JP2001335405A - Antibacterial antifungal agent - Google Patents

Abstract

(57) Abstract: A complex in which a compound selected from histidine, aspartic acid, pyrrolidone carboxylic acid and oxotetrahydrofuran carboxylic acid is coordinated to silver ions, and an antibacterial and antifungal agent containing the same. The silver complex of the present invention has a broad and strong antibacterial and antifungal spectrum, and is particularly useful as a material for daily life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a complex having excellent antibacterial and antifungal activity and useful as a material for a wide range of lifestyles, and an antibacterial and antifungal agent containing the same.

[0002]

2. Description of the Related Art In recent years,
Many attempts have been made to develop functional materials having new functions by applying agents having antibacterial and antifungal activities to materials for daily life, for example, materials such as fibers, sanitary products, tableware and packaging materials. These functional materials are provided with new functions by adding or kneading agents having antibacterial and antifungal activity to the materials. When applying antibacterial and antifungal agents to these functional material fields,
The drug is required to have a wide range of antibacterial and antifungal spectrum and safety, and it is required that the drug does not affect the quality of the material, durability, residual effect, economy, etc. .

[0003] Agents used so far as antibacterial and antifungal agents include benzimidazole, nitrile, isothiazoline, haloallyl sulfone, iodopropargyl, benzothiazole, phenol, organotin, pyridine. System, diphenyl ether system, chlorhexidine system and the like. However, many of these antibacterial and antifungal agents cannot show a sufficient antibacterial and antifungal effect by only one kind of agent. In addition, even if the drug itself has excellent antibacterial and antifungal activity, it causes a problem in compatibility with the material, and when applied to the material, does not necessarily show a sufficient antibacterial and antifungal effect. . Therefore, development of an antibacterial / antifungal agent having a broad antibacterial / antifungal spectrum and excellent in durability, residual effect, safety and the like without affecting the material used has been desired.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned circumstances, and as a result, a complex in which a specific amino acid or a specific carboxyl-containing heterocyclic compound is coordinated with silver ions has been widely used. The present invention has been found to exhibit an excellent antibacterial and antifungal spectrum and to be useful as a material for a wide range of lifestyles, thereby completing the present invention.

That is, the present invention provides a complex in which a compound selected from histidine, aspartic acid, pyrrolidonecarboxylic acid and oxotetrahydrofurancarboxylic acid is coordinated to silver ions.

[0006] The present invention also provides an antibacterial and antifungal agent comprising the above-mentioned complex as an active ingredient. Furthermore, the present invention provides an antibacterial and antifungal composition comprising the above-mentioned complex and a carrier.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The ligand of the complex of the present invention is a compound selected from histidine, aspartic acid, pyrrolidone carboxylic acid and oxotetrahydrofuran carboxylic acid. Among them, histidine, aspartic acid and 2-pyrrolidone-5 are used. -Carboxylic acid and 5-oxo-2-tetrahydrofurancarboxylic acid are more preferred. These ligands have stereoisomers, and in the present invention, both optically active forms and optically inactive forms can be used. Preferred examples of the optically active substance include L-histidine, L-aspartic acid, D-aspartic acid, (S)
-(-)-2-pyrrolidone-5-carboxylic acid, (R)-
(+)-2-pyrrolidone-5-carboxylic acid, (S)-
(+)-5-oxo-2-tetrahydrofurancarboxylic acid and (R)-(-)-5-oxo-2-tetrahydrofurancarboxylic acid.

The compound of the present invention is a compound in which the above-mentioned amino acid ligand or carboxyl-containing heterocyclic ligand is coordinated with silver to form a complex, and as a source of silver ions used in the present invention. In the above, a water-soluble silver compound or a sparingly soluble silver compound is used. Examples of the water-soluble silver compound include silver nitrate, and examples of the poorly soluble silver compound include silver oxide. In the compound of the present invention, the number of moles of the ligand to be reacted with respect to the number of moles of silver ions is not particularly limited, and varies depending on the kind of the ligand. Basically, the reaction molar ratio and the reaction pH are important, and may be appropriately set according to the compound to be obtained.

The compound of the present invention thus obtained has an excellent antibacterial and antifungal activity, and can be used as it is as an antibacterial and antifungal agent. The compound of the present invention can also be used as an antibacterial and antifungal composition by blending it with various carriers. Here, as the carrier, any of a solid carrier, a liquid carrier, and a mixture thereof can be used. Examples of the solid carrier include an inorganic solid carrier and an organic solid carrier. Examples of the inorganic solid carrier include silica, hydroxyapatite, zeolite, and titanium oxide. In the composition containing the inorganic solid carrier and the compound of the present invention, the compound of the present invention is preferably immobilized on the solid carrier. In order to immobilize the compound of the present invention on this carrier, it is preferable to carry out, for example, a heat treatment, a chemical bonding method or the like. The composition of the present invention containing such an inorganic solid carrier and the compound of the present invention has an antibacterial activity by a silver substitution reaction in the presence of a salt, which is a disadvantage of existing silver-containing antibacterial agents represented by, for example, zeolite-silver. And no discoloration due to silver ion light.

[0010] Examples of the organic solid carrier include various waxes and resins. Examples of the liquid carrier include water, alcohols, and acetone.

The antibacterial and antifungal agent of the present invention has a broad antibacterial and antifungal spectrum, does not affect the quality of the material, and its effect lasts for a long time. Properties, low mucous membrane irritation, etc., various materials such as fibers, sanitary products, foods, fruits and vegetables, clean films, packaging materials, bactericidal materials, paints,
It is applicable to glass filters for inorganic materials. on the other hand,
It is also effective in preventing bacterial infection due to wounds, bedsores, etc., and can be applied to the treatment thereof. At present, the emergence of antibiotic-resistant bacteria as a result of heavy use of antibiotics has become a major social problem, and the antibacterial antifungal agent of the present invention solves such a problem at once.

[0012]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The methods for measuring the antibacterial and antifungal activities in each of the examples are common, and the minimum growth inhibitory concentration (MIC) for bacteria, yeast and fungi is shown. The specific measuring method is as follows.

Bacteria: Inoculated into 5 mL of Soybean Casein Digest (SCD) liquid medium, pre-cultured at 35 ° C. for 24 hours, and 0.1 mL of a 100-fold dilution of the pre-cultured bacterial liquid was used as an SCD liquid containing 2 mL of a sample. The medium was inoculated. 35 ° C,
After shaking culture for 48 hours, the presence or absence of proliferation was determined.

Yeast: Inoculated into 5 mL of glucose / peptone (GP) liquid medium, pre-cultured at 35 ° C. for 24 hours, and 0.1 mL of a 100-fold dilution of the pre-cultured bacterial liquid was added to a GP liquid medium containing 2 mL of a sample. Inoculated. After shaking culture at 35 ° C. for 48 hours, the presence or absence of proliferation was determined.

Mold: After inoculating potato dextrose (PD) or M40Y slant medium, spores pre-cultured at 27 ° C. for 1 week are used to prepare a spore suspension (spore count: about 10 ⁶ / mL).
Was prepared. 0.1 mL of spore suspension containing 2 mL of sample
D or M40Y liquid medium was inoculated. After shaking culture at 27 ° C. for one week, the presence or absence of proliferation was determined.

Example 1 Synthesis and isolation of a silver complex with L-histidine (LH ₂ his) were performed. In aqueous solution _{Ag 2 O: L-H 2} his = 1:
The mixture was reacted at a molar ratio of 4 for 2 hours, and the resulting yellow transparent solution was added dropwise to excess ethanol to obtain a white powder soluble in water and insoluble in an organic solvent (yield: 72.1%) (Compound 1A) ).

Elemental analysis Actual value: C, 28.15; H, 3.63; N, 15.82. Calculated value: (for C _6.4 H _9.2 N ₃ O _2.2 Ag or monomer unit as [Ag (Hhis)] · 0.2EtOH. ): C, 28.3
4; H, 3.42; N, 15.49%.

3.39% weight loss by TG / DTA decomposition temperature. Decomposition temperature: 196 ° C Endothermic peak: 91.255 ° C Exothermic peak: 197 ° C

Mass spectrometry (positive ion ESI) 525.0 [M + H] ⁺ ([Ag (Hhis)] ₂ )

IR (KBr): 1635, 1577, 1459, 1417, 1342, 1314,
1271,1252,1148,977,967,925,837,777,624,537,426 (cm
^-1 )

¹ H NMR (D ₂ O, 25 ° C.) δ: 1.17 (EtOH), 3.65 (EtO
H), 3.06-3.24 (H6, two double doublets, 2H), 3.75-3.79
(H7, doublet of doublet, 1H), 7.12 (imd H5, s, 1H), 7.81
(imd H2, s, 1H) ppm.

¹³ C NMR (D ₂ O, 25 ° C.) δ: 19.5 (EtOH), 60.1 (EtOH
OH), 35.3 (C6), 59.6 (C7), 119.8 (imd C5), 136.4 (imd C4),
140.4 (imd C2), 181.0 (C8) ppm.

¹⁵ N NMR in solid state (24.5 ° C., BF = 200 Hz, refe
renced to NH ₄ NO ₃ ) δ: 40.5 (amino), 112.4 (Nτ), 149.5 (N
π) ppm.

Further, colorless plate crystals were obtained by slow evaporation of the reaction solution (yield: 39.6%).
(Compound 1B).

Elemental analysis Found: C, 27.78; H, 2.76; N, 15.74 Calculated: (C ₆ H ₈ N ₃ O ₂ Ag or monomer unit [Ag (Hhi
s)]): C, 27.50; H, 3.08; N, 16.04%.

IR (KBr): 1632,1575,1462,1402,1343,1255,
1148,973,912,835,780,624,551cm ^-1 .

Solid state ¹³ C NMR (24.8 ° C.) δ: 38.3 (C6), 5
7.9 (C7), 114.1 (imd C5), 137.4 (imd C4), 140.7 (imd C2),
180.6 (C8) ppm.

¹⁵ N NMR in solid state (24.7 ° C., BF = 200 Hz, refe
renced to NH ₄ NO ₃ ) δ: 1.1 (amino), 159.4 (Nτ), 191.3 (N
π) ppm.

TG / DTA No weight loss. Decomposition temperature: 183 ℃ Exothermic peak: 213,240,403 ℃

The histidine (L-H ₂ his) silver complex has two types, a water-soluble white powder and an insoluble colorless plate-like crystal, which have different structures. Elemental analysis, TG / DTA, FT-IR,
ESI-MS, measurement of molecular weight in aqueous solution, ¹ HN in solution
Characterization was performed by MR, ¹³ C NMR, ¹⁰⁹ Ag NMR, solid state ¹³ C and ¹⁵ N NMR, and the like. For insoluble crystals, elemental analysis, TG / DT
A, FT-IR, solid state ¹³ C NMR and ¹⁵ NNM
R, and further characterization by single crystal X-ray structure analysis. In both cases, the coordination atoms to the silver ion were Nπ of the imidazole ring and the amino group nitrogen N _amino , and the Nτ atom of the imidazole ring and the carboxyl group oxygen were not involved in coordination. Water-soluble powder in aqueous solution [Ag
(Hhis)], which is a binuclear complex having a composition of _{2. In} the solid state, this binuclear complex is used as a core to form an imidazole ring Nτ
A polymer {[Ag (His)] ₂ } _n is formed by hydrogen bonding between an atom and a carboxyl group of the adjacent binuclear complex. On the other hand, insoluble crystals are obtained by slow evaporation of a yellow transparent solution of a water-soluble powder. The composition is a [Ag (Hhis)] _n, one from the single crystal X-ray structure analysis Hhis ^- another and imidazole Nπ atoms of the ligand ligand N _amino is straight bidentate coordinated to silver AgN ₂
It was a polymer with repeating units and had a left-handed helical structure. However, insoluble crystals do not have a binuclear complex core like a water-soluble powder. Table 1 shows the measurement results of the antibacterial activity. The activity of the water-soluble complex tended to be stronger than that of the insoluble complex. However, it was effective against bacteria, yeast and mold.

[0032]

[Table 1]

Example 2 Racemic aspartic acid (DL-H_Twoasp)
The silver complex was synthesized and isolated. Ag in aqueous solution_TwoO: H_Two
The reaction was carried out at a molar ratio of asp = 1: 2 for 2 hours.
The color-clear solution was dropped into excess acetone, and slightly dissolved in water.
A white powder insoluble in the organic solvent was obtained (70.0% yield). Ma
The colorless transparent solution obtained by the reaction was used as an internal solvent,
Vapor di at room temperature using ethanol as an external solvent
Colorless needle crystals were obtained by ffusion (yield 62.
2%). These crystals are also slightly soluble in water and insoluble in organic solvents.
Was. White powder is used for elemental analysis, TG / DTA, FT-IR,
¹Characterized by HNMR. Colorless needles
Crystals are analyzed by elemental analysis, TG / DTANMR, FT-IR,¹H
NMR,¹³Characterized by CNMR and further
A single crystal X-ray structure analysis was performed. In this complex,
Unlike gin complex, colorless needle crystals and white powder have the same structure
It was a compound of. As a result of single crystal X-ray analysis,
Structure has Ag-Ag interaction (distance 2.870 °)
Ag_Two(Carboxyl O)_TwoA dinuclear complex of the core,
The g atom is surrounded by Ag-Ag bonds and carboxyl oxygen.
It was a three-coordinate structure. Two carboxyl groups are syn
Anti-crosslinking. N_aminoAtoms are involved in coordination
I didn't. From the elemental analysis, the composition was [Ag (DL-H
asp)]_Two・ H_TwoO. The solid state of this complex
X-ray diffraction data is not sufficient for higher-order structures,
Not decided yet. The enantiomeric ligand, ie
D-form and L-form aspartic acid are used as ligands, respectively.
Silver complex [Ag (D-Hasp)]_TwoAnd [Ag (L
-Hasp)]_TwoWas also synthesized. Each with white powder
Obtained (Yield: [Ag (D-Hasp)] _Two71.2
%; [Ag (L-Hasp)]_Two70.0%). these
Was obtained as a crystal, but was suitable for X-ray structural analysis.
Was not a crystal. Below, DL-aspartic acid-
The data of the colorless needle crystal of the silver complex is shown.

A 3.73% weight loss from room temperature to 165 ° C. (This corresponds to 1.0 water). Decomposition temperature: Decomposes gradually from around 165 ° C. Exothermic peak: 183,347 ° C Endothermic peak: 80 ° C

Elemental analysis Found: C, 19.54; H, 2.50; N, 5.26 Calculated: (as Ag (DL-Hasp) 0.5 H ₂ O) C, 19.30; H, 2.83;
N, 5.63.

FT / IR (KBr): 1600, 1487, 1393, 1353, 1308, 12
. 30,1147,1108,1066,987,900,850,817,660,531cm ^{-1 1} H NMR (solvent: D ₂ O, internal standard: TSD, measurement temperature: RT) δ: 2.6
_{3-2.85 (2H, m, CH 2} ), 3.90 (1H, q, CH, J = 3.66Hz) ppm 13 C NMR. ( Solvent: D ₂ O, internal standard: DSS, measurement temperature: RT) δ: 39 .
08 (CH ₂ ), 54.85 (CH), 176.83 (COOH), 179.99 (COOH) ppm.

The results of the measurement of the antibacterial activity are shown in Table 2. Both complexes were effective against bacteria, yeast, and mold, and were even more effective against mold.

[0038]

[Table 2]

Example 3 (S)-(-)-2-Pyrrolidone-5-carboxylic acid (S
-H_Twopyrrld) as a ligand
Was. Ag in aqueous solution_TwoO: SH_Twopyrrld = 1: 2
The reaction solution in molar ratio was stirred at room temperature for 2 hours and the resulting colorless
The clear solution is added dropwise to excess acetone, soluble in water, organic
A white powder insoluble in the solvent was obtained (yield: 76.0%). Also
A clear and colorless aqueous solution is used as the internal solvent, and acetone is used as the external solvent.
Vapor diffusion at room temperature
Water-soluble colorless needle crystals were obtained (yield: 66.7%). water
Elemental analysis, TG / DTA, FT-I for soluble powder
R, ESI-MS, molecular weight measurement in aqueous solution,¹
HNMR,¹³CNMR, solid state¹³CNMR and^Fifteen
Characterization by NNMR and the like was performed.
The white powder and the acicular crystals were compounds having the same structure. Acicular
The structure of the crystal was determined by single crystal X-ray diffraction.
The molecular structure of this complex is based on the Ag-Ag interaction (distance 2.9).
Ag having 022)_Two(Carboxyl O)_TwoCore Two
Nuclear complex [Ag (S-Hpyrrld)]_TwoAnd Ag
Around the atom by Ag-Ag bond and carboxyl oxygen
It had a three-coordinate structure. This binding mode is DL-asparag
It is very similar to the molecular structure of the silver phosphate complex. Two in a binuclear complex
Two carboxyl groups had a syn-syn bridge.
Also, the N atom in the heterocycle did not participate in coordination. Solid
In the body state, the carbonyl oxygen in the ring of this binuclear complex is different
-Assembly of a binuclear complex coordinated to one of the silver atoms of a dinuclear complex
Polymer by combination [Ag (S-Hpyrrrl
d)]_Two｝_nHad formed. This polymer is left-handed
It had a spiral structure (spiral pitch 12.736 °). Minute
From the measurement of the amount of particles and ESI-MS measurement,
The compound exists as a binuclear complex. Enantiomeric
Ligand, (R)-(+)-2-pyrrolidone-5
Carboxylic acid (R-H_Twopyrrld) as a ligand
Complex ｛[Ag (R-Hpyrrld)]_Two｝_nAnd race
Myloid ligand (SH)_Twopyrrrd and RH_Twopyrrl
d) in a ligand [Ag
_Two(R-Hpyrrld) (S-Hpyrrld)]_nof
Synthesis was also performed (yield: ｛[Ag (R-Hpyrrrl)
d)]_Two｝_n57.4% of crystals; [Ag_Two(R-Hpyrr
ld) (S-Hpyrrld)]_nPowder 86.2%).
Each was obtained as a colorless needle-like crystal and subjected to X-ray structural analysis.
Was. The R-body complex has an Ag-Ag interaction (distance 2.89)
9Å) having a carboxyl group having a syn-syn bridge
Right-handed helical polymer by self-assembly of binuclear complex [A
g (R-Hpyrrld)]_Two｝_n(Spiral pick
12.740 °). Therefore, the S-body complex {[Ag (S
-Hpyrrld)]_Two｝_nIs an enantiomer of La
Semi-complex is SH _Twopyrrrd and RH_Twopyrrl
Each anion of d is syn-anti crosslinked to silver atom
Coordinated binuclear complex [Ag_Two(R-Hpyrrld) (S
-Hpyrrld)] A sheet-like po-
Rimmer [Ag_Two(R-Hpyrrld) (S-Hpyrld)
rld)]_nMet. Ag-Ag interaction in binuclear complex
(Distance 2.875 °) is for S- and R-complexes.
It was slightly shorter than them. Below, [Ag (S-Hpyrr
ld)]_TwoThe data of is shown.

Elemental analysis Found: C, 25.10; N, 2.27; N, 5.79%. Calculated: (as monomer unit Ag (Hpyrrld)): C, 25.4
5 ;, H, 2.56; N, 5.94%.

No weight loss to TG / DTA decomposition temperature. Decomposition temperature: 188 ° C Exothermic peak: 194 ° C

Mass spectrometry (ESI) 472.9 [M + H] ⁺

IR (KBr): 1676,1593,1458,1407,1298,1154,
1106,1042,1010,721,496cm ^-1 .

¹ H NMR (D ₂ O, 25 ° C.) δ: 1.98-2.07 (H4a, m, 1
H), 2.37-2.41 (H3, m, 2H), 2.45-2.55 (H4b, m, 1H), 4.16-4.1
9 (H5, double doublet, 1H) ppm.

¹³ C NMR (D ₂ O, 25 ° C.) δ: 28.1 (C4), 32.4 (C3),
61.0 (C5), 183.0 (C6), 184.5 (C2) ppm.

Solid state ¹⁵ N NMR (24.0 ° C., BF = 120 Hz, refere
nced to NH ₄ NO ₃ ) δ: 72.3 ppm.

The results of the measurement of the antibacterial activity are shown in Table 3. All of the complexes were effective against bacteria, yeast, and mold, and showed extremely high activities.

[0048]

[Table 3]

Example 4 2-Pyrrolidone-5-carboxylic acid (H ₂ pyrrrld)
As a ligand related to the ligand, a water-soluble silver complex having 5-oxo-2-tetrahydrofurancarboxylic acid (Hothf) in which the NH group in the ring was substituted with oxygen was synthesized. The only coordinating donor atom present in the molecule of this ligand is oxygen. The ligand has an enantiomer, and in the complex synthesis, an S-form (S-Hothf), an R-form (R-Hothf), and a 1: 1 mixture thereof (racemic) are used as the ligands. . In each of these syntheses, an aqueous solution having a molar ratio of Ag ₂ : Hothf = 1: 2 was stirred at room temperature for 2 hours, and the obtained colorless and transparent solution was used as an internal solvent, and acetone was used as an external solvent at room temperature.
Colorless crystals were obtained by diffusion. S-
The complex and the R-complex were each obtained as needle crystals, and the racemic complex was obtained as cubic crystals. Yield 4
3.7%, 67.1%, and 32.1%. For these crystals, elemental analysis, TG / DTA, FT-IR,
¹ H NMR, ¹³ C NMR and ¹³ CN in solid solution
Characterization by MR was performed. Attempts were made to measure the molecular weight in the solution, but the solubility was low and a sufficient concentration could not be obtained, and no data could be obtained. Structural analysis of the three complexes could be performed by single crystal X-ray diffraction. All were polymers by self-assembly of a binuclear complex of Ag ₂ (carboxyl O) ₂ core. The Ag—Ag interaction in the binuclear complex is 2.823 ° for both the S- and R-complexes, and these values are shorter than those of the 2-pyrrolidone-5-carboxylic acid complex. Particularly, in the case of the racemic complex, it is 2.781 °, which is the value of Ag-Ag in metallic silver.
It is shorter than the distance (2.88 °). The two carboxyl groups are sy in the S- and R-complexes.
n-syn cross-linked, and in racemic complex, syn-a
anti crosslinked.

S-body complex {[Ag (S-oth
f)] ₂ ｝ _n is a ribbon-shaped left-handed helical structure (helical pitch 5.416 Å), an R-complex {[Ag (R-oth
f)] ₂ ｝ _n is its mirror image, and is a ribbon-shaped right-handed helical structure (helical pitch 5.4)
17Å). Self-assembly method is 2-pyrrolidone-
Unlike the case of the 5-carboxylic acid complex, in the S-form complex and the R-form complex, not only the carbonyl group oxygen in the ring but also one oxygen in the coordinated carboxyl group is determined by the adjacent binuclear complex. Participates in bonding with silver atoms. On the other hand, in the racemic complex [Ag ₂ (S-othf) (R-othf)] _n , the carbonyl oxygen in the ring does not participate in self-assembly, and two carboxyl oxygens bind to the silver atom of the adjacent binuclear complex. Each formed a stair-like polymer bonded. An aqueous solution of a 1: 1 molar ratio mixture of the S-complex and the R-complex was vaporized with acetone at room temperature.
Upon diffusion, a racemic complex [Ag ₂ (S-oth) identical to that obtained from the racemic ligand was obtained.
f) (R-othf)] _n was obtained (yield 43.5).
%). Therefore, it is understood that ligand exchange has occurred between the S-form complex and the R-form complex in the aqueous solution. The data of [Ag (S-othf)] and [Ag (R-othf)] are shown below.

[Ag (S-othf)] Elemental analysis Found: C, 25.09; H, 1.80%. Calculated: (Ag (S-othf) as monomer unit): C, 25.
34; H, 2.13%.

No weight loss to TG / DTA decomposition temperature. Decomposition temperature: 162 ° C, Endothermic peak: 238, 254 ° C. Exothermic peak: 246,258,319 ° C.

IR (KBr): 1760,1605,1416,1344,1291,1189,
1151,1046,1007,914cm ^-1 .

¹ H NMR (D ₂ O, 25 ° C.) δ: 2.16-2.23 (H4, m, 1H),
2.58-2.65 (H3 and H4, m, 3H), 4.91-4.94 (H5, m, 1H) ppm.

¹³ C NMR (D ₂ O, 25 ° C.) δ: 28.8 (C4), 30.6 (C3),
82.0 (C5), 179.8 (C6), 184.0 (C2) ppm.

[Ag (R-othf)] Elemental analysis Found: C, 25.38; H, 2.04%. Calculated: (Ag (R-othf) as monomer unit): C, 25.
34; H, 2.13%.

No weight loss up to TG / DTA decomposition temperature. Decomposition temperature: 169 ° C, Endothermic peak: 241,255 ° C. Exothermic peak: 246, 260, 313 ° C.

IR (KBr): 1761,1604,1419,1341,1291,1191,
1151,1048,1011,915 ppm.

¹ H NMR (D ₂ O, 25 ° C.) δ: 2.13-2.55 (H4, m, 1H),
2.57-2.67 (H3 and H4, m, 3H), 4.90-4.96 (H5, m, 1H) ppm.

¹³ C NMR (D ₂ O, 25 ° C.) δ: 28.8 (C4), 30.6 (C3),
82.0 (C5), 179.8 (C6), 184.0 (C2) ppm.

Table 4 shows the results of the measurement of the antibacterial activity. All of the complexes were effective against bacteria, yeast, and mold, and showed extremely high activities.

[0062]

[Table 4]

[0063]

The silver complex of the present invention has a broad and strong antibacterial and antifungal spectrum and is particularly useful as a material for daily life.

Claims (4)

[Claims] 1. A complex in which a compound selected from histidine, aspartic acid, pyrrolidonecarboxylic acid and oxotetrahydrofurancarboxylic acid is coordinated to silver ions. 2. The method according to claim 1, wherein the ligand is histidine, aspartic acid, 2-pyrrolidone-5-carboxylic acid or 5-oxo-.
The complex according to claim 1, which is a compound selected from 2-tetrahydrofurancarboxylic acid. 3. An antibacterial and antifungal agent comprising the complex according to claim 1 as an active ingredient. 4. An antibacterial and antifungal composition comprising the complex according to claim 1 and a carrier.