hours can work.

The result of the hydrolysis stage is free germin in solution together with degradation products and other impurities received. The germin is obtained from it by adding the hydrolyzate to the is subjected to the step described below to form a two-phase adduct. According to a preferred Embodiment of the invention, wherein a lower alkanol, in particular methanol in the hydrolysis medium is used, it is therefore preferred to remove substantially all of the methanol, before the hydrolyzate with the halogenated hydrocarbon in the stage of adduct formation treated. The reason for this procedure is probably the effect that the methanol has acts on the solubility of free germin in water. Methanol seems to be the solubility of the Increase germins in water. As a result, the adduct formation takes place when the next step is carried out incomplete removal of germin from the water phase takes place, namely in the Measure of the amount of methanol present. Other alkanols behave similarly. It is therefore preferred so much as possible from the alkanol when using this. The distance is practical of all the alkanol from the system can be

Fan manner can be achieved by evaporating the hydrolyzate to dryness, the amorphous Germin together with the other degradation products of hydrolysis in Fon α of a solid residue remains behind. It is preferred to add an acid to the hydrolyzate prior to evaporation to neutralize. Mineral acids are suitable for this, in particular hydrochloric acid or sulfuric acid. However, any other acid can also be used

The adduct formation step involves the use of a two-phase system of water and an organic substance as a medium for the formation of a solid gennin adduct. That on the above Way obtained amorphous solid hydrolyzate, or a liquid; Hydrolyzate system if no alkanol is used has been, in the presence of water with a liquid, immiscible with water treats halogenated hydrocarbon capable of complexing with germin, preferably in an alkaline medium. When using the solid residue that is preferred water is added from the outside. On the other hand, when the liquid hydrolyzate is used, it is usually enough water already. In either case, enough should be enough for best results Water and sufficient in excess of the amount of hydrocarbon needed to form the solid adduct liquid hydrocarbon may be present to form a two-phase liquid system.

The solid adduct precipitates out of solution, generally at the interface between the The water phase and the water-immiscible hydrocarbon phase. Halogenated hydrocarbons, which are suitable for forming a solid adduct with germin are the halogenated aliphatic Hydrocarbons, preferably the chlorinated and saturated hydrocarbons in particular Methylene chloride, chloroform, carbon tetrachloride, dichloroethane, 1,2-D ^ chloroethane and the same.

According to a preferred embodiment of the invention, the formation of the adduct in the basic Medium made. This causes the solubility of the adduct in the water phase to continue is reduced and leads to a maximum formation of the germin adduct. Practically every base is suitable for this suitable. However, it is preferred to use an alkali metal hydroxide such as sodium or potassium hydroxide to use. Most preferred is sodium hydroxide.

The precipitation of the germin adduct is facilitated at lower temperatures. You can in simpler Way effected by temporarily stirring the mixture and then allowing it to stand will. Temperatures below room temperature are particularly preferred. Temperatures from 0 to 10 ° C are suitable.

The solid adduct is then separated from the two-phase system and the impurities dissolved in it, for example by filtration. The solid adduct can be used to produce the germin diacetate, as described above, can be used as such. However, it is preferred to use the product to be treated in order to obtain free germin from it. This is done by putting the adduct in a suitable solvent, preferably an alcohol such as a lower alkanol, e.g. B. methanol, Ethanol, isopropanol, butanol, t-butanol and the like, solves. The system preferably also contains an acid to dissolve the To support adduct in the alkanol. Suitable acids are mineral acids, glacial acetic acid and the like, acetic acid being preferred. However, practically any acid can be used for this purpose. To the Regeneration of the GermiEj are slightly increased temperatures in the area of 35 to 5U ° C, before-

preferably from 40 to 50 ° C, preferred. The free germin is then known from the solution in Way crystallized. So z. B. the solution using a suitable base, such as ammonia, an alkali metal hydroxide and the like. Neutralized or

X _{5 made} alkaline and left to stand. This creates crystalline germin, which can still be associated with part of the solvent from which it is crystallized. However, as already stated, this does not pose any problems with regard to the subsequent production of the diacetate from the standpoint of purity.

As a result of the above-described process, pure crystalline germin is obtained, namely im generally in yields of about 20 to 50 percent by weight based on the weight of the solid extract from the used as starting material Alkaloid plants. The formation of the germin adduct eliminates all requirements for countercurrent extraction, d. H. Pillars and similar measures.

example

A dry alkaloid extract from Veratrum album (100 g), from which the protoveratrine is previously

removed is dissolved in 250 ml of anhydrous ether and left to stand for one week at room temperature. A solid (7 g) separates out and is filtered off. Its IR spectrum determines that it's Jervin.

The essential mother liquors, which with the exception of the germin values of alkaloid derivatives in the are essentially free, are evaporated to dryness in vacuo and treated with a solution of Treated 30 g of sodium hydroxide in 600 ml of methanol. The solution will reflux moderately for 30 minutes left, cooled for 20 minutes and then slowly neutralized with about 50 ml of concentrated hydrochloric acid, the temperature being kept low by cooling in running water. After 30 minutes If left to stand, a precipitate forms, consisting mainly of sodium chloride. This precipitate is filtered off.

The neutralized hydrolyzate (filtrate) is then placed in a 21 flask and in vacuo Evaporated to dryness to remove virtually all of the methanol present. At this time there is some foaming and pounding. Then 100 ml of water and 150 ml of chloroform added. The aqueous solution is made strongly alkaline with 10% sodium hydroxide solution. The biphasic system is shaken well and left in the refrigerator overnight. At the interface A solid adduct of chloroform and germin forms between the two layers. This precipitation is filtered off, washed well with water and chloroform and dried in a steam oven (Weight: 40 to 50 g). The solid is heated in 300 ml of methanol and about 10 ml

Dissolved glacial acetic acid, filtered off and concentrated the filtered solution to 200 ml. After the solution has been made alkaline with ammonia, it is allowed to cool overnight. Plate-like crystals of germin form in the process. Melting point: 215 to 220 ⁰ C (with decomposition); preliminary sintering: at 160 ° C), optical rotation [«] ₀ = + 5 ° C (C, 2.77) in chloroform. Yield: 21 to 23 g.

After the chloroform-germin adduct has been filtered off, the remaining alkaline substances become Mother liquors extracted with 10 100 ml portions of chloroform. The extracts obtained are combined, washed, dried and in a vacuum to dryness

evaporated (weight: about 5 g). Recrystallization from methanol gives 700 to 800 mg of germine crystals, which soften at 160 ° C and melt at 220 to 224 ° C.

Similar results are obtained when the above procedure is repeated with equivalents Quantities of the following substances are used in place of the reagents listed:

Methylene chloride, carbon tetrachloride or dichloroethane instead of chloroform;

Sodium hydroxide or lithium hydroxide in place of potassium hydroxide;

Ethanol, propanol, isopropanol, butanol or other t-butanol instead of methanol.

Claims (1)

Germine Diaceiate, "New England Journal of Me- Patent claims * cine, 275, 1207 to 1214 (1966) W. Flacke et J-patent claims. , ____.__,. ^ _{that a series of synthetic Ger} . Process for obtaining a germin admine acetate, in particular germin diacetate, for the production of germin values by treating the symptom relief of Myasthema Gravis germin values, which is essentially suitable for proto. Since germin is a starting material veratrine free, after removal of the larger one for the production of germin diacetate, em ώ part of the solvent with a basic, straight economic process for the production of hydrolysis system and treatment of the relatively pure germin obtained is desirable,
The separation and isolation of Gerrn. in a water-immiscible halogenated plant extract containing germin values, the hydrocarbon is characterized by the complex nature of the plant extracts, that before the stage of handling complicated. As noted, with the halogenated hydrocarbon, these typically hold a large majority of substantially all of the lower alkanol x5 of alkaloids, the presence of which removes the separation. and the isolation of a particular one is greatly interfering with. In Veratrum extracts are typically used e.g. B. found the following substances : Jervin, Rubijervin, Veratra- min, esters of protoverine, such as protoveratrine and 20 germin values, such as esters of germin, e.g. B. Germitetrin, Germitrin, Neogermitrin, Germanitrin, Ger-Germin is a highly hydroxylated alkamine, desmerin and much more, as they are z. B. in the sen structure by S. Morris Kupchan and CR publication "Hypotensive Veratrum Ester Al-N araya ι a η in Journal of The American Chemi- kaloids", Journal of Pharmaceutical Science, cal Society, 81, 1913 (1959) described would. Sun- 25 Vo. 50, No. 4, April 1961. As it is currently known that this compound occurs in extracts, the content of germin values is not naturally present in free form. It usually exists in the range from 0.25 to 0.50 weight but in the form of its complex derivatives, of which the ester derivatives are particularly noteworthy, based on the weight of the dried. Made from plant material. Thus, they are a good source of various sources, which are detailed below for the material. The earlier processes for the production of Gerder-like esters have already been isolated. The derimines mentioned saw the use of complex countervates are hydrolyzable and result in free current extraction methods that are very compli-germin. Under the designation used herein, ornate and expensive equipment required. To the- "Germin values" should be understood to mean derivatives of germin that are found in the extracts of various scientific methods for separation and Gewinkaloidplants can be found and available for germination of germin from germin values are hydrolyzable. placed that contained relatively large amounts of germin in In nature, germin values are mainly given in a relatively pure form. found the species of the Veratrum plant species. The subject of the present invention is therefore Within this type are the species Veratrum album, a process for obtaining a germin adduct Veratrum viride, Veratrum eschscholtzii and Vera- from Germin values by treating the Germintrum fimbriatum readily available and especially values that are essentially free of protoveratrine suitable. are, after removing the greater part of the Crude extracts from Veratrum plants were solvent with a basic hydrolyzing system used for medical purposes for many years; and treating the hydrolyzate obtained in Gez. B. for the treatment of high blood pressure, as tonicity of water with one with water not ierungsmittel for the heart and as a counter-irritant, miscible halogenated hydrocarbon that is involved Neuralgia. In the last few years the for- is characterized by that one before the stage of Research work mainly focused on the treatment with the halogenated hydroactive substance Principles determine in the plant and matter essentially all of the lower alkanol the corresponding pharma- removed according to the respective principle. assign an ecological effect. The purification of ^ In "The Veratrine Alkaloids, Paper XVII," Lyman Plant extracts has shown that the extracts in C. C r a i g and Walter .A. Jacobs, Journal of Really very complex mixtures of a variety of 55 Biological Chemistry, 148, pp. 57 to 66, and “The represent number of alkaloids. Further work has Veratrine Alkaloids, Paper XV «, Walter A. J a c ο b s ben shown that the germin esters contained therein and Lyman C. Craig, Journal of Biological Cherelativ good antihypertensive properties bemistry, 148, pp. 41 to 50, a sitting, drive for the production of germin adducts. Earlier work has also shown that 60 wrote, but these known ones differ Veratrum alkaloid extracts for treating methods of the subject matter of the present invention myastenia gravis is of moderate effectiveness. The manure primarily by the fact that the treatment Use of the alkaloids in the treatment of the hydrolyzate in the presence of not neglected However, disease has been severely restricted to detectable levels of a lower alkanol, ζ. Β. from which is likely due to the presence of 65 methanol. So with this one Certain alkaloids in the extracts conditionally process the methanol, which during the hydro-side effects is due. In the publica- tion stage it is present before the addition of the chlorination “Treatment of Myasthenis Gravis With roforms not completely removed, so that merely