417 research outputs found
Synthesis, Vasodilating, Antithrombotic and Cardioprotective Activity of Pyridyl Substituted 5-Silyl(Germyl)Isoxazolines-2
The reactions of [2+3] cycloaddition of pyridylnitrile oxides to vinyl- and allylgermanes
proceed regioselectively and afford 5-Ge-substituted isoxazolines-2. We have synthesized 9 new
pyridyl substituted 5-Si(Ge)-isoxazolines-2 and investigated their biological activity. The
vasodilating, anticoagulant and cardioprotective activities of 5-Si(Ge) substituted isoxazolines-2
have been studied in vitro and in vivo. Substitution of the silicon atom for the germanium one
leads to the significant increase in vasodilating, antithrombotic and cardioprotective activity. The
insertion of the methylene group between Ge and the isoxazoline ring reduces the vasodilating
activity. The most active isoxazoline - 3-(5‵-triethylgermyl-3‵-isoxazolinyl)pyridine hydrochloride
protects the heart from rhythm disturbances and lethality during ischaemia-reperfusion
Synthesis and Biological Activity of Silyl- and Germylsubstituted Trifluroacetylfurans
A series of silyl, germyl and alkyl substituted trifluoroacetylfurans has been synthesized under Friedel-Crafts electrophilic acylation conditions. Biological investigations have demonstrated that germyl
derivatives of trifluoroacetylfuran are more toxic than the silicon analogues. 5-Triethylgermyl-2-trifluoroacetylfuran was the most toxic compound
(LD50, 11.2 mg kg-1, i.p. for white mice), 200 times more
toxic than the silicon analogue. 5-t-Butyl- and 5-trimethylsilyl-2-trifluroacetylfuran prolong the duration
of ethanol anaesthesia by 220 and 140%. 5-Triethylgermyl-2-trifluroacetylfuran exibited high anesthetic
activity in hexobarbital test (prolonged the duration by 137%). Some of compounds influenced muscle tone
and locomotor coordination parameters. 5-Triethylgermyl-2-trifluomacetylfuran exibited analgesic activity
(ED50, 0.9 mg kg-1)
Synthesis of Silicon and Germanium Containing Heteroaromatic Sulfides as Cholesterol Level Lowering and Vasodilating Agents
Silicon and germanium containing heteroaromatic sulfides have been prepared using
phase transfer catalytic (PTC) system thiol / Si or Ge containing alkyl halide / solid KOH / 18-
crown-6 / toluene. The target sulfides were isolated in yields up to 92 %. It has been found that 2-{[dimethyl (β-triethylgermylethyl)-silylmethyl]thio}-1-methylimidazole and 2-{[dimethyl(β-triphenylsilylethyl)
silyl-methyl]thio}benzothiazole are the most active cholesterol level lowering and
vasodilating agents
Synthesis and Cytotoxicity of Silicon and Germanium Containing Pyridine Oxime O-Ethers
Silicon and germanium containing pyridine aldoxime, ketoxime and amidoxime O-ethers have been
prepared using phase transfer catalytic systems oxime alkyl halide solid KOH 18-crown-6 benzene and
oxime alkyl halide solid K2CO3 or Cs2CO3 18-crown-6 toluene. Cytotoxic activity of silicon and
germanium containing pyridine oxime O-ethers was tested in vitro on two monolayer tumor cell lines: MG-
22A (mouse hepatoma) and HT-1080 (human fibrosarcoma). O-[3-Yriethylsilylpropyl]- and O-[3-(1-methyl-
1-silacyclopentyl)propyl] oximes of pyridine aldehydes and ketones exhibit high cytotoxicity. Presence of
methyl group in the pyridine ring considerably decreased activity of amidoxime O-ethers. Oxime ethers
containing two elements are essentially inactive. For 2-acetylpyridine oxime ethers the activity increases in
order of alkyl substituents: Et3GeCH2CH2SiMe2CH2 < Et3SiCH2CH2CH2 < (CH2)4SiCH2CH2CH2.
Cytotoxicity of ketoxime O-ethers is considerably lower in comparison with aldoxime O-ethers
Cytotoxic Activity of Silyl- and Germyl-Substituted 4,4-Dioxo-3a,6a-Dihydrothieno[2,3−d]isoxazolines-2
The [2+3] dipolar cycloaddition of nitrile oxides to the double C = C bonds of thiophene-1, 1-dioxides leads to formation of the fused isoxazolines-2 (1, 2). Tumor growth inhibition of these compounds strongly depends on the nature of group IV A element increasing from slightly active tert-butyl derivatives to silicon and germanium containing analogues. The products of benzonitrile oxide cycloaddition have greater cytotoxic effect than the compounds obtained from the cycloaddition reaction of 2, 5-disubstituted thiophene-1, 1-dioxides with acetonitrile oxide. Fused silyl substituted isoxazolines-2 are stronger NO-inducers than their germyl and tert-butyl analogues
(E)-2-(4-Benzyloxy-2-hydroxybenzylidene)-N-phenylhydrazinecarbothioamide
The title compound, C21H19N3O2S, exists in the thione form. The configuration about the C=N bond is E. The hydrazinecarbothioamide unit adopts an almost planar arrangement, with maximum deviations of 0.016 (3) and −0.016 (2) Å for the two thiourea N atoms. An intramolecular O—H⋯N hydrogen bond occurs. Weak intermolecular N—H⋯S, C—H⋯O and C—H⋯π interactions are observed in the crystal structure
Ethyl 1-tert-butyl-2-(4-methoxyphenyl)-1H-benzimidazole-5-carboxylate
In the title molecule, C21H24N2O3, the imidazole ring is essentially planar, with a maxium deviation of 0.015 (1) Å. The dihedral angle between the benzene and imidazole rings is 65.47 (6)°. The crystal packing is stabilized by weak intermolecular C—H⋯O and C—H⋯N hydrogen bonds, forming zigzag chains along the c axis. The crystal structure is further stabilized by C—H⋯π interactions
Silacyclic Derivatives of Heteroaromatic Sulfides as Selective Cholesterol Level Lowering and Vasodilating Agents
Silacyclic derivatives of heteroaromatic sulfides have been prepared by using phase transfer catalytic
(PTC) system thiol / silacyclopropyl iodide / solid K2CO3 / 18-crown-6 / toluene. The target sulfides were
isolated in yields up to 70 %. The S-derivatives of N-methylimidazolyl, benzoxazolyl and 1,3,4-triazolyl
thiols selectively lowered the low density lipoprotein (LDL) level in mice with the high cholesterol diet in
nutrition
catena-Poly[[cadmium-bis(μ-triethylenetetramine-κ4 N,N′:N′′,N′′′)-cadmium-(μ-triethylenetetramine-κ4 N,N′:N′′,N′′′)] hexafluoridogermanate]
The title fluoridogermanate, {[Cd2(C6H18N4)3][GeF6]}n, was synthesized hydrothermally. The crystal structure comprises undulated cationic [Cd2(TETA)3]4+ chains (TETA is triethylenetetramine) propagating parallel to [101]. The central CdII atom is six-coordinated in a CdN6 set by three TETA ligands. The isolated [GeF6]2− units, serving as counter-anions, occupy the inter-chain spaces and simultaneously link adjacent chains into a three-dimensional network through extensive N—H⋯F hydrogen-bonding interactions. One of the ethylene bridges of one TETA ligand is disordered around a twofold rotation axis
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