JP2005179304A - New phenylpropanoid condensed iridoid and antimalarial composition comprising the same as active ingredient - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new phenylpropanoid condensed iridoid, its preparation method and a new antimalarial composition comprising a series of phenylpropanoid condensed iridoid compounds including the new phenylpropanoid condensed iridoid as active ingredients. <P>SOLUTION: The antimalarial composition comprises the phenylpropanoid condensed iridoid of formula (2) (wherein R<SP>1</SP>is a hydroxy group, a lower alkylamino group or a lower alkoxy group; R<SP>2</SP>, R<SP>3</SP>and R<SP>5</SP>are identical to or the same as each other and are each a hydrogen atom, a lower alkyl group, an acyl group, a lower alkylcarbamoyl group or a lower alkoxycarbonyl group; R<SP>4</SP>is a hydrogen atom, a lower alkoxy group, -OCOR<SP>7</SP>, -OCONHR<SP>7</SP>or OCOOR<SP>7</SP>[wherein R<SP>7</SP>is a lower alkyl group]; A is a single or double bond, provided that when it is a single bond, R<SP>6</SP>is a hydroxy group or a lower alkoxy group, and when it is a double bond, R<SP>6</SP>is an oxygen atom) or its pharmacologically acceptable salt as the active ingredient. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel phenylpropanoid condensation-type iridoid, a method for preparing the same, and a pharmaceutical composition comprising the same as an active ingredient of antimalarial. Furthermore, this invention relates to the novel use as an active ingredient of an antimalarial composition (pharmaceutical composition) about a well-known phenyl propanoid condensation-type iridoid.

  Malaria is currently the world's largest parasitic protozoan infection that infects approximately 300 million people worldwide and kills 2 million people annually. WHO is the number of patients and deaths in 2010. Both are estimated to double. Moreover, due to the widespread transmission of multidrug-resistant protozoa and the difficulty in developing vaccines, malaria is positioned as the most threatening disease on a global scale along with AIDS. Therefore, at present, the development of a novel chemotherapeutic agent for malaria is considered to be an urgent important issue for humanity.

  The drugs that have been used for the treatment of malaria have been 1) a series of aminoquinoline compounds typified by chloroquine developed from quinine bark derived from South America as a seed compound, 2) Chinese herbal medicines It is roughly classified into three types: peroxide compounds such as artemisinin developed from Aozora, and 3) antifolate antimetabolites targeting dihydrofolate reductase. However, there are currently some infected areas where protozoa resistant to all three antimalarial drugs have been confirmed by patients, and the spotted mosquitoes that mediate malaria infection are among the various insecticides. In the current situation where there is no effective means to control the transmission of resistant protozoa, it is warned that the spread of multi-drug resistant protozoa to all infected areas is also a time issue. ing.

  In particular, among the above-mentioned existing antimalarial drugs, aminoquinoline compounds and folate antimetabolites have been confirmed to be resistant in most infected areas, and it is now possible to treat malaria with these drugs. It is almost difficult. Artemisinin has a phenomenon called “relapse” in which a new protozoa appears in the bloodstream several weeks after the disappearance of the malaria parasite in the bloodstream. This is the biggest problem with artemisinin. For this reason, artemisinin is currently used mainly to lower the malaria parasite concentration in the body in the early stage of treatment, and intravenous injection of quinine, which is effective only as an injection, has been implemented as a cure for malaria. Yes.

  Thus, there is an urgent need to discover a novel antimalarial active ingredient having a structure different from that of the conventional antimalarial drug and to develop a novel antimalarial therapeutic agent.

For these purposes, attempts have been widely made to search for antimalarial active ingredients from many medicinal plants. For example, Patent Document 1 discloses that an extract containing tannin and quinine obtained from Anona senegalensis is effective for the treatment of malaria, and Patent Document 2 discloses that an acridine derivative obtained naturally or synthetically is an effective antimalarial agent. It is effective as a component, Patent Document 3 discloses that mixed herbal medicines such as cinnamon bark, ground yellow, glaze, Kawakyu, Toki, ginseng, and licorice are effective as antimalarial agents. Colpensamine and colpensamine derivatives obtained from plants of the genus Ancistrocladus are effective as antimalarial active ingredients, and Patent Document 5 has an excellent antimalarial activity against vocamin, an alkaloid component of the plants of the genus Peshira. Reference 1 includes ajugarin-1 and e contained in the medicinal plant Ajuga remota used for antimalarial in Kenya rgosterol-5,8-endoperoxide has antimalarial activity (in vitro), and Non-Patent Document 2 describes that the medicinal plants Cassia occidentalis, Morinda morindoides, and Phyllanthus niruri have antimalarial activity. .
JP 60-54323 A Japanese Patent Laid-Open No. 02-101015 Japanese Patent Laid-Open No. 07-82165 Japanese National Patent Publication No. 10-501518 Special table 2002-507570 gazette Kimani AM Kuria et al., "The Antiplasmodial Activity of Isolates from Ajuga remota", Journal of Natural Products, 2002, Vol.65, No.5, pp.789-793 Tona L et al., "In-vivo antimalarial activity of Cassia occidentalis, Morinda morindoides and Phyllanthus niruri" ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY, 95 (1), 47-57 (2001).

  An object of the present invention is to provide a novel phenylpropanoid condensation-type iridoid and a method for preparing the same. A second object of the present invention is to provide a novel antimalarial composition comprising a series of phenylpropanoid condensed iridoid compounds containing the novel phenylpropanoid condensed iridoid as an active ingredient. Furthermore, the present invention thirdly provides a method for preparing a series of phenylpropanoid condensed iridoid compounds containing the novel phenylpropanoid condensed iridoid, and a method for preparing an antimalarial composition containing the compound as an active ingredient. For the purpose.

  The inventors of the present invention have been diligently studying day and night to achieve the above object, and have found that a series of compound groups belonging to phenylpropanoid condensed iridoids have antimalarial activity. It was confirmed that one phenylpropanoid condensation type iridoid to which it belongs was a novel compound not yet published in literature.

  The present invention has been completed based on such knowledge.

That is, the present invention relates to the following.
Item 1. The following formula:

A novel phenylpropanoid condensation-type iridoid represented by
Item 2. Item 2. The method for preparing a phenylpropanoid condensation-type iridoid (1) according to Item 1, comprising a step of extracting Morinda morindoides with a solvent containing an organic solvent, and a step of adsorbing the resulting extract fraction.
Item 3. A pharmaceutical composition comprising the phenylpropanoid condensed iridoid (1) or a pharmaceutically acceptable salt thereof according to Item 1 as an active ingredient.
Item 3-1. A pharmaceutical composition comprising an antimalarial effective amount of the phenylpropanoid condensed iridoid (1) or a pharmaceutically acceptable salt thereof according to Item 1.
Item 3-2. Item 6. An antimalarial composition comprising the phenylpropanoid condensation-type iridoid (1) or a pharmaceutically acceptable salt thereof according to Item 1 as an active ingredient.
Item 4. General formula (2):

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group, a lower alkylcarbamoyl group or R ⁴ represents a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond or (When A is a single bond and R is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when it is a double bond, R ⁶ represents an oxygen atom.)
The antimalarial composition which uses the phenylpropanoid condensation-type iridoid shown by these, or its pharmaceutically acceptable salt as an active ingredient.
Item 5. The active ingredient is the following formula (1):

The following formula (3):

The following formula (4):

The following formula (5):

And the following formula (6):

Item 5. The antimalarial composition according to Item 4, which is at least one selected from phenylpropanoid condensation-type iridoids represented by:

Item 6. The following steps (1) to (4):
(1) extracting Morinda morindoides leaves with lower alcohol,
(2) extracting the lower alcohol extract obtained in (1) with a mixed solvent of n-hexane and water and separating the layers;
(3) extracting the aqueous layer obtained in (2) with ethyl acetate and separating the layers; and
(4) General formula (2) having a step of subjecting the ethyl acetate extract fraction obtained in (3) to an adsorption treatment:

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group or a lower alkylcarbamoyl group. Or a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
A method for preparing a phenylpropanoid condensation-type iridoid represented by the formula:
Item 7. The following steps:
A. (1) Morinda morindoides leaves are extracted with lower alcohol,
(2) extracting the lower alcohol extract obtained in (1) with a mixed solvent of n-hexane and water and separating the layers;
(3) extracting the aqueous layer obtained in (2) with ethyl acetate and separating the layers; and
(4) A phenylpropanoid condensed iridoid represented by the following general formula (2) is prepared by a method having a step of subjecting the ethyl acetate extract fraction obtained in (3) to an adsorption treatment,

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group or a lower alkylcarbamoyl group. Or a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
B. Next, a step of blending the phenylpropanoid condensed iridoid with a pharmaceutically acceptable carrier or additive,
Item 6. A method for preparing an antimalarial composition according to Item 4 or 5, wherein
Item 8. General formula (2):

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group or a lower alkylcarbamoyl group. Or a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
The antimalarial composition which uses the solvent extract of Morinda morindoides containing the phenylpropanoid condensation type iridoid shown by this as an active ingredient.
Item 9. The solvent extract of Morinda morindoides is
(1) extracting Morinda morindoides leaves with lower alcohol,
(2) extracting the lower alcohol extract obtained in (1) with a mixed solvent of n-hexane and water and separating the layers; and
(3) A step of extracting the aqueous layer obtained in (2) with ethyl acetate and separating the layers,
Item 9. The antimalarial composition according to Item 8, which is a fraction extracted with ethyl acetate obtained in (8).

(1) Novel phenylpropanoid condensation-type iridoid and method for producing the same The present invention provides a novel phenylpropanoid condensation-type iridoid having a structure represented by the following formula (1).

  The novel phenylpropanoid condensation-type iridoid (1) can be chemically synthesized, but is prepared by extraction and isolation from plants, specifically Morinda morindoides, a medicinal plant in Central Africa. You can also.

  Morinda morindoides has long been known as a medicinal plant. For example, leaf decoction is known to be effective in the improvement and treatment of many diseases such as fever, rheumatism, and malaria (Non-Patent Document 2, etc.) reference). However, it is not yet known which component contained in Morinda morindoides has antimalarial activity, and the existence of the phenylpropanoid condensed iridoid (1) is also unknown.

  When the phenylpropanoid condensation-type iridoid (1) is isolated and prepared from Morinda morindoides, Morinda morindoides used as a raw material may be whole plant or part thereof. Preferably, it is a leaf or a part containing a leaf.

  The preparation of the phenylpropanoid condensation-type iridoid (1) is not limited. For example, (1) Morinda morindoides whole plant or a part thereof (preferably a leaf or a leaf-containing portion) is mixed with an organic solvent. And (2) an adsorption process for the extracted fraction obtained in this step.

  Morinda morindoides is extracted by immersing raw or dried Morinda morindoides whole or part of it (preferably leaves) in the extraction solvent under low temperature, warming or boiling conditions. A method of performing extraction with stirring under low temperature, warming or boiling conditions; or a percolation method. The extraction solvent used for such extraction is not particularly limited, and water, lower alcohol, or a mixture thereof can be exemplified. Preferred is a lower alcohol. Examples of the lower alcohol include C1-C4 lower alcohols such as methanol, ethanol, propanol, isopropyl alcohol, and butanol.

  The extraction treatment can be repeated once or a plurality of times using the same or different extraction solvents for the extract obtained by the above method. For example, the extraction fraction obtained by the above-described extraction treatment may be further extracted using a mixed solution of water and a nonpolar organic solvent as an extraction solvent. Here, examples of the nonpolar organic solvent include n-hexane, ethyl acetate, benzene, dichloromethane and the like.

  As a more specific extraction method, as shown in the Examples, (a) whole plant of Morinda morindoides or a part thereof (preferably leaves) is extracted with lower alcohol, and (b) alcohol extraction obtained After the product was extracted with a mixed solvent of water and n-hexane, the layers were separated, and (c) the obtained aqueous layer fraction was extracted with a mixed solvent of water and ethyl acetate, and then the layers were separated and extracted with ethyl acetate. The method of fractionating can be mentioned.

  The obtained extracted fraction can be subjected to the next treatment step as it is or after being concentrated, after removing solids by filtration, coprecipitation or centrifugation as necessary.

  The adsorption treatment can be performed according to a conventional method in the art. For example, adsorption treatment with activated carbon, silica gel, porous ceramic, etc .; styrene-based duolite S-861 (trademark “Duolite”, USA Diamond Shamrock, the same shall apply hereinafter), duolite S-862, duolite S-863 Or Duolite S-866; aromatic Sepa beads SP70 (trademark “Separ beads”, manufactured by Mitsubishi Chemical Corporation, the same shall apply hereinafter), Sepa beads SP700, Sepa beads SP825; Diaion HP10 (trademark “Diaion”, Mitsubishi Chemical Corporation) ), Diaion HP20, Diaion HP21, Diaion HP40, and Diaion HP50; or Amberlite XAD-4 (trademark “Amberlite”, manufactured by Organo, the same shall apply hereinafter), Amberlite XAD-7, An adsorption resin treatment using a synthetic adsorption resin such as Amberlite XAD-2000 can be given.

  In such adsorption treatment, Morinda morindoides extract or treated product thereof is applied to a resin carrier, and impurities are adsorbed on the resin, and the fraction containing phenylpropanoid condensation-type iridoid (1) is obtained or obtained. After the phenylpropanoid condensation type iridoid (1) is adsorbed to the resin, the resin is washed to remove impurities, and then the phenylpropanoid condensation type iridoid (1) is desorbed and eluted from the resin with an appropriate eluent. The method can be adopted. Moreover, the method of acquiring the peak fraction of phenylpropanoid condensation type iridoid (1) using HPLC etc. is also employable. Furthermore, an ion exchange process, a crystallization process, etc. can also be performed as needed. In addition, the description of the Example mentioned later can be referred for the detail of the preparation method of phenyl propanoid condensation type iridoid (1).

  The phenylpropanoid condensation-type iridoid (1) thus obtained has an antimalarial activity and low cytotoxicity as shown in the examples described later, and is therefore effective as an active ingredient of an antimalarial pharmaceutical composition. Can be used. The phenylpropanoid condensed iridoid (1) of the present invention includes any of the structural isomers comprehensively represented by the above structural formula.

(2) Antimalarial composition The present invention also provides the following general formula (2):

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group, a lower alkylcarbamoyl group or R ⁴ represents a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkyl group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [and R ⁷ is a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
The antimalarial composition which uses as an active ingredient the phenylpropanoid condensation-type iridoid shown by these, or its pharmacologically acceptable salt.

Here, the lower alkyl group represented by R ² , R ³ , R ⁴ or R ⁵ means a linear or branched alkyl group having 1 to 6 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tertiary butyl group, n-pentyl group, isopentyl group, and n-hexyl. The group can be mentioned. Preferably, they are a methyl group and an ethyl group.

Even lower alkyl group used in the lower alkylcarbamoyl group or a lower alkoxycarbonyl group represented by R ^2, R ³ or R ^5; a lower alkoxy group represented by R ¹ and R ^4; lower alkylamino group represented by R ¹ The above can be mentioned.

  Here, as the lower alkylamino group, specifically, methylamino group, ethylamino group, n-propylamino group, isopropylamino group, n-butylamino group, isobutylamino group, sec-butylamino group, n-pentylamino group A group, an isopentylamino group, and an n-hexylamino group. A methylamino group and an ethylamino group are preferred.

  Specific examples of the lower alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, an n-pentoxy group, an isopentoxy group, and an n-hexoxy group. Can be mentioned. A methoxy group and an ethoxy group are preferable.

  Specific examples of the lower alkylcarbamoyl group include a methylcarbamoyl group, an ethylcarbamoyl group, an n-propylcarbamoyl group, an isopropylcarbamoyl group, an n-butylcarbamoyl group, an isobutylcarbamoyl group, a sec-butylcarbamoyl group, an n-pentylcarbamoyl group, Examples thereof include an isopentylcarbamoyl group and an n-hexylcarbamoyl group. A methylcarbamoyl group and an ethylcarbamoyl group are preferred.

  Specific examples of the lower alkylcarbonyl group include methylcarbonyl group, ethylcarbonyl group, n-propylcarbonyl group, isopropylcarbonyl group, n-butylcarbonyl group, isobutylcarbonyl group, sec-butylcarbonyl group, n-pentylcarbonyl group, An isopentylcarbonyl group and an n-hexylcarbonyl group can be mentioned. A methylcarbonyl group and an ethylcarbonyl group are preferred.

As the lower alkyl group (R ⁷ ) used in —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ represented by R ⁴ , the above-mentioned ones can be exemplified. Preferably, they are a methyl group and an ethyl group.

Examples of the acyl group represented by R ² include acetyl group, propionyl group, butyryl group, isobutyryl group, valeryl group, isovaleryl group, and hexanoyl group. Preferably, an acetyl group and a propionyl group can be mentioned.

R ¹ is preferably a hydroxyl group or a lower alkoxy group, more preferably a lower alkoxy group; R ² is preferably a hydrogen atom and an acyl group; R ³ is preferably a hydrogen atom and an acyl group, more preferably a hydrogen atom; R ⁴ is preferably a hydrogen atom and an alkoxy group; R ⁵ is preferably a hydrogen atom and an acyl group, more preferably a hydrogen atom. R ⁶ is preferably a hydroxyl group when A is a single bond, and an oxygen atom when A is a double bond.

  The phenylpropanoid condensed iridoid used as an active ingredient of the antimalarial composition of the present invention includes structural isomers comprehensively included in the general formula (2).

  Specific compounds contained in the phenylpropanoid condensed iridoid represented by the general formula (2) are represented by the following formulas (1), (3), (4), (5), and (6). Mention may be made of phenylpropanoid condensation type iridoids.

  The method for preparing the phenylpropanoid condensed iridoid (MM-2) represented by the formula (1) is as described above. Similarly, the phenylpropanoid condensed iridoids (MM-1, MM-3, MM-4, and MM-5) represented by formulas (3) to (6), respectively, are all of Morinda morindoides or a part thereof. (Preferably a leaf or a part containing a leaf). These preparation methods are described in detail in Examples described later, and can be referred to.

  The phenylpropanoid condensed iridoids of the present invention other than MM-1, MM-2, MM-3, MM-4, and MM-5 represented by formula (1) and formulas (3) to (6) ( 2) can be prepared from MM-1, MM-2, MM-3, MM-4 or MM-5 as starting materials according to the common general technical knowledge in the art.

As an example, phenylpropanoid condensed iridoid of general formula (2) containing various functional groups as R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ using MM-4 as a starting material The method of synthesizing is illustrated in the following reaction formulas I, II, III, and reaction formula IV. In addition, other phenylpropanoid condensation type iridoids contained in the general formula (2) should be similarly synthesized using MM-1, MM-2, MM-3, or MM-5 as a starting material. Can do.

  Here, by performing the following reactions (1) and (2) using MM-4 as a starting material, the carboxylic acid (a) of MM-4, the ester (b) of MM-4, and the amide, respectively Body (c) can be synthesized.

  (1) MM-4 is dissolved in 10% KOH in methanol and stirred at room temperature for 30 minutes. The reaction solution is adjusted to pH 3 and an extraction operation is performed to obtain carboxylic acid (a).

(2) The carboxylic acid (a) produced in (1) and a lower alcohol (R ⁸ OH, R ⁸ is a lower alkyl group [the definition is the same as described above]), or a lower alkyl amine (R ⁸ NH ₂ , R ⁸ is a lower alkyl group) dissolved in dichloromethane, DCC (dicyclohexylcarbodiimide) and DMAP (4-dimethylaminopyridine) are added, and the mixture is stirred at room temperature for 3 hours. Next, the ester form (b) or amide form (c) of MM-4 is obtained by an extraction operation.

  Here, using MM-4 as a starting material, the following reactions (3) and (4) are carried out, whereby the 13-position carbonyl compound (d) of MM-4 and the 13-position alkoxy (e) of MM-4, respectively. Can be synthesized.

  (3) Dissolve MM-4 in 1,4-dioxane, add DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) and stir at room temperature for 2 hours. By doing this, the 13-position carbonyl compound (d) of MM-4 is obtained.

(4) MM-4 was dissolved in dichloromethane, Et ₃ N was added and stirred at room temperature for 30 minutes, then R ⁸ -Br (R ⁸ is a lower alkyl group) was added, and the mixture was further stirred for 1 hour. The 13-position alkoxy (e) of MM-4 is obtained by extraction from the reaction solution.

Here, by performing the following reactions (5) to (7) using MM-4 as a starting material, a 6 ″ -acyl form (f) of MM-4 and an alkylidene form (g) of MM-4, respectively. , MM-4 6 ″ -carbonate body (h) and 6 ″ -carbamate body (i) can be synthesized.
(5) MM-4 is dissolved in pyridine, an acid anhydride [(R ⁸ CO) ₂ O, R ⁸ is a lower alkyl group] is added, and the mixture is stirred at 0 ° C. for 30 minutes. Subsequently, the 6 ″ -acyl form (f) of MM-4 is obtained by an extraction operation.
(6) Dissolve MM-4 in THF (tetrahydrofuran), add aldehyde (R ⁸ CHO, R ⁸ is lower alkyl group) and catalytic amount of TsOH (paratoluenesulfonic acid) and stir at room temperature for 1 hour. . Subsequently, the alkylidene body (g) of MM-4 is obtained by extraction operation.
(7) Dissolve MM-4 in pyridine, add R ⁸ COCl (R ⁸ is lower alkyl group) or isocyanate (R ⁸ —N═C═O, R ⁸ is lower alkyl group) and stir at room temperature for 30 minutes. To do. Subsequently, the 6 ″ -carbonate body (h) or 3 ′, 4′-carbamate body (i) of MM-4 is obtained by an extraction operation.

Here, by performing the following reactions (8) to (11) using MM-4 as a starting material, catechol body (j), 3 ′, 4′-diacyl body (k), 3 A ', 4'-carbonate body (l), a 3', 4'-carbamate body (m), and a 3 ', 4'-alkoxy body (n) can be synthesized.
(8) Dissolve MM-4 in dichloromethane, add BBr ₃ at -78 ° C, and stir at 0 ° C for 1 hour. Subsequently, the catechol body (j) of MM-4 is obtained by extraction operation.
(9) Dissolve the catechol body (j) produced in (8) in pyridine, add an acid anhydride [(R ⁸ CO) ₂ O, R ⁸ is a lower alkyl group], and stir at 0 ° C. for 30 minutes. . Subsequently, the 3 ′, 4′-diacyl (k) of MM-4 is obtained by extraction operation.
(10) The catechol body (j) produced in (8) is dissolved in pyridine, and R ⁸ COCl (R ⁸ is a lower alkyl group) or isocyanate (R ⁸ —N═C═O, R ⁸ is a lower alkyl group) And stir at room temperature for 30 minutes. Subsequently, MM-4 3 ′, 4′-carbonate (l) or 3 ′, 4′-carbamate (m) is obtained by extraction operation.
(11) Dissolve the catechol body produced in (8) in dichloromethane, add NaH, stir at 0 ° C. for 30 minutes, then add R ⁸ -Br (R ⁸ is a lower alkyl group) and stir at room temperature for 1 hour. To do. Next, the 3 ′, 4′-alkoxy form (n) of MM-4 is obtained by extraction from the reaction solution.

  The antimalarial composition of the present invention comprises a series of phenylpropanoid condensed iridoids represented by the general formula (2), particularly MM-1, MM- represented by the formulas (1) and (3) to (6). In addition to 2, MM-3, MM-4, and MM-5, these pharmaceutically acceptable salts can also be used as active ingredients. Here, the pharmaceutically acceptable salt is not particularly limited, but is an addition salt with an inorganic acid such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, or phosphoric acid; acetic acid, lactic acid, succinic acid, malic acid, Mention may be made of addition salts with organic acids such as maleic acid, fumaric acid, oxalic acid, citric acid, tartaric acid, methanesulfonic acid and p-toluenesulfonic acid.

  In addition, the antimalarial composition of this invention does not ask | require especially the refinement | purification degree of the active ingredient to mix | blend, unless the effect of this invention is impaired. Accordingly, a series of phenylpropanoid condensed iridoids represented by the above general formula (2), particularly MM-1, MM-2, MM-3, MM represented by the formulas (1) and (3) to (6) -4, and MM-5, or a pharmaceutically acceptable salt thereof may be included as a crude product. Examples of such crudely purified products include extract fractions containing these phenylpropanoid condensed iridoids prepared from the above-mentioned Morinda morindoides whole plant or a part thereof (preferably a leaf or a portion containing a leaf). it can.

  In addition, the antimalarial composition of the present invention is not particularly limited in combination with other known or future developed antimalarial drugs as long as the effects of the present invention are not impaired.

  The antimalarial composition of the present invention may contain a pharmaceutically acceptable carrier or additive in addition to the active ingredient, and the active ingredient may be used as it is or together with the carrier or additive to form tablets, powders. Oral dosage forms such as fine granules, granules, capsules, emulsions or syrups; parenteral dosage forms such as injections, drops, suppositories and the like. Such an oral preparation is usually prepared by combining the active ingredient with an excipient, binder, disintegrant, lubricant, colorant, flavoring agent and the like in an appropriate combination, and then preparing the various forms according to conventional methods. Can do.

  When preparing injections or infusions, add pH adjusters, buffers, stabilizers, solubilizers, etc. as necessary to the active ingredients, and freeze-dry if necessary. These can be prepared as subcutaneous, muscular, intravenous and intraperitoneal injections, and drops by conventional methods.

  In addition to these components, these preparations can also contain components such as fragrances, surfactants, soothing agents, stabilizers and the like.

  The dose of the antimalarial composition of the present invention varies depending on the degree of symptoms and the weight and age of the patient. For example, when administered to humans as an oral preparation, the dose of phenylpropanoid condensed iridoid is 10 to 20 mg. / Kg can be administered once to several times a day.

  In the following, in order to clarify the configuration and effects of the present invention, Production Examples, Examples, Comparative Examples, and Experimental Examples are described. However, the present invention is not affected by these examples.

Example 1
A. Preparation of specimen (1) Methanol extraction 4 g of methanol was added to 600 g of dried pulverized Morinda morindoides leaves and extracted at room temperature for 3 hours. Then, this was filtered and the filtrate was collect | recovered. On the other hand, 4 L of methanol was added to the obtained residue, followed by extraction with heating under reflux for 2 hours, followed by filtration to collect a filtrate. This heating reflux extraction was performed again on the residue obtained here, and all the collected filtrates were collected and concentrated to obtain 15 g of a solid (hereinafter referred to as “methanol extract”).

(2) n-hexane / H ₂ O treatment 8.12 g of the methanol extract obtained in (1) was added to a 700 mL / 700 mL mixture (1000 mL) of n-hexane / H ₂ O and stirred well. The solution was distributed and dissolved in both layers. Subsequently, the aqueous layer and the n-hexane layer were separated and recovered by layer separation. The collected n-hexane layer was completely dried to obtain 1.69 g of a solid (hereinafter referred to as “n-hexane extract”).

(3) Extraction with ethyl acetate On the other hand, 500 mL of ethyl acetate was added to the aqueous layer side recovered by the layer separation in (2), and the mixture was stirred well to partition and dissolve in both layers. The layers were separated and recovered into an aqueous layer and an ethyl acetate layer. To the recovered aqueous layer side, 500 mL of ethyl acetate was further added, and the mixture was stirred again, and dissolved and distributed in both layers. The layers were separated, and the aqueous layer and ethyl acetate layer thus obtained were recovered in the previously recovered water layer. The layers and ethyl acetate layer fractions were combined. The combined ethyl acetate layers were completely dried to obtain 1.27 g of a solid (hereinafter referred to as “ethyl acetate extract”).

(4) Extraction with n-butanol Add 350 mL of n-butanol to the aqueous layer collected and obtained by layer separation in (3) above, shake well, and then separate the layers to separate into an aqueous layer and an n-butanol layer. It was collected. To the recovered aqueous layer side, 350 mL of n-butanol was further added and shaken well, and then the layers were separated. The obtained n-butanol layer was collected and dried together with the n-butanol layer collected previously to obtain 1.66 g of solid (hereinafter referred to as “n-butanol extract”). . Similarly, the aqueous layer was dried together with the previously recovered aqueous layer to obtain 5.5 g of a solid (hereinafter referred to as “water extract”).

B. Measurement of antimalarial activity of each specimen In order to evaluate the antimalarial activity of each extract (specimen) prepared in (1) to (4), P. falciparum Honduras-1 strain [Dartmouth, USA Using a medical university (Department of Microbiology Dartmouth Medical School Lebanon, NH03756, USA), chloroquine sensitivity was measured to measure the growth inhibition rate of malaria parasites.

  For the medium, dissolve 10.4 g of RPMI1640 (GIBCOBRL) powder in 1 L of distilled water, add 2 g of sodium bicarbonate, stir for 2 to 3 hours, adjust the pH to 7.4, suction filter, 25 mL of HEPES buffer and 10 mg / It was prepared by adding 1 mL of a gentamicin solution having a ml concentration, and further adding 100 mL of sterile human type A serum. Malaria parasites extracted from liquid nitrogen were collected according to the method of Diggs et al. (Diggs, CL et al., Am. J. Trop. Med. Hyg., 24, 760-766 (1975)), and 10% human type A serum After adding fresh erythrocytes so that hematocrit was 3% with 5 mL of added RPMI1640, the cells were cultured in a petri dish (5 mL). The culture was performed in an incubator at 37 ° C. in an atmosphere of 5% oxygen, 5% carbon dioxide, and 90% nitrogen.

  Before measuring the malaria parasite growth inhibition rate, Lambros and Vandenberg et al. (Lambros, C., Vandenberg, JP, J. Parasitol., 65, 418-420 ( 1979)), the malaria parasite was exposed to 5% of the cell pellet volume of 5% sorbitol for 10 minutes. Thereafter, it was washed with RPMI1640 and re-cultured using the above medium. The culture solution of this malaria parasite was injected into a 50 μL 96-well plate. This culture has a hematocrit value of 2% and an infection rate of 0.5%.

Specifically, the growth inhibition rate of the malaria parasite was measured as follows.
Each specimen (the above extract) was dissolved in DMSO and diluted to an appropriate concentration using the above medium to obtain a test sample (DMSO final concentration 1%). 50 μL of this test sample was added to a 96-well plate to which a culture solution of malaria parasite (50 μL) had been previously added (total of 100 μL). The final concentration of DMSO in the mixture is 1%. This was cultured at 37 ° C. for 72 hours. Thereafter, a smear film was prepared on a slide glass, and this was stained with Giemsa staining solution, and the number of infected red blood cells out of 10,000 red blood cells was determined under a microscope. In place of the above test sample, DMSO and medium-adjusted solution (50 μL, DMSO final concentration 1%) was added and tested in the same manner, and the malaria parasite infection rate (control infection rate) From the malaria parasite infection rate (the infection rate in the presence of the specimen), the malaria parasite growth inhibition rate was calculated according to the following formula. In addition, quinine was used as a positive control drug. The test sample was diluted to 1 μg / mL and 5 μg / mL as final concentrations.

Malaria parasite growth inhibition rate (%)
= (Control infection rate-infection rate in the presence of sample) / control infection rate x 100.

C. Toxicity evaluation of each specimen (each extract) In order to evaluate the cytotoxicity of each specimen (each extract) prepared in (1) to (4) above, the MTT method (MCAlley, et al., “Feasibility of According to Drug Screening with Panels of Human Tumor Cell Lines Using a Microculture Tetrazolium Assay ", Cancer Res., 48, 589 (1988)), the growth inhibition rate% of human cancer cells KB3-1 was measured.

First, the above specimen (extract, dry solid) was dissolved in DMSO and diluted to an appropriate concentration (5 μg / mL, 50 μg / mL) using a medium (RPMI1640 medium containing 10% fetal bovine serum). Samples were prepared (DMSO final concentration 1%). 100 μL of this test sample was added to 100 μL (2 × 10 ⁴ cells / mL) of a suspension of KB3-1 cells, and cultured at 37 ° C. under 5% CO ₂ .

  After 72 hours of culturing, 25 μL of MTT reagent (3- (4,5) -dimethylthiazo-2,5-dimethyltetrazolium bromide) was added, followed by further culturing for 3 hours. Subsequently, the medium alone was removed by suction, 200 μL of DMSO was added, and the produced MTT folmazan was extracted, and the amount of the dye was quantified by a colorimetric method (540 nm). The number of viable cells was calculated from the amount of dye produced. The amount of dye produced when a test solution (100 μL, DMSO final concentration 1%) was added instead of the test sample (100 μL) and tested, and the amount of dye produced in the presence of the sample. From the amount of pigment produced (the amount of pigment in the presence of the specimen), the growth inhibition rate% in the presence of the test sample was determined according to the following formula, and the cytotoxicity of each specimen (extract) was evaluated. Colchicine was used as a positive control.

  Growth inhibition rate (%) = (control dye amount−dye amount in the presence of specimen) / control dye amount × 100.

  The results are shown in Table 1.

  As a result, it was found that the ethyl acetate extract (1 μg / mL) has a relatively high antimalarial activity, particularly from the results of the growth inhibition rate (%) of the malaria parasite of each extract having a concentration of 1 μg / mL.

  The growth inhibition rate (%) of quinine against malaria parasites as a positive control test was 83.1% at 0.1 μg / mL and 35.0% at 0.033 μg / mL. The growth inhibition rate (%) of colchicine for KB3-1 cells, which was conducted as a positive control test, was 42.2% at 5 ng / mL.

Example 2
(1) Acquisition of purified fractions 1.26 g of ethyl acetate extract of Morinda morindoides (leaves) obtained in Example 1 was fractionated and purified using silica gel column chromatography. Specifically, 1.26 g of ethyl acetate extract was dissolved in CHCl ₃ : MeOH = 96: 4, and this was filled with SiO ₂ (30 g) and previously equilibrated with a solvent (CHCl ₃ : MeOH = 96: 4). It was adsorbed on a glass column (inner diameter 30 mm, length 10 cm), and 100 mL of a mixed solution of chloroform and methanol (CHCl ₃ : MeOH = 96: 4) was introduced as an elution solvent, and fraction A (62.4 mg [ The weight of the dried product, the same shall apply hereinafter, yield 4.95%). Further, an elution solvent with a mixed ratio of chloroform and methanol was passed through the column, and fraction B (elution solvent [CHCl ₃ : MeOH = 10: 1], 77.6 mg, yield 6.16%), fraction C (elution solvent [CHCl ₃ : MeOH = 10: 1], 213.7 mg, yield 17.0%), fraction D (elution solvent [CHCl ₃ : MeOH = 7: 1], 182.4 mg, yield 14.5%), Fraction E (elution solvent [CHCl ₃ : MeOH = 7: 3], 242.2 mg, yield 19.2%) and fraction F (elution solvent [MeOH], 134.1 mg, yield 10.6%) were obtained, respectively.

(2) Anti-malarial activity and toxicity of fractions A to F The anti-malarial activity and toxicity of fractions A to F were compared with the growth inhibition rate (%) of malaria parasite and KB3-1 cells according to the same method as in Example 1. Evaluation was based on the growth inhibition rate (%). The results are shown in Table 2.

  As a result, it was found that fractions C, D and E had relatively high antimalarial activity, particularly from the results of the malaria parasite growth inhibition rate (%) of each extract at a concentration of 1 μg / mL.

  As a positive control test, the growth inhibition rate (%) of quinine against Plasmodium was 91.8% at 0.1 μg / mL and 52.4% at 0.033 μg / mL. The growth inhibition rate (%) of colchicine for KB3-1 cells, which was conducted as a positive control test, was 49.7% at 5 ng / mL.

Example 3 Fraction C
(1) Purification of fraction C The fraction C (40.1 mg) obtained in Example 2 was further purified using silica gel HPLC. Specifically, fraction C (40.1 mg) was dissolved in EtOAc: EtOH = 15: 1 and then subjected to HPLC under the following conditions.

<HPLC conditions>
Column: cosmosil 5SL-II 10 mm id x 250 mm (Nacalai Tesque)
Mobile phase: EtOAc: EtOH = 15: 1
Flow rate: 3.0 mL / min
Detector: UV 250 nm.

  As a result, two peaks (Rt .9.0 min and Rt. 10.0 min) were detected. Each peak fraction was collected, the first peak fraction was designated as fraction MM-1 (12.5 mg, yield 31.2%), and the second peak fraction was fractionated MM-2 (10.1 mg, yield). Rate 25.2%).

(2) Identification of fractions MM-1 and MM-2 The fractions MM-1 and MM-2 obtained above were measured for ¹ H-NMR, ¹³ C-NMR and FAB-MS. The compound was identified.

(2-1) Fraction MM-1
The data results of ¹ H-NMR, ¹³ C-NMR and FAB-MS obtained for fraction MM-1 are shown below.
¹ H NMR (500 MHz, CD ₃ OD) d: 7.51 (1H, brs, 3), 7.35 (1H, brs, 10), 7.27 (2H, d, J = ca.7.9 Hz, 3 ', 5' ), 6.78 (2H, d, J = 7.9 Hz, 2 ', 6'), 6.47 (1H, dd, J = 5.5, 2.4 Hz, 6) 5.59 (1H, dd, J = 5.5, 1.8 Hz, 7) , 5.35 (1H, brs 13), 4.99 (1H, d, J = 4.9 Hz, 1), 4.62 (1H, dd, J = 7.9, 1.8 Hz, 1``), 4.24 (1H, brd, J = 12.2 , 6 "a), 4.21 (1H, dd, J = 12.2, 6.1, 6" b), 3.88 (1H, dd like, J = 7.9, 1.2 Hz, 5), 3.74 (3H, s, COOMe), 3.44 -3.47 (1H, m, 5 "), 3.38 (1H, dd, J = 9.2, 8.5, 3"), 3.35 (1H, m, 4 "), 3.18 (1H, dd, J = 9.2, 7.9, 2 "), 2.93 (1H, dd, J = 7.9, 4.9 Hz, 9), 1.86 (3H s, 6" -CH ₃ CO).
・¹³ C NMR (125 MHz, CD ₃ OD) dc: 172.6 (6 "-COCH ₃ ), 172.1 (12), 168.1 (14), 158.4 (4 '), 152.2 (3), 149.8 (10), 141.2 (6), 138.1 (11), 133.2 (1 '), 129.9 (7), 129.4 (3', 5 '), 116.2 (2', 6 '), 111.0 (4), 100.5 (1 "), 97.8 (8), 94.3 (1), 77.6 (3 "), 75.6 (5"), 74.2 (2 "), 71.4 (4"), 69.7 (13), 64.6 (6 "), 52.0 (COOMe), 51.0 (9), 39.9 (5), 20.7 (6 "-CH ₃ COO).
・ FAB-MS: 589 (MH) ^- .

  By comparing this result with literature reported values (J. Nat. Prod. 2003, 66, 97-102), it was determined that fraction MM-1 was a compound having the following structure.

(In the formula, Ac means an acetyl group (—COCH ₃ ), and Me means a methyl group (—CH ₃ ).)
(2-2) Fraction MM-2
The data results of ¹ H-NMR, ¹³ C-NMR and FAB-MS obtained for fraction MM-2 are as follows.
¹ H NMR (500 MHz, CD ₃ OD) d: 7.51 (1H, brs, 3), 7.28 (1H, brs, 10), 7.01 (1H, brs, 2 '), 6.89 (1H, d, J = 8.6 Hz, 6 '), 6.79 (1H, d, J = 7.9 Hz, 5'), 6.48 (1H, dd, J = 5.5, 2.4 Hz, 6), 5.59 (1H, dd, J = 5.5, 1.8 Hz , 7), 5.35 (1H, brs, 13), 4.97 (1H, d, J = 3.1 Hz, 1), 4.54 (1H, d, J = 7.9 Hz, 1``), 4.20 (1H, dd, J = 12.2, 6.1 Hz, 6``a), 4.15 (1H, brd, J = 12.2 Hz, 6``b), 3.89 (3H, s, 3'-OMe), 3.86 (1H, brd, J = 7.9 Hz, 5), 3.74 (3H, s, COOMe), 3.12-3.43 (4H, m, 2``, 3 '', 4``, 5 ''), 2.98 (1H, dd, J = 7.9, 3.6 Hz, 9).
・<sup>13</sup> C NMR (125 MHz, CD <sub>3</sub> OD) dc: 172.3 (12), 152.1 (3), 149.8 (10), 149.1 (3 '), 147.7 (4'), 140.7 (6), 138.3 (11) , 134.0 (1 '), 130.3 (7), 121.3 (6'), 116.2 (5 '), 111.5 (4), 111.6 (2'), 100.4 (1``), 97.8 (8), 94.0 (1 ), 77.7 (3``), 75.6 (5 ''), 74.2 (2``), 71.4 (4 ''), 70.0 (13), 64.6 (6``), 56.7 (3 ''-OMe) , 52.0 (COOMe), 51.0 (9), 39.4 (5).
・ FAB-MS: 619 (MH) ^- .

  From the above data, MM-2 was determined to be a novel compound having the following structure.

(In the formula, Ac means an acetyl group (—COCH ₃ ), and Me means a methyl group (—CH ₃ ).)
Example 4 Fraction D
(1) Purification of fraction D Fraction D (25.2 mg) obtained in Example 2 was further purified using silica gel HPLC. Specifically, fraction D (25.2 mg) was dissolved in EtOAc: EtOH = 10: 1 and then subjected to HPLC under the following conditions.

<HPLC conditions>
Column: cosmosil 5SL-II 10 mm id x 250 mm (Nacalai Tesque)
Mobile phase: EtOAc: EtOH = 10: 1
Flow rate: 3.0 mL / min
Detector: UV 250 nm.

  As a result, two peaks (Rt. 8.9 min and Rt. 9.9 min) were detected. Each peak fraction was collected, the first peak fraction was designated as fraction MM-3 (4.5 mg, yield 17.9%), and the second peak fraction was fractionated MM-4 (12.4 mg, yield). (Rate 49.2%).

(2) Identification of fractions MM-3 and MM-4 For the fractions MM-3 and MM-4 obtained above, ¹ H-NMR, ¹³ C-NMR and FAB-MS were measured. The compound was identified.
(2-1) Fraction MM-3
The data results of ¹ H-NMR, ¹³ C-NMR and FAB-MS obtained for fraction MM-3 are shown below.
・¹ H NMR (500 MHz, CD ₃ OD) d: 7.51 (1H, d, J = 1.4 Hz, 3), 7.44 (1H, d, J = 1.2 Hz, 10), 7.27 (2H, d, J = 8.5 Hz, 3 ', 5'), 6.77 (2H, d, J = 8.5 Hz, 2 ', 6'), 6.46 (1H, dd, J = 5.7, 2.4 Hz, 6), 5.56 (1H, dd, J = 5.7, 2.2 Hz, 7), 5.35 (1H, brs 13), 5.14 (1H, d, J = 4.9 Hz, 1), 4.66 (1H, d, J = 7.9 Hz, 1 "), 3.90 (1H , brdd, J = 7.7, 1.8 Hz, 5), 3.78 (1H, dd, J = 12.2, 2.0 Hz, 6 "a), 3.74 (3H, s, COOMe), 3.68 (1H, dd, J = 12.2, 2.0 Hz, 6 "b), 3.36-3.38 (2H, m, 3", 4 "), 3.27 (1H, m, 5"), 3.20 (1H, t-like, J = 7.9 Hz, 2 "), 2.90 (1H, dd, J = 7.7, 4.9 Hz, 9).
・¹³ C NMR (125 MHz, CD ₃ OD) dc: 172.2 (12), 168.3 (14), 158.4 (4 '), 152.5 (3), 150.0 (10), 141.6 (6), 137.8 (11), 133.3 (1 '), 129.9 (7), 129.7 (3', 5 '), 116.2 (2', 6 '), 110.7 (4), 100.5 (1 "), 97.9 (8), 94.4 (1), 78.3 (5 "), 77.8 (3"), 74.4 (2 "), 70.8 (4"), 69.8 (13), 62.1 (6 "), 52.0 (COOMe), 50.7 (9), 40.3 (5).
・ FAB-MS: 547 (MH) ^- .

  By comparing the above data with literature reported values, it was determined that fraction MM-3 was a compound having the following structure.

(In the formula, Me means a methyl group (—CH ₃ ).)
(2-2) Fraction MM-4
The data results of ¹ H-NMR, ¹³ C-NMR and FAB-MS obtained for fraction MM-4 are shown below.
・¹ H NMR (500 MHz, CD ₃ OD) d: 7.50 (1H, d, J = 1.4 Hz, 3), 7.32 (1H, brs, 10), 7.00 (1H, d, J = 1.4 Hz, 2 ' ), 6.90 (1H, dd, J = 8.1, 1.6 Hz, 6 '), 6.78 (1H, d, J = 8.1 Hz, 5'), 6.47 (1H, dd, J = 5.5, 2.6 Hz, 6), 5.56 (1H, dd, J = 5.5, 1.6 Hz, 7), 5.36 (1H, brs 13), 5.12 (1H, d, J = 3.7 Hz, 1), 4.57 (1H, d, J = 7.9 Hz, 1 "), 3.90 (1H, m, 5), 3.88 (3H, s, 3'-OMe), 3.74 (3H, s, COOMe), 3.71 (1H, dd, J = 12.2, 2.2 Hz, 6" a) , 3.66 (1H, dd, J = 12.2, 4.5 Hz, 6 "b), 3.33-3.35 (2H, m, 3", 4 "), 3.21 (1H, m, 5"), 3.14 (1H, dd, J = 7.9, 9.2 Hz, 2 ''), 2.97 (1H, dd, J = 7.9, 3.7 Hz, 9).
・¹³ C NMR (125 MHz, CD ₃ OD) dc: 172.2 (12), 168.3 (14), 151.9 (3), 149.6 (10), 148.9 (3 '), 147.5 (4'), 140.7 (6) , 138.1 (11), 133.8 (1 '), 130.1 (7), 121.1 (6'), 115.9 (5 '), 111.4 (2'), 111.3 (4), 99.9 (1 "), 97.8 (8) , 93.6 (1), 78.1 (5 "), 77.7 (3"), 74.3 (2 "), 70.6 (4"), 69.9 (13), 61.9 (6 "), 56.4 (3'-OMe), 51.8 (COOMe), 50.7 (9), 40.0 (5).
FAB-MS: 577 (MH) ^- .

  By comparing the above data results with literature reported values (J. Nat. Prod. 2003, 66, 97-102.), Fraction MM-4 was determined to be a compound having the following structure.

(In the formula, Me means a methyl group (—CH ₃ ).)
Example 5 Fraction E
(1) Purification of Fraction E Fraction E (240 mg, dry solid weight) obtained in Example 2 was further purified using an ODS column and silica gel HPLC. Specifically, after fraction E (240 mg) was dissolved in water, it was adsorbed by passing it through an ODS (8 g) packed glass column (inner diameter 20 mm, length 5 cm) that had been equilibrated with water. Then, water was introduced as an elution solvent to obtain a fraction E1 (32.6 mg [weight of dry matter], yield 13.6%). Further, a water-containing methanol solution (MeOH: H ₂ O = 20: 80) was introduced as an eluting solvent to fraction F2 (103.9 mg [dry solid weight], yield 43.3%), and then methanol was passed. Fraction E3 (67.5 mg [dry solid weight], yield 28.1%) was obtained, respectively.

Further, 18.6 mg of the concentrated dry solid (103.9 mg) of fraction E2 obtained above was dissolved in CH ₂ Cl ₂ : MeOH = 9: 1, and then subjected to silica gel HPLC under the following conditions.

<HPLC conditions>
Column: cosmosil 5SL-II (10 mm id x 250 mm),
Mobile phase: CH ₂ Cl ₂ : MeOH = 9: 1
Flow rate: 3.0 mL / min
Detector: UV 250 nm.

  As a result, one peak (Rt 18.2 min) was detected. This peak fraction was separated and purified to obtain fraction MM-5 (2.9 mg, yield 15.6%).

(2) Identification of fraction MM-5 The fraction MM-5 obtained above was measured for ¹ H-NMR, ¹³ C-NMR and FAB-MS. The results are shown below.
¹ H NMR (500 MHz, CD ₃ OD) d: 7.86 (1H, brs, 10), 7.51 (1H, d, J = 1.8 Hz, 3), 7.50 (1H, d, J = 1.8 Hz, 2 ' ), 7.49 (1H, dd, J = 8.5, 1.8 Hz, 6 '), 6.90 (1H, d, J = ca. 8.5 Hz, 5'), 6.54 (1H, dd, J = 5.5, 2.4 Hz, 6 ), 5.67 (1H, dd, J = 5.5, 2.4 Hz, 7), 5.49 (1H, d, J = 4.9 Hz, 1), 4.65 (1H, d, J = 7.9 Hz, 1 "), 3.99 (1H , dd, J = 7.9, 2.4 Hz, 5), 3.93 (3H, s, 3'-OMe), 3.80 (1H, dd, J = 12.2, 2.4 Hz, 6 "a), 3.74 (3H, s, COOMe ), 3.65-3.71 (1H, m, 6 "b), 3.23-3.33 (3H, m, 3", 4 ", 5"), 3.15 (1H, dd, J = 9.2, 7.9, Hz, 2 ") , 3.09 (1H, dd, J = 7.9, 4.9Hz, 9).
・¹³ C NMR (125 MHz, CD ₃ OD) dc: 188.5 (13), 169.9 (12), 168.3 (14), 159.1 (10), 155.5 (4 '), 152.5 (3), 149.6 (3') , 142.4 (6), 131.6 (11), 129.1 (7), 129.1 (1 '), 127.1 (6'), 116.2 (5 '), 112.7 (2'), 111.2 (4), 100.0 (1 ") , 97.8 (8), 94.0 (1), 78.7 (5 "), 77.7 (3"), 74.6 (2 "), 71.7 (4"), 62.9 (6 "), 56.5 (3'-OMe), 52.0 (COOMe), 51.4 (9), 40.6 (5).
・ FAB-MS: 575 (MH) ^- .
By comparing the above data results with literature reported values (J. Nat. Prod. 2003, 66, 97-102), fraction MM-5 was determined to be a compound having the following structure.

(In the formula, Me means a methyl group (—CH ₃ ).)
Example 6 Antimalarial Activity of Each Compound Antimalarial activity and toxicity of each compound obtained in Examples 3 to 5 were evaluated according to the method described in Example 1. Specifically, for antimalarial activity, samples of various concentrations were prepared for each compound obtained in Examples 3 to 5, and P. falciparum Honduras-1 strain was prepared according to the method described in Example 1. The growth inhibition rate was measured, and the sample concentration at which 50% of the malaria parasite was lethal was determined as IC ₅₀ . Toxicity was adjusted such that each compound obtained in Examples 3 to 5 was 150 μM, and the growth inhibition rate% of human cancer cells KB3-1 in the sample was determined according to the method described in Example 1 (MTT method). Asked. The results are shown in Table 3.

  In the above test, the growth inhibition rate (%) of quinine against malaria parasites as a positive control test was 90.1% at 0.1 μg / mL and 49.1% at 0.033 μg / mL. The growth inhibition rate (%) of colchicine for KB3-1 cells, which was conducted as a positive control test, was 49.0% at 5 ng / mL.

  From these results, antimalarial activity was observed in all the compounds, and in particular, MM-5 and MM-2 had higher antimalarial activity. Furthermore, the cytotoxicity results indicate that these compounds are both relatively safe compounds with low toxicity. That is, it can be seen that these compounds can be active ingredients of relatively safe antimalarials with low toxicity.

Formulation Example 1
Compound MM-1 200 mg, lactose 3 g, corn starch 1.28 g, hydroxypropylcellulose 200 mg, magnesium stearate 20 mg are mixed well, granulated, and then tableted to form an antimalarial in a tablet form of 100 mg per tablet. It is set as a composition.

Formulation Examples 2-5
Instead of Compound MM-1 200 mg in Production Example 1, Compound MM-2 20 mg (Production Example 2), Compound MM-3 500 mg (Production Example 3), Compound MM-4 50 mg (Production Example 4) or Compound MM -5 Using 10 mg (Production Example 5), in the same manner as in Production Example 1, the ingredients were mixed well, granulated, and then tableted to form an antimalarial composition in the form of a tablet of 100 mg per tablet. To do.

Formulation Example 6
Methanol extract fraction 1000 mg, lactose 2.5 g, potato starch 1.75 g, crystalline cellulose 240 mg, and magnesium stearate 10 mg are mixed well, this mixture is filled into capsules, and the methanol extract in one capsule is 1000 mg It is set as the antimalarial composition of the tablet form contained in a ratio.

  The present invention provides a novel phenylpropanoid condensation-type iridoid that has not been published in the literature and a method for preparing the same. The novel phenylpropanoid condensation-type iridoid has antimalarial activity and is useful as an active ingredient of an antimalarial composition. Moreover, according to this invention, the novel antimalarial composition which uses a series of phenylpropanoid condensation-type iridoid compounds containing the said novel phenylpropanoid condensation-type iridoid as an active ingredient can be provided.

Claims (7)

The following formula (1):

A novel phenylpropanoid condensation-type iridoid represented by The method for preparing a phenylpropanoid condensation-type iridoid (1) according to claim 1, comprising a step of extracting Morinda morindoides with a solvent containing an organic solvent and a step of adsorbing the resulting extract fraction. A pharmaceutical composition comprising the phenylpropanoid condensed iridoid (1) or a pharmaceutically acceptable salt thereof according to claim 1 as an active ingredient. General formula (2):

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group or a lower alkylcarbamoyl group. Or a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
An antimalarial composition comprising a phenylpropanoid condensed iridoid represented by the formula (I) or a pharmaceutically acceptable salt thereof as an active ingredient. The active ingredient is the following formula (1):

The following formula (3):

The following formula (4):

The following formula (5):

And the following formula (6):

The antimalarial composition according to claim 4, which is at least one selected from phenylpropanoid condensed iridoids represented by The following steps (1) to (4):
(1) extracting Morinda morindoides leaves with lower alcohol,
(2) extracting the lower alcohol extract obtained in (1) with a mixed solvent of n-hexane and water and separating the layers;
(3) extracting the aqueous layer obtained in (2) with ethyl acetate and separating the layers; and
(4) General formula (2) having a step of subjecting the ethyl acetate extract fraction obtained in (3) to an adsorption treatment:

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group or a lower alkylcarbamoyl group. Or a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
A method for preparing a phenylpropanoid condensation-type iridoid represented by the formula: The following steps:
A. (1) Morinda morindoides leaves are extracted with lower alcohol,
(2) extracting the lower alcohol extract obtained in (1) with a mixed solvent of n-hexane and water and separating the layers;
(3) extracting the aqueous layer obtained in (2) with ethyl acetate and separating the layers; and
(4) A phenylpropanoid condensed iridoid represented by the following general formula (2) is prepared by a method having a step of subjecting the ethyl acetate extract fraction obtained in (3) to an adsorption treatment,

(Wherein R ¹ represents a hydroxyl group, a lower alkylamino group or a lower alkoxy group, and R ² , R ³ and R ⁵ are the same or different and represent a hydrogen atom, a lower alkyl group, an acyl group or a lower alkylcarbamoyl group. Or a lower alkoxycarbonyl group, R ⁴ represents a hydrogen atom, a lower alkoxy group, —OCOR ⁷ , —OCONHR ⁷ , or OCOOR ⁷ [or more, R ⁷ represents a lower alkyl group], and A represents a single bond. Or when A is a single bond, R ⁶ is a hydroxyl group or a lower alkoxy group, and when A is a double bond, R ⁶ represents an oxygen atom.)
B. Next, a step of blending the phenylpropanoid condensed iridoid with a pharmaceutically acceptable carrier or additive,
A method for preparing an antimalarial composition according to claim 4 or 5.