The reactions of lupinine alkaloid and its chlorine derivative with cinnamoyl chloride and 2-K-isoindole-1,3-dione were investigated to obtain 3-phenylacrylic acid octahydroquinolizin-1-ylmethyl ester and 2-(octahydroquinolizin-1-ylmethyl)isoindole-1,3-dione, respectively. The optimal conditions for carrying out the aforementioned reactions were determined, taking into account the nature of the solvent and medium. It was established that acylation of the molecule in a benzene medium, in the presence of trimethylamine, resulted in the formation of 3-phenylacrylic acid octahydroquinolizin-1-ylmethyl ester, with an 82% yield. It was demonstrated that the interaction of chlorolupinine with 2-K-isoindole-1,3-dione under Gabriel reaction conditions resulted in the formation of 2-(octahydroquinolizin-1-ylmethyl)isoindole-1,3-dione. The conformer with an axial orientation of the isoindole-1,3-dione substituent was observed to exhibit greater stability than the conformer with an equatorial orientation. The structure of the synthesized compounds was investigated by IR, 1H, and 13C NMR spectroscopy. The use of two-dimensional spectra in COSY (1H-1H) and HMQC (1H-13C) formats enabled the establishment of homo- and heteronuclear interactions, thereby confirming the structure of the compounds under investigation. The values of chemical shifts, multiplet and integrated intensity of 1H and 13C signals in one-dimensional NMR spectra of the novel compounds were determined. The crystal structures of 3-phenylacrylic acid octahydroquinolizin-1-ylmethyl ester and 2-(octahydroquinolizin-1-ylmethyl)isoindole-1,3-dione were elucidated through X-ray analysis.
В результате изучения химического состава эндемичного вида Казахстана танацетопсиса Пятаевой (Tanacetopsis Pjataevae (Kovalevsk.) Karmyscheva) впервые выделены сесквитерпеновые γ-лактоны гваянового ряда арглабин, β-изоэпоксиэстафиатин, новый гваянолид 3-кето-10β-гидрокси-5,7α,4,6β(Н)-гвай-1,11(13)-диен-6,12-олид. Пространственное строение соединений установлено рентгенодифракционным методом.
There has been presented data on the synthesis of monoamides and cyclic imides which are derivatives of isonicotinic acid hydrazide. Cyclic anhydrides of carboxylic acids (succinic, maleic and phthalic) easily react with the hydrazide of isonicotinic acid with cycle opening, forming isonicotinoylhydrazide of dicarboxylic acids, and under more severe conditions the latter are transformed into cyclic acid imides. The structures of the synthesized compounds were studied using 1H- and 13C-NMR spectroscopy, as well as data from twodimensional COSY (1H-1H) and HMQC (1H-13C) spectra. The values of chemical shifts, multiplicity and integral intensity of 1H and 13C signals in one-dimensional NMR spectra were determined. Homo- and heteronuclear interactions confirming the structure of the studied compounds were established using spectra in the COSY (1H-1H) and HMQC (1H-13C) formats. In the approximation of the density functional B3LYP with a base set of 6-31G(d), the enthalpy of the reactions ΔHr in the absence and in the presence of a solvent — isopropanol (self-consistent reaction field method) were calculated quantum-chemically
As a result of studying the chemical composition of the Kazakhstan endemic species Tanacetopsis Pjataevae ( Tanacetopsis Pjataevae (Kovalevsk.) Karmyscheva), the following guaianolide-type γ-lactones are isolated: arglabin, β-isoepoxyestafiatin, and a new 3-keto-10β-hydroxy-5,7α,4,6β(H)-gvai-1,11(13)-diene-6,12-olide guaianolide. The structure of these compounds is established by X-ray diffraction.
(E)-1-(2-(4-bromobutoxy)-6-hydroxy-4-methoxyphenyl-3-phenylprop-2-en-1-one was synthesized from the pinostrobin molecule. The tetrahydropyran cycle was opened in acetone under heating (50–60 °C) mixtures of components for 16 hours in the presence of 3 moles of K2CO3 and 1,4-dibromobutane. The resulting substance is a yellow powder of the composition C20H21BrO4, mp 83.7–86.6 °C. The structure of the obtained compound was established on the basis of the data of elemental analysis, IR and NMR spectra. As a result of X-ray diffraction analysis, it was found that the hydrogen atoms in the C8=C9 bond take the transconformation. The rotation of the С1…С6 phenyl ring (flat with an accuracy of ±0.008 Å) relative to the С10…С15 cycle (flat with an accuracy of ±0.004 Å) is 14.3°. In the crystal, the molecules are linked by an intramolecular hydrogen bond O4-H....O1 (distances O-H 0.95(8) Ǻ, O····O 2.469(6) Ǻ, H····O 1.58 (8) Ǻ, angle O-H····O 153(7)°). The formation of (E)-1-(2-(4-bromobutoxy)-6-hydroxy-4-methoxy-1-phenylprop-2-en-1-one can be explained by the ease of the retro-Michael reaction of the pyran ring and the subsequent O-alkylation of the resulting chalcone. Carrying out the reaction in the presence of other bases (cesium carbonate, triethylamine) did not lead to success. The starting substance (pinostrobin) was completely converted into oligomeric compounds.
The article presents the results of a chemical study of semi-dry wormwood (Artemisia semiarida), an endemic plant of Kazakhstan. The amount of extractive substances was obtained by extraction with chloroform from air-dried crushed above-ground part of the plant collected in the vegetative phase. The compound was isolated using a column chromatography method. Silica gel of the KSK brand was used with the ratio of the sum of substances – carrier = 1:10. When the column was eluted with a 13:7 petroleum ether – ethyl acetate mixture, a yellow crystalline substance of the composition C18H16O7 with m.p. 234–237° C was obtained (recrystallization from ethyl acetate). The structure of the obtained compound (5,7-dihydroxy-6,3′,4′-trimethoxyflavone or eupatilin) was established by analysis of IR and NMR spectra. The spatial structure of eupatilin was determined by X-ray diffraction. In the crystal structure of 5,7-dihydroxy-6,3′,4′-trimethoxyflavone the rotation of the phenyl ring relative to the main framework (chromene ring) was found to be only 4.1°. Four conformers with different rotations of the phenyl ring (the torsional angles of O1C2C1′C2′ are 30°, 140°, 210° and 320°, respectively) and small energy barriers (about 8.4 kJ/mol) can be realized in the free state of the molecule.
N-cyanomethylanabasine is prepared with an yield of 70% by the interaction of the alkaloid anabasine with glyconitrile. It is shown that the highest yield of the product is achieved by conducting the reaction in aqueous or water-alcohol environments. The structure of the synthesized compound is established by 1H and 13C NMR spectroscopy and by using the HMQC 2D spectroscopy data (1H–13C). The crystal structure of N-cyanomethylanabasine is determined by XRD. It is shown that the orientation and rotation of the pyridine ring relative to the piperidine ring is determined by Van der Waals interaction with the substituent at the nitrogen atom of the piperidine ring. It is established that this compound activates predominantly type B monoamine oxidase, which indicates the presence of a nootropic effect.
The article presents results on the synthesis and investigation of the structural features of a number of 1,4-disubstituted 1H-1,2,3-triazole derivatives of the alkaloid lupinine. Lupinine modification reactions have been carried out at the hydroxymethylene group in the C-1 position of the quinolysine backbone. It has been shown that (octahydro-2H-quinolysine-1-ylmethyl)methanesulfonate in high yield (93%) is formed by the in-teraction of lupinine with methanesulfonyl chloride in methylene chloride. Subsequent treatment of this com-pound with sodium azide in dimethylformamide on heating leads to the formation of 1-(azidomethyl)octahydro-2H-quinolysine in 61% yield. It has been found that the reaction of a new azide with terminal alkynes of various nature in the presence of aqueous СuSO4 and sodium ascorbate in dimethylfor-mamide can form the corresponding 4-substituted (1S,9aR)-1-[(1,2,3-triazol-1-yl)methyl]octahydro-1H-quinolysines. New 1,2,3-triazole derivatives of lupinine containing various aryl substituents at the C-4 posi-tion of the triazole ring have been obtained. The high selectivity of the reaction is explained by the action mechanism of the Sharpless catalyst. The spatial structure of the molecules of lupinine methanesulfonate, 4-aryltriazolylmethyl-octahydroquinolysines has been established by X-ray diffraction analysis. X-ray structur-al analysis data of new compounds have been deposited in the form of CIF files at the Cambridge Crystallo-graphic Data Center
The article presents the results of a chemical study of Tanacetopsis pjataevae, which is an endemic plant in Kazakhstan. The number of extractive substances was obtained by extraction with chloroform from the air-dry crushed above-ground part of the plant collected in the flowering phase. Isolation of compounds was carried out by column chromatography on a column of silica gel brand KSK at a ratio of sum - carrier = 1:20. A colorless crystalline substance of the composition C15H18O4 with m.p. 189-191 degrees C (recrystallized from diethyl ether) was found when the column was eluted with a mixture of petroleum ether-ethyl acetate (87.5:12.5). The structure of the obtained new compound (3-oxo-10 beta-hydroxy-5,7 alpha(H),6 beta(H)-guai-1,11(13)-diene-6,12-olide) was established based on IR, NMR analysis and mass spectra. The spatial structure was determined by the X-ray diffraction method. It was established that the 3-oxo-10 beta-hydroxy-5,7 alpha(H),6 beta(H)-guai-1,11(13)-diene-6,12-olide molecule in the crystal is disordered over two conformational states in the 6 :4 ratio. The stability of these conformers was confirmed by semi-empirical quantum-chemical calculations. It was established that the difference in the heat of formation of two conformers was 6.3 kJ/mol for a free molecule.
A three-component reaction of 3,5-diacetyl-2,6-dimethylpyridine, p-N-dimethylaminobenzaldehyde and phenylhydrazine in the presence of KOH in ethanol gave the condensation product of two p-N-dimethylaminobenzaldehyde and phenylhydrazine molecules, namely bis(biarylhydrazone). Structure of the obtained derivative was proved by the 1H and 13C NMR spectroscopy and X-ray diffraction analysis data. It was shown that the bis(biarylhydrazone) derivative has high antiradical and cytoprotective activity.
The article presents the results of a chemical study of Tanacetopsis pjataevae, which is an endemic plant in Kazakhstan. The number of extractive substances was obtained by extraction with chloroform from the air-dry crushed above-ground part of the plant collected in the flowering phase. Isolation of compounds was carried out by column chromatography on a column of silica gel brand KSK at a ratio of sum - carrier = 1:20. A colorless crystalline substance of the composition C15H18O4 with m.p. 189–191°C (recrystallized from diethyl ether) was found when the column was eluted with a mixture of petroleum ether-ethyl acetate (87.5:12.5). The structure of the obtained new compound (3-oxo-10β-hydroxy-5,7α(Н),6β(Н)-guai-1,11(13)-diene-6,12-olide) was established based on IR, NMR analysis and mass spectra. The spatial structure was determined by the X-ray diffraction method. It was established that the 3-oxo-10β-hydroxy-5,7α(Н),6β(Н)-guai-1,11(13)-diene-6,12-olide molecule in the crystal is disordered over two conformational states in the 6 :4 ratio. The stability of these conformers was confirmed by semi-empirical quantum-chemical calculations. It was established that the difference in the heat of formation of two conformers was 6.3 kJ/mol for a free molecule.
In order to obtain new potentially bioactive substances and to investigate the effect of bulky functional groups on the formation of supramolecular complexes, 20-hydroxyecdysone triacetate has been synthesized, its spatial structure has been determined, and its complexation with β-cyclodextrin has been studied by means of NMR. The anti-inflammatory activity of the obtained water-soluble complex has been assessed.
Based on (–)-cytisine alkaloid and ethyl isothiocyanate, N-ethyl-N-cytisinocarbothioamide is synthesized and its structure is proved by 1H NMR spectroscopy and single crystal X-ray diffraction. The mesomeric effect is shown in the carbothioamide group formed. It is found that π-conjugation between nitrogen atoms and the thiocarbonyl group is weakened due to the steric hindrance between hydrogen atoms of the piperidine ring and the thioamide group.
As a result of studying the interaction of chlorolupinine with potassium phthalimide, the optimal synthesis conditions for N-lupinylphthalimide by the Gabriel method are identified. The crystal structure of N-lupinylphthalimide is determined for the first time by single crystal XRD. The energy characteristics are calculated using the quantum chemical method. It is found that the conformer with the chair conformation of the cycles with the axial orientation of the phthalimide substituent is more stable than that with the equatorial orientation.
В результате изучения химического состава казахстанского эндемика — полыни полусухой (Artemisia semiarida (Krasch. Et Lavr) Filat.) — впервые выделены сесквитерпеновые γ-лактоны эвдесманового ряда таурин: 8α-ацетокситаурин и 8α-гидрокситаурин. Рентгенодифракционным методом установлено их пространственное строение. Также выделен новый эвдесманолид, названный 8α-ацетокси-2-ен-таурином. На основании данных рентгеноструктурного анализа ему приписано строение 1-кето-8α-ацетокси-7α,6,11β(Н)-эвдесм-2,4-диен-6,12-олид.
As a result of studying the chemical composition of the Kazakh endemic Artemisia semiarida ((Krasch. Et Lavr.) Filat.), sesquiterpene γ-lactones of the eudesman type are isolated for the first time: taurine, 8α-acetoxytaurine, and 8α-hydroxytaurine. Their spatial structures are determined by Xray diffraction (XRD). New eudesmanolide named 8α-acetoxy-2-en-taurine is also isolated. Based on the single crystal XRD data, its structure is 1-keto-8α-acetoxy-7α,6,11β(H)-eudesm-2,4-diene-6,12-olide.
The synthesis of some cytisine derivatives was carried out in the work. The article provides the data of quantum-chemical calculation and virtual screening of the alkaloid cytisine derivatives synthesized. At the same time, the reaction centers of the cytisine derivatives molecules were determined. In order to study the reactivity of the derivatives obtained (namely cinnamoylcytisine, lipoylcytisine, and cytisinylisoalantholactone) the quantum-chemical calculations were conducted to determine the energy and charge characteristics of the molecules. The results indicate a sufficient thermodynamic stability of the cinnamoylcytisine and lipoylcytisine molecules. The cytisinylisoalantholactone molecule is not stable according to the results of quantum chemical calculations. The data on the energy values of the frontier molecular orbitals show that, in general, all molecules exhibit electrophilic properties. A bioprediction was implemented using PASS (Prediction of Activity Spectra for Substances) as one of the most efficient and well-known computer program with the aim of detailed study and the probable establishment of the biological activity of the synthesized cytisine derivatives. Based on the results of virtual screening, promising types of alkaloid cytisine derivatives were identified, which are potential sources of original drugs.
На основе алкалоида (–)-цитизина и этилизотиоцианата синтезирован N-этил-N-цитизинокарботиоамид, строение которого доказано методами 1Н ЯМР спектроскопии и рентгеноструктурного анализа. Показано, что наблюдается мезомерный эффект в образованной карботиоамидной группе. Установлено, что π-сопряжение между атомами азота и тиокарбонильной группой ослаблено вследствие возникающего стерического напряжения между атомами водорода пиперидинового цикла и тиоамидной группы.
Experimental transition current curves for polytetrafluoroethylene after exposure to high-energy ionizing radiation are obtained. The transient current curves in irradiated polytetrafluoroethylene are analyzed based on the discrete Fourier transform. It is shown that there is an intense maximum of dielectric absorption in the infralow frequency region. This maximum is characterized by abnormally large values of the dielectric increment, permittivity, and the dielectric loss factor. It is concluded that the volume polarization of the irradiated polytetrafluoroethylene is uniform. The polarization observed in this frequency range is associated with the activation of migration of trapped charge carriers within microscopic regions.