DE102006019861A1 - Preparing extract from Ginkgo biloba having reduced content of 4'-O-methyl pyridoxine and/or biflavones for treating e.g. dementia involves preparing Ginkgo extract solution; applying solution to adsorber resin or an acidic ion exchanger - Google Patents

Abstract

Preparing an extract from Ginkgo biloba having a reduced content of 4'-O-methyl pyridoxine and/or biflavones involves (a) preparing a Ginkgo extract solution in a solvent; (b) applying the solution to an adsorber resin and eluting the purified extract from the adsorber resin; and/or (c) applying the solution to an acidic ion exchanger and eluting the purified extract from the ion exchanger; and optionally (d) concentrating and drying the extract solution to the dry extract, where steps (b) and (c) can be carried out in reverse order. Preparing an extract from Ginkgo biloba having a reduced content of 4'-O-methyl pyridoxine and/or biflavones compared to the original extract involves: (a) preparing a Ginkgo extract solution in a solvent; (b) applying the solution to an adsorber resin and eluting the purified extract from the adsorber resin using a solvent, where the biflavones remain on the adsorber resin; and/or (c) applying the solution to an acidic ion exchanger and eluting the purified extract from the ion exchanger using a solvent, where the 4'-O-methyl pyridoxine remains on the ion exchanger; and (d) optionally concentrating and drying the extract solution to the dry extract, where steps (b) and (c) can be carried out in reverse order. An independent claim is included for the extract from Ginkgo biloba having a reduced content of 4'-O-methyl pyridoxine and/or biflavones compared to the original extract. ACTIVITY : Nootropic. MECHANISM OF ACTION : None given.

Description

• (a) Herstellung einer Ginkgoextrakt-Lösung in einem geeigneten Lösungsmittel, sowie
• (b) Aufbringen der Lösung auf ein Adsorberharz und Elution des gereinigten Extrakts mit einem geeigneten Lösungsmittel vom Adsorberharz, wobei die zu beseitigenden Biflavone auf dem Adsorberharz verbleiben, und/oder
• (c) Aufbringen der Lösung auf einen sauren lonenaustauscher und Elution des gereinigten Extrakts mit einem geeigneten Lösungsmittel vom lonenaustauscher, wobei das zu beseitigende 4'-O-Methylpyridoxin auf dem lonenaustauscher verbleibt, und gegebenenfalls
• (d) Einengen und Trocknen der Extraktlösung zum Trockenextrakt, wobei die Schritte (b) und (c) auch in umgekehrter Reihenfolge durchgeführt werden können.

The present invention relates to a process for the preparation of an extract from Ginkgo biloba with a reduced content of 4'-O-methylpyridoxine and / or biflavones compared to the starting extract, characterized by the following process steps:

• (a) Preparation of a ginkgo extract solution in a suitable solvent, as well
• (b) applying the solution to an adsorbent resin and eluting the purified extract with a suitable solvent from the adsorbent resin, leaving the biflavones to be removed on the adsorbent resin, and / or
• (c) applying the solution to an acidic ion exchanger and eluting the purified extract with a suitable solvent from the ion exchanger, leaving the 4'-O-methylpyridoxine to be removed on the ion exchanger, and optionally
• (D) concentration and drying of the extract solution to the dry extract, wherein the steps (b) and (c) can also be carried out in the reverse order.

The The invention further relates to extracts of Ginkgo biloba with respect to Initial extract reduced content of 4'-O-methylpyridoxine and / or biflavones, available according to the inventive method as well as their use.

extracts from the leaves Ginkgo biloba has been used as a medicine for decades. Currently, they are used to treat various types of dementia and their symptoms as well as cerebral and peripheral circulatory disorders. Ingredients with which the effectiveness is linked are terpene lactones (Ginkgolide A, B, C and bilobalide) as well as glycosides of flavones (Quercetin, Kämpferol and Isorhamnetin). The leaves But Ginkgo biloba also contains components that are not desired efficacy contribute, but for Risks and side effects may be responsible. In addition to non-polar plant ingredients such as Ginkgolic acids these are 4'-O-methylpyridoxine and biflavones. In an effective and at the same time as possible safe and low-side-effect ginkgo extract should be the substances mentioned as possible largely missing.

Biflavone:

• Amentoflavon: R¹ = R² = R³ = H
• Bilobetin: R¹ = R³ = H, R² = OCH₃
• Ginkgetin: R³ = H, R¹ = R² = OCH₃
• Isoginkgetin: R¹ = H, R² = R³ = OCH₃
• Sciadopitysin: R¹ = R² = R³ = OCH₃

4'-O-methylpyridoxine can cause symptoms of intoxication such as seizures and unconsciousness, which is why this compound is also referred to as ginkgotoxin. The biflavones contained in Ginkgo have immunotoxic potential and can trigger contact allergies. The biflavones contained in Ginkgo are predominantly the compounds amentoflavone, bilobetin, ginkgetin, isoginkgetin and sciadopitysine. 4'-O-methyl:

biflavones:

• Amentoflavone: R ¹ = R ² = R ³ = H
• Bilobetin: R ¹ = R ³ = H, R ² = OCH ₃
• Ginkgetine: R ³ = H, R ¹ = R ² = OCH ₃
• Isoginkgetine: R ¹ = H, R ² = R ³ = OCH ₃
• Sciadopitysine: R ¹ = R ² = R ³ = OCH ₃

In the EP 1037646 B1 Already described methods for the depletion of 4'-O-methylpyridoxine and biflavones and the extracts obtained. The 4'-O-methylpyridoxine is retained with an acidic cation exchanger and the biflavones are adsorbed on activated carbon. These depletion steps are preferably carried out after stage f) of the process of EP 1037646 B1 (Page 3), ie after "treating the solution with a lead compound or an insoluble polyamide".

In the EP 1037646 B1 the depletion of the biflavones and of 4'-O-methylpyridoxine is carried out at a point in the process (step f)), at which relatively high levels of lead and ammonium salts are present, so that an increased amount of ion exchanger must be used.

This Restricted procedure but a complex sequence of several processing steps.

Also become the depletions of biflavones and 4'-O-methylpyridoxine described and claimed only in combination with each other. Dependent on of possibly future limits and against the background of the requirement one possible small change the extract composition could but it is desirable be to remove only the biflavones or the 4'-O-methylpyridoxine.

Furthermore the depletion is only with a single ion exchanger (Merck I) in the case of 4'-O-methylpyridoxine and a single adsorbent (activated carbon) in the case of biflavones described. The activated carbon has the disadvantage, typically not very selective to bind and not be regenerated.

task Thus, the present invention is a process for the preparation of ginkgo extracts in which 4'-O-methylpyridoxine and / or biflavones across from the original extract largely possible be depleted and that about it In addition, simple and inexpensive carried out can be. The invention also relates to ginkgo extracts, available by this method are.

The This problem has been solved By separating the biflavones by adsorber resins and / or that of 4'-O-methylpyridoxine via acid Ion exchanger takes place.

• (a) Herstellung einer Ginkgoextrakt-Lösung in einem geeigneten Lösungsmittel, sowie
• (b) Aufbringen der Lösung auf ein Adsorberharz und Elution des gereinigten Extrakts mit einem geeigneten Lösungsmittel vom Adsorberharz, wobei die zu beseitigenden Biflavone auf dem Adsorberharz verbleiben und mit organischen Lösungsmitteln wie z. B. Aceton vom Harz eluiert werden können, so dass dieses erneut eingesetzt werden kann, und/oder
• (c) Aufbringen der Lösung auf einen sauren lonenaustauscher und Elution des gereinigten Extrakts mit einem geeigneten Lösungsmittel vom lonenaustauscher, wobei das zu beseitigende 4'-O-Methylpyridoxin auf dem lonenaustauscher verbleibt und mit einer Säure wie z. B. wässriger Salzsäure vom lonenaustauscher gewaschen werden kann, so dass dieser erneut eingesetzt werden kann, und gegebenenfalls
• (d) Einengen und Trocknen der Extraktlösung zum Trockenextrakt, wobei die Schritte (b) und (c) auch in umgekehrter Reihenfolge durchgeführt werden können.

In the method according to the invention, the following method steps are carried out:

• (a) Preparation of a ginkgo extract solution in a suitable solvent, as well
• (B) applying the solution to an adsorber resin and elution of the purified extract with a suitable solvent from the adsorbent resin, wherein the biflavones to be removed remain on the adsorbent resin and with organic solvents such. As acetone can be eluted from the resin, so that it can be used again, and / or
• (c) applying the solution to an acidic ion exchanger and eluting the purified extract with a suitable solvent from the ion exchanger, leaving the 4'-O-methylpyridoxine to be removed on the ion exchanger and mixing with an acid such as e.g. B. aqueous hydrochloric acid can be washed by the ion exchanger, so that it can be used again, and optionally
• (D) concentration and drying of the extract solution to the dry extract, wherein the steps (b) and (c) can also be carried out in the reverse order.

Particularly suitable solvents in steps (a), (b) and (c) are, independently of one another, aqueous C ₃ -C ₆ ketones (eg acetone, 2-butanone) and C ₁ -C ₃ alkanols (methanol, ethanol, n-propanol and isopropanol), preferably aqueous acetone and ethanol, preferably at a concentration of 30 to 70% by weight. Preferred adsorbent resins in (b) are resins based on optionally substituted styrene / divinylbenzene base such as. Diaion HP-20, HP-21 or Sepabeads SP-207 and SP-850. Particularly preferred adsorbent resins are copolymers based on styrene or brominated styrene and divinylbenzene. Preferred ion exchangers in (c) are strongly acidic ion exchangers such. Merck I or Amberlite IR-120.

Out the starting solution (Ginkgo extract solution according to step (a)) becomes the starting extract used for baseline determination obtained by drying to dry extract.

at the method according to the invention in step (b), the amount of resin used and polarity or composition of the solvent used to coordinate each other so that the desired extract constituents first as possible Completely eluted from the resin while the biflavones remain on the resin. This results in a higher content of water in the solvent to a better depletion of the biflavones, i. to their whereabouts on the resin. Depending on solubility of the extract, the water content of the solvent is in the above specified range of 30 to 70 wt .-%.

• • Einfachextrakte, hergestellt nach bekannten Verfahren z. B. gemäß Europäischem Arzneibuch durch Extraktion von getrockneten Blättern von Ginkgo biloba mit organischen Lösungsmitteln oder deren Gemischen mit Wasser, z. B. mit Ethanol/Wasser- oder Aceton/Wasser-Gemischen oder
• • Extrakte, deren Zusammensetzung durch die zusätzliche Durchführung von einem oder mehreren Verfahrensschritten mehr oder weniger stark vom zugrunde liegenden Einfachextrakt abweichen (sogenannte Spezialextrakte).

As starting extracts (in the form of or obtained from ginkgo extract solutions according to step (a)), which are to be liberated via the adsorbent resin of 4'-O-methylpyridoxine and / or biflavones, come into question

• • Simple extracts, prepared by known methods z. B. according to European Pharmacopoeia by extraction of dried leaves of Ginkgo biloba with organic solvents or mixtures thereof with water, eg. As with ethanol / water or acetone / water mixtures or
• • Extracts whose composition deviates more or less from the basic simple extract by the additional performance of one or more process steps (so-called special extracts).

The latter extracts can be obtained, for example, by a liquid-liquid distribution according to the EP 360556 B1 or through some steps of the EP 431535 B1 such as The steps (a) to (c) or by the complete process of EP 431535 B1 or the US 6117431 be prepared.

The Ginkgo extract solutions according to step (a) can either directly from the extract manufacturing process or through Dissolve a dry extract or other extract.

object The invention further extracts, especially dry extracts, those according to the inventive method available are and through one opposite the starting extracts used reduced content of 4'-O-methylpyridoxine and / or biflavones. The contents of 4'-O-methylpyridoxine are the extracts of the invention at a maximum of 20 ppm, preferably at most 10 ppm and in particular maximum 5 ppm. The contents of biflavones are at most 25%, preferably at most 11% and in particular at most 6% of the initial value of the starting extract.

dry extracts have according to the European Pharmacopoeia generally a dry residue of at least 95% by weight.

The extracts according to the invention can in the form of powders, granules, tablets, dragees or capsules preferably be administered orally. For the production of tablets The extract is made with suitable pharmaceutically acceptable Auxiliaries such. Lactose, cellulose, silica, croscarmellose and magnesium stearate and pressed into tablets, optionally with a suitable coating z. B. from hydroxymethylcellulose, polyethylene glycol, dyes (eg, titanium dioxide, iron oxide) and talc. The extract according to the invention can also, optionally with the addition of excipients such. Stabilizers, fillers etc., filled in capsules become. The dosage is done so that per day 10 to 2000 mg, preferably 50 to 1000 mg and more preferably 100 to 500 mg extract become.

object The invention is above In addition, medicinal products, foodstuffs and other preparations containing these extracts, possibly in combination with other substances, such as. B. active ingredients and / or excipients. Are under food here especially dietary Food, nutritional supplements as well as "medical food "and" dietary supplements " understand.

Starting solution for comparative example 1 and the examples according to the invention 1 to 3

200 g dried and ground leaves of Ginkgo biloba were at a temperature of about 50 ° C twice each with 7 times the amount (w / w) of ethanol / water 60/40 (w / w) extracted and filtered.

Comparative Example 1 (preparation Simple extract as starting extract)

25% of the above starting solution was concentrated under reduced pressure and freeze-dried Dries: 14.0 g (28.0% based on the dried leaves).

Inventive example 1 (removal of biflavones)

25% the above starting solution were on a pillar with 100 ml Sepabeads SP-850 Added adsorbent resin and eluted with 300 ml of 40 wt .-% ethanol. The Eluate was concentrated under reduced pressure and freeze-dried: 11.5 g (23.0 based on the dried leaves).

Inventive example 2 (removal of 4'-O-methylpyridoxine)

25% the above starting solution were on a pillar with 20 ml of strongly acidic ion exchanger Amberlite IR-120 given and eluted with 60 ml of 60% by weight ethanol. The eluate was concentrated under reduced pressure Pressure concentrated and freeze-dried: 13.0 g (26.0% relative on the dried leaves).

Inventive example 3 (elimination of biflavones and 4'-O-methylpyridoxine)

25% the above starting solution were on a first pillar with 100 ml of Sepabeads SP-850 adsorbent resin and with 300 ml 40 wt .-% ethanol eluted. The eluate was on a second column with 20 ml of strongly acidic ion exchanger Amberlite IR-120 given and eluted with 100 ml 40 wt .-% ethanol. The resulting solution was concentrated under reduced pressure and freeze-dried: 10.1 g (20.2% based on the dried leaves).

Starting solution for comparative example 2 and the examples of the invention 4 to 6

200 g dried and ground leaves of Ginkgo biloba were at a temperature of about 50 ° C twice each with 7 times the amount (w / w) of ethanol / water 60/40 (w / w) extracted and filtered. The extract solution was largely concentrated (145 g), diluted with water to about 400 g and stored for about 19 h at 10 ° C. The resulting precipitate was filtered off.

Comparative Example 2 (Production Special extract as starting extract)

25% the above starting solution were concentrated under reduced pressure and freeze-dried: 9.4 g (18.8% relative to the dried leaves).

Inventive example 4 (removal of biflavones)

25% the above starting solution were on a pillar with 50 ml Sepabeads SP-207 Added adsorbent resin and eluted with 150 ml of 40 wt .-% ethanol. The Eluate was concentrated under reduced pressure and freeze-dried: 9.4 g (18.8% relative to the dried leaves).

Inventive example 5 (removal of 4'-O-methylpyridoxine)

25% the above starting solution were on a pillar with 20 ml of strongly acidic ion exchanger Amberlite IR-120 given and eluted with 100 ml of 40% by weight ethanol. The eluate was under concentrated and freeze-dried: 8.7 g (17.4% relative to the dried leaves).

Inventive example 6 (elimination of biflavones and 4'-O-methylpyridoxine)

25% the above starting solution were on a first pillar with 50 ml Sepabeads SP-207 adsorbent resin and with 150 ml 40 Wt .-% ethanol eluted. The eluate was on a second column with 20 ml of strongly acidic ion exchanger Amberlite IR-120 added and with 100 ml 40 wt .-% Ethanol eluted. The resulting solution was concentrated under reduced pressure Pressure concentrated and freeze-dried: 8.3 g (16.6% relative on the dried leaves).

The Contents of the resulting extracts of biflavones and 4'-O-methylpyridoxine are shown in the following table. One recognizes that the sum the biflavones in the inventive examples 1, 3, 4 and 6 is significantly lower than in the associated comparative examples 1 or 2. Analogously, the contents of 4'-O-methylpyridoxine in the inventive examples 2, 3, 5 and 6 opposite the associated Comparative Examples 1 and 2 significantly reduced.

Table 1: Composition of the extracts according to the above examples

Continuation Table 1:

Claims (17)

Process for the preparation of an extract Ginkgo biloba with opposite the starting extract reduced content of 4'-O-methylpyridoxine and / or biflavones, characterized by the following process steps: (a) Preparation a ginkgo extract solution in a solvent, such as (b) applying the solution on an adsorbent resin and elution of the purified extract with a Solvent from Adsorber resin, wherein the biflavones to be removed on the adsorber resin remain, and / or (c) applying the solution to an acidic ion exchanger and elution of the purified extract with a solvent from the ion exchanger, wherein the to be eliminated 4'-O-methylpyridoxine remains on the ion exchanger, and optionally (D) Concentrating and drying the extract solution to the dry extract, wherein Steps (b) and (c) are also performed in reverse order can. The method of claim 1, wherein the solvent in steps a), b) and c) is independently selected from an aqueous C ₁ -C ₃ alkanol and C ₃ -C ₆ ketone. Process according to claim 2, wherein the alkanol is methanol, Ethanol, n-propanol or isopropanol and the ketone is acetone. A method according to claim 2 or 3, wherein the water content is in a range of 30 to 70 wt .-%. Method according to one of claims 2 to 4, wherein the water content of the solvent in steps (a), (b) and (c) is the same or different. A method according to any one of claims 1 to 5, wherein the adsorbent resin is a copolymer based on styrene and divinylbenzene. A method according to any one of claims 1 to 5, wherein the adsorbent resin a copolymer based on brominated styrene and divinylbenzene is. A process according to any one of claims 1 to 5, wherein the ion exchanger a strongly acidic ion exchanger. Extract of Ginkgo biloba with respect to the Initial extract reduced content of 4'-O-methylpyridoxine and / or biflavones, available according to the method according to one the claims 1 to B. Extract according to claim 9, wherein the content of 4'-O-methylpyridoxine at a maximum of 20 ppm. Extract according to claim 9, wherein the content of 4'-O-methylpyridoxine at a maximum of 10 ppm. Extract according to claim 9, wherein the content of 4'-O-methylpyridoxine at a maximum of 5 ppm. Extract according to any one of claims 9 to 12, wherein the content on biflavones at a maximum of 25% of the starting value of the starting extract lies. Extract according to any one of claims 9 to 12, wherein the content on biflavones at a maximum of 11% of the initial value of the starting extract lies. Extract according to any one of claims 9 to 12, wherein the content on biflavones at a maximum of 6% of the starting value of the starting extract lies. Use of the extract according to any one of claims 9 to 15 for the manufacture of a medicament, food or a other preparation for the treatment of dementia and its symptoms and / or cerebral and peripheral circulatory disorders. Medicinal product, food or other preparation, characterized by a content of a Ginkgo extract according to a the claims 9 to 15.