І. О. Шишкін, О. В. Нікітін, В. О. Гельмбольдт ІДЕНТИФІКАЦІЯ АМОНІЄВИХ ГЕКСАФТОРОСИЛІКАТІВ З ВИКОРИСТАННЯМ ХІМІЧНИХ МЕТОДІВ АНАЛІЗУ Одеський національний медичний університет, Одеса, Україна Метою роботи було дослідження можливостей методів хімічного аналізу для ідентифікації потенційних антикарієсних агентів -3-гідроксиметил-, 4-гідроксиметилпіридинію, 2-карбоксиметилпіридинію та октенідинію гексафторосилікатів (I-IV відповідно).Процедури аналізу включали ідентифікацію піридинового циклу, гідроксиметильної та карбоксильної груп, гексафторосилікатного аніону у складі I-IV.Використовували 1%-ві водні та метанольні розчини I-IV.Встановлено, що для ідентифікації I-IV може бути використана реакція розкриття піридинового

Interaction of 2‐, 3‐, 4‐carboxyethylpyridines (L1, L2, L3) with fluorosilicic acid results in the corresponding bis(pyridinium) hexafluorosilicates I–III, characterized by elemental analysis, IR, 1H, 19F nuclear magnetic resonance (NMR), and mass spectrometry, solubility data, and X‐ray crystallography. Crystallographic data: Fdd2, Z = 8, a = 28.610(2) Å, b = 18.8378(14) Å, c = 7.3236(5) Å (I); P‐1, Z = 1, a = 6.2712(4) Å, b = 7.1706(5) Å, c = 10.9721(7) Å, α = 102.514(6)°, β = 97.037(5)°, γ = 93.640(6)° (II); P21/c, Z = 2, a = 10.0345(6) Å, b = 9.8734(5) Å, c = 9.4704(6) Å, β = 94.347(6)° (III). The dominant intermolecular contacts from the Hirshfeld surface analysis are H…F/F…H, H…H, and H…O/O…H with percentages of 33.3%–34.5%, 26.4%–30.0%, and 16.0%–21.8%. The infrared spectra for I–III exhibit stretching vibrations ν(N+H) at 3300–3050 cm–1; stretching and deformation vibrations ν(SiF) and δ(SiF2) for [SiF6]2– anions are registered near 740 cm–1 and in the range of 480–440 cm–1. In the 19F NMR spectra of aqueous solutions of I–III, strong singlet signals of the [SiF6]2– anion were registered at δ(F) = −133.35 ppm (I), –131.43 ppm (II), –129.02 ppm (III) with two satellites due to the spin‐spin interaction 29Si–19F (J(29Si–19F) = 107.5 Hz (II), 107.6 Hz (III)). I–III reveal high solubility in water and dimethyl sulfoxide and very poor solubility in methanol and ethanol. All compounds demonstrate noticeable anticaries activity and absence of hepatotoxic effects, and bis(3‐carboxyethylpyridinium) hexafluorosilicate II displays the highest caries‐preventive efficacy, which significantly exceeds values for the reference preparations, NaF and (NH4)2[SiF6].

The aim of the work. Determination of toxicometric characteristics of octenidine hexafluorosilicate (OHFS), characterized by significant pharmaceutical potential, in an acute experiment on rats by oral administration. Materials and Methods. A study of the acute toxicity of octenidine hexafluorosilicate was carry out on 42 male Wistar rats weighing 180–200 grams. The main criterion for quantifying the toxicity of octenidine hexafluorosilicate was LD50, which was determined using the least squares method. In addition, the following hazard indicators were calculated: 1/LD50 – median lethal dose (absolute toxicity), LD84/LD16 – the range of lethal doses (zone of acute toxic effect), 1/(LD50-S) – the total toxicity index and the S-function angle of inclination (variability of lethal doses). Statistical processing of the results was carry out using the «StatPlus 2009» software (AnalystSoft, USA, 2009). Results and Discussion. The results of the acute toxicity determination of octenidine hexafluorosilicate show that this compound, in the oral route of administration, belongs to the III class of toxicity for the human (slightly hazardous) and to the IV class of toxicity for the animals (white rats). Based on the variability of lethal doses, the studied hexafluorosilicate can be attribute to compounds that do not pose a high potential risk of the onset and development of poisoning. The calculated toxicity and hazard values of octenidine hexafluorosilicate show that it does not pose a particular danger to humans. Extrapolation to humans of acute toxicity parameters obtained in animals was determined using the coefficient of resistance to the species and is 132.15 mg/kg body weight. Conclusions. The results of determining the toxicometric characteristics of octenidine hexafluorosilicate in rats by oral administration allow to classify this compound as moderately toxic substances (LD50 = 555.05 mg / kg, toxicity class IV). The determined parameter of acute toxicity of OHFS is close to the LD50 values of other hexafluorosilicates known from the literature; relative safety and high caries-prophylactic and periodontal-protective efficacies of OHFS indicate the prospects for further studies of this compound.

In the present study, adequate quantitative structure-activity relationship (QSAR) models were developed to analyze the water solubility of some ammonium hexafluorosilicates. All models were developed using structural descriptors calculated by the SiRMS method based on the simplex representation of the molecular structure and Dragon descriptors. Log P, equalized electronegativity, molecular refraction, and molecular weight were used as integral descriptors in addition to 2D structural descriptors. All QSAR models were obtained using the partial least squares (PLS) method. Model M1 examined the influence of various physicochemical and structural factors on the water solubility of the studied compounds. The interpretation results are consistent with the qualitative data of previous experimental works. It was possible to detail the features of the hydrogen bonds effect on the water solubility for investigated compounds The non-trivial nature of the effect of the hydrogen bond was also shown. QSPR model M2 could predict the solubility of new compounds of the studied type with satisfactory accuracy.

In recent years, a high carioprophylactic efficacy of ammonium hexafluorosilicates with biologically active cations has been discovered (АHBC). In the case of using AHBC, there is a potential possibility of enhancing the anticaries effect of the fluorine-containing anion as a result of the contribution of the effects of cations, for example, anti-inflammatory effects. The purpose of the work is a virtual analysis of the biological activity and lipophilicity of pyridine derivatives containing pharmacophores associated with anti-inflammatory activity (AIA), as possible candidates for the synthesis of AHBC as anticaries agents. Objects of research are the commercially available pyridine derivatives (PubChem database) containing pharmacophore groups – residues of acetic, propionic, phenylacetic acids, the presence of which is associated with the manifestation of AIA. Assessment of the potential biological activity of the compounds was carried out using the program. PASS 2017 Professional. The lipophilicity values of logP pyridines were calculated using software packages ALOGPS, KowWin, model QSPR. It has been established that in the series of acetic acid derivatives the highest probability of the presence of AIA (Ра) is expected for isomeric pyridine acetic acids: there is a relative increase in the values of Pa in the series of 2-, 3-, 4-isomers (Ра = 0,454, 0,506, 0,537 respectively). The introduction of the second substituent into the pyridine ring (fluorine, bromine, chlorine atoms, CF3 group) is accompanied by a decrease in the values Ра. In the rows of 2-, 3-, 4-substituted derivatives of phenylacetic and propionic acids, an increase in the likelihood of AIA manifestation is also recorded; the introduction of substituents in the propionic acid residue (fluorine atoms, НО-, H2N-groups) leads to lower values Ра. For all studied derivatives, there was no significant probability of manifestation of hepatotoxicity and nephrotoxicity (Ра < 0,5), the calculated lipophilicity values of the compounds are in the range of -2,65‒2,26. Thus, all the studied pyridine derivatives correspond to Lipinsky's «rule 5» and can be classified as low toxic «drug-like» compounds. Despite the presence of pharmacophores in the pyridines, the presence of which is associated with AIA, for almost all structures the probability of the appearance of this type of activity is small (Ра ≤ 0,5). In our opinion, compounds with phenylacetic and propionic acids fragments are interesting as objects of further experimental research as the models for elucidating the influence of the position of the pharmacophore group in the structure of the pyridine ring on the value of the CPE and AIA of the corresponding AHBC.

The hexafluorosilicate with the composition (LH)(2)SiF6 center dot H2O(I, L = 3-hydroxymethylpyridine) was obtained by reaction of 45 % hexafluorosilicic acid with a methanol solution of L (H2SiF6 : L = 3: 1). The crystal structure I is stabilized by OH center dot center dot center dot O, NH center dot center dot center dot F, and OH center dot center dot center dot F H-bonds, and CH center dot center dot center dot F contacts. The symmetry of the SiF62- anion is close to D-4h. The solubility of I in water was 1.63 mol. % and the degree of hydrolysis of the salt in a 1.10(-4) M aqueous solution was 91.6 %. A PASS-analysis of the spectrum of biological activity L highlighted a low probability of toxic effects.

Мета роботи. Визначення розчинності 2-, 3-, 4-карбоксиметилпіридинію, 2-аміно-4,6-дигідроксипіримідинію та октенідину гексафторосилікатів як перспективних антикарієсних агентів. Матеріали і методи. 2-, 3-, 4-карбоксиметилпіридинію, 2-аміно-4,6-дигідроксипіримідинію та октенідину гексафторосилікати були синтезовані за описаними раніше методиками. Визначення розчинності гексафторосилікатів проводили відповідно до рекомендацій ДФУ. Ізотермічні умови експериментів за визначенням розчинності солей забезпечували за допомогою ультратермостату U15. Результати й обговорення. Визначена розчинність у воді, метанолі, етанолі та диметилсульфоксиді нових потенційних антикарієсних агентів – 2-, 3-, 4-карбоксиметилпіридінію, 2-аміно-4,6-дигідроксипіримідинію та октенідину гексафторосилікатів. Сіль 2-аміно-4,6-дигідроксипіримідинію характеризується низькою розчинністю у всіх використаних розчинниках. Встановлено взаємозв’язок між розчинністю у воді вивчених гексафторосилікатів і характеристиками будови відповідних амонієвих катіонів. Висновки. Встановлено, що 2-, 3-, 4-карбоксиметилпіридинію гексафторосилікати дуже легкорозчинні у воді, розчинні у ДМСО та малорозчинні у метанолі і етанолі. Сіль октенідину легкорозчинна у метанолі, розчинна у етанолі та дуже малорозчинна у ДМСО. Відповідна сіль 2-аміно-4,6-дигідроксипіримідинію малорозчинна у воді та дуже малорозчинна в органічних розчинниках.

In recent years, ammonium hexafluorosilicate and hexafluorosilicates of organic amonium cations are actively studied, which demonstrate certain advantages over traditional compounds of fluorine. Previously, it was shown that hexafluorosilicates with bactericidal cations of chlorhexidine, polyhexamethyleneguanidine and cetylpyridinium effectively reduce the number and depth of carious lesions of teeth in rats and at the same time significantly improve the biochemical parameters of the pulp of the teeth. The aim of the work – study of the cariesprophylactic and periodontoprotective effectiveness of octenidine hexafluorosilicate. The investigated preparations were applied to the teeth and gums of rats in the composition of phyto-gels based on Na-salt of carboxymethylcellulose. In the slurry of the incisors, the activity of alkaline (ALP) and acidic (ACP) phosphatases, elastase, lysozyme was determined and the mineralizing index (MI) was calculated. The number and depth of carious lesions of the teeth were counted and caries of prophylactic efficacy (CPE) were calculated. In the gums, the level of malonic dialdehyde (MDA), activity of elastase, catalase, lysozyme and urease was determined. The degree of dysbiosis and the antioxidant-prooxidant index of the API were calculated. The degree of atrophy of the alveolar process was determined and the periodontitis protective efficiency (PPE) was calculated. The effect of octenidine hexafluorosilicate on the damage to the caries of the teeth of rats receiving CGR was shown. It has been shown that octenidine hexafluorosilicate has caries prophylactic action, as evidenced by its stronger anti-carious effect in comparison with NaF. The results of the determination of the depth of carious lesions in the slurry of the incisors and the activity of phosphatase showed that octenidine hexafluorosilicate significantly increases the activity of ALP and ACP but has no effect on the mineralizing index of MI. Octenidine hexafluorosilicate significantly increases the activity of elastase in the pulp and reduces the activity of lysozyme. CPE of octenidine hexafluorosilicate is higher than that of NaF by more than 1.7 times. In the gingival rats of octenidine hexafluorosilicate causes a significant decrease in the marker of inflammation – elastase. The degree of dysbiosis in the gums of rats receiving CGR increases by 1.73 times and decreases to practically intact rats after octenidine hexafluorosilicate gel applications and vice versa, catalase activity and API index significantly decrease in CGR, and when gel application is increased to intact rats. It is shown that the sucrose diet significantly increases the degree of atrophy (by 31%), and octenidine hexafluorosilicate reduces the degree of atrophy by 17%. It has been established that octenidine hexafluorosilicate has a significant (54.7%) PPE. The results of studying the properties of octenidine hexafluorosilicate indicate its rather high cariesprophylactic efficacy and periodontal protective effect, which makes it possible to treat it as a potential treatment and prevention of caries and periodontal diseases.

In the last decade, high cariesprophylactic efficacy of ammonium hexafluorosilicates, including salts with substituted biologically active ammonium cations, has been demonstrated. Among the promising anti-caries agents are recently synthesized 2-, 3-, 4-carboxymethylpyridinium hexafluorosilicates, for whose cations anti-inflammatory activity is expected. The aim of the work is to assess the presence of anti-inflammatory activity in the series of 2-, 3-, 4-carboxymethylpyridinium hexafluorosilicates in the experiment. 2-, 3-, 4-Carboxymethylpyridinium hexafluorosilicates (I–III, respectively) were synthesized according to the previously proposed technique, carrageenan is a commercial preparation, reference drug is a indomethacin. Experiments on the anti-inflammatory activity of hexafluorosilicates were performed on 77 white Wistar male rats weighing 174–190 g using the carrageenan model of inflammation. The inflammatory reaction was reproduced by subplantary administration of 0.1 ml of a 0.2% solution of carrageenan, the studied compounds were administered orally in doses 1/10, 1/20, 1/50 from LD50 for the compound III. It was established that after administration of carrageenan, animals of the control group showed marked paw edema, which gradually increased and was maximal after 24 hours of observation. According to the data obtained, the indices for compounds I-III practically do not differ from those of the control group. This indicates that, despite the results of the PASS forecast and the presence of acetic acid residue, an anti-inflammatory pharmacofor, in compounds I-III, the compounds under study do not have an anti-inflammatory effect in the carrageenan model. 2-, 3-, 4-Carboxymethylpyridinium hexafluorosilicates do not show the expected anti-inflammatory activity in the carrageenan model of inflammation.

The article is devoted to the study of Polish-Ukrainian relations during the Second World War. In particular, the concepts of solving the Ukrainian question in the Polish political thought of the period 1939-1945 are investigated. It should be noted that the primary attention is paid to the analysis of various kinds of analytical studies, memos, theoretical developments, informational reports carried out by various structural elements of the Polish emigration government, which actively worked on the development of the latest position on the Ukrainian question. In addition, the official declarations adopted by the Polish government in emigration concerning both the problem of national minorities in general and the Ukrainian question, in particular, are studied. An important role is also played by the study of policy documents of the main political parties that were part of the Polish “London group.” This made it possible to highlight the positions of various political forces as well as assess their proposals. The main policy directions of political parties regarding the Ukrainian question are shown. Much attention is dedicated to the study of the program documents of those political parties that cooperated with the Polish government in emigration, and their representatives were included in various structures in its composition, which, in turn, made it possible to directly influence the development of the governmental concepts and its official position. The official statements of such political forces as the National party, the Peasant party, the Democratic party, the LEI (WRN) party (Liberty, Equality, Independence (Wolność, Równość, Niepodległość) – the socialist party) are analyzed. Based on the comparison of the crucial program documents, the party press, various kinds of appeals to citizens, the evolution of Polish political thought regarding the Ukrainian question during the Second World War is shown. The official documents developed in the military representation of the government in the country (Home Army), as well as its civilian exposition in the province (Government Delegation), are analyzed.

Hexafluorosilicate with the composition (LH)2SiF6 (I), (L = 4-hydroxymethylpyridine) is isolated as the interaction product of an L methanol solution and 45% hydrofluorosilicic acid (L:H2SiF6 = 1:3). It the crystal structure of I the cations and anions are linked by NH···F (N···F of 2.809(2) Å,2.824(2) Å) and OH···F (O···F of 2.7036(18) Å) H bonds; the geometry of the SiF62− anion is a distorted octahedron (Si–F distances 1.6780(11)-1.6877(11) Å). In the IR spectrum of I the absorption bands of the main vibrations are identified; the solubility of I in water and some organic solvents and the degree of hydrolysis of the salt in a 1·10−4 M aqueous solution are determined.

The following article is devoted to the study of documents and materials of Polish resistance movement, which give an opportunity to research Ukrainian question in the policy of Polish «London Camp» representatives as well as its civilian and military units. The official documents, development of theories made by Polish government in exile, Home Army (Armia Krajowa) and Government Delegation (Delegatura Rządu), the reminiscences of events contemporaries, periodicals as well as political programs of Polish most influential parties were analyzed.

Мета роботи. Вивчення токсикометричних характеристик 4-карбоксиметилпіридинію гексафторосилікату як потенційного антbкарієсного препарату в гострому експерименті на щурах при пероральному введенні. Матеріали і методи. Проведено дослідження гострої токсичності 4-карбоксиметилпіридинію гексафторосилікату на 48 щурах-самцях лінії Вістар масою 180–200 г. Основним критерієм кількісної характеристики токсичності 4-карбоксиметилпіридинію гексафторосилікату була ЛД50, яка визначалася з використанням методу найменших квадратів. Розраховано такі показники небезпеки: 1/ЛД50 – обернена величина середньосмертельної дози (абсолютна токсичність), ЛД84/ЛД16 – діапазон смертельних доз (зона гострої токсичної дії), 1/(ЛД50 – S) – сумарний показник токсичності та S – функція кута нахилу (варіабельність смертельних доз). Статистичну обробку отриманих результатів проводили з використанням програми «StatPlus 2009» (компанія AnalystSoft, США, 2009). Результати й обговорення. Результати визначення гострої токсичності 4-карбоксиметилпіридинію гексафторосилікату показують, що ця сполука при пероральному шляху введення належить до III класу токсичності (помірно токсичні сполуки). З огляду на варіабельність смертельних доз, вивчений гексафторосилікат можна зарахувати до сполук, які не становлять високої потенційної небезпеки виникнення та розвитку отруєння. Розрахункові показники токсичності та небезпеки 4-карбоксиметилпіридинію гексафторосилікату показують, що він не становить особливої небезпеки і для людини. Висновки. Гостра токсичність 4-карбоксиметилпіридинію гексафторосилікату в експерименті на щурах при пероральному шляху введення становить 481,28 мг/кг, що дозволяє віднести це похідне до III класу токсичності (помірно токсичні сполуки).

З використанням методу фотоколориметрії проведено визначення ступеня гідролізу гексафторосилікатів 3,5-дизаміщених похідних 1,2,4-триазолу в 1×10-4 М водних розчинах їх солей. Встановлено, що ступінь гідролізу солей змінюється в межах 63,8 – 92,0 %. Знайдено розчинність їх солей у воді, яка становить ≤ 0,0002 мол. %.

Мета роботи. Здійснити синтез октенідину гексафторосилікату як потенційного карієспрофілактичного і антибактеріального препарату.Матеріали і методи. Вихідні реагенти, октенідину дигідрохлорид і кремнефтороводнева кислота є комерційно доступними реактивами. ІЧ-спектри поглинання реєстрували на спектрофотометрі Spectrum BX II FT-IR System (Perkіn-Elmer), мас-спектри FAB – спектрометрі VG 7070 (VG Analytіcal), спектри ЯМР 1H, 19F – на спектрометрі Varіan Gemini-400. Термогравіметричний аналіз проводили на дериватографі Q-1500 D системи F. Paulik – J. Paulik – L. Erdey.Результати й обговорення. Одержано октенідину гексафторосилікату моногідрат на основі реакції іонного обміну між метанольним розчином октенідину дигідрохлориду і кремнефтороводневою кислотою. Склад і іонна будова синтезованої сполуки підтверджено методами ІЧ-, ЯМР 1H, 19F-спектроскопії, мас-спектрометрії. Термоліз комплексу супроводжується процесами дегідратації і деструкції з подальшим окисленням фрагментів катіону.Висновки. Синтезовано октенідину гексафторосилікату моногідрат, нове похідне октенідину, що становить інтерес як потенційний карієспрофілактичний і антибактеріальний засіб.

Introduction Today as potential caries-preventive agents hexafluorosilicate ammonium and hexafluorosilicates organic "onium" cations actively studied, which have certain advantages over traditional means of fluoride treatment and prevention of tooth decay. Among these compounds are exposed to saliva hydrolysis to form a soluble form of silica that catalyzes the formation of phosphate sludge (fluoride) calcium and provides prolonged occlusion tubul dentin. As one of the most important physical and chemical characteristics of drugs is their solubility in water and hydrolytic instability, because the purpose of the present study investigated the solubility in water, hydrolytic instability and potential biological activity of 3,5-disubstituted 1,2,4-triazolium hexafluorosilicates in order to estimate their potential use as caries-preventive agents. Investigation methods The method of synthesis hexafluorosilicates (LH)2SiF6 * nH2O (L1 = 3-pyridine-3-yl-5- (2'-aminophenyl) -1H-1,2,4-triazole, n = 1; L2 = 3-benzofuran- 2-yl-5- (2'-amino-3'-methyl-phenyl) -1H-1,2,4-triazole, n = 1; L3 = 5- (2'-amino-5'-chloro-phenyl) -3-furan-3-yl-1H-1,2,4-triazole, n = 1; L4 = 3-adamantane-1-yl-5- (2'-amino-phenyl) -1H-1,2 4-triazole, n = 2; L5 = 5- (2'-amino-3'-methyl-phenyl) -3-furan-3-yl-1H-1,2,4-triazole, n = 1; L6 = 3-thiophene-3-yl-5- (2'-amino-3'-fluoro-phenyl) -1H-1,2,4-triazole, n = 2; L7 = 3-thiophene-2-yl-5 - (2'-amino-3'-fluoro-phenyl) -1H-1,2,4-triazole, n = 3). Working 1×10-4 Maqueous salt solutions were prepared in a plastic container. Determination of the soluble form of silica products of hydrolysis hexafluorosilicates conducted photocolorimetric method. The measurement was performed at a wavelength of 380 nm. Results and discussion We found a general tendency to reduce the values of α for hexafluorosilicates 1,2,4-triazole compared with pyridinium salts, which is close to the degree of hydrolysis quantity. In the case of salts of 1,2,4-triazole less efficient release of fluoride ions by hydrolysis circuits may be accompanied by a decrease caries-preventive effect of the studied compounds. During the preparation 1×10-4 M salt solutions in all cases observed precipitate soluble free base L by hydrolysis in cation. For a given concentration of solutions villages are not subjected to further dissolution prolonged aging, to evaluate the upper limit of solubility of salts of 1,2,4-triazole in ≤ 0.0002 mol. %. Very low solubility studied in this paper salts of 3,5-disubstituted 1,2,4-triazole derivatives and 3,5-diamino-1,2,4-triazole related obviously dominated lipophilic contribution to the hydrophilic-lipophilic balance heterocyclic bases L1 - L7. Conclusions Estimated value of solubility hexafluorosilicates 3,5-disubstituted 1,2,4-triazole derivatives in water in the lowest number of similar salts of heterocyclic cations. The degree of hydrolysis of 1,2,4-triazole hexafluorosilicates in aqueous solution by an average of 10 - 30% lower compared with the corresponding values for pyridinium salts. The experimental and calculated data do not consider hexafluorosilicates 3,5-disubstituted 1,2,4-triazole derivatives as promising caries-preventive agents.

Three pyridinium hexafluorosilicates with the compositions (LH)(2)[SiF6] (I, II, III, where L = 2-, 3-, 4-carboxymethylpyridine) were obtained as crystalline solids upon interaction of hexafluorosilicic acid with isomeric carboxymethylpyridines. All compounds were characterized by elemental analysis, IR, NMR F-19 and mass spectrometry, solubility data, and X-ray crystallography. The binary ionic solids are stabilized by the interplay of intermolecular interactions including strong charge assisted and conventional hydrogen bonds of the NH center dot center dot center dot F, and OH center dot center dot center dot O types along with CH center dot center dot center dot F contacts and pi-pi stacking interactions. The different supramolecular motifs in I-III are dictated by the different arrangement of the principal binding sites in the isomeric carboxymethylpyridines. The relationship between the salts structure and solubility data is discussed. All hexafluorosilicates reduce the depth and the number of dental caries, and provide efficiency of caries prevention up to 45%.

The aim of the work. The synthesis of octenidine hexafluorosilicate as potential caries preventive and antibacterial agent. Materials and Methods. The starting materials, octenidine dihydrochloride and hexafluorosilicic acid, are commercial sources. The IR-absorption spectra were recorded on a spectrophotometer Spectrum BX II FT-IR System (Perkin-Elmer), FAB mass spectra – on a spectrometer VG 7070 (VG Analytіcal), 1H and 19F NMR spectra – on a Varian Gemini-400 spectrometer. Thermogravimetric analysis was performed on a Q-1500 D derivatograph of F. Paulik – J. Paulik – L. Erdey’s system. Results and Discussion. The novel octenidine hexafluorosilicate monohydrate was synthesized via ionic exchange reaction between octenidine dihydrochloride in methanol solution and hexafluorosilicic acid. The composition and ionic structure of synthesized compound were confirmed by IR-, 1H, 19F NMR spectroscopy, mass-spectrometry. The thermolysis of complex is accompanied by processes of dehydration and destruction with further oxidation of cation fragments. Conclusions. Octenidine hexafluorosilicate monohydrate, a new derivative of octenidine, was synthesized as potential caries preventive and antibacterial agent.