JPH0825992B2 - Isothiuronium salt - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to an isothiuronium salt, a method for producing the same, and a pharmaceutical composition containing the same. Most of the isothiuronium salts are novel compounds. The compounds have useful antitumor, antiparasitic and immunostimulatory effects and can be used in human and veterinary therapy.

Background Art General Formula I Compounds in which R ¹ is methyl, ethyl or benzyl and R ² represents hydrogen are known (French Patent 788,429 and West German Patent 2,426,683). However, in these publications the compounds are only mentioned as intermediates and this publication does not describe any of their biological activity or their therapeutic use.

DESCRIPTION OF THE INVENTION According to a feature of the invention, the general formula I (Wherein R ¹ is, C _{1 ~ 6} alkyl, C _{2 ~ 6} alkenyl, C _{2 ~ 6}
Alkynyl, C _{3 ~ 6} cycloalkyl, Earl alkyl or aryl, said group being by connexion optionally substituted one or more hydroxy, mercapto and / or halogen, R ² is hydrogen, C _{1 1-6} alkyl, C _{2 - 6} alkenyl, C _{2 - 6}
Indicates alkynyl or C _{3 ~ 6} cycloalkyl, X represents an organic or inorganic anion, when R ² represents a hydrogen, R ¹ is other than methyl, ethyl or benzyl. ) Novel compounds and salts are provided.

The term "C _{1 ~ 6} alkyl" is a straight-chain or branched-chain saturated aliphatic hydrocarbon groups (e.g., methyl, ethyl, n- propyl, isopropyl, n- butyl, isobutyl, etc.). The term "C _{2 ~ 6} alkenyl" is a straight or branched chain olefinic unsaturated groups (e.g., vinyl, allyl, methallyl, etc.). The term "C _{2 ~ 6} alkynyl" is a linear or branched aliphatic group having at least one triple bond (e.g. propargyl etc.). The term "C _{3 ~ 6} cycloalkyl" is a cyclic saturated aliphatic hydrocarbon group (e.g., cyclobutyl, cyclopentyl, cyclohexyl, etc.). The term "aryl group" refers to mono- and polycyclic aromatic hydrocarbon groups (eg, phenyl, naphthyl, etc.).
The term “aralkyl” is an alkyl group substituted with at least one aryl group (eg, benzyl, β-phenyl-ethyl, etc.). The term "halogen" includes fluorine, chlorine, bromine and iodine atoms.

The alkyl, alkenyl, alkynyl, cycloalkyl, aryl and aralkyl groups may optionally carry one or more substituents selected from the group consisting of hydroxy, mercapto and halogen. Thus,
Examples of the substituent include the following groups: 2-chloro-ethyl,
3-bromo-propyl, 2-hydroxy-ethyl, 3-
Chloro-2-hydroxy-propyl and the like are indicated.

A preferred group of compounds of general formula I are those derivatives in which R ¹ is allyl.

A further preferred group of compounds of general formula I are those derivatives in which R ¹ is 2-halogeno-ethyl.

R ² preferably represents hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, allyl or cyclohexyl.

X preferably represents a halide anion, in particular chlorine, bromine or iodine ion.

Particularly preferred examples of compounds of general formula I are the pharmaceutically acceptable salts of the following derivatives:

N-aminoiminomethyl-S-methyl-isothiuronium salt, N-aminoiminomethyl-S-propyl-isothiuronium salt, N-aminoiminomethyl-S-allyl-isothiuronium salt, N-aminoiminomethyl-S- (2- Chloroethyl)-
Isothiuronium salt, N-aminoiminomethyl-S- (1-chloro-2-hydroxy-propyl) -isothiuronium salt, N-aminoiminomethyl-S- (3-chloro-propyl) -isothiuronium salt, N-aminoiminomethyl -S- (2-hydroxyethyl) -isothiuronium salt, N-aminoiminomethyl-S- (glycidyl) -isothiuronium salt.

Further preferred compounds of general formula I are N-aminoiminomethyl-N'-alkyl-S-allyl-isothiuronium salts, especially the corresponding N'-methyl, N'-ethyl, N '.
-N-propyl and N'-isopropyl compounds.
According to another aspect of the invention: a) the general formula II (Wherein, R ² than are those mentioned above) alkylating agent of the compound or a suitable salt, can be introduced R ¹ group, preferably the general formula R ¹ -Y (wherein R ¹ is the And Y is a leaving group, preferably halogen,) or is reacted with an alkylating agent of b) or of formula III A compound of the general formula R ¹ -SH, where R ¹ is as defined above.
Reacting with a compound of formula (I) and, if desired, converting the product thus obtained into a salt by reacting with an acid of the general formula HX, where X is an anion of an organic or inorganic acid. Methods of making compounds of general formula I and salts thereof are provided.

In the reaction, an isothiuronium salt is formed.
This reaction generally involves the formation of N-alkylated byproducts.

DETAILED DESCRIPTION OF THE INVENTION According to a preferred mode of realization of method a), the starting materials of the general formula II are not in the free base form but are used in the form of their suitable salts, preferably carbonates. The formation of N-alkylated derivatives is thus suppressed, and this is because the carbon dioxide evolved lowers the pH of the strongly basic medium.

As alkylating agents preferably the corresponding alkyl halides or dialkyl sulphates can be used, but other alkylating agents likewise apply. The reactants are used in equimolar amounts or the alkylating agent is added in excess. As reaction medium, inert organic solvents are used, preferably alcohols, aliphatic ketones, aliphatic nitriles or ethers.

The reaction is achieved at a temperature of 20-80 ° C under atmospheric pressure.

According to a preferred mode of realization of method a), the starting material of general formula II and the alkylating agent are in a molar ratio of 1: 1 to 1: 1.8,
The reaction is carried out in absolute ethanol, acetonitrile, dimethylformamide, acetone or ether at temperatures between 20 ° C and 30 ° C.

According to method b), the general formula IV Compounds of formula (which form a narrow subgroup of compounds of general formula I and R ² is hydrogen) are prepared by reacting compounds of formula III with thioalcohols of general formula R ¹ -SH. It Reactants are used in equimolar amounts or have the general formula
The R ¹ -SH thioalcohol is applied in excess. Alcohol, especially ethanol, is preferably used as the reaction medium. This reaction is optionally accomplished under pressure. Preference is given to working under a pressure of 1 to 5 bar and at a temperature of 20 to 100 ° C.

The starting materials of general formula II are known or can be prepared by methods known per se. Thus, N-aminoiminomethyl-thiourea can be easily prepared by reacting dicyandiamine with hydrogen sulfide (Houben-Weyl VIII., 214). N-aminoiminomethyl-N'-alkyl-thiourea derivatives of general formula II can be prepared by reacting a guanidine base with the corresponding alkyl isothiocyanate (US Pat. No. 4,009,163).

The starting material of formula III can be prepared by known methods.

The product thus obtained can be converted into a pharmaceutically acceptable salt formed with an organic or inorganic acid. For salt formation, formic acid, lactic acid, citric acid, maleic acid or sulfuric acid, hydrochloric acid, phosphoric acid or bromic acid are preferably used.

The compounds of general formula I have antitumor and immunostimulant properties acting against parasites. The strength and direction of activity and toxicity depend on the displacement of the molecule. Structurally the general formula I
Gutimine, which is related to the compound of G., has been tested pharmacologically as an antihypoxic agent [CA 66 452, 929 (1972
Year); Pathol.Phys.Exp.Ther, 10 (6)], and clinically tested as a substance causing microcirculatory disorders [Gemato.
l. Transfusiol. (1984), 29 (1), 49-52].

It has been found that the compounds of general formula I either maintain the tissue's depressed natural immune system at normal levels or increase them to the same normal level.

Thus, animal and human tissues have an immune system (eg, an oncolytic system). Once the activity of the system has diminished or stopped, various diseases and tumors appear and become manifest themselves. The compounds of general formula I activate the innate immune system,
And thus useful in all cases when it is desired to increase the reduced activity of the immune system and further increase its normal activity.

The compounds of general formula I show further useful biological effects (for example, the treatment of microcirculatory disorders, the binding of harmful radicals to health, the improvement of the function and the longevity of cells in the anoxia phase).

The bioactivity of the compounds of general formula I is shown by the following tests. However, it does not show all the effects of highly active compounds.

Tests for specific effects Immune tests From blood obtained from paying lymphocytes, healthy donors and patients with malignant lymphoma and solid tumors that metastasize, respectively, Ficoll-Uro
miro (Byum 1968) Lymphocytes were isolated on a physiological gradient. When choosing patients belonging to the latter group, attention was paid to reduced ADCC and NK activity. Phagocytic cells were removed by treatment with iron powder and a magnet. ADCC and ADCC have been modified a little (Lung et al.
l) 1981) Perlman and P.
erlman) (1970). 10 ^{5 51} c
Chicken red blood cells labeled with r and coated with anti-chicken red blood cell rabbit serum were incubated with lymphocytes for 4 hours at 37 ° C. The reaction in which the activity of the circularly separated cells floating on the surface was stopped was measured by a gamma ray measuring instrument. The rate of chromium release is expressed as the Cytotoxicity index (CI%). This value is one of the previous publications of the present inventors (L
ng et al., 1980). See Table 1. NK : NK activity was measured by the method of Jondal and Pross (1975) with some modifications (Lng et al., 1981). TC19 constructed with ⁵¹ cr labeled K-562 tumor cells containing 10% non-complementary calf serum
9 Cultured with fector cells in liquid nutrient medium. The reaction in which the radioactivity (chromium release) of the circularly separated cells floating on the surface was stopped was measured by a gamma ray meter. Killing of cells of interest (cytotoxicity index) was expressed as the difference between the test release and the spontaneous release.

Statistical calculations were performed by single sample test. Some compounds of general formula I show significant immunostimulatory effects (eg compounds prepared according to Examples 11, 12 and 16).
The compounds enable normal and strongly diminished NK and K cell activity to be significantly increased above normal levels. The effect is very strong and restores the cytotoxic activity, which was reduced to 1/10 of the initial value, to the initial level (Table II).

In the dose range corresponding to the expected human plasma concentration, the compounds of general formula I increase the NK and K cell activity of human lymphocytes and stimulate the NCMC and ADCC responses at dose-dependent rates, respectively. Furthermore, according to the preliminary results of the immunological test, this compound enhances Bastos transformation and migration.

When substitutions on the nitrogen atom are made, the molar isotropic immunostimulatory effects associated with toxicity are generally reduced.

Since the cytotoxic activity of patients suffering from tumors is reduced proportionally to the stage of the disease, and this is further reduced by conventional cell fixation therapy, the compounds of general formula I have a strong immunostimulatory effect. Having and being not an immunosuppressant is very important. This is especially important from the perspective of recovery.

Leukocyte migration The spontaneous (irregular) migration of leukocytes is carried out with some slight modifications (Kalmr and Jersey (Kalmr
and Gergely), 1982) by Matsukoi et al.
cCoy et al) (1977) and measured on agarose microdroplets.

A 2 ml agarose drop (0.2%) was placed on the transfer plate. (Greiner, Federal Republic of Germany). TC199
Liquid nutrient medium was added and the plates were hermetically sealed. After 24 hours, the transition area was measured with a stereomicroscope. The transition area is expressed in mm ² .

Translocation of white-red spheres Direct (irregular) translocation of healthy donor polymorphonuclear cells was increased by the compounds according to Examples 11, 12 and 14. The optimal dose reached 1.0 μg / ml. At high doses (10 μg / ml), the effect was poor (Table III).

Mitogen-induced bud transformation 10% non-complementary calf serum, antibiotics and 25mH HEPES (Se
The lymphocytes were cultured in TC199 liquid nutrient medium finished with rva). 2.10 200 μl of cell suspension containing ⁵ lymphocytes
Microplate (Manufacturer: Sterili (Sterili
n) United Kingdom) and conducted 5 experiments in parallel.

Phytohemagglutinin / leukocyte agglutinin (manufacturer: Falmaty, Sweden) at 2 and 10 μg / ml respectively and Concanavalin A (Calbiochem) at 25 μg / ml were added to the cultures, the above values being related to the final concentration.
The culture was incubated at 37 ° C for 72 hours. Eight hours before the end of the culture period, 0.5 μCi ³ H thymidine (Kemapol, Thiecoslovakia) was added to the sample. Incubation was stopped by freezing the culture. After melting, the sample was filtered on an automatic harvester (Dynatec). The radioactivity of the sample was measured with a scintillator counter. This activity is c.
Expressed as pm (Tables IV and V).

Statistical analysis Significance was measured by a single sample 2T2 test. Example 1
The results obtained with the product of 1 are shown in Tables I, II and III.

Preliminary rapid test for determination of antitumor and immunostimulatory effects This method was devised in our laboratory for rapid testing of large numbers of samples. CFLP female mice (average weight 30g)
4 million ascites lymphoma cells were inoculated ip.

In this study, animals were used which had an easily visible tumor on day 4, ie ascites. At least 10 animals were used for each group, and mice were orally treated with 1/10 of the LD ₅₀ value.

Twenty-four hours after oral treatment, the results were evaluated by Giemsa stained ascites application specimens based on cytological analysis. The control group used the same number of animals as in the treatment group.

Tumor cell damage, tissue activation and terminal toxic effects were evaluated.

To assess antitumor efficacy, the percentage of killed and healthy tumor cells was assessed. The results are expressed according to the following scale. Tumor cell killing Specific effect 0-30% No effect.

30-70% Moderate effect.

70-100% Strong effect (suppression).

The increase in the tissue's immune system was assessed on the basis of the number and activity of neutrophilic granule cells, lymphocytes and macrophages found in ascites tumor cells and involved in the immune system. The activity of the immune system is also demonstrated by the rate at which the cells in ascites form plasma-crosslinks with tumor cells. If there were no differences in the number and activity of the cells according to this evaluation, there would be no increase over control. A moderate effect is observed when the increase in cell number or activity over control reaches 20%. This effect is strong when the increase in cell number and immune system activity is 20% or more higher than the control.

Toxicity was measured by assessing morphological changes in neutrophil granule cells and lymphocytes, plasma vasoquarization, nuclear division, multinodular formation and toxic granulation. Toxicity is expressed on the scale below. Test 1. In Vuitoro K-562 human erythroid leukemic cells and P-388 mouse changes high toxic anti-tumor effect on the observed results toxicity own cells exceeding 20% above No change toxic 20% change moderate toxicity Lymphocyte cell cultures were treated with 1-100 μg / ml test substance.

2. In vivo a) NK-like ascites lymphoma 1 million Nemeth-Kellner ascites lymphocytes in 20 CFLP male mice (average weight 30g) ip
Transplanted. [The new mouse ascites tumor should be used as a screening tool. Neoplasm
a) Volume 8, page 337 (1961)]. Subjected half of the animals as a control, and were each day and 5 days po and ip treated with various compounds of general formula I 1/10 of the other half LD ₅₀ values. (Lower doses were used when 1/10 of the LD ₅₀ value was effective.) In the group exposed to daily treatment, cytomorphologic measurements of ascites smears were made after 24 hours, and The ratio of damaged and killed cells was assessed respectively. The survival ratio was measured in the group treated for 5 days.

b) L ₁₂₁₀ tumor 10 ⁶ L ₁₂₁₀ tumor cells in 20 BDF ₁ female mice (body weight 20 g)
IP transplanted to. Treatment started 24 hours after tumor implantation and continued for 8 days. Each group consisted of 5 animals and the daily doses were 5, 50 and 500 mg / kg po. The control group also consisted of 5 animals. The survival ratio was observed.

c) Lewis long tumor 6 animals were used in each group. The dose is 5 and 50 mg / kg. The control group also consisted of 6 animals. C ₅₇ B _{1 in} exam
Female mice (weight 20 g) were used.

The tumor was sc implanted in the muscle of the right leg. After 10 days, the legs were amputated, the oral procedure started and continued for 9 days. Animals were sacrificed and metastases were counted under a stereomicroscope.

d) Naturally-occurring mammalian tumors of various species (tube c
Dogs with c.) were treated with 1-10 mg / kg oral dose of test substance for 4 weeks. Trial resections were performed and tissue samples were collected for histological analysis.

The compounds according to Examples 11, 13, 14, 15, 27, 28, 34, 35, 36, 38 show a marked antitumor effect. Thus Example 11
Compounds according to K- in tissue culture at a concentration of 4 μg / ml
562 Inhibits human erythroid leukemia cells. On the other hand, this compound inhibits the growth of P-388 cells only at a concentration of 40 μg / ml and increasing the concentration to 400 μg / ml does not enhance the activity. Compounds with strong activity show a dose-dependent effect in the concentration range of 0.5-5 μg / ml, whereas compounds with low activity are not dose-dependent. According to in vivo tests, this group of compounds has no or very little activity on L ₁₂₁₀ .

This compound significantly reduces the number of lung metastases in Lewis long tumors. Compounds 11, 13, 14, 15, 22, 27, 28, 45
Is effective at doses lower than 1/10 of the LD ₅₀ value. Example
A compound according to 14 produces 50 lung metastases at a dose of 5 mg / kg.
%, And this result is particularly significant due to the fact that LD ₅₀ = 2380 mg / kg.

It has been found that this effect can be greatly enhanced by repeated treatment rather than increasing dose.

The compounds according to Examples 11, 13, 14, 20, 22, 27, 45 are:
It was proved to be active against NK-like ascites tumor at a concentration lower than 1/10 of LD ₅₀ value. These compounds show a dose-dependent increase in survival ratio and longevity. These compounds show an immunostimulatory effect at low doses, while at the same time exhibiting a direct antitumor effect at high doses. Thus Example 11
Compounds 22 and 22 show immunostimulatory effects at doses of 25 mg / kg and 20 mg / kg, respectively. The compounds of Examples 11 and 22 are
It is cytotoxic at doses ranging from 250 to 500 mg / kg and 40 to 160 mg / kg. S-allyl-, S-1-chloro-2-hydroxy-propyl- or S-1-bromo-of formula I
The 2-hydroxy-propyl-substituted compounds are highly active against naturally occurring mammalian tumors in dogs. Biopsies taken after 3-4 weeks of treatment showed that the tumor (tubular cc.) Consisting of lymphocytes and neutrophilic granule cells, macrophages and possibly eosinophilic granule cells was aggressive. Cell invasion was observed. Altered degeneration and strong degradation were observed on tumor cells.

NK cells form plasma cross-links with tumor cells and this causes a large dilution of tumor cells in plasma foam degeneration and nuclear DNS stands. This nuclei-plasma relationship changes, the nuclei swell strongly and the plasma basophilicity decreases.

In about 1/4 of these cases, erythrocyte invasion in the tumor is negligible, while tumor cells swell and degenerate to clear.
Intercellular stands deposit very high amounts of hyaline pollutants.

Oral administration of 30 to 120 mg (0.5 to 2 mg / kg) daily 6 to 12
Upon administration of the compound of Example 11 in the month, significant improvement or recovery of human-derived metastases of mammalian tumor, ovarian tumor and pancreatic tumor was observed.

Test of antitumor effect in combination 1) Combination with known cell-immobilizing agents Various cell-immobilizing agents having biological alkylation action together with the compound of general formula I have NK-like ascites tumor CF
It was administered to LP mice. The cell fixative is 1/5 or 1 of the LD ₅₀ value.
Oral, intraperitoneal or intravenous injection was given at a dose equivalent to / 10 or at the most effective dose indicated in the prior art. The compounds of general formula I were administered orally once or several times at a dose of 1/10 or 1/20 of the LD ₅₀ value 48 hours after the treatment with the cell-immobilizing agent. Thus, on the one hand cyclophosphoamide, carnomustine, degranol, cibromodulcitol and dibromomannitol and on the other hand Examples 11, 13, 14, 15, 1
Combinations of 6, 27, 28, 45 compounds were administered. The antitumor effect was enhanced and the immunosuppression was reduced compared to the control group treated only with the cell fixative.

2) Combinations with known vitamins The isothiuronium salts of general formula I can be effectively combined with medium doses of vitamins A and D ₃ and high doses of vitamin C. Good results have been obtained in both pharmacological studies and human clinical cases.

3) Combination with known hormones In the treatment of hormone-dependent tumors, this combination proved to be useful both in pharmacological studies and in human clinical cases.

4) Use in surgery The compounds of general formula I have been successfully used in pharmacological studies in the case of solid tumors before and after surgery (NK-like solid, Yoshida). On the basis of pharmacological tests, it can be stated that the compounds of general formula I are likewise suitable for human surgical applications for pre- and post-treatment.

Testing for antiparasitic effect The compounds of general formula I were administered orally for 3 days to dogs infected with ticks (Ixodes lysinus). Thus N-aminoiminomethyl-S-allyl-isothiuronium hydrogen chloride was administered orally at a dose of 1-2 mg / kg and the killing ratio of ticks was recorded. 48 hours after administration of the active ingredient of general formula I, all ticks were killed in the dog.

Clark Radical Binding The compounds of Examples 9, 10, 11, 16, 23 and 29 significantly reduce the toxicity (LD ₅₀ ) of hydrogen peroxide, organic peroxides and biological alkylating (free radical forming) agents. Let Based on these preferred toxicity data, the compounds of general formula I are more suitable for binding free radicals and protecting against radiation than the known isothiuronium derivatives obtained from the corresponding thioureas. Thus Example 23
The therapeutic effect of the compound of is better than that of beta-aminoethyl-isothiuronium hydrogen chloride.

Cardioprotective effect on isoprenaline necrosis 5 mg / kg of isoproterenol was added to male CFY rat (weight 250
~ 300g) ip. 10 animals were used in each group. Some animals were used as controls and others used Compound N
o.14 was administered at 1 to 5 mg / kg, ip or 10 to 50 mg / kg po. Two weeks later, the heart was subjected to histological evaluation. Necrosis ratio and intact area of heart muscle were measured. It has been found that all treatments with N-aminoiminomethyl-S-allyl-isothiuronium hydrogen chloride of general formula I lead to a significant reduction in necrosis.

In the damaged area, the test compound is believed to exert its effect through the binding of hydrogen peroxide produced by neutrophil granule cells. Other free radical binding and antioxidant molecules exert similar effects in this model.

Circulatory and Respiratory Effects The compound according to Example 11 does not significantly affect the circulation parameters and respiratory function of cats with open and closed chest when administered at an iv dose of 10 mg / kg. The following parameters were tested. Ventricular and ambient pressure, cardiac cycle (motion) ECG, volume / min, elasticity, respiratory volume, respiratory rate and resistance. Intravenous administration above 10 mg / kg reduced left ventricular pressure and cycle. At the 50 mg / kg dose, these effects were significant and long lasting. At iv dose of 100 mg / kg, strong blood circulation changes were observed, but the cat died. Effect of N- (aminoiminomethyl) -S-allyl-isothiuronium salt (halide). (Compound A) According to yet another feature of the invention, a compound of the general formula I wherein R ¹ is C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, C _3-6 cycloalkyl, arealkyl or Aryl, the group optionally substituted with one or more hydroxy, mercapto and / or halogen, R ² is hydrogen, C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _3-6 cycloalkyl, and X represents an organic or inorganic anion.) Is provided as an active ingredient.

The pharmaceutical compositions of the present invention can be prepared by methods of the pharmaceutical industry known per se. The active ingredient of the general formula I can be preferably finished in the form of capsules in a mixture with the commonly used auxiliaries (slip agents etc.), which capsules are manufactured by using automatic encapsulation machines. It The pharmaceutical compositions can likewise be prepared in the form of non-oral compositions for powder ampoule injection and infusion, which compositions are likewise prepared by methods known per se. As the solvent, for example, distilled water or physiological saline can be used.

The active ingredients of the general formula I can likewise be finished in the form of ointments, especially lipophilic ointments. Active ingredients of the general formula I which have a strong odor are preferably finished by encapsulation in microcapsules, for example by the formation of cyclodextrin-comprising complexes.

The pharmaceutical compositions according to the invention likewise may contain, in addition to the compounds of the general formula I, one or more known physiologically active substances as active principle.

The pharmaceutical composition of the present invention can be used for both human and veterinary treatment. When used as an immunostimulant,
Oral or rectal dose is preferably 0.5-25 mg / kg
Is. Higher doses are preferably applied for topical treatment.

Industrial Applicability The present invention mainly relates to novel compounds having antitumor and immunostimulatory effects.

Modes for Carrying Out the Invention Further details of the present invention are shown in Examples, but the scope of protection is not limited to these Examples.

Starting Materials Example 1 N-aminoiminomethyl-thiourea carbonate.

Fill the autoclave with 84.0 g (1.0 mol) of dicyandiamide and 300 ml of water. 34.0 in closed autoclave
G (1 mol) of gaseous hydrogen sulfide is introduced as follows. That is, at a temperature of 20 ° C, the pressure in the autoclave is 1.
Sufficient hydrogen sulfide gas is introduced to reach 5 bar. The gas introduction is stopped and the autoclave is allowed to cool and heat to 80 ° C. During that time gaseous hydrogen sulfide is introduced at a rate such that the pressure in the autoclave is constant and is 1.5 bar. After the entire amount of hydrogen sulfide gas has been introduced, the autoclave is heated to 80 bar until the pressure drops to 0.3-0.4 bar.
Keep at ° C. The reaction mixture is cooled to 20 ° C., flushed with nitrogen and filtered. Cool the clear filtrate to 0 ° C.,
Then add carbon dioxide gas. Precipitated white crystalline N
The-(aminoiminomethyl) -thiourea carbonate is filtered off, washed with cold water and dried at 60-80 ° C. Thus, 100 g of the desired compound, yield 67%, melting point 127-129 ° C.
Is obtained.

The IR spectrum of the product thus obtained is compared with that of a standard sample of the compound.

Example 2 N-aminoiminomethyl-N'-methyl-thiourea carbonate.

To a solution of 5.9 g (0.1 mol) guanidine base and 30 ml acetone is added a solution of 7.3 g (0.1 mol) methyl isothiocyanate in 10 ml acetone. This isothiocyanate solution is added to the guanidine solution at a rate such that the temperature of the mixture does not exceed 40 ° C. This reaction mixture is mixed with 40
Let stand for 4 hours at 0 C, then the solvent is removed in vacuo. The residual light yellow oil is suspended in water to give a opalescent solution. Carbon dioxide gas is introduced into the solution thus obtained, and the desired compound precipitates in the form of white crystals.

Yield: 12.0 g (73.5%). Melting point: 132-134 ° C.

Example 3-8 In a manner similar to Example 2, the following compounds are prepared.

3.N-aminoiminomethyl-N'-ethyl-thiourea-carbonate 4.N-aminoiminomethyl-N'- n -propyl-thiourea-carbonate 5.N-aminoiminomethyl-N'-isopropyl-thiourea-carbonate 6.N-aminoiminomethyl-N'- n -butyl-thiourea-carbonate 7.N-aminoiminomethyl-N'-allyl-thiourea-carbonate 8.N-aminoiminomethyl-N'-cyclohexyl-thiourea-carbonate The following examples show the preparation of final products of general formula I.

Example 9 N-aminoiminomethyl-S-methyl-isothiuronium iodide.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are suspended in 50 ml absolute ethanol. To the suspension thus obtained is added 17.0 g (0.12 mol) of methyl iodide. The reaction mixture is heated to a soft boil, which produces carbon dioxide. The reaction mixture is heated to boiling for 30 minutes and cooled to room temperature. The mixture is filtered to remove the resulting crystalline precipitate. The clear filtrate is evaporated in vacuo and the residual oil is recrystallized from ethyl acetate. The yellow crystals are filtered off and dried at 40-50 ° C. Thus 22.1 g of the desired compound are obtained. Yield 85%, melting point: 124-125 ° C Example 10 N-aminoiminomethyl-S- n -propyl-isothiuronium bromide.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are suspended in 50 ml absolute ethanol. Carbon dioxide is evolved when the suspension mixture is gently heated to boiling with stirring. The reaction mixture is heated to boiling for 45 minutes and cooled to room temperature. The mixture is filtered to remove the resulting crystallized material. The clear filtrate is evaporated in vacuo and the oily residue is crystallized from ethyl acetate. The white crystals are filtered and dried at 40-50 ° C. Thus 1
9.5 g of the desired compound are obtained. Yield 81%, melting point 122-1
24 ° C.

Example 11 N-aminoiminomethyl-S-allyl-isothiuronium bromide.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are added to 50 ml absolute ethanol.
To this suspension thus obtained is added 14.5 g (0.12 mol) allyl bromide. The reaction mixture is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 30 minutes and cooled to room temperature. The mixture is filtered in order to remove the resulting precipitated material. The filtrate is evaporated in vacuo and the oily residue is crystallized from ethyl acetate. The precipitated crystals are filtered and dried at 40-50 ° C. This gives 19.6 g of the desired compound. Yield 8
2%, melting point: 123-125 ° C.

Example 12 N-aminoiminomethyl-S-allyl-isothiuronium chloride.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are added to 50 ml absolute ethanol.
9.18 g (0.12 mol) of allyl chloride are added to the suspension thus obtained and the reaction mixture is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 1 hour and cooled to room temperature. This mixture is
Filter to remove the resulting crystallization.
The filtrate is evaporated under vacuum. The oily residue is crystallized from ethyl acetate. The precipitated crystals are filtered and dried at 40-50 ° C. This gives 15.7 g of the desired compound. Yield 81%, melting point: 125-127 ° C.

Example 13 N-aminoiminomethyl-S- (2-chloroethyl)-
Isothiuronium bromide.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are added to 50 ml absolute ethanol.
In the suspension thus obtained, 17.2 g (0.12 mol) of 1-
Bromo-2-chloro-ethane is added and the reaction mixture is heated to boiling with vigorous stirring. The reaction mixture is refluxed for 90 minutes and cooled to room temperature. The mixture is filtered to remove the resulting precipitated material. The clear filtrate is evaporated in vacuo. The oily residue crystallizes from ethyl acetate. The precipitated white crystals are filtered and 40 ~
Dry at 50 ° C. This gives 17.2 g of the desired compound. Yield 66%, melting point: 142-143 ° C.

Example 14 N-aminoiminomethyl-S- (1-chloro-2-hydroxy-propyl) -isothiuronium bromide.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are added to 50 ml absolute ethanol.
The suspension thus obtained contains 20.8 g (0.12 mol) of 1-
Bromo-2-hydroxy-3-chloro-propane is added. The reaction mixture is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 90 minutes and cooled to room temperature. The mixture is filtered to remove the resulting precipitated material. The clear filtrate evaporates in vacuo. The oily residue is crystallized from ethyl acetate. The slightly cream-colored crystals that have precipitated are filtered off and 40-5
Dry at 0 ° C. This gives 17.8 g of the desired compound. Yield 61%, melting point: 118-119 ° C.

Example 15 N-aminoiminomethyl-S- (3-chloropropyl)
-Isothiuronium bromide.

14.9 g (0.05 mol) of N-aminoiminomethyl-thiourea carbonate are added to 80 ml of acetonitrile. 18.9 g (0.12 mol) of 1 in the suspension thus obtained
-Bromo-3-chloro-propane is added and the reaction mixture is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 90 minutes, the solid material is removed by filtering the hot reaction mixture and the filtrate is allowed to cool to room temperature. The white crystals that have precipitated are filtered off and
Dry at 40-50 ° C. This gives 17.3 g of the desired compound. Yield 65%, melting point: 129-131 ° C.

Example 16 N-aminoiminomethyl-S- (2-hydroxyethyl) -isothiuronium chloride.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are added to 50 ml absolute ethanol.
To this suspension is added 9.7 g (0.12 mol) ethylene chlorohydrin and the reaction mixture is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 90 minutes and cooled to room temperature. The mixture is filtered to remove the resulting precipitated material and the clear filtrate evaporated in vacuo. The oily residue is crystallized from ethyl acetate. The crystals are filtered and dried at 40-50 ° C.
This gives 13.5 g of the desired compound. Yield 68%, melting point: 134-136 ° C.

Example 17 N-aminoiminomethyl-S-glycidyl-isothiuronium bromide.

14.9 g (0.05 mol) of N-aminoiminomethyl-thiourea carbonate are added to 80 ml of acetonitrile. 16.5 g (0.12 mol) of epibromohydrin are added to the suspension thus obtained, and the reaction mixture is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 2 hours and filtered while hot. The clear filtrate is cooled to room temperature. The white crystals which have precipitated are filtered off and dried at 40-50 ° C. This gives 13.5 g of the desired compound. Yield 53%, melting point: 138-139 ° C.

Example 18 N-aminoiminomethyl-S-benzyl-isothiuronium chloride.

14.9 g (0.05 mol) N-aminoiminomethyl-thiourea carbonate are added to 50 ml absolute ethanol.
To the suspension thus obtained, 15.2 g (0.12 mol) of benzyl chloride are added and the reaction mixture is heated to boiling under vigorous stirring. The reaction mixture is refluxed for 1 hour and cooled to room temperature. The mixture is filtered to remove the resulting precipitated material. The clear filtrate is evaporated in vacuo and the oily residue is crystallized from ethyl acetate. The white crystals which have precipitated are filtered off and 40 to 50 ° C.
To dry. This gives 19.1 g of the desired compound.
Yield 78%, melting point 159-161 ° C.

Example 19 The isothiuronium salt prepared according to Examples 9-18 can optionally be recrystallized by the following method. This method is illustrated by using N-aminoiminomethyl-S-allyl-isothiuronium chloride.

10 g of N-aminoiminomethyl-S-allyl-isothiuronium chloride are added to 60 ml of a 5: 1 mixture of ethanol and methanol. Small amounts of undissolved crystals are removed by filtering the hot mixture. The filtrate is optionally purified on activated carbon. The clear filtrate is cooled to room temperature whereby white crystals precipitate. The mixture is cooled to 0-5 ° C, left at this temperature for 1 hour and filtered. The crystals are washed with ice-cold ethanol and dried at 40-50 ° C.
Thus 8.1 g of the desired compound is obtained. Yield 81%.

Example 20 N-aminoiminomethyl-N'-methyl-S-allyl-
Isothiuronium chloride.

16.3 g (0.05 mol) N prepared according to Example 2
-Aminoiminomethyl-N'-methyl-thioureacarbonate is added to 50 ml absolute ethanol. To the suspension thus obtained is added 9.18 g (0.12 mol) of allyl chloride and the reaction mixture is heated to boiling with vigorous stirring. The reaction mixture is refluxed for 1 hour and cooled to room temperature. The mixture is filtered to remove the resulting precipitated material. The clear filtrate is evaporated in vacuo. The oily residue is crystallized from ethyl acetate.
The white crystals are filtered off and dried at 40-50 ° C. Thus
13.6 g of the desired compound are obtained. Yield 61%, melting point: 137
~ 139 ° C.

Example 21 N-aminoiminomethyl-N'-isopropyl-S-allyl-isothiuronium chloride.

19.1 g (0.05 mol) of N-aminoiminomethyl-N'-isopropyl-thioureacarbonate prepared according to Example 5 are added to 50 ml of absolute ethanol.
To the suspension thus obtained, 9.18 g (0.12 mol) of allyl chloride are added and the reaction mixture is heated to boiling with vigorous stirring. The reaction mixture is refluxed for 1 hour and cooled to room temperature. The mixture is filtered in order to remove the resulting precipitated material. The clear filtrate is distilled in vacuo and the oily residue is crystallized from ethyl acetate. The white crystals which have precipitated are filtered off and dried at 40-50 ° C. Thus 13.3 g of the desired compound is obtained. Yield 56%, melting point: 134-135 ° C.

Example 22 N-aminoiminomethyl-N'-cyclohexyl-S-
Allyl-isothiuronium chloride.

23.1 g (0.05 mol) N prepared according to Example 8
-Aminoiminomethyl-N'-cyclohexyl-thiourea carbonate is added to 50 ml absolute ethanol.
To the suspension thus obtained is added 9.18 g (0.12 mol) of allyl chloride and the reaction mixture is heated to boiling with vigorous stirring. The reaction mixture is refluxed for 1 hour and cooled to room temperature. The mixture is filtered to remove the resulting precipitated material and the clear filtrate evaporated in vacuo. The oily residue is crystallized from ethyl acetate. The white crystals that have precipitated are filtered and dried at 40-50 ° C. 20.85 g of the desired compound are thus obtained. Yield 85%, melting point: 129-130 ° C.

Examples 23-31 In a manner similar to Example 12, the following isothiuronium compounds of general formula I are prepared.

23. N-aminoiminomethyl-S-ethyl-isothiuronium bromide. Melting point: 123-124 ° C.

24. N-aminoiminomethyl-S-isopropyl-isothiuronium bromide. Melting point: 120-122 ° C.

25.N- Aminoiminomethyl -S- n - butyl - isothiuronium bromide. Melting point: 116-118 ° C.

26. N-aminoiminomethyl-S-isoamyl-isothiuronium bromide. Melting point: 111-113 ° C.

27. N-aminoiminomethyl-S- (2-bromo-ethyl) -isothiuronium bromide. Melting point: 129-131 ° C.

28. N-aminoiminomethyl-S- (3-bromo-propyl) -isothiuronium bromide. Melting point: 127-129 ° C.

29. N-aminoiminomethyl-S- (3-hydroxy-propyl) -isothiuronium bromide. Melting point: 132-135 ° C.

30. N-aminoiminomethyl-S- (3-mercapto-propyl) -isothiuronium bromide. Melting point: 141-142 ° C.

31. N-aminoiminomethyl-S-propargyl-isothiuronium bromide. Melting point: 131-133 ° C.

Examples 32-40 The following compounds are prepared in an analogous fashion to Example 20.

32.N-aminoiminomethyl-N'-methyl-S- (2-
Hydroxyethyl) -isothiuronium bromide. Melting point: 1
47-148 ° C.

33.N-aminoiminomethyl-N'-ethyl-S- (2-
Chloroethyl) -isothiuronium bromide. Melting point: 143-1
44 ° C.

34. N-aminoiminomethyl-N'-ethyl-S-allyl-isothiuronium chloride. Melting point: 138-139 ° C.

35.N-aminoiminomethyl-N'-isopropyl-S-
(3-Chloropropyl) -isothiuronium bromide. Melting point: 140-142 ° C.

36.N-aminoiminomethyl-N'-isopropyl-S-
Methallyl-isothiuronium chloride. Melting point: 138-139
° C.

37.N-aminoiminomethyl-N'-cyclohexyl-S
- n - propyl - isothiuronium bromide. Melting point: 133-13
5 ° C.

38.N-aminoiminomethyl-N'-cyclohexyl-S
-Methallyl-isothiuronium bromide. Melting point: 130-132
° C.

39.N-aminoiminomethyl-N'-cyclohexyl-S
-Glycidyl-isothiuronium chloride. Melting point: 143-145
° C.

40.N-aminoiminomethyl-N'-cyclohexyl-S
-Benzyl-isothiuronium chloride. Melting point: 147-149
° C.

The melting points and IR spectra of compounds of general formula I are
It is summarized in Table VIII.

Example 41 Preparation of tablets and dragees.

Tablets and dragees are prepared with a press equipped with an automatic feeder. The active ingredient is granulated beforehand by suitable dry or wet methods with suitable auxiliaries. If wet granules are prepared, the granules are preferably dried under vacuum.
The granules used to prepare tablets or dragee cores are pressed through a suitable non-metallic sieve. For the preparation of granules,
Preferably a granular simple composition according to the Pharmacopeia or other suitable composition is used. Tablets and dragee cores containing 30 mg of the active ingredient are prepared and 70 mg of excipient (eg granules alone) is applied.

Example 42 Preparation of capsules.

An automatic filling device is preferably used. The active ingredient is granulated with suitable auxiliaries (eg granules alone) or other inert additives. The granules are of suitable particle size, sieved and filled into capsules. The active ingredient content of the capsules reaches 30 mg.

Example 43 Preparation of a powder ampoule No additional auxiliaries are used for the preparation of a powder ampoule. The powdered ampoule has an active ingredient content of 10 and 20 mg, respectively. Solvent ampoules each contain 1 or 2 ml of distilled water or saline solution. It is preferred to dilute with at least 100 ml of infusion and to use the contents of the ampoule directly after dissolution.

Example 44 N- (aminoiminomethyl) -S-methallyl-isothiuronium bromide.

14.9 g of N- (aminoiminomethyl) -thiourea carbonate are suspended in 50 ml of pure alcohol. 16.1g
Of methallyl bromide are added and the reaction mixture is refluxed for 30 minutes. After filtration, the solvent is distilled off in a vacuum. 21 g of a honey-like product which crystallizes on standing are obtained.

Example 45 N- (aminoiminomethyl) -N'-allyl-S-allyl-isothiuronium bromide.

17.6 g N- (aminoiminomethyl) -N'-allyl-thioureacarbonate is suspended in 50 ml absolute ethanol. 14.5 g of allyl bromide are added and the reaction mixture is refluxed for 1 hour with vigorous stirring, at which time the mixture is filtered and the solvent is distilled off in vacuo. 23 g of oily viscous product are obtained.

Example 46 N-aminoiminomethyl-S-allyl-isothiuronium chloride.

A mixture of 4.2 g dicyandiamine, 20 ml ethanol saturated with hydrochloric acid and 3.7 g allyl mercaptan is gently heated to boiling with vigorous stirring. The reaction mixture is refluxed for 3 hours and cooled to 0 ° C. The crystals which have precipitated are filtered off and washed with ethanol. This gives 7 g of the desired compound. Melting point: 125-1
27 ° C.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location A61K 31/335 ABD C07D 303/34

Claims (30)

[Claims] 1. A general formula I (In the formula, R ¹ is C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, C _3-6 cycloalkyl, arealkyl or aryl, and the group is selected from hydroxy, mercapto and halogen. Optionally substituted by one or more of the following, R ² represents hydrogen, C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _3-6 cycloalkyl, X is organic or R ¹ represents an inorganic anion, and when R ² represents hydrogen, R ¹ is not methyl, ethyl or benzyl.). 2. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S-allyl-isothiuronium salt. 3. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S- (2-halogeno-ethyl) -isothiuronium salt. 4. N-aminoiminomethyl-S-propyl-
The compound and salt according to claim 1, which is an isothiuronium salt. 5. An N-aminoiminomethyl-S-allyl-isothiuronium halide as claimed in claim 1.
A compound or salt according to the item. 6. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S- (2-chloroethyl) -isothiuronium salt. 7. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S- (1-chloro-2-hydroxy-propyl) -isothiuronium salt. 8. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S- (3-chloro-propyl) -isothiuronium salt. 9. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S- (2-hydroxy-ethyl) -isothiuronium salt. 10. The compound and salt according to claim 1, which is an N-aminoiminomethyl-S-glycidyl-isothiuronium salt. 11. The compound and salt according to claim 1, which is an N-aminoiminomethyl-N'-alkyl-S-allyl-isothiuronium salt. 12. General formula (In the formula, R ¹ is C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, C _3-6 cycloalkyl, arealkyl or aryl, and the group is selected from hydroxy, mercapto and halogen. Optionally substituted by one or two or more, R ² represents hydrogen, C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _3-6 cycloalkyl, and X represents an organic group. Or a compound of formula (1), which represents an inorganic anion. A compound of formula (wherein R ² is as described above) or a suitable salt thereof, and an alkylating agent capable of introducing the R ¹ group,
Preferably it is reacted with a compound of the general formula R ¹ -Y, in which R ¹ is as defined above and Y represents a residue, preferably halogen, or b) formula III Reacting a compound of formula I with a thioalcohol of formula R ¹ —SH, where R ¹ is as described above, and optionally adding a compound of formula I thus obtained to a compound of formula NX A method comprising converting to its salt by reacting with an acid of the formula wherein X is as described above. 13. A process according to claim 12, wherein the starting material of the general formula II is used in the form of its salt, preferably carbonate, according to the reaction of a). 14. The method according to claim 12 or 13, wherein an alkyl halide or dialkyl sulfate is used as an alkylating agent according to the reaction of a). 15. The method according to any one of claims 12 to 14, wherein the reaction a) is carried out in the presence of at least one selected from organic solvents, preferably alcohols, aliphatic ketones, nitriles and ethers. The method described. 16. According to the reaction of b) above, an equimolar amount of reactants is used or a thioalcohol of the general formula R ¹ -SH is applied in excess, the general formula IV A process according to claim 12 for the preparation of a compound of the formula wherein R ¹ is as described in claim 12 above. 17. The general formula I (In the formula, R ¹ is C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, C _3-6 cycloalkyl, arealkyl or aryl, and the group is selected from hydroxy, mercapto and halogen. Optionally substituted with one or more of the following, R ² represents hydrogen, C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _3-6 cycloalkyl, and X represents an organic group. Or an inorganic anion), as an active ingredient,
An immunostimulatory pharmaceutical composition comprising the free base or a pharmaceutically acceptable salt thereof in the form of a mixture with a suitable inert pharmaceutical carrier, excipient or both. 18. The general formula I (In the formula, R ¹ is C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl, C _3-6 cycloalkyl, arealkyl or aryl, and the group is selected from hydroxy, mercapto and halogen. Optionally substituted with one or more of the following, R ² represents hydrogen, C _1-6 alkyl, C _2-6 alkenyl, C _2-6 alkynyl or C _3-6 cycloalkyl, and X represents an organic group. Or an inorganic anion), as an active ingredient,
A cell-fixed pharmaceutical composition comprising the free base or a pharmaceutically acceptable salt thereof in the form of a mixture with a suitable inert pharmaceutical carrier, excipient or both. 19. The pharmaceutical composition according to claim 17, which comprises an N-aminoiminomethyl-S-allyl-isothiuronium salt as an active ingredient. 20. The pharmaceutical composition according to claim 17, which contains N-aminoiminomethyl-S- (2-halogeno-ethyl) -isothiuronium salt as an active ingredient. 21. The pharmaceutical composition according to claim 17, which comprises an N-aminoiminomethyl-S-methyl-isothiuronium salt or an N-aminomethyl-S-ethyl-isothiuronium salt as an active ingredient. 22. The pharmaceutical composition according to claim 17, which contains N-aminoiminomethyl-S-propyl-isothiuronium salt as an active ingredient. 23. The pharmaceutical composition according to claim 17, which comprises N-aminoiminomethyl-S-allyl-isothiuronium halide as an active ingredient. 24. The pharmaceutical composition according to claim 17, which contains N-aminoiminomethyl-S- (2-chloroethyl) -isothiuronium halide as an active ingredient. 25. The pharmaceutical composition according to claim 18, which comprises an N-aminoiminomethyl-S-allyl-isothiuronium salt as an active ingredient. 26. The pharmaceutical composition according to claim 18, which contains N-aminoiminomethyl-S- (2-halogeno-ethyl) -isothiuronium salt as an active ingredient. 27. The pharmaceutical composition according to claim 18, which comprises an N-aminoiminomethyl-S-methyl-isothiuronium salt or an N-aminomethyl-S-ethyl-isothiuronium salt as an active ingredient. 28. The pharmaceutical composition according to claim 18, which comprises an N-aminoiminomethyl-S-propyl-isothiuronium salt as an active ingredient. 29. The pharmaceutical composition according to claim 18, which comprises N-aminoiminomethyl-S-allyl-isothiuronium halide as an active ingredient. 30. The pharmaceutical composition according to claim 18, which contains N-aminoiminomethyl-S- (2-chloroethyl) -isothiuronium halide as an active ingredient.