JPH0269431A - Production of reduced curcuminoid and use thereof - Google Patents

Abstract

NEW MATERIAL:Tetrahydrocurcuminoid expressed by formula I (R1 and R2 are H, OH or alkoxy). USE:A safe antioxidant derived from a natural product and enabling application to food, medicine or cosmetic industry by improving coloring properties by reducing deep yellow color tone of curcuminoids and simultaneously increasing antioxidation activity. PREPARATION:Radix of Curcuma longa is extracted with an organic solvent and the resultant extract (a compound expressed by formula II) is reduced in the presence of hydrogen in an organic solvent by a metal catalyst to provide the reduced curcuminoids (a compound expressed by formula I).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is directed to the use of turmeric, a tropical ginger plant.
The present invention relates to a method for producing reduced curcuminoids using a curcuminoid-containing mixture derived from S. rcuma longa as a raw material.

Curcuminoids are a group of compounds mainly composed of curcumin, a diketone that has been widely used as a yellow pigment in spices, curry powder, pickles, etc., but reduced curcuminoids obtained by reducing this are new substances. It not only has strong antioxidant activity, but also has the characteristic of significantly reducing the yellow color that curcumin inherently has.

Therefore, the present invention can be widely applied to the food industry, pharmaceutical industry, cosmetic industry, etc. as a safe and well-colored antioxidant derived from natural products.

(Prior Art) Food products are generally manufactured from agricultural products, marine products, livestock products, and the like. However, storage of food raw materials and products.

During the preservation process, food ingredients and products deteriorate due to microbial contamination and putrefaction, as well as chemical and physical effects, reducing their commercial value. For this reason, various food additives have been developed, and methods such as temperature treatment, oxygen removal treatment, vacuum packaging, low temperature storage, and radiation treatment have been developed and put into practical use.

Among these types of deterioration of food materials and products, the most problematic is the oxidation or peroxidation reaction of food components caused by oxygen in the air. Oxygen is important for maintaining the life of living organisms through respiration, but on the other hand, since it is a highly reactive compound, it reacts with various components in food, oxidizing or peroxidizing them.

It is known that not only does it reduce the value of the product, but it also causes the production of harmful substances in food. For example, nutritionally essential unsaturated fatty acids such as linoleic acid and lylunic acid are contained in foods.

It has been reported that it is easily peroxidized by oxygen in the air, producing peroxidized fatty acids and reactive radicals (free radicals), as well as carcinogenic substances such as malondialdehyde. In addition, peroxidized lipids, which are produced by peroxidation of unsaturated fatty acid molecules in lipids, are produced by chemical reactions.
It has also been reported that it alters proteins and nucleic acids in living organisms, causing carcinogenic effects and other effects on living organisms. ("Mutagen and Toxicity" Vol. 5, p. 243 (1982); "Food Packaging" Vol. 17, p. 106 (1986)).

In order to prevent such peroxidation of lipids, packaging techniques such as removing oxygen from packaging using an oxygen scavenger, vacuum packaging, and nitrogen gas displacement packaging are used. On the other hand, with the development of the chemical industry, synthetic antioxidants such as butylated hydroxyanisole (81-IA) and butylated hydroxytoluene (BIT) have been commonly used. However, as the use of these synthetic antioxidants increases, food pollution increases, leading to major safety issues, and consumers increasingly reject synthetic antioxidants, leading to a decline in their usage. The current situation is that

On the other hand, as mentioned above, peroxides and carcinogens that are generated in animal bodies due to the toxic effects of oxygen are thought to have a negative effect on animal cells. is thought to be related to cell aging and, ultimately, to lifespan (free radical aging theory). As a substance that supports the body's defense mechanism, it is highly expected to be used in foods, especially in the technical fields of health foods and nutritional foods, as well as pharmaceuticals and cosmetics.

However, natural antioxidants that are expected to be used in place of synthetic antioxidants that pose food pollution problems include vitamin C produced by chemical synthesis and vitamin E extracted from natural products (IW). tocopherol) is in practical use.

These naturally derived antioxidants are used in foods and medicines.

In order to use them appropriately in cosmetics, etc., it is important to find natural antioxidants with different properties and utilize them under conditions that exhibit their respective characteristics.

Plant-derived spices contain various compounds with antioxidant activity, and spices have been added to foods as food preservatives.

(Food Packaging, Vol. 19, No. 1, p. 97, 1987) However, many spices exhibit strong aromas and colors, and these properties make it difficult to add them to foods as antioxidants.
For example, it has been used in food products since ancient times. Curcumin contained in turmeric has an antioxidant effect and has been used to preserve and stabilize foods as the main component of spices produced from turmeric.

In other words, curcumin has a phenolic hydroxyl group of vitamin E in its molecule and a beta-diketone structure (Journal of Agricultural and・Hood Chemistry Volume 33 7
), p. 7, 1985), it is known to exhibit strong antioxidant activity.

On the other hand, curcumin is known to be a pigment that exhibits a strong yellow color in addition to the above-mentioned antioxidant properties (Phytochemistry, Vol. 27, No. 4, p. 969, 1988).
, and is used as a food additive color.

It is used as a raw material for curry powder and for coloring takuan.

The present invention uses curcumin and its analogs (curcuminoids), which have been used in foods as naturally derived spices, curry powder, and food yellow pigments since ancient times, as raw materials, and uses them as antioxidants through a normal reduction operation. Strongly active,
It produces a mixture of reduced curcuminoids, providing an alternative to synthetic antioxidants that is related to naturally derived substances, but this is not true for curcumin alone. The mixture of talcuminoids is completely unknown and new.

(Problems to be Solved by the Invention) Currently used are various synthetic antioxidants and naturally derived antioxidant substances. By improving naturally derived substances with strong antioxidant properties to replace vitamin C and vitamin E, and supplying highly safe antioxidant substances, we have made it possible to apply them to food, medicine, and cosmetics. It is something to do.

In particular, curcumin, which is known as an antioxidant, has a strong yellow tone, so if it is applied to foods, it will be colored yellow. The unavoidable disadvantage is that curcumin cannot be used and the versatility is significantly lacking.

In this way, substances with two types of properties are advantageous when both properties are utilized at the same time, but their uses are often limited in food products that require a variety of properties. is the current situation.

As for antioxidants, a highly versatile, safe, and inexpensive antioxidant that exhibits strong antioxidant activity and does not have coloring ability has not yet been developed.

(Means for Solving the Problems) The present invention has been made to solve these problems all at once, and in particular, from the viewpoint of pollution prevention and ensuring safety, which have been drawing attention recently. It is better to improve highly safe naturally derived substances that have been used in food since ancient times and to utilize the useful properties of naturally derived substances than to use synthetic chemicals. This was done based on the idea that it would be industrially useful.

As a result of various studies, it was produced from natural plants and has been used in food and medicine since ancient times. We focused on curcumin, a yellow pigment that is the main component of turmeric (genus Curcuma) and has antioxidant properties.

I had the idea that if I modified this chemically, I could obtain the desired new antioxidant.

After experimenting with various chemical modifications, it was discovered that when curcumin was hydrogenated, this reaction could be carried out efficiently and quantitatively, and that the resulting compound (tetrahydrocurcumin) was a new substance superior to curcumin. They discovered that not only does it have antioxidant properties, but its yellow color fades.

Moreover, this useful new knowledge can also be applied to the whole curcumin analogs (talcuminoids) contained in the rhizome of turmeric, that is, it can be applied to the whole mixture without separating it into each component. did.

The present invention was completed as a result of further research based on this new and outstanding knowledge.

(In the formula, R1 and R2 are the same or different and represent a hydrogen atom, a hydroxyl group, or an alkoxyl group.) Thus, the tetrahydrocurcuminoids newly obtained by the present invention by hydrogen reduction of curcuminoids are molecular It was discovered that due to the absence of double bonds in it, the yellow tone is bleached. This property exactly overcomes the drawback of curcuminoids, which had a strong yellow color that limited their use in industrial applications.

This is an epoch-making product that will expand its application to food additives, cosmetic additives, etc.

Even more surprisingly, it was discovered that reduced curcuminoids, which do not have double bonds in their molecules, have significantly increased antioxidant activity compared to talcuminoids, which have double bonds. This is thought to be because the antioxidant effect was suppressed by the conjugated double bond in the molecule.

Curcumin is already known to be a yellow pigment with antioxidant activity (Phytochemistry No. 27).
(Vol. 4, p. 969, 1988), the tetrahydrocurcumin produced by the present invention is a completely new compound. In addition, the present invention is the first to demonstrate the strong antioxidant activity and decolorization properties of tetrahydrocurcumin.

As described above, in the present invention, a mixture of talcuminoids that can be easily extracted from turmeric roots is hydrogen-reduced, decolorized, and has enhanced antioxidant activity without separating it into each component. It is characterized by obtaining a mixture of reduced talcuminoids.

Talcuminoids are contained in the rhizomes of turmeric.
It can be obtained in relative abundance by organic solvent extraction.

For example, after degreasing turmeric root with petroleum ether,
The orange powder obtained by extraction with benzene and concentration to dryness contains about half of curcumin (1) and substance (2) (3
) contained 20 to 25%, and (4) contained 5 to 10% (structural formula ■).

R1=R2=-OCH3(1) R1=H,R,=-OCH,(2) R=R,=H(3) R,:R,=OH(4) Antioxidant activity used in the present invention The analysis method is a chemical analysis method using an autooxidation reaction system of linoleic acid (Agricultural and Biological Chemistry, Vol. 45, p. 735, 1981), which is commonly used in research on antioxidant substances. In addition to the peroxidation reaction of rabbit red blood cell membrane lipids, which is commonly used as an analysis method similar to biological systems, and an analysis method using a rat liver microsomal enzyme system (antimutagenesis and anticarcinogenesis mechanism).

Plenum Publishing Corporation, 131
p. 1986), but in both analytical methods, the reduced talcuminoids used in the present invention exhibited strong antioxidant activity.

Next, we will describe a method for obtaining reduced talcuminoids from turmeric roots.

The dried root powder of turmeric is extracted with petroleum ether and defatted, and then further extracted with an organic solvent such as benzene.

A yellow extract is thus obtained, which is concentrated to dryness under reduced pressure to yield an orange powder. Since these include curcumin and its analogues, they are called talcuminoids in the present invention, and their structural formulas are as shown above. This is dissolved in an organic solvent such as acetone, methanol, or ethanol.1 Using a hydrogenation catalyst such as an activated Raney nickel catalyst, which is commonly used to produce hydrogenated oils for food additives, margarine, and shortening. Hydrogen gas can reduce the double bonds in the molecules of talcuminoids. In addition to acetone, the solvent may be any solvent that can dissolve talcuminoids.

In addition to reduced nickel, the hydrogenation catalyst may be any catalyst used in the production of edible hydrogenated oil, such as a manganese catalyst, a copper catalyst, or a zinc catalyst. Further, the conditions for the reduction reaction using hydrogen can be carried out in accordance with the production of hydrogenated oil (Food Oils and Fats and Their Processing, p. 74, Kenpakusha, 1981).

It is easy to recover reduced talcuminoids obtained by the reduction reaction. Since the reduction reaction proceeds in a constant manner, the entire amount of raw material talcuminoids is converted to reduced talcuminoids. Therefore, after removing the catalyst from the reaction solution.

By concentrating this to dryness, it is possible to obtain a crude product. Further, as a purification method, talcuminoids can be purified by a commonly used silica gel chromatography method, and if necessary, they can be further separated into individual products.

Next, we will discuss the confirmation of reduced talcuminoids obtained by reduction reaction. It was obtained by hydrogen reduction using pure curcumin using a Raney nickel catalyst. Confirmation of tetrahydrocurcumin is normal.

The analysis was carried out using methods such as mass spectrometry and proton NMR, which are used for structural analysis of chemical substances.

FIG. 1 is a development diagram obtained by silica gel chromatography. In addition, the chart diagram based on the mass spectrometry method is shown in the second page.
As shown in the figure. This shows that the molecular weight is 372. A proton NMR chart is shown in FIG. From this, it is analyzed that the double bond of curcumin is reduced. Thus, the structure of tetrahydrocurcumin was determined to be R1=R2=-QC)l in the following structural formula (II).

[Structural formula■]

Using a similar analysis method, the chemical structures of reduced forms of curcumin analogs were also analyzed, and R1 = 1. R2=
OCH, compounds, R, =R, =H, and R
It was determined to be a compound with 1=R,=QH.

Next, the antioxidant activity of the reduced talcuminoids thus obtained will be described.

FIG. 4 shows the thiobarbic acid method, which tracks the degree of inhibition of natural oxidation of linoleic acid by atmospheric oxygen. The antioxidant activity of reduced talcuminoids was demonstrated. Since no antioxidant substance was added to the control, the degree of color development of thiobarbic acid increased. This indicates autoxidation of linoleic acid. Reduced talcuminoids have been found to have stronger antioxidant activity than α-tocopherol.

Since the antioxidant according to the present invention is a chemically modified talcuminoid derived from a natural product, the antioxidant has an imperceptibly low toxicity and is extremely safe. This antioxidant can be used as it is, dissolved in a solvent, or dissolved in fats, oils, essential oils, etc.
It can be used as an additive to foods and cosmetics, or in some cases, talcuminoids or turmeric extract can be added to foods and cosmetics, etc. and then hydrogenated to directly use it as an antioxidant in foods and cosmetics. .

Moreover, since the antioxidant according to the present invention is obtained by reducing the talcuminoids as a mixture without isolating each component, there is no need to carry out a complicated and costly separation process, making the production easier. It can be carried out at low cost and in a short time, and furthermore, since various antioxidants are mixed, a wide range of antioxidant properties can be imparted.

The present invention will be explained below with reference to Examples and Test Examples, but these are illustrative and do not limit the present invention.

Example 1 1 kg of dried turmeric root powder was soaked in 2Q petroleum ether and extracted day and night with intermittent stirring. This was filtered to obtain a defatted powder. Next, 2Q of benzene was added and extraction was performed in the same manner. After obtaining a yellow extract by filtration, this was concentrated to dryness under reduced pressure to obtain 13 g of an orange dry powder. When this product was analyzed by liquid chromatography, which is commonly used for separation analysis, it was found that it contained 8.3 g of talcuminoids represented by structural formula (1).

1 g of the talcuminoids thus obtained was dissolved in 201g of acetone and placed in a glass reduction reaction vessel with a capacity of 100 mM. After adding 500 mg of activated Raney nickel catalyst to this, the air in one reaction vessel was replaced with hydrogen gas by a conventional method.

A rubber balloon filled with hydrogen gas is attached to the top of the reaction vessel to maintain a constant pressure, so that the hydrogen gas consumed by the reaction can be supplied. The temperature of the reaction vessel was maintained constant using a constant temperature bath kept at 30°C.

The mixture was stirred and a reduction reaction was carried out for 2 hours.

The Raney nickel catalyst was removed from the reaction finished solution by filtration, evaporated to dryness by vacuum concentration, and again dissolved in a small amount of acetone.The yellow color of the zero reaction finished solution was significantly reduced, indicating that it had been decolored due to the reduction reaction. Ta.

Separately, the diameter is 23. A glass chromatography column having a length of 30 ai was filled with silica gel for chromatography, and n-hexane was flowed to prepare the column. A sample solution containing the reactant was added thereto and adsorbed onto silica gel, followed by elution with a mixed solvent of n-hexane and ethyl acetate. 30 to 60% ethyl acetate (by volume)
Since the reduced curcuminoids were eluted by the mixed solvent containing the curcuminoids, they were collected and concentrated to dryness under reduced pressure, yielding 7111 mg of reduced curcuminoids.

When this was analyzed by liquid chromatography, it was confirmed that it was a mixture of reduced talcuminoids.

Test Example 1゜The reduced talcuminoid mixture prepared in Example 1 was used as a standard, and curcumin was used as a comparison substance.

Antioxidant activity was compared using the synthetic antioxidant BHA and the natural antioxidant α-tocopherol.

The thioparturic acid method used in the analysis is a method commonly used to measure antioxidant activity, and its principle will be briefly described.

Using linoleic acid, an unsaturated fatty acid, as a substrate, quantifying the thiobarbylic acid-reactive substance produced by the autoxidation reaction of linoleic acid using oxygen in the air as the oxidizing agent.6 The autooxidation product of linoleic acid reacts with thiobarbylic acid. As a result, a red pigment is produced, and by measuring the absorbance of this at 532 nanometers, the amount of autoxidation of linoleic acid can be measured. The antioxidant activity of the specimen is determined by the degree of inhibition of linoleic acid autooxidation in such a reaction system.

The antioxidant activities of the preparations obtained in accordance with the present invention by such a method are shown in FIG. 5. 200 μg of each preparation was added to 0 reaction solution 20Q.

As shown in the figure, reduced talcuminoid strongly suppressed the oxidation of linoleic acid even during the 20-day autoxidation reaction.

(Effects of the Invention) The present invention is naturally derived and has been used in foods and the like since ancient times. Improved curcuminoids produced from turmeric roots. It provides a new antioxidant substance that can be used safely and inexpensively as a raw material for foods, medical quantities, cosmetics, etc. as an antioxidant that can replace conventionally produced synthetic antioxidants. be.

[Brief explanation of the drawing]

FIG. 1 is a silica gel thin layer chromatogram. The developing solvent is a mixture of n-hexane and ethyl acetate at a ratio of 2:3 (volume ratio). The substance was detected by absorption of ultraviolet light (1) in the figure is curcumin. (II) is tetrahydrocurcumin. FIG. 2 is a chart of the mass spectrum of tetrahydrocurcumin. FIG. 3 is a proton NMR spectrum diagram of tetrahydrocurcumin. FIG. 4 is a diagram of antioxidant activity measured by the thiobarbic acid method. 10-: Control group 10-: Talcumin group 1Δ-: α-tocopherol group-・-: R of structural formula (II),=R,=-OCH3-×
-: R,=H,R,=-QC)I of structural formula (II). -〇-: R, =R, =H of the structural formula (If) -〇-: R1 = R, =OH of the structural formula [■] Figure 5 is a diagram showing the measurement of antioxidant activity by the thiobarbic acid method. 10-: Control group 10-: Orange powder extracted from turmeric root and concentrated to dryness.
HA district agent Patent attorney Door 1) Parent first 1 Origin of solvent precedent (I) (II)

Claims (1)

[Claims] 1. Reduced curcuminoids characterized by extracting turmeric rhizomes with an organic solvent and reducing the obtained extract with a metal catalyst in an organic solvent in the presence of hydrogen. Production method. 2. Curcuminoids in an organic solvent in the presence of hydrogen,
A method for producing reduced curcuminoids, characterized by reduction using a metal catalyst. 3. Antioxidant containing reduced curcuminoids as active ingredients.