Process for isolating galanthamine

The subject matter of the present invention is a process for the Isolation of the Alkaloids Galanthamine, according to this method Produced galanthamine itself, the use of the So prepared galanthamine in galenic preparations, And the thus prepared galanthamine for treatment The narrow angle glaucoma, the Alzheimer 's disease and the Alcohol and nicotine dependence.

Galanthamine (4a, 5,9,10,11,12-hexahydro-3-methoxy-11-methyl-6-H-benzofuro- (3a, 3,2-ef) - (2) -benzazepin-6-ol) Is a tetracyclic Alkaloid, which due to its pharmacological Properties to the group of reversibly acting cholinesterase inhibitors And in its effects the physostigmine And the Neostigmin. It has however Also specific characteristics, such as With morphine comparable strong analgesic effects. As Cholinesterase inhibitor possesses galanthamine because of its im Comparison to physostigmine and neostigmine lower toxicity A therapeutic width of three to six times. This advantage weighs its dose-related somewhat lower Cholinesterase inhibitory activity. Galanthamine is used in poliomyelitis And various disorders of the nervous system , But mainly in the treatment of narrow-angle glaucoma And as an antidote after curare applications. Galanthamine is used for Alzheimer's disease Respectively. Recently, the treatment has also been The alcohol and nicotine dependence described (DE-OS 40 10 079, DE-OS 43 01 782).

Both the therapy of Alzheimer's disease, the alcohol- And nicotine dependency as well as narrow-angle glaucoma Require long-term, adapted to the particular circumstances Pharmaceutical preparations. As such, in the treatment of the Narrow-angle glaucoma. Difficult therapies And duration infusions come for obvious reasons For treating Alzheimer's disease, alcohol- Or nicotine dependence is not a question. In these diseases Is a transdermal therapeutic System (TTS), as described, for example, in DE-OS 43 01 783. Neither the intact skin nor the Cornea of ​​the eye allows a resorption of active substance salts. Galanthamine hydrochloride or galanthamine hydrobromide Can therefore be used in the therapy of narrow-angle glaucoma, the Alzheimer's disease or alcohol or nicotine dependence With ointments or the TTS can not be used. For this reason the pure galanthamine base must be used will.

Due to its complex tetracyclic structure with Three optically active carbon atoms is one Economic synthesis of the galanthamine base is not possible. Galanthamine is therefore usually produced from plants of the Amaryllidaceae, For example from Galanthusarten, such as the Snowdrop or Leucojum aestivum, isolated. These Plants have the advantage of galanthamine in concentrations Of up to 0.3%, at the same time a small proportion of By weight, of secondary alkaloids, so that the process described in DE-PS 11 93 061 Can be found. Both the Galanthusarten and Leucojum Aestivum, however, are protected by nature. Secondly used The extraction process described in DE-PS 11 93 061 Preferably chlorinated hydrocarbons, which Have fallen into disrepute for toxicological reasons. The Western medicines therefore demand the residual Of chlorinated hydrocarbons to <10 ppm. The use of chlorinated hydrocarbons Consequently, in the provision of drugs be avoided. Moreover, in the known method The solvent extract is adsorbed onto aluminum oxide To the separation of the resinous and secondary alkaloids to ensure. From the after filtration of the aluminum oxide The galanthamine is then passed over the Galanthamine hydrobromide, with which associated Disposal of halogenated salts. For use in ointments and The TTS must then also remove the galanthamine base from this Galanthamine hydrobromide.

The object of the present invention is therefore to provide A process for the isolation and purification of galanthamine, Which has the disadvantages of the prior art Method. In particular, the cleaning Be facilitated, the use of chlorinated Hydrocarbons and purification via galanthamine salts be avoided. The object is achieved according to the invention by a Method with the characteristics of claim 1. Preferably Embodiments are characterized in the subclaims.

DETAILED DESCRIPTION OF THE INVENTION Isolation of galanthamine from biological material, the From cultivated Amaryllidaceae or From those which are generally considered to be "weeds" and not Under nature protection, preferably from the onions of this Plants. These amaryllidaceae include For example daffodils or crinum species. Particularly suitable Are Narcissus pseudonarcissus "Carlton" or the Asian climbing plant Crinum amabile. Although this Plants only about one-tenth the amount of galanthamine Protected plants and beyond Contain up to twelve secondary alkaloids, surprisingly succeeds With the process according to the invention The galanthamine base in pharmaceutically acceptable grade To isolate.

According to the invention, galanthamine-containing biological A material which is preferably comminuted and mixed with alkali metal powders, Preferably with sodium hydroxide biscuits, soda, potash Or similar salts which are suitable for preparing bases of biological Material and for the presentation of pharmacological Active substances are mixed, with toxicological Harmless organic solvents And the galanthamine from this extract by liquid / liquid Extraction. Really important For the success of the method according to the invention is compliance Of the pH in the first stage of liquid / liquid extraction. The liquid / liquid extraction is performed In a first stage at a pH of about 4 and in A second stage at a pH of about 9. To adjust the pH, nebem can be concentrated Ammonia also uses soda solution or another base will. As toxicologically safe organic Solvent, diethyl ether or special benzine is used. Special benzine is preferably used since So that a certain preliminary purification can already be achieved. The Solvent is removed, the galanthamine is removed from a suitable Solvent, preferably recrystallized from isopropanol. The white galanthamine base is obtained with one Melting point of 129 to 130 ° C. The purity of the thus obtained Galanthamine is shown in HPLC chromatogram (FIG. 2).

This result is all the more astonishing, as is the case so far Are used in the process described in DE-PS No. 11 93 061 for insulation Of galanthamine from biological material, the little galanthamine And up to 12 secondary alkaloids is considered unsuitable Exposed. With the method described in DE-PS 11 93 061 A non-breaking emulsion is formed, So that extraction is not possible. One easy Modified process resulted in an oily residue, According to the HPLC chromatogram, by at least four substances Is contaminated (Fig.1).

It must therefore be regarded as extremely surprising, That from biological material, the little galanthamine In addition to a large number of secondary alkaloids, With the aid of the simple method according to the invention Free galanthamine base in pure form and in good yield Without an additional adsorption step Alumina is required.

The galanthamine base produced according to the invention is suitable for the Treatment of narrow-angle glaucoma, for the treatment of Alzheimer's Illness or alcohol and nicotine dependency Can be used. The galanthamine base produced according to the invention Can also be used in galenic preparations, such as For example, in eye sockets or transdermal therapeutic agents Systems which are also used for treatment Of the abovementioned diseases can.

The following examples are intended to illustrate the invention, Without limiting them:

<u>Example 1 (Comparison</u>):

Analogously to the process described in DE-PS 11 93 061 10 kg air - dried, crushed onions of Narcissus pseudonarcissus "Carlton" carefully with 2.5 l of one 8% strength aqueous ammonia solution. The material Swells; The entire approach gelatinized. The for extraction Provided addition of 23 l of dichloroethane leads to a Emulsion which can not be broken.

<u>Example 2 (comparison):</u>

The methods of isolation known in the art Of galanthamine (DE-PS 11 93 061) has been modified. 10 kg Air-dried, crushed onions from Narcissus pseudonarcissus "Carlton" is carefully mixed with 400 g of sodium carbonate mixed. 23 l of dichloroethane are then added. The mixture is allowed to stand for 10 hours; Then the Solvent. The onions are washed again 23 l of dichloroethane, which was poured off after 2 to 3 hours becomes. Subsequently, the onions become a third Sometimes 17 l of dichloroethane are added, but this is directly Is poured out again. The combined dichloroethane extracts Are extracted by means of 10% sulfuric acid (2 × each 600 ml; 2 x 300 ml each). The acidic extracts are combined And by shaking with diethyl ether from the traces of Dichloroethane. Thereafter, with stirring and cooling To 15 to 20 ° C about 200 ml of 25% aqueous Ammonia solution to the alkaline lacquer reaction. The pH is from 7 to 8. Unlike in the prior art The secondary alkaloids are not excluded. The alkaline Solution is saturated with saline and with Diethyl ether. After evaporation of the ether, Unlike the prior art, is negligible Small residue left. Through saturation with The pH of the aqueous phase is adjusted to about 14 . The aqueous phase is washed several times with Diethyl ether. The combined ether extracts are Evaporated to dryness, the remaining Galanthamine-containing residue in acetone (50 ml). Different As indicated in the prior art, does not form Precipitation. Add 350 ml of acetone, add 200 g of alumina And stirred for 45 minutes. The alumina Is filtered off and washed twice with 100 ml of acetone each time. The combined acetone solutions are evaporated to dryness. 1.3 g of an oily residue are obtained Help of the HPLC is examined. The chromatogram is shown in FIG 1. The main peak, the galanthamine, is Respectively. It is clear that this is due to this Galanthamine isolated by at least four substances Is contaminated.

<u>Example 3:</u>

100 kg air-dried, crushed onions from Narcissus Pseudonarcissus "Carlton" are treated with 4 kg of sodium carbonate Carefully mixed. The mixture is equal in three Parts are divided and poured with 15 l of special gasoline 80/110 each. The mixture is allowed to stand for 24 hours. The solvents are used in each case Twice renewed, collected and in a weak vacuum to the Dry constriction. The extracts are dissolved in 2% strength aqueous Sulfuric acid and treated with concentrated aqueous Ammonia solution to a pH of 4. Subsequently Is extracted five times with diethyl ether. The Aqueous phase is adjusted to pH with concentrated ammonia Of 9 and extracted five times with diethyl ether. These ether fractions are collected, with sodium sulfate Dried and concentrated. There are 20 g of a Slightly yellowish oily residue, which is obtained from Hot isopropanol. This gives 10 g White galanthamine base having a melting point of 129 - 130 ° C. In the HPLC chromatogram, only a peak is too high (Fig.2).