A hepatic disorder suppressant comprising extracts having hepatic disorder suppressing effect as effective ingredients, wherein the extracts is obtained by extracting an avocado plant and/or a processed product thereof with an organic solvent is disclosed.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a hepatic disorder suppressant, and extracts and compounds which can be used as effective ingredients of a hepatic disorder suppressant.

<1> The Hepatic Disorder Suppressant of the Present Invention

The first hepatic disorder suppressant of the present invention is a hepatic disorder suppressant comprising extracts having hepatic disorder suppressing effect as effective ingredients, wherein the extracts is obtained by extracting an avocado plant and/or a processed product thereof with an organic solvent. The extracts having hepatic disorder suppressing effect comprise the extracts extracted with an organic solvent and the purified products thereof. Hereafter they are referred to as "substances having hepatic disorder suppressing effect" and explained.

The substances having hepatic disorder suppressing effect of the present invention are contained in sarcocarps, pericarps, seeds, leaves, leafstalks and branches of an avocado plant and the processed products thereof that are crushed, dried, or concentrated. Since the substances are contained especially in sarcocarps and pericarps, it is preferable to use these tissues and the processed products thereof.

The avocado plants used for the present invention belong to the genus Persea of the Laurel family. Alligator pear or Persea includes P. americana, Mexican race, Guatemalan race, Indian race and the like, especially P. americana is preferable. The extraction process of avocado plants is carried out by a conventional method such as the continuous method and batch-type method and so on, and by using cold or warm solvent for the desired period of time. For example, dry powder of an avocado plant is crushed, and dipped or shaken with an extracting solvent for 1 to 48 hours at room temperature. Then, the extraction residue is removed from the extracted solution, and the extract solution is concentrated by the filtration under reduced pressure or ultrafiltration. If necessary, the solvent is taken away by evaporation.

Among the solvents used for such an extraction process, organic solvents are preferable, and nonpolar organic solvents are more preferable. Specific examples of the solvents include n-hexane, cyclohexane, benzene and carbon tetrachloride. Of these solvents, n-hexane is preferable.

The extraction example of the substances having hepatic disorder suppressing effect of the present invention is illustrated below, but the present invention is not limited to these extraction examples. First, an avocado plant is freeze-dried, then to the dry powder thereof, n-hexane (not water-soluble and a nonpolar organic solvent) is added, thereby extracting the components soluble in this solvent. The amount of the solvent added to the avocado plant is preferably 1 to 200 ml per gram of the dry powder, more preferably 5 to 50 ml. Concerning extraction process, after this solvent is added to an avocado plant, the solution is stirred well with a stirrer and the like, thereby extracting the fractions soluble in a nonpolar organic solvent. This process is usually preferably repeated two times to 5 times. The solvent of the extraction fractions obtained in such a way is removed to obtain an oily extract. Concerning removing process of the solvent, various conventional methods can be applied such as evaporating away the solvent under atmospheric pressure or reduced pressure.

Furthermore, various chromatography methods such as adsorption chromatography and partition chromatography are used solely or combination with other methods to carry out chromatographic fractionation of the above extract, thereby further separating and purifying the extract. It is preferable to isolate and purify the unsaturated fatty acid derivatives represented by the formulae (1) to (5) to be contained in the hepatic disorder suppressant of the present invention from the fraction comprising the substances having hepatic disorder suppressing effect which is obtained by the above fractionation. The fractionated product comprising the substances having hepatic disorder suppressing effect (that is, the fraction comprising unsaturated fatty acid derivatives) is characterized by Rf value of between 0.19 and 0.25 when thin-layer chromatography (Silica Gel 60; Merck & Co., Inc., developing solvent; hexane/ethyl acetate=4/1) is carried out. Using this feature as an index, selection of fractionated products can be conducted.

The examples of chromatographic fractionation of the substances having hepatic disorder suppressing effect of the present invention are illustrated below, but the present invention is not limited to these examples.

The above-described extract is dissolved in solvent having low eluting ability, and the obtained eluent is subjected to fractionation by adsorption chromatography on a silica gel column. The elution is carried out step by step by adding solvents having high eluting ability with gradient. Then, the obtained eluents are fractionated by sampling periodically to separate and purify the extract. The fractionated extract comprising the substance having hepatic disorder suppressing effect can be obtained by removing the solvent from the fractions. Various conventional methods of removing the solvent such as evaporating the solvent under atmosphere pressure or reduced pressure can be used. Selection of the fractionated extract can be performed according to the above-mentioned method.

Well-Known methods for testing hepatic disorder effect can be used to determine whether the above-mentioned extracts and fractionated extracts comprise the substances having hepatic disorder suppressing effect or not. For example, models animals such as mouse and the like are divided into two groups.

While the extracts or the fractionated extract are administered for a certain period of time to the model animals of one group, nothing is administered to the model animals of the other group. After substances inducing hepatic disorders such as D-galactosamine are administered to them of each group, enzyme activities such as ALT and AST in model animals of each group are measured. The obtained data is used as an index of hepatic disorder to determine whether the extracts have hepatic disorder suppressing effect or not. Thus, it can be determined whether the extracts comprise the substances having hepatic disorder suppressing effect or not.

Next, the second hepatic disorder suppressant of the present invention is explained. The second hepatic disorder suppressant of the present invention comprises the compounds represented by the formulae (1) to (5) as effective ingredients. The compounds used as effective ingredients of the hepatic disorder suppressant of the present invention encompass novel linoleic acid derivatives represented by the formula (1) or (2), a novel oleic acid derivative represented by the formula (3), and linoleic acid derivatives represented by the formula (4) or (5). Hereafter the compounds represented by the formulae (1) to (3) are referred to "novel unsaturated fatty acid derivatives", and compounds represented by the formulae (1) to (5) are referred to "unsaturated fatty acid derivatives" and explained hereinafter.

First, novel unsaturated fatty acid derivatives used as effective ingredients of a hepatic disorder suppressant are described. The novel unsaturated derivatives of the present invention are the compounds having the structures of the above-described formula (1) to (3). That is, Compound 1 represented by the formula (1) (molecular weight 318: C.sub.21H.sub.34O.sub.2) is (2E,5E,12Z,15Z)-1-hydroxyhenicosa-2,5,12,15-tetraen-4-one. Compound 2 represented by the formula (2) (molecular weight 320: C.sub.21H.sub.36O.sub.2) is (2E,12Z,15Z)-1-hydroxyhenicosa-2,12,15-trien-4-one. Compound 3 represented by the formula (3) (molecular weight 380: C.sub.23H.sub.40O.sub.4) is (5E,12Z)-1-(acetyloxy)-2-hydroxyhenicosa-5,12-dien-4-one. The unsaturated fatty acid derivatives of the formula (1) to (3) are novel compounds that are first isolated, purified and identified in the present invention, and have excellent hepatic disorder suppressing effect, especially chronic hepatic disorder suppressing effect.

The unsaturated fatty acid derivatives represented by the formula (4) and (5) are known compounds that are isolated from an avocado, and together with the above compounds represented by the formula (1) to (3), they were isolated and purified as compounds showing hepatic disorder suppressing effect.

It has been reported that Compound 4 of the formula (4) has inhibitory effect on NO and O.sub.2.sup.- generation (BIO INDUSTRY, Vol.15, No.8, pp. 34 40 (1998)). Compound 5 of the formula (5) is called "persin", and is observed to have various growth suppressing effect as well as inhibitory effect on NO and O.sub.2.sup.- generation, and its physiological effect has been studied (Journal of Natural Products, Vol.61, No.9, pp. 1168 1170 (1998), Natural Toxins, 3, pp. 344 349 (1995), BIO INDUSTRY, Vol.15, No.8, pp. 34 40 (1998), WO 95/22696). However, hepatic disorder suppressing effect of the compounds of formula (4) and (5) has not yet been reported. It has been proved for the first time in the present invention that these compounds have excellent hepatic disorder suppressing effect, especially chronic hepatic disorder suppressing action.

Thus, all of the unsaturated fatty acid derivatives represented by the formulae (1) to (5) have hepatic disorder suppressing effect, and are colorless and oily compounds at room temperature having molecular weights of 300 to 400. Since these compounds can be dissolved in various solvents such as hexane and ethyl acetate, for example, they can be used by being mixed properly with fat-soluble substances such as various fatty acids which is liquid at room temperature.

The unsaturated fatty acid derivatives of the above-described formula (1) to (5) can be obtained by solvent extracting from an avocado plant, separating and purifying by the following method, or can be obtained by chemical synthesis.

In respect of chemical synthesis methods, the unsaturated fatty acid derivatives of the present invention can be synthesized by aldol condensation of aldehyde derivatives and methyl ketone (Paterson I, Goodman J M, Lister M A, Schumann R C, McClure C K, Norcross R D, Tetrahedron 46, pp. 4663 4684 (1990)), for example, as described in Natural Toxins, 3, pp. 344 349 (1995). These derivatives can also be synthesized in combination with known methods properly. These derivatives can be synthesized by the method described in International Publication WO95/22969 or the modified method thereof.

The unsaturated fatty acid derivatives of the formula (1) to (5) having hepatic disorder suppressing effect of the present invention can be obtained, for example, by extracting from an avocado plant with an organic solvent, isolating and purifying as described above.

The fractionated extracts comprising hepatic disorder suppressing effect is further fractionated by high performance liquid chromatography (HPLC), for example under the condition that the composition of eluents is properly adjusted, to obtain the novel compounds 1 to 3 of the present invention and compounds 4 and 5 having hepatic disorder suppressing effect. Identification of the compounds isolated and purified by the fractionation can be performed by using the observed data obtained by conventional methods such as .sup.1H-NMR, .sup.13C-NMR, IR spectrum and UV spectrum.

When the hepatic disorder suppressant of the present invention comprises the compounds of the above-described formula (1) to (5) as effective ingredients for suppressing hepatic disorders, these compounds of the formula (1) to (5) can be used solely, or in combination of two compounds or more.

<2> The pharmaceutical composition for suppressing hepatic disorders comprising a hepatic disorder suppressant of the present invention

The pharmaceutical composition of the present invention is a composition that comprises the above-described hepatic disorder suppressant, produced by conventional methods, and it is not particularly limited as long as it is expected to have hepatic disorder suppressing effect.

Dosage form of the pharmaceutical composition of the present invention is not particularly limited, however, such as tablet, granule, capsule, julep, drink and the like is preferable under the condition that the hepatic disorder suppressant is mixed with one or more kinds of carrier, excipient, integrator, preservative, stabilizer, flavor and the like as long as generally permitted for preparation. Such a preparation can be carried out by conventional methods used for usual production of pharmaceutical composition. The dosage of the above-described pharmaceutical composition varies depends on kinds of diseases, symptoms, ages of patients, weights of patients and the like, in case of adult, it is preferable to administer, orally, 1 to 100 mg of the unsaturated fatty acid derivatives of the formula (1) to (5) per day at once or at several times. It is also preferable to administer, orally, 100 to 1000 mg of the extract of an avocado plant with a nonpolar organic solvent at once or at several times, and 10 to 500 mg of fractionated extract obtained by chromatographic fractionation at once or at several times.

<3> The food composition for suppressing hepatic disorders comprising a hepatic disorder suppressant of the present invention

The food composition of the present invention is a composition that comprises the above-described hepatic disorder suppressant, produced by conventional methods. The food composition of the present invention is not particularly limited as long as it comprises the above-described hepatic disorder suppressant. The extract comprising hepatic disorder suppressant can be mixed with food materials together with various optional components, which are conventionally used as foods for desired amount. When the extract is added, particular attention needs not to be paid. Health foods and functional foods can be produced by conventional processing methods. The amounts of the extract depend on the kinds of foods. It is preferable to add 0.001 to 1% by weight of the unsaturated fatty acid derivatives of the formulae (1) to (5), and 0.01 to 10% by weight of the above-described extract or fractionated product, against whole weight of the foods in order not to change the taste of the foods and but to achieve enough hepatic disorder suppressing effect.
 

Claim 1 of 3 Claims

1. A linoleic acid derivative compound represented by the following formula (1) or (2): ##STR00005## (see Original Patent).

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