JPH024240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [] BACKGROUND TECHNICAL FIELD OF THE INVENTION The present invention relates to novel triterpenoid saponins and methods for producing the same. These compounds can be extracted and isolated from the pericarp of Sapindus mukurossi Gaertn. (hereinafter referred to as "Enmeich"). PRIOR ART Saponins have only made progress in research over the past decade due to the difficulty in purifying and isolating them and the complexity of their structures. The characteristics of saponin are represented by foaming properties in aqueous solutions, red blood cell destruction activity (hemolytic activity), toxicity to fish, and ability to form complexes with cholesterol (steroids). In addition to central depression, anti-fatigue, anti-ulcer, promotion of cholesterol metabolism, promotion of lipid metabolism, promotion of synthesis of nucleic acids and proteins, pharmacological effects such as infection prevention and antitumor activities have been discovered in recent years. The saponin-containing herbal medicines that have a relatively high saponin content and are still listed in the Japanese Pharmacopoeia include Senega, Onji, Kikiyo, Licorice, Goshitsu, Saiko, Chikusetsu Ginseng, Carrot, Bakumondo, and Osmanthus. Saponins are classified into steroid saponins and triterpenoid saponins depending on the chemical structure of their sapogenin moieties. Enmeihi saponin, a type of triterpenoid saponin, has not been used for medical purposes until now, but its anti-inflammatory effect was investigated due to the similarity of its chemical structure, and it was shown to have an inhibitory effect on carrageenan edema and adjuvant arthritis in rats. There are reports that. Various pharmacological effects of saponins have been discovered as described above, but full-scale pharmacological research has just begun, and there is a possibility that new pharmacological effects not found in conventional drugs will be discovered in the future. is hidden. In addition, triterpenoid saponins containing hederagenin as genin include, for example, Akebia
guinata Decne.) (Chem.Pharm.Bull.24, 1021
(1976), Caulophyllum
robustum Maxim, ) (CA 85 , 106644h (1976)),
Fatsia japonica Decne.
(Phytochemistry 15 , 781 (1976)), Sapindus mukurossi Gaertn. (CA 73 ,
77544, 110062m, 110071p (1970) and CA 74 ,
13384f (1971)), Lecaniodiscus cupanioides
Planch, ex Benth. (Phytochemistry 20 , 1939
(1981)), but full-scale pharmacological research on saponins has not progressed because it is difficult to separate and purify them in large quantities. Furthermore, Tschesche classifies triterpenoid saponins into monodesmosides and bisdesmosides based on their chemical structure (Forts-
Chritte der Chemie Organischer Naturstoffe,
30, p. 461, Springer-Verlag (1973)), and when it comes to Sapindium, very few belonging to the latter category have been found (CA 74 , 13384f (1974)). Generally, due to its structure, the former contains a portion in which a carboxyl group or a hydroxyl group is in a free form, and its solubility in water is lower than that of the latter. Recently, the present inventor discovered that a herbal medicine extract containing saponin components and three types of Japanese saponin have the effect of promoting the absorption of pharmacologically active substances (Japanese Patent Application Laid-Open No. 57-145816 (Japanese Patent Application No. 56-32012) ), JP-A No. 58-057400 (Japanese Patent Application No. 56-155731) and JP-A No. 58-152817 (Japanese Patent Application No. 57-36138)
(See No.). Among these, Enmeihi saponin belongs to the monodesmosides mentioned above. [] Summary of the Invention The present invention relates to novel triterpenoid saponins. That is, the triterpenoid saponin according to the present invention is represented by the following formula (). In addition, the method for producing triterpenoid saponin represented by the following formula () according to the present invention is to prepare the pericarp of Sapindus mukurossi Gaertn without or after defatting, and then using a lower aliphatic alcohol or a mixture of water and lower alcohol. This method is characterized in that a target compound is obtained from an extracted fraction obtained by extraction using an extractant. ( _R in the formula is _H (compound also has excellent solubility in water (at least 5 mg/5
cc or more). Furthermore, the compound of the present invention has the effect of increasing the solubility of other substances in water by adding the compound. As an example, the present compound X,
A mixture consisting only of Y ₁ and Y ₂ (X: (Y ₁ + Y ₂ )
= 1:6.7 (weight ratio)) saponin A,
Changes in water solubility of B and C (Japanese Patent Application No. 56-155731) are shown in the table below. [Table] (Here, saponin A, B and C are each 3
-O-[α-L-arabinopyranosyl-(1→3)
-α-L-rhamnopyranosyl (1→2)-α-L
-arabinopyranosyl]-hederagenin, 3-O
-[β-D-xylopyranosyl-(1→3)-α-
L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl]-hederagenin, 3-O-[α-
L-arabinofuranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl]-hederagenin. ) In this test agent, the mixture of the compound of the present invention was added at 5 mg/
Saponin A, B by adding _5c.cH2O
The solubility of and C is increased approximately 200 to 900 times, respectively. Saponins A, B, and C have been found by the present inventors to be useful as drug absorption aids (see the above-mentioned patent application). It can be expected to be applied to increase the solubility of substances, especially other useful compounds (such as steroids) that have low solubility in water. The above discovery that the compound of the present invention has an action as a solubilizing agent is the first of its kind for this kind of compound. When the compound of the present invention is used as such a solubilizing agent, it can be used in various applications where this property can be utilized, such as in the manufacturing process or formulation process of pharmaceuticals, and it may also be used as a product that uses the compound of the present invention itself. It is conceivable that it could be used for things such as removing substances. As mentioned above, full-scale pharmacological research on this type of saponin has not progressed, and it goes without saying that the possibility that the compounds of the present invention have pharmacological effects similar to those of common saponins cannot be denied. . [] Detailed Description of the Invention 1 Compound X As is clear from the preceding formula (), Compound X has the following formula:
3-O-[α-L-rhamnopyranosyl (1→2)-
It is a β-sophorosyl ester of α-L-arabinopyranosyl]-hederagenin. Some of the physical and chemical properties of this compound are as follows. [Table] [Table] 2 Compound Y ₁ Compound Y ₁ is 3-O-[β-D-xylopyranosyl (1
→3)-α-L-rhamnopyranosyl (1→2)-α
-L-arabinopyranosyl]-hederagenin β
- sophorosyl ester. Some of the physical and chemical properties of this compound are as follows. [Table] 3 Compound Y ₂ Compound Y ₂ is 3-O-[α-arabinopyranosyl (1→
3) -α-L-rhamnopyranosyl (1→2)-α-
L-arabinopyranosyl]-hederagenin β-
Sophorosyl ester. Some of the physical and chemical properties of this compound are as follows. [Table] [Table] [Table ^] 4 Confirmation of structures _of compounds
L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl]-β-sophorosyl ester of hederagenin, Y ₁ is 3-O-[β-D-xylopyranosyl(1→3)-α- L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl]-β-sophorosyl ester of hederagenin, Y ₂ is 3-
O-[α-L-arabinopyranosyl (1→3)-α
-L-Rhamnopyranosyl(1→2)-α-L-arabinopyranosyl]-β-sophorosyl ester of hederagenin. The structures of these compounds were confirmed as follows. That is, first, three types of triterpenoid saponins were each saponified and then partitioned with butanol-ethyl acetate and water, and the aqueous layer was acid-hydrolyzed in a conventional manner, and glucose was confirmed from the resulting sugar moiety. The organic layer was similarly subjected to acid hydrolysis and partitioned between chloroform and water, and hederagenin was confirmed from the chloroform layer, arabinose and rhamnose for X, arabinose, rhamnose and xylose for Y ₁ from the aqueous layer,
The presence of arabinose and rhamnose was confirmed for _Y2 . From these, X, Y ₁ and Y ₂ have hederagenin as an aglycone, a sugar moiety with glucose as a constituent sugar is bonded to the carboxyl group at the 17-position, and 3
It is presumed to be a bisdesmoside in which sugar moieties having arabinose and rhamnose for X, arabinose, rhamnose, and xylose for _Y1 , and arabinose and rhamnose for _Y2 , respectively, are bound to the hydroxyl group at the - position. In addition, the acetylated product obtained by acetylating X by a conventional method has the following properties according to the EI-MS spectrum:
Hexosyl hexose unit at m/z619,
A methylpentoseyl pentose unit was confirmed at m/z 489, a hexose unit at m/z 331, and a methylpentose unit at m/z 273.
According to ¹³ C-NMR, X is the 3-
α-L-rhamnopyranosyl (1→
2) -α-L-arabinopyranose binds, 17
It was determined that this is a saponin in which β-D-glucopyranosyl (1→2)-β-D-glucopyranose is bound to the carboxyl group at the − position. The acetylated product obtained by acetylating Y ₁ by a conventional method has m/
z705 has a pentosyl methyl pentose pentose unit, m/z 619 has a hexosyl hexose unit, m/z 489 has a pentosyl methyl pentose unit, m/z 331 has a hexose unit,
A pentose unit was confirmed at m/z 259, and ¹³ C-NMR revealed that Y ₁ is the 3-unit of hederagenin.
β-D-xylopyranosyl (1→
3) -α-L-rhamnopyranosyl (1→2)-β-
L-arabinopyranose is bonded to the 17-position carboxyl group to form β-D-glucopyranosyl (1→
2) It was determined that it is a saponin bound to -β-D-glucopyranose. The acetylated product obtained by acetylating Y ₂ by a conventional method has m/
z705 has a pentosyl methyl pentose pentose unit, m/z 619 has a hexosyl hexose unit, m/z 489 has a pentosyl methyl pentose unit, m/z 331 has a hexose unit,
A pentose unit was confirmed at m/z 259, and ¹³ C-NMR revealed that Y ₂ is the 3-unit of hederagenin.
α-L-arabinopyranosyl (1→
3) -α-L-rhamnopyranosyl (1→2)-α-
L-arabinopyranose is bonded to the 17-position carboxyl group to form β-D-glucopyranosyl (1→
2) It was determined that it is a saponin bound to -β-D-glucopyranose. 5. Production of Compounds X, Y ₁ and Y ₂ Compounds X ₁ , Y ₁ and Y ₂ of the present invention can be obtained from Enmeich. The details of the manufacturing process for one specific example are as follows. After degreasing the enmeihi without defatting it or by defatting it with a common fat-soluble organic solvent, it is extracted with a lower aliphatic alcohol, especially a C ₁ to _{C 4} monohydric alcohol, or a mixture of water and a lower aliphatic alcohol. An extract is obtained by subjecting it to extraction. This extract is optionally chromatographed using a reversed-phase adsorbent or a normal-phase adsorbent (preferably silica gel).
Chromatography using [developing solvent is an insoluble organic solvent (e.g. ethyl acetate, chloroform,
1-butanol) and a mixed solvent of alcohols (e.g. methanol, ethanol) and water], and if necessary and possible, perform purification operations such as recrystallization to obtain the desired saponin. obtain. 6 Production of Experimental Compounds X, Y ₁ and Y ₂ 80 g of Enmeihi was broken into small pieces by hand and degreased by cold immersion in benzene (room temperature, 400 ml x 3 times). The crude drug after defatting was digested and extracted with methanol (70
℃. 400ml x 5 times). The methanol extract layer was evaporated to obtain 43.3 g of methanol extract. This extract was subjected to column chromatography using "Diaion" (Mitsubishi Kasei) (eluent: methanol 10% → 50% → 75% → 100%), and 1.43 g of the mixture was extracted from the fraction eluted with 75% methanol. Obtained. This mixture was subjected to silica gel column chromatography [developing solvent = chloroform-methanol-water (20:10:1)] to obtain fractions No. 1 to 30.
87 mg of Compound X was obtained from the residue obtained by distilling off the solvent from fraction No. 12. In addition, 361 mg of the residue obtained by distilling off the solvent from fraction Nos. 16 to 19 was subjected to silica gel column chromatography [developing solvent = chloroform-methanol-water (10:
5:1)] to obtain fraction Nos. 31 to 40.
Regarding fractions No. 33 to 36 (residue 327 mg), further silica gel column chromatography [developing solvent = ethyl acetate-methanol-water (10:3:1)]
Fractions Nos. 41 to 55 were obtained. From the residues obtained by distilling off the solvent from fractions No. 48 and No. 52, 25 mg of compound Y ₁ and 40 mg of compound Y ₂ were obtained, respectively.
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Claims (1)

[Claims] 1. A triterpenoid saponin represented by the following formula. (R in the formula is H, [formula] or [formula].) 2 Sapindus mukurossi Gaertn.
The compound represented by the following formula is extracted from the extracted fraction obtained by subjecting the pericarp to extraction using a lower aliphatic alcohol or a mixture of water and lower aliphatic alcohol as an extractant without or after defatting the pericarp. A method for producing triterpenoid saponin, which comprises fractionating it. (R in the formula is H, [formula] or [formula].)