FI104902B - Procedure for collecting Sennosides A, B and A1 - Google Patents

Abstract

The invention concerns a method of extracting sennosides A, B and A1. The method comprises the following steps: a sennoside mixture is reduced to the corresponding anthrone-8-glucosides, the aloe-emodin components are removed by liquid-liquid separation of the anthrone-8-glucosides, and the rheine-9-anthrone-8-glucoside obtained after the separation step is oxidized again to sennosides A, B and A1. The invention also concerns sennosides A, B and A1 obtained by this method and pharmaceutical agents containing them.

Description

104902

A method for recovering sennosides A, B and A1. - Förfarande för tillvara-tagande av sennosider A, B and A1.

The invention relates to a method for extracting the senescent A, B and A1, which are substantially free of the senescent bonds C, D and D1 and the aloe-emodine components.

Sennosides are laxative active substances found in the dried herbs of the genera Cassia and Rheum. Sennaceae consists of dried leaves and shoots (Schoten) of the Sennaceae plant, for example the Indian Senna (Cassia acutifolia).

10

The laxatively active sennosides are dianthrone glucosides derived from rhein and aloe-emodine. The most important are the sennosides A, B, A1, C, D and D1. They correspond to the formula:

° · Η „06-0 O OH

15 ι <ϊιΓ „ιΓί ΟφίΤ

20 ο, η ,, ο, - O o ÖH

In the sennosides A, B and A1, the group R is COOH and in the sennosides C, D and D1 the group R is CH 2 OH. Sennosides A, B and A1 or C, D and D1 are stereoisomers and differ in configuration at C atoms 10 and 10 '.

25

In addition to sennosides, crude feed also includes aglycones (sennidines), semi-glycosylated sennidines, polymers, degradation products of sennosides, aloe-emodine and its derivatives, and the like, which can cause unwanted side effects such as nausea, vomiting, vomiting.

30

Methods for extracting sennosides from sennacea are described, for example, in DE-B1617667, FR-M6611, GB-A832017 and DE-A3200131. The sennosides extracted by these methods contain, according to the particular herb, a mixture of sennosides, 2,104,902, containing 1.5 to 5% of sennosides C, D and D1. As stated above, these contain in their molecule the aloe-emodine of the formula:

HO o OH

5 υόόι

Y CH 3 OH

O

derived part. It would be desirable to be able to recover sennosides which are substantially free of sennosides C, D and D1.

10

Substantial complete separation of the sennosides C, D and D1 from the sennoside mixture is not known in the art.

It is therefore an object of the invention to provide a way to extract the sennosides 15A, B and A1 which are substantially free of unwanted accompanying substances, in particular the sennosides C, D and D1.

This object is solved by the process of the invention, characterized in that A) the senenoside mixture is subjected to reduction to a rheine-9-anthrone-8-glucoside, B) a liquid / liquid partitioning of the obtained compounds between a partially miscible, polar organic solvent and an aqueous phase , and after partitioning C), the reine-9-anthrone-8-glucoside in the aqueous phase is oxidized to the sennosides A, B and A1 and these are recovered.

: Step A

30

Generally, the starting material for the process of the invention is the sennoside mixture as it occurs when extracting the sennar grass according to the above methods. Useful starting materials are, for example, a sennocidal mixture obtained as described in DE-A3200131. According to this 3 104902, the sennaro herb is first extracted with aqueous methanol. After complete removal of the methanol, the remaining concentrate contains the sennosides in the form of the potassium salt. This concentrate can be used as a starting material for the process of the invention.

5

The concentrate can be further purified by liquid / liquid extraction with water, in part, with soluble alcohols or ketones (e.g., 2-butanol, 2-butanone, acetone) (raffinate). The raffinate is acidified to a pH of about 1.5 to 2.0 and the sennosides are crystallized with seed crystals. The resulting crude posture mixture is likewise useful as starting material for the process of the invention. If desired, the crude positional mixture may be further recrystallized.

Alternatively, the starting material may be a concentrate to which has been added with water a portion of the soluble alcohol or ketone, in particular 2-butanol.

15

The ratio of the herb to the extraction solvent is preferably from 1: 4 to 1:15, in particular from 1: 4 to 1:10, for the extraction of senna.

The extraction is preferably carried out in the presence of a buffer, for example trisodium citrate, glycine, sodium carbonate or sucrose.

In accordance with the process of the invention, these starting materials are subjected to complete reduction to the corresponding reine-9-anthrone-8-glucoside (R = COOH) and the corresponding aloe-emodine-9-anthrone-8-glucoside (R = CH 2 OH). : c6Hii ° * ~

Reducing reagents with suitable reduction potential include tin (II) chloride, sulfur dioxide, alkali metal boron hydrogen, and preferably alkali metal dithionite, especially sodium dithionite.

30th 104902 The starting material may be in an aqueous solution or suspension for the purpose of reduction, and the reducing agent is added in solid form or dissolved in water. It is also possible, in particular with the use of the senna fruit primer extract, to operate in accordance with DE-A3200131 (= aqueous concentrate) 5 in a 2-phase mixture with the addition of a water-miscible polar organic solvent, especially 2-butanol or acetone.

Can be reduced at ambient temperature or higher. The reduction is conveniently carried out at 40-60 ° C, in particular at 10-50 ° C. The mild acidic to mildly alkaline pH, preferably pH 5-10.5, is employed in the solution or suspension of the parent stock solution. If desired, the reduction may be carried out several times, particularly 2 to 10 times.

The resulting d-anthron-8-glucosides are precipitated by adjusting the acid, for example sulfuric acid, to an acidic pH of about 2 to 4.5. In this case, the temperature should conveniently not exceed 40 ° C. Conveniently, the precipitation of the anthrone glucosides and their isolation (e.g., by filtration) is carried out under nitrogen to avoid uncontrolled oxidation of these compounds.

20

It is essential that the reduction proceeds completely. Therefore, a large excess of the reduction reagent is expediently used. Dithionites, in particular sodium dithionite, are generally used in amounts of 1 to 4 times by weight, based on the concentration of the parent material sennosides. Further, the reduction reagent is administered for at least 2 hours, preferably at least 3 hours. Generally, the reduction does not last longer than 10 hours. Preferably, the subsequent reduction is carried out under said conditions.

! Preferably, the resulting product is precipitated prior to use in Step B, where it is dissolved in an aqueous solution by addition of a base (NaOH, KOH) to a pH of about 6-7, the aqueous solution is extracted with 2-butanol, 2-butanone or acetone, by adding acid to an acidic pH of about 2 to 4.

5, 104902

Step B

At this point, the aloe-emodine components, in particular aloe-emodine-9-anthrone-8-glucoside, are removed. To this end, a liquid / liquid partitioning of the resultant product 5 between a partially miscible polar organic solvent and the aqueous phase is carried out. Suitable polar organic solvents include C 1-4 alkanols and di-C 1-4 alkyl ketones such as 1-butanol, 2-butanol, 2-butanone and acetone.

Preferably, a reducing agent is added to the aqueous phase to provide the aqueous phase with an oxidation / reduction potential of -210 mV or more throughout the liquid / liquid distribution. Conveniently, the same reducing agent as in step A is employed. When using the alkali metal dithionite as the reducing agent, a 2-4 wt% solution at pH 7-10.5 is generally sufficient to maintain said potential conditions.

The volume ratio of the aqueous phase (heavy phase) to the organic phase (light phase) is generally in the range of 1: 5 to 1:40.

The liquid / liquid extraction preferably takes place in the countercurrent. The mixture of anthrone compounds is then added in the form of a solution after reduction, or, if the anthron compounds are isolated, in the form of a 3 to 15% by weight solution.

•

After partitioning, the desired reine-9-anthron-8-glucoside is in the aqueous phase. It is precipitated by adjusting the acid to pH 2-4 and recovered in the usual manner.

Step C

At this point, the reine-9-anthrone-8-glucoside is again oxidized to the corresponding sennoside compounds. Suitable oxidizing reagents for this purpose are hydrogen peroxide, manganese dioxide, permanganate, manganese (II) acetonyl acetonate.

6 104902

Preferably, however, the oxidation is carried out with oxygen. The oxygen source can be air, for example.

Because reine-9-anthrone-8-glucoside is insoluble in water, it is converted to a soluble form for oxidation. This is effected, for example, by altering the appropriate base by adding to a pH of about 6-7 an alkali metal salt or a calcium salt. If desired, a small amount (about 30% v / v) of a solvent that is miscible with water, especially 2-butanol, may be added to the solution.

10

The oxidation is carried out in a solution as concentrated as possible, since the formation of the desired sennosides is favored in this way. Conveniently, the oxidation is carried out with a solution containing about 250-300 g of reine-9-anthrone-8-glucoside per liter of solvent. When used as an oxidizing agent, oxygen is conveniently passed through the solution.

Oxidation with oxygen can be facilitated by a catalyst. Suitable catalysts are, for example, palladium black or iron (III) salts, in particular iron (III) chloride. The amount of catalyst is generally in the range of 0.2 to 2% by weight based on the amount of rhein-9-anthron-8-20 glucoside, and in particular in the range of 0.5 to 1% by weight.

Alternatively, the oxidation may be carried out with iron (III) salts, for example: Fe 2 (SO 4) 3 or FeCl 3 at a pH of 8 to 8.5. This is suitably carried out at 30-50 ° C and in the presence of trisodium citrate.

25

The oxidation is carried out for so long that the rhein-9-anthron-8-glucoside can no longer be detected. (Absence of UV fluorescence of anthrone compounds).

The sennosides are recovered by adjusting the solution to an acidic pH in the usual manner. Suitably, the solution is diluted to 2-3 times the volume prior to addition of the acid as the solvent used (e.g., water / 2-butanol). In this way, the by-product reine-8-glucoside is largely retained in solution when precipitated by the sennosides.

7 104902

Separation of reine-8-glucoside can also occur via the calcium salt, since the calcium salt of the reine-8-glucoside is insoluble and precipitates, while the calcium salt of the sennosides remains in solution.

Sennosides are compounded by adjusting the acid to an acidic pH of about 2 to 4, and then recovering in the usual manner.

Sennosides A, B, and A1 are generally concerned.

They are substantially free of sennosides C, D and D1 and other aloe-emodin-10 impurities. The concentration of cennosides C, D and D1 in the product obtained according to the invention is less than 100 ppm (as determined by the analytical methods mentioned in the examples).

The field of application, the dose to be administered, and suitable dosage forms are already known from the aforementioned publications.

The following examples illustrate the invention.

EXAMPLE 1 20 Recovery of Sennocidal Mixture as a Starting Material: Add 40 kg of Sennacht each to two parallel-mounted percolators with a volume of 250 L and cover with a teared steel plate.

25

The extraction solvent used is 70% methanol, which is passed to the drug in the first percolator. The solution formed in the first percolator is led to a drug in the second percolator. The solvent is then allowed to flow freely through the first percolator.

A total of 160 l of solvent is used for extraction of 40 kg of henna grass. After passing this volume of 70% methanol through both percolators and collecting the same amount of percolate, the percolator drain hose is connected to a post-percolate vessel, and another 60,170% of 8,104,902 methanol is passed through the percolators. Thereafter, the remaining free solvent from the first percolator is introduced into the top of the second percolator and collected after the percolate to a total of 120 l. to cover the herb in the percolator. Next, the temperature of the solution is adjusted to 30 ° C. After that, allow to stand overnight.

This percolate is combined with the previously extracted, and the extraction is performed as described above.

For each 40 kg of grass a 160 L percolate is collected, from which methanol is removed by means of a vacuum rotary evaporator equipped with a filler column. About 30 l of base product are obtained.

This concentrate is extracted with an equal volume of 2-butanol saturated with water. The phases are separated and the aqueous phase is further treated.

Step A: Reduction of Sennosides to Rhein-9-Anthron-8 Alucosides 1.0 L of extracted concentrate is adjusted to pH 7.5 with 48% sodium hydroxide solution.

·. Heat to 60 ° C, and the solution is added with stirring during half an hour 90 g of sodium dithionite in solid form. After completion of the addition, stir for an additional hour. Next, concentrated sulfuric acid is added to pH 2 with stirring. The mixture is cooled to room temperature over two hours, the precipitated crystalline precipitate is filtered off and washed with water containing sulfur dioxide.

If desired, the crude reine-9-anthrone-8-glucoside is reconstituted. The still wet filter cake is then dissolved in a mixture of 15 parts by volume of 2-butanol and 85 parts by weight of water containing 0.5% by weight of sodium pyrosulphate to add: 10% by weight of 48% sodium hydroxide solution to pH 7. solution (w / v). The solution is adjusted to pH 2.8 or less with concentrated hydrochloric acid 9 104902 and allowed to stand for 2 hours. The precipitated precipitate is filtered off and washed with water containing sulfur dioxide or sodium pyrosulfate and dried.

Yield: 90%.

The product thus obtained undergoes a further reduction (post-reduction) in the following manner: 3.0 g of crude dried rhein-9-anthrone-8-glucoside or an equivalent amount of a moist product are dissolved together with 1.4 g of sodium dithionite and 2.3 g of ml of 5N NaOH in 15 ml of water. Next, make up to 24 ml with water and heat the solution at 55 ° C for 24 hours. A further 1.5 g of sodium dithionite are then added and the mixture is heated for 20 min at 55 ° C. Next, 0.9 ml of 15 N NaOH and 1.5 g of sodium dithionite are added. After warming to 55 ° C for 20 min, 0.9 ml of 5N NaOH is added once more. The resulting solution is directly passed to the following liquid / liquid extraction.

Step B: Separation of Aloe-Emodine Components

The separation of the aloe-emodin components occurs by 9-anthrone-8-glucosides ·. liquid / liquid partition upstream using a device having 60 mixer / separator units ("Mixer-Settler" device). The aqueous heavy phase used is a solution of 3.0 g of sodium dithionite in 3.5 ml of 5N NaOH and 96 ml of water. The organic, light phase used is 2-Butaol (water-saturated) or acetone. Both phases are transmitted through the apparatus so that the volume ratio of the heavy phase to the light phase is 1:10.

The separable mixture is introduced into the apparatus in the form of a fresh reduced solution or a solution having the same pH and concentration of 9-anthrone-8-glucoside from Step A, and using 30 volumes of the organic phase per volume of the mixture to be separated. .

10 104902

The pH of the solution containing the mixture is maintained at 9 to 9.5 using a glycine buffer. To a buffer of 3 volumes of 7.5% glycine solution and 1 volume of 1N NaOH is added 240 ml of buffer solution / 150 g of crude rhein-9-anthrone-8-glucoside. The undesirable aloe-emodine compounds are enriched in the organic phase, while the rheine-9-anthrone-8-glucoside remains in the aqueous phase. The aqueous phase is acidified to pH 2.8 with sulfuric acid, the precipitate formed is filtered and washed with water and acetone and air dried at ambient temperature. In this way, rhein-9-anthrone-8-glucoside is obtained with a concentration of 49 ppm aloe-emodine components (defined as aloe-emodine).

Yield 97%, based on reine-9-anthrone-8-glucoside.

Step C:

Oxidation of Reine-9-Anthrone-8-Glucosides 15.8 g of the obtained reine-9-anthrone-8-glucoside are dissolved in 56 ml of water and 11 ml of 2-butanol, whereby 17 N NaOH is added to pH 6.5. This solution is blown in a cylindrical vessel with a glass melt (Glasfritte) for 5 hours with stirring air. The air flow rate is 40 ml / min. The course of oxidation is monitored by HPLC.

20

When it is no longer possible to detect rhein-9-anthrone-8-glucoside, the solution is diluted to about 200 ml with water / butanol 56/11. The acidic pH is adjusted to 1.5-2.0 with concentrated hydrochloric acid, stirred for 2 hours at ambient temperature, the precipitated crystals are filtered off and washed with water and acetone and dried. 14.4 g (76%) of pure sennocidal mixture containing 41 ppm aloe-emodine components (determined as aloe-emodine) are obtained according to the analytical method described in Step C, Example 2.

Example 2 30

The procedure described in Example 1 is repeated, however, but the oxidation in step C is carried out as follows: 150 g of pure rhein-9-anthrone-8-glucosides and 75 g of iron (III) chloride hexahydrate are dissolved in 480 ml of water and 120 ml of 2 butanol. Add H 104902 48% sodium hydroxide solution to pH 6.5 and until rheine-9-anthrone-8-glucoside is dissolved. The solution is added to a container having a sintered bottom plate. A strong air stream is then passed through the solution. The oxidation is complete after about 30 min. Subsequently, the solution is diluted with a mixture of 5 120 ml of 2-butanol and 480 ml of water, 7.5 g of sodium dithionite are added and the pH of the solution is adjusted by adding concentrated hydrochloric acid to an acidic pH of 2.0. The solution is stirred for 18 hours. Next, the precipitate is filtered off, washed with 600 ml of water and 800 ml of acetone, and dried. The concentration of anthranoid compounds in the product is between 94 and 95%.

10

The product is taken up in 200 ml of 2-butanol and mixed with 800 ml of water and 5.5 g of sodium pyrosulphite added. After filtering off the precipitated precipitate and drying, 95.4 g of the product of the anthranoid compounds having the following composition (according to HPLC, analysis of a typical experiment) are obtained:

Reine-8-glucosides 1.5%

Sennoside B 49.7%

SennosideAl 13.3%

Sennoside A 33.6% 20 Sennidine Monoglucoside 1.1%

Rein 0.02% 99.22% • HPLC was not able to detect cennosides C and D or aloe-emodine glucoside. The total concentration of aloe-emodine and its derivatives was determined according to the following procedures to 30 ppm.

Sennosides C, D and aloe-emodine-8-glucoside can no longer be reliably determined by HPLC to be a sennoside. Therefore, conversion of the test substance to iron (III) by oxidation and simultaneous hydrolysis with hydrochloric acid in a 2-phase mixture of the aqueous solution and carbon tetrachloride to reine or aloe-emodine is required. The reine is then converted into a salt so that it can be extracted into the aqueous phase and the aloe-emodine can be determined in the organic phase by HPLC. This law may be used to report the total content of cennosides C, D, aloe-emodine-8-glucosides and other aloe-emodine components, expressed as aloe-emodine.

Example 3

Repeat the extraction of the henna herb described in Example 1 and the reduction of the hippocampus. Subsequent reduction is then carried out as follows: 10.0 g of sucrose, 4.5 g of sodium dithionite (85%) and 13.3 g of potassium acetate are dissolved in 133 ml of water and 1.3 ml of 48% sodium hydroxide solution are added. 3 g of potassium carbonate. Next, 293 ml of acetone and 50 ml of water are mixed. The mixture is shaken in a separatory funnel and the phases are separated to give 373 ml of the upper phase (acetone phase) and 130 ml of the lower phase.

Dissolve 1.4 ml of 48% sodium hydroxide solution and 10 g of crude reine-9-anthrone-8-glucoside in 98 ml of subphase. Warm to 45-50 ° C and keep at this temperature for 20-30 minutes. Next, 1.0 ml of 48% sodium hydroxide solution and 3.4 g of sodium dithionite are added and the mixture is further heated for 20-20-30 minutes to 45-50 ° C. Next, 1.0 ml of 48% sodium hydroxide solution and 3.4 g of sodium dithionite are added again and warmed to 45-50 ° C for 20-30 minutes.

The separation of the aloe-emodine component occurs by a liquid / liquid-25 split of the reduced solution upstream of the above-mentioned upper phase (acetone phase). The effluent raffinate phase containing the rhein-9-anthron-8-glucoside is evaporated to 400 ml and mixed with 20 ml of 2-butanol or acetone. Acidify with hydrochloric acid or sulfuric acid to pH 4.0 - 4.2. The precipitate formed is filtered off, washed with 40 ml of water and 30 ml of acetone, and subsequently dried. The next oxidation takes place as described in Example 2.

13 104902

Example 4

The concentrate obtained after the extraction of the strain of the senna is mixed with about 2 l of 2-butanol. The reduction of the blend concentrate / 2-butanol mixture is then carried out in 7 steps under nitrogen gas. After the reduction step I, the precipitation of crude reine-9-anthrone-8-glucoside occurs.

Reduction step I

10,1001 of the pennant fruit concentrate / 2-butanol mixture containing about 4 kg of the pennoside is added to the mixing vessel and nitrogen is introduced onto it. 620% (w / w) sodium hydroxide solution is added with stirring followed by 350 L of water-saturated 2-butanol (e.g. from step II) in succession and stirred for 15 min.

The batch is heated to 42-50 ° C and mixed with 7 kg of sodium dithio-15 rivet. Stir for another 45 min. The pH is maintained at 20% (w / w) with sodium hydroxide solution at pH 7.5 to 8. The reduction potential (against Ag / AgCl electrode) is maintained on demand with an addition of sodium dithionite below -630 mV. After cooling to 30-33 ° C, 10% (w / w) sulfuric acid is precipitated within 1.5 hours to pH <4. The resulting suspension is stirred at low agitation-20 at <25 ° C for 10 hours. The precipitate formed is filtered off. The precipitate is suspended in 60 ml of 15% (w / w) 2-butanol, stirred for 30 min at 50-60 ° C and filtered next. The residue is washed with 100 Lilac. demineralized water. The crude yield of reine-9-anthrone-8-glucoside based on the sennosides used is over 82%.

25

Reduction step II

3.3 kg of crude rhein-9-anthrone-8-glucoside from step I is suspended in a mixture of 42 l of demineralized water and 7,412-butanol. The suspension is dissolved in 2 l of 20% (w / w) sodium hydroxide solution and 9.9 kg of trisodium citrate and then mixed with 3.3 kg of sodium dithionite and 350 l of water-saturated 2-butanol (e.g. from step III). The batch is heated to 42-45 ° C. The pH is maintained with 20% (w / w) sodium hydroxide at pH &gt; 14,104,902 8.5-9. The reduction potential (against Ag / AgCl electrode) is maintained as needed with an addition of sodium dithionite below -750 mV.

After standing for about 30 min, the upper phase is removed and the lower phase is further processed in Step III.

Reduction step III

The sub-phase from Step II repeats the reduction / extraction procedure described in Step II, adding the following chemicals: 1.65 kg of sodium dithionite in 0.8 L of 20% (w / w) sodium hydroxide in 350 L of water-saturated 2-butanol 15 (e.g.

Reduction steps IV - VII

For the sub-phase, the reduction / extraction method described in step II is repeated from the preceding step, adding the following chemicals: 0.825 kg sodium dithionite ·. 0.4 L of 20% (w / w) sodium hydroxide solution 350 L of water-saturated 2-butanol 25 (e.g. from each of the following steps - countercurrent principle)

In step VII, the separated subphase is cooled to 30-35 ° C and the rhein-9-anthron-8-glucoside is precipitated - as described in step I. The precipitate formed is filtered and washed with 100 l of demineralized water. Next, 30 l of iron (III) sulphate solution (28 kg Fe 2 (SO 4) in 3 100 l of demineralized H 2 O) are covered.

The reine-9-anthrone-8-glucoside is then converted to the sennoside as described in Example 1 or 2: the sennosides.

is 104902

Example 5

The oxidation of reine-9-anthrone-8-glucoside can also be carried out in the following manner: 6.0 kg of filter-moist reine-9-anthrone-8-glucoside are mixed with 12.6 kg of trisodium citrate. This mixture is dissolved with vigorous stirring in 7.0 1N NaOH and mixed with 0.7 L of 2-butanol. Next, 8.8 L of iron (III) sulfate solution (28 kg Fe 2 (SO 4) in 3100 h of demineralized H 2 O) as well as 20% NaOH are added to a pH of about 8, 3. The reaction is allowed to proceed for 3-4 hours at about 40 ° C, adjusted with 52% H 2 SO 4 to an acidic pH of 1.8 to 2.0, and further treated as in Example 1.

Example 6 15

Alternatively, the rhein-9-anthrone-8-glucoside in 50 mL of water is brought to solution by adding a calcium hydroxide / sucrose solution (prepared by suspending 7.0 g of calcium hydroxide in a solution of 30.0 g of sucrose in 100 mL of H 2 O and removing insoluble calcium). 20 ml of 2-butanol are added thereto and a vigorous air stream is passed through the solution for 90 minutes.

Add 5.0 g of CaCl 2 - 2H 2 O and adjust the pH to 8.5 with a solution of calcium hydroxide / sucrose. The precipitate formed is filtered off and the filtrate is diluted with H 2 O to 340 mL, mixed with 60 mL of 2-butanol and adjusted to pH 2.0 with concentrated hydrochloric acid.

Further processing takes place as described in Example 1.

Farmer Research *

The laxative effect

The laxative effect of the sennocidal composition of the invention was determined in mice. Male NMRI i mice, which were kept in plexiglas cages during the experiments and received a standard feed mixture of paste-like consistency with tap water (1: 1), were used. No separate addition of drinking water occurred during the trials.

The animals received 100, 200 and 400 mg / kg of the sennoside mixture in 10 ml of 0.5% 5 NaHCO 3 / kg by gastric tube.

After administration of test compounds, animal faeces and urine were collected within 24 hours and assayed. The results obtained are summarized in the following table, based on kg body weight.

10

It is clear that sennosides have a good laxative effect, which starts relatively quickly. However, the time of the first occurrence of a soft faeces (2 hours) can be further combined with the transport of the small intestine and prior to the opening of sennosides intestinal flora through. There is a dose / effect-15 ratio.

Acute toxicity:

In each case, 10 male and female Wistar rats were dosed with feeding sennosides at doses of 2,000-25,000 mg / kg 20 times via a feeding tube.

Substance-dependent macroscopic organ damage could not be observed in rats. Received ·. LD50 values are: + 840) 25 male rats: 5200-720) mg / kg + 380) female rats: 3530-340) mg / kg.

In male and female mice (n = 8, strain NMRI), the highest dose administered at 5,000 mg / kg did not result in any death. All mice developed diarrhea, although to a lesser extent than rats. LDS0 values were> 5,000 mg / kg in both sexes.

17 104902

Table

Laxative effect of the sennocidal composition according to the invention in mice 5 Soft stool

In Normal Soft%

Dose Total number of faeces pellets (mg / kg) of animal faeces pellets Number of teas secretions 0 30 1265 0 0 10 100 40 587 144 28.0 200 30 223 239 56.0 400__30__236__282__60,0 • · ·

Claims (10)

1. A method of recovering the sennosides A, B and A1 having the formula: 5 ο, η ,, ο, -Ρ 9, OH 10 QyO C 6 H 10 O 5 O 0 OH and substantially free of the sennosides C, D and D 1 and aloe-emodine components, characterized in that the 15 A) sennoside mixture is subjected to reduction to reine-9-anthrone-8-glucoside and aloe-emodine-9- B) subjecting the resulting compounds to a liquid / liquid partitioning between the water-only miscible polar organic solvent and the aqueous phase, and after C) partitioning the aqueous phase to the reen-9-anthrone-8-glucoside to re-oxidize to the corresponding sennosides, and these will be recovered. Process according to Claim 1, characterized in that the senne diis mixture is obtainable by extraction of the sennar herb in aqueous methanol, preferably in the presence of a buffer. Process according to claim 1 or 2, characterized in that in step A alkali metal dithionite is used as the reducing agent. Process according to Claim 3, characterized in that it is carried out at a pH of 5 to 10.5. • · 104902 Process according to one of the preceding claims, characterized in that 2-butanol is used as the polar organic solvent in step 6. Process according to claims 1-4, characterized in that in step B acetone is used as the polar organic solvent. Process according to one of the preceding claims, characterized in that in step B an aqueous phase is used which has an oxidation / reduction potential of 10 or less than -210 mV. Method according to one of the preceding claims, characterized in that the liquid / liquid partitioning in step B is performed upstream. Process according to one of the preceding claims, characterized in that the oxidation in step C is carried out with oxygen or an iron (III) salt. Process according to claim 9, characterized in that the oxidation with oxygen is carried out at a slightly acidic pH or in the presence of a catalyst, in particular an iron (III) salt. • · • · 20 104902