JP2003277203A - Antibacterial agent based on phlorotannins - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antibacterial agent based on a phlorotannin. <P>SOLUTION: The antibacterial agent is based on a phlorotannin. More particularly, the agent is one wherein the phlorotannin is selected from among phloroglucinol, eckol, phlorofucofuroeckol A, dieckol, 8,8'-bieckol, or a combination of at least two of these substances. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an antibacterial agent containing phlorotannins as a main component. More specifically, phloroglucinol, ecko
l), phlorofucofuroeckol
A), an antibacterial agent containing one or more phlorotannins selected from the group consisting of dieckol and 8,8'-bieckol as a main component.

[0002]

2. Description of the Related Art Today, application of antibacterial agents and antibacterial products is advancing in a wide range of fields for the purpose of controlling harmful microorganisms in human social life. They are (i) public health control, (ii) food hygiene control, (iii) pharmaceutical hygiene control, and (iv)
It is heavily involved in the daily living environment, such as in the industrial and public environmental hygiene management fields. These basic antibacterial substances permeate many living environment fields in a wide variety of states depending on the composition / type, application / purpose.

However, the following problems have been raised in the use of the above-mentioned antibacterial substances / antibacterial products and are increasing as a social problem: (1) What kind of chemical substances and at what concentration are contained in the antibacterial products. There are many unclear points as to whether they are used as antibacterial ingredients and their safety; (2) Frequent health hazards such as skin disorders, respiratory disorders and nervous system disorders; (3) MRSA in the medical field , VRE, antibiotic resistant bacteria problem, antibacterial spectrum problem, prevention
Limitation of therapeutic use, new problems for emerging bacterial infections; (4) Limitation of application of organic chemical antibacterial agents, waste liquid / environmental pollution problem; and (5) Inefficient application method to social life. As described above, the current antibacterial substances / antibacterial products cause many problems, but are inevitably used. In addition to these environmental problems, there are situations in each application field where not only environmental burden but also expensive facility maintenance and countermeasure costs must be taken in order to control specific disease microbes.

More specific examples include the following cases. (I) Vibrio parahaemolyticus Food poisoning due to Vibrio parahaemolyticus that occurs every summer is endless. Vibrio parahaemolyticus is a food poisoning caused by bacteria attached to fresh seafood, and as a countermeasure, there are places where measures such as ozone sterilization of live fish cages and ultraviolet sterilization seawater are being promoted in the distribution process of marine products. However, there are problems of ozone odor, facility costs, space, and operation, and there is an insufficient problem in the eradication effect of the bacteria themselves adhering to marine products. In addition, Vibrio vulnificus is often a fatal infection for people with liver damage, which is a serious medical problem. Urgent preventive and therapeutic measures are required for this disease.

(II) Salmonella bacteria Food poisoning caused by Salmonella bacteria has become a social problem as a problem of Salmonella bacteria contamination of the livestock industry environment itself and food poisoning via produced meat and eggs, and sufficient preventive and hygiene measures have not yet been advanced. . Further, in recent years, the problem of resistant bacteria due to antibiotics and the like has been highlighted. (III) Opportunistic infectious bacteria Opportunistic infectious bacteria are also bacteria that cause nosocomial infections, but in the medical field the problem of anti-resistant bacteria, environmental pollution due to disinfectants, sanitary environment, increased economic burden on facility development, identification It has problems such as long-lasting efficacy against bacteria and antibacterial spectrum.

(IV) Legionella bacterium Legionella bacterium is an infectious disease that causes pneumonia, and recently,
Breeding in cooling facilities such as circulating baths and buildings poses a problem, and a great deal of cost is required for countermeasures. Circulating bathtubs, etc. that have spread nationwide are environments where this bacterium is easy to breed, and people with weak resistance such as the elderly are easily affected and often fatal. Although ultraviolet rays and ozone sterilization of circulating water, purifying agents, membrane filtration, etc. are applied as countermeasures for this, the economic burden is large and sufficient results have not necessarily been obtained. The cooling water (cooling water) that circulates as a heating and cooling facility of a building has a high rate of Legionella bacteria breeding, which causes social problems in public environmental hygiene. Existing chlorine-based bactericides will cause metal corrosion in the facility,
Difficulty in persistence of effects and emission of toxic gas. Recently, there are cases in which organic antibacterial agents corresponding to them are used, but in any case, considerable expense is required for measures against Legionella. As a result, it has not spread enough, and as a result, it poses a familiar public health problem nationwide.

(V) Sick House Syndrome Sick house syndrome is a kind of allergic disease caused by an antibacterial component such as formalin contained in building materials, etc., and the antibacterial component composed of such a chemical substance has a safety problem. It indicates that there is. As can be seen from these examples, current antibacterial agents have different types, application areas, applications,
There are many problems in usage, and there are many parts that require countermeasures for each case, and improvement measures are required.

Generally, the antibacterial agents are roughly classified according to their composition into inorganic antibacterial agents and organic antibacterial agents. Among them, organic antibacterial substances include quaternary ammonium salt type, amino acid type, biguanide type, phenol type, aldehyde type, organic arsenic type,
There are pyridine-based antibacterial agents, natural antibacterial agents, and so-called pharmaceutical antibiotics, which are used in various fields depending on their properties. Among these, natural antibacterial agents are preferable from the viewpoint of safety. The natural antibacterial agents have various practical applications such as various essential oils, herbs and tree extracts, Chinese herbs, catechins, and hinokitiol. However, many conventional natural antibacterial agents are not practically effective in terms of their effectiveness. Therefore, it has practically sufficient efficacy and safety for each application, and
There is a strong demand for the development of antibacterial agents that are environmentally friendly.

[0009]

[Means for Solving the Problems] As a result of intensive studies by the present inventors, phlorotannins obtained by alcohol extraction from brown algae such as chrome, arame, and swordfish have strong antibacterial activity against various fungi. They found that they had activity, and completed the present invention.

[0010]

The present invention relates to an antibacterial agent containing phlorotannins as a main component. Specific examples of the phlorotannins include phloroglucinol, eckol, and phlorofucophloecol A.
ofuroeckol A), dietol, 8,8'-
One or two selected from bieckol
One or more of them can be used alone or in admixture as appropriate. The structural formula of each of these phlorotannins is shown in FIG. The above phlorotannins are seaweeds, especially,
It can be obtained by alcohol extraction from brown algae such as chrome, arame, and swordfish. It can also be obtained by chemical synthesis or the like based on the structural formula shown in FIG.

Examples of the fungi in which the phlorotannins obtained according to the present invention exhibit antibacterial activity include 32 kinds of fungi, such as food poisoning fungi, opportunistic infectious diseases, fish disease fungi, etc. listed in Table 1. It is not limited. The phlorotannins obtained by the present invention can be used as a bactericide against various disease-causing bacteria in water. For example, it is effective as a bactericidal agent for Vibrio bacteria adhering to the surface of seafood. Vibrio bacterium is a causative bacterium that causes food poisoning, and when Vibrio bacterium adheres to the body surface of red sea bream and prawns during transportation, it causes food poisoning symptoms when ingested by humans. Therefore, by putting the seafood in the seawater containing the phlorotannins of the present invention before or after the transport of red sea bream or the prawns, or by adding the phlorotannins to the seawater for transport, It is possible to remove the Vibrio bacterium from seafood. Such usage of phlorotannins can also be applied to other fish and shellfish distribution processes that have similar problems.

Further, the phlorotannins of the present invention can effectively act also in the control of disease-causing bacteria that propagate in circulating water or cooling water and adversely affect the public health environment and preventive measures against infectious diseases. For example, by adding the phlorotannins of the present invention to cooling water or bath water containing Legionella bacteria, it becomes possible to effectively sterilize aquatic Resinio bacteria. Further, phlorotannins of the present invention, as a result of an oral ingestion test in mice, no abnormality is observed in weight gain or general symptoms, therefore, food or drink with uptake or contact with the living body,
It can be safely used in any of additives, cosmetics, cleaning disinfectants, disinfectants, pharmaceuticals, daily necessities and the like. In addition, the phlorotannins of the present invention have an effect of preventing infection against bacterial infections, and are therefore also effective as prophylactic or therapeutic agents against bacterial infections.

[0013]

EXAMPLES Examples of the present invention are shown below, but the present invention is not limited thereto. Example 1 : Fluorotannin extraction method / type / property / ingredients Brown algae Ecklonia kurome was dried and pulverized. Krome powder (water content about 10%, 800g) was shaken with methanol (2,400mL) at 5 ℃ for 48 hours (90revmi
n ^-1 ) and extracted. The extract was concentrated under reduced pressure, methanol (240 mL), chloroform (480 mL), water (180 mL)
Was added, the mixture was separated into an upper layer and a lower layer, and the upper layer was extracted twice with ethyl acetate (300 mL). Crude phlorotannin was obtained by concentrating the ethyl acetate layer under reduced pressure. The yield of crude phlorotannin from chrome powder is about 3%.

Crude phlorotannins are phloroglucinol (2%) and equol (eckol: 9).
%), Phlorofucofuroecko
l A: 28%), dietol (dieckol: 24%), 8,
8'-Bayécol (8,8'-biekcol: 7%), others (3
0%), silica column chromatography (15mm id
X 150 cm, Wakogel C-300HG, Wako Pure Chemical Industries, Ltd.) and separated with chloroform: methanol: water (80: 20: 2, v / v). The collection of the single spots on the TLC plate of the separated fractions is called equol,
Florofco Froecol A, Dietol, 8,8'-Bayequol. Phloroglucinol (hydrate, purity
(98% or more) manufactured by Wako Pure Chemical Industries, Ltd., catechin (purity of 90% or more) and epigallocatechin gallate (EGCG; purity of 95% or more), which are one of the tannins contained in tea leaves, are manufactured by Kurita Industry Co., Ltd. The manufactured product was used for the following tests.

Example 2 : Antibacterial activity measurement method The minimum bactericidal concentration MBC (concentration of sterilizing 99.9% of the initial number of bacteria within 24 hours) was 24 well microplate and broth for sensitivity measurement (StB, Eiken chemical,
Japan) was used. For the reaction, 10 ⁴ to 10 ⁵ c of each fresh culture was used.
It was floated so that it was fu / mL, and 1 mL was put in each well.
Dissolve isolated phlorotannin, crude phlorotannin, or catechin in 70% methanol, add 20 μL to the wells, and shake at 37 ° C for 24 hours under aerobic conditions (60 rev mi
n ^-1 ) Cultured. 20 MBC measurements from each well
Approximately 200 μL was sampled at a fixed time, cultured in BHIA, and aerobically cultured at 37 ° C. for 24 hours, and the number of colonies was counted.
Since the following bacteria require special culture conditions,
The procedure was as follows. V. parahaemoliticu
s , V. vulnificus , V. cholerae ) contains 2.5% NaCl in the medium.
Was added. For Campylobacter, use Skiro agar medium (Becton Dickinson) and use Campy Po
Microaerobic culture using uch (manufactured by Becton Dickinson) was carried out for 72 hours. In addition, P. piscici which is a fish disease fungus
da , L. garvieae , V. anguillarum , S.iniae NIRA-2 ,
A. hydrophila was cultivated at a culturing temperature of 25 ° C. for 48 hours, and for the preceding four bacterial species, 2.5% of NaCl was added to the medium. A. salmonicida was grown on plain agar at 18 ℃ and 48 ℃.
The culture was carried out for a time. Further, the culture of Legionella bacteria was carried out using BCYE agar medium (manufactured by Becton Dickinson) at 37 ° C. for 4 days of carbon dioxide gas culture. In addition, white bacterium was cultured in Sabouraud medium at 37 ° C. for 3 days. For Helicobacter pylori, the reaction was carried out in Brucella broth medium, followed by microaerobic culture at 37 ° C. for 5 days using ABHK medium (manufactured by Nissui Pharmaceutical Co., Ltd.). Methanol (final concentration of 1.4% in the medium) did not affect the growth of the fungus.

Example 3 : Bactericidal action of crude phlorotannin Table 1 shows the bactericidal action of crude phlorotannin against 32 strains of 58 pathogenic bacteria. As is clear from Table 1, crude phlorotannin showed a bactericidal action against all strains used in the test. The tested bacteria are food poisoning bacteria, opportunistic infectious diseases bacteria, pathogens derived from animals and fish, and disease bacteria which are a problem in public health and health life. As a result, it was shown that crude phlorotannin has broad bactericidal activity against pathogenic bacteria that threaten our living environment. Although it had different susceptibility to food poisoning bacteria such as Salmonella, Vibrio parahaemolyticus, Campylobacter, and Bacillus cereus depending on the strain and strain, it had a fairly strong bactericidal action as a natural extract. It also had a strong bactericidal activity against MRSA, which is a problem as a resistant bacterium. In addition, lethal rates for patients with various opportunistic infection-causing bacteria, Legionella bacteria that are a public health problem, Helicobacter pylori bacteria that have been pointed out to be associated with gastrointestinal ulcers, and gastric cancer, and liver disease. A strong bactericidal action was also observed against Vibrio vulnificus, which has a high incidence, and Trichophyton, which is a skin disease-causing bacterium. Such a bactericidal effect can be caused by living things other than human beings (animals,
The same was true for disease-causing bacteria against seafood).

Table 1

[Table 1]

Table 1 (continued)

[Table 2]

Example 4 : Bactericidal activity of isolated phlorotannins Five types of isolated phlorotannins (phloroglucinol, equol, phlorofucofuroecol A, dietol and 8,8'-byecol) and tea leaves were used. For catechin and EGCG, which are one of the contained tannins, MBC was measured for 5 standard strains and 2 clinical isolates (Table 2).
As a result, among the phlorotannins, four kinds of equol, phlorofucofuroecol A, dietol and 8,8'-baiecol showed strong antibacterial activity against all the bacteria. Further, all of these four types of phlorotannins showed stronger antibacterial activity than catechin and EGCG which are tannins contained in tea leaves. Phloroglucinol, which is one of the phlorotannins, showed antibacterial activity only against the Regionola strain among the bacteria used in this test.

Table 2

[Table 3]

Next, various isolated phlorotannins and EGCG
The time course of the antibacterial activity of Vibrio parahaemolyticus against Vibrio parahaemolyticus is shown in FIG. At twice the concentration of MBC, equol, Fluorofukofuroequol A, and diecol killed the bacteria in 0.5 hours and 8,8'-baiecol was able to kill them in 2 hours, while EGCG was 4 times. Almost no bactericidal effect was observed over time. Thus, as in the case of the crude phlorotannins, the isolated phlorotannins were able to kill Vibrio parahaemolyticus in a short time.

Example 5 : Sterilizing Effect of Phlorotannins on the Surface of Red Sea Bream Body It was tested whether or not the antibacterial effect of phlorotannins can be expected in the actual cultivation or transportation of active red sea bream. That is, after the live red sea bream was immersed in the Vibrio parahaemolyticus solution (5 × 10 ⁴ CFU / ml) under aeration for 15 minutes to attach the bacteria, 0 (control), 25 mg / L, 50
It was bred for 24 hours in seawater adjusted to a crude phlorotannin concentration of mg / L and 75 mg / L. Take out the red sea bream at regular intervals, wipe the body surface on both sides with sterile gauze, 3% NaCl
The bacteria were washed out in PBS adjusted to the concentration, and the number of bacteria of Vibrio parahaemolyticus was counted using TCBS agar medium (Nissui Pharmaceutical). As a result, as shown in FIG. 3, in the 75 mg / L group, Vibrio parahaemolyticus was not detected from the surface of red sea bream 6 hours after breeding, and a clear decrease in the number of bacteria was confirmed. Also in 50 mg / L ward,
Vibrio parahaemolyticus was hardly detected after 12 hours of breeding. As described above, the bactericidal activity of the crude phlorotannin-added group was clear as compared with the control group.

Example 6 Sterilizing Effect of Phlorotannins on the Surface of Shrimp Prawns Tests were conducted to see if the antibacterial effect of phlorotannins can be expected in the actual shipping form of active prawns. In other words, live car shrimp with vibrio under aeration
After immersing it in a varnificus bacterium solution (3 × 10 ⁵ CFU / ml) for 10 minutes to attach the bacterium, 0 (control), 100 mg
The mixture was placed in seawater adjusted to a crude phlorotannin concentration of / L and 400 mg / L for 5 minutes under aeration. After that, the prawns were taken out, packed in a box together with sawdust, and placed in a thermostat at 15 ° C as is conventionally done.

One hour, one day, and two days after the packaging, the shrimp were taken out, the body surface was wiped with sterile gauze moistened with sterile physiological saline, and the bacteria were washed out with PBS adjusted to 3% NaCl concentration, and then TCBS was added. The viable count of Vibrio vulnificus was counted using an agar medium (Nissui Pharmaceutical). As a result, as shown in FIG. 4, in the 400 mg / L group, the number of bacteria was 1% or less of the control group after 1 hour of boxing, and a clear decrease in the number of bacteria was confirmed. One day after boxing, a decrease in the number of bacteria was also confirmed in the control group, but the bacteria remained at about 10 ³ CFU / shrimp. On the other hand, no bacteria were detected in the 400 mg / L group, and the bactericidal activity was clear as compared with the control group.

Example 7 : Antibacterial effect of phlorotannins against Legionella (1) Confirmation test on whether the antibacterial effect of phlorotannins is effective in control of disease fungi and preventive measures against infectious diseases in public health environment in hydrosphere I went. Using the Legionella bacterium pre-cultured in BCYE medium, the bactericidal effect of the present invention against the Legionella bacterium was added using a mixture of phlorotannin (crude phlorotannin) and isolated phlorotannin (diecole) in physiological saline. It was examined by the subsequent change in the number of viable bacteria. The number of viable cells over time is 4 after coating on the surface of BCYE medium.
The one cultivated for a day was used as an index. As a result, as shown in FIG. 5 and FIG. 6, even if the phlorotannins are single products or a mixture thereof, the viable cell count of about 500,000 cells per cc is about 24 hours after 6.3 hours at the 6.3 ppm concentration. 1% to 12.5
At ppm, it decreased to about 0.02%. The bactericidal activity continued after that, and even after 0.8 hours, even at 0.8 ppm, the initial viable cell count was 0.1% or less. The bactericidal effect lasted for a long time.

Example 8 : Antibacterial effect of phlorotannins against Legionella (2) In order to see the effect of addition of phlorotannins to cooling water and bath water, the actual water temperature was used and the environmental water temperature was adjusted to 15
The sterilization effect of Legionella by crude phlorotannin at -40 ℃ was examined. The culture method for preparation of Legionella bacteria and evaluation of viable cell count was in accordance with Example 1. As a result, FIG.
As shown in FIG. 7 and FIG. 8 (cooling water) and FIG. 10 and FIG. 11 (bath water), the bactericidal effect per concentration of the use of phlorotannin tends to progress faster and stronger when the environmental water temperature is higher. The bactericidal effect gradually progressed even in a low temperature environment. As described above, it was found that the application of phlorotannin kills the aquatic Legionella bacterium, and the effect continues. Crude phlorotannin is 12.5 mg / L in these water systems
With a certain degree, it is possible to easily sterilize and control Legionella bacteria. This indicates that the current measures against Legionella bacteria are high in cost, and have problems in efficacy and environmental protection, whereas application of the phlorotannins of the present invention is an epoch-making improvement measure. .

Example 9 : Safety of phlorotannins Various forms are conceivable for contacting or incorporating phlorotannins into the living body and utilizing them. For example, foods and drinks, additives, cosmetics, cleaning disinfectants, disinfectants, medicines, daily necessities, etc. are conceivable, but first, the safety in vivo was tested using small animals. ICR male and female mice (4
(Week-old) and added to the breeding water, free drinking water for 14 days,
Oral administration (single large dose) was performed, and the health condition thereafter was examined by the change in body weight. As a result, as shown in FIG. 12, no matter whether male or female, even if he continued to drink high-concentration phlorotannin-added water or swallowed a large amount at a time, there was no abnormality in weight gain in any case. Also, no abnormality was shown in the general condition.

In the present example, the phlorotannin mixture taken into the body was administered to the drinking water for 14 days, and 1500 mg / kg / da
y, female 1286mg / kg / day, single dose 168.2mg / kg / day, female
This intake is equivalent to 193.7 mg / kg / day, which is a large amount that cannot be obtained in normal life, and it has been shown to be highly safe in the actual application range to the living body. This indicates that there is little hindrance to incorporating phlorotannins into the living body for health inhibition by disease-causing bacteria and for the purpose of preventing and treating diseases, and one embodiment of an effective usage of phlorotannins As a result, it is suggested that it can be applied to medicines and foods and drinks.

Example 10 : Protective effect of phlorotannins against infection of Vibrio vulnificus Vibrio vulnificus is a serious infectious disease associated with acute sepsis in humans. Especially in the summer, there are many cases of infection due to fresh seafood and wounds at the seaside, which is particularly serious and highly fatal to people with liver disease. Here, using a mouse experimental infection model of Vibrio vulnificus isolated from the above patients, the protective effect of phlorotannins was examined. As a mouse, a 5-week-old ddy male (SPF) was used. D-galactosamine hydrochloride was added in advance at 1 mg / in order to artificially induce liver damage.
A mouse body weight of 1 g was intraperitoneally administered. Within 1 hour after that, a fresh culture of Vibrio vulnificus (2.5% NaCl
A lethal dose (2 × 10 ⁵ CFU) of supplemented BHI broth medium at 37 ° C. for 18 hours was intraperitoneally administered to mice, and 5 minutes after that, crude phlorotannin (400 mg / L) was intraperitoneally administered to 0.2 ml mice. , And the effect of preventing infection was examined by the survival rate over time.

As a result, as shown in FIG. 13, in the control group, the survival rate was 20% on the third day after the infection with Vibrio vulnificus, whereas in the phlorotannin-administered group, the survival rate was 3%.
Even after the day, the survival rate was as high as 80%. Thus, it was shown that phlorotannins have a protective effect against infection in the Vibrio vulnificus infection test using liver-injured mice. From Tables 1 and 2 and the above results, it was shown that the phlorotannins are useful for infection defense measures by acting on diseased bacteria in vitro and in vivo. Thus, in consideration of the results showing that the safety tolerance range was large (Example 9), the phlorotannins were found to be a drug against various infectious disease-causing bacteria and a health inhibitor associated with various disease-causing bacteria. It can be applied as a material for health foods and health drinks for the purpose of prevention and treatment, and also as an antibacterial processed product and sanitizing application.

[0031]

INDUSTRIAL APPLICABILITY The antibacterial agent containing phlorotannins as a main component of the present invention requires (1) a field requiring a broad antibacterial spectrum with one agent, and (2) disinfection / sterilization of a specific bacterial species. Use (3) When existing antibacterial agents do not work or cannot be used, (4) When a large economic effect is obtained,
(5) Fields of use in measures that emphasize environmental pollution, (6) Fields of application when importance is placed on safety for humans and animals,
Providing this product for each purpose according to the use such as (7) applications where antibiotic-resistant bacteria are not produced, (8) fields requiring new applications and usages, and (9) fields where a sustained effect is expected As a result, it has been possible to provide a very useful natural antibacterial substance that can solve the use problems of existing antibacterial agents. The application range of the antibacterial activity of the present invention is not particularly limited, but medical / public health fields, animal production / culture fields, environmental hygiene fields, daily necessities, industrial materials, food / beverage products, feed, medicinal and veterinary drugs, It can be used in various fields requiring antibacterial activity in social activities such as cosmetics.

[Brief description of drawings]

FIG. 1 is a diagram showing the structural formula of each phlorotannins.

FIG. 2 is a view showing a time course of antibacterial activity of various isolated phlorotannins and EGCG against Vibrio parahaemolyticus.

FIG. 3 is a view showing a bactericidal effect on the red sea bream body surface by fluorotannins.

FIG. 4 is a view showing the bactericidal effect on the surface of Kuruma prawn body by phlorotannins.

FIG. 5 is a view showing an antibacterial effect of phlorotannins against Legionella (a phlorotannin mixture).

FIG. 6 is a diagram showing the antibacterial effect of phlorotannins against Legionella bacteria (diecol).

FIG. 7 is a view showing the antibacterial effect of phlorotannins against Reginola in cooling water (37 ° C.).

FIG. 8 is a view (25 ° C.) showing the antibacterial effect of phlorotannins against Resiniocola in cooling water.

FIG. 9 is a graph (15 ° C.) showing the antibacterial effect of phlorotannins against Resiniocola in cooling water.

FIG. 10 is a view (40 ° C.) showing an antibacterial effect of phlorotannins against resinoella in bath water.

FIG. 11 is a view (25 ° C.) showing the antibacterial effect of phlorotannins against resinoella in bath water.

FIG. 12 is a graph showing the rate of weight gain in mice orally administered with phlorotannins.

FIG. 13 is a graph showing the protective effect of phlorotannins against Vibrio vulnificus.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) A61K 31/357 A61K 31/357 4C206 35/80 35/80 Z 4H011 A61P 31/04 171 A61P 31/04 171 // C07D 319/24 C07D 319/24 407/04 407/04 493/04 106 493/04 106C (72) Inventor Takashi Nakamura 1-9-45, Nanamikuma, Jonan-ku, Fukuoka-shi, Fukuoka (72) Inventor Iwamura Kenri 1-6-1 Okubo, Kumamoto City, Kumamoto Prefectural Institute of Human Chemistry and Serum Therapy (72) Inventor Akihiro Ginaga 1-6-1 Okubo, Kumamoto City, Kumamoto Foundation F Terms (reference) 4B021 LW03 MC01 MK05 4C063 AA01 BB01 CC82 DD82 EE01 4C071 AA01 AA08 BB01 BB07 CC13 EE05 FF16 HH05 JJ01 LL01 4C086 AA01 AA02 BA15 CA01 GA02 MA01 MA04 MA52 NA14 ZB35 ZC61 4C088 AA13 AC01 BA10 BA32 CA06 MA52 NA14 ZB35 ZC61 4C206 AA01 AA02 CA19 KA01 KA18 MA01 MA04 MA13 MA72 NA14 ZB35 ZC61 4H011 AA02 BA06 BB03 BB08 DD01

Claims (11)

[Claims] 1. An antibacterial agent containing a fluorotannin as a main component. 2. The phlorotannins are phloroglucinol, equol, eckol, phlorofucofuroeckol A, dietol, 8,8'-biequo.
The antibacterial agent according to claim 1, which is one or a combination of two or more selected from l). 3. The antibacterial agent according to claim 1, wherein the phlorotannins are phlorotannins derived from seaweed. 4. The antibacterial agent according to claim 3, wherein the seaweed-derived phlorotannin is a seaweed-derived phlorotannin selected from brown algae such as chrome, sea bream, and swordfish. 5. An antibacterial agent for a disease fungus in water, which comprises the phlorotannins according to any one of claims 1 to 4 as a main component. 6. The antibacterial agent according to claim 5, wherein the disease bacterium is a disease bacterium that attaches to seafood. 7. The antibacterial agent according to claim 6, wherein the disease bacterium adhering to the seafood is Vibrio bacterium. 8. The antibacterial agent according to claim 5, wherein the disease bacterium is a disease bacterium contained in circulating water or cooling water. 9. The antibacterial agent according to claim 8, wherein the disease bacterium contained in the circulating water or the cooling water is Legionella. 10. A prophylactic or therapeutic agent for bacterial infection, which comprises the phlorotannins according to any one of claims 1 to 4 as a main component. 11. The agent for preventing or treating bacterial infection according to claim 10, wherein the bacterium is Vibrio vulnificus.