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Results for “Organosilicon Compounds”

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At least 19 recordsLinked to original sources
PubMed1988

Genotoxicity studies on selected organosilicon compounds: in vivo assays.

Six organosilicon compounds which had been found to have clastogenic activity in an in vitro battery of genotoxicity assays were evaluated in rat bone marrow cytogenetic assays for assessing clastogenicity in an in vivo system. None of the six compounds produced significant increases in chromosome aberrations in the rodent assay. However, trimethylsilanol produced a single value at the high-dose level/48-hr sampling interval that was significantly elevated when compared to the low concurrent control value. Both an independent repeat of the bone marrow cytogenetic assay and performance of the rat dominant lethal test failed to substantiate the presence of any significant clastogenic activity. Organosilicon compounds involved in the synthesis and degradation of polydimethylsiloxanes were not genotoxic in the in vivo clastogenicity tests employed in these studies.

Animals↗
PubMed1988

Genotoxicity studies on selected organosilicon compounds: in vitro assays.

A series of 12 organosilicon compounds representing potential intermediates in the synthesis and degradation of polydimethylsiloxanes were evaluated for genotoxic potential with a battery of in vitro assays. Microbial assays included the Ames bacterial reverse mutation in Salmonella, mitotic gene conversion in Saccharomyces cerevisiae D4 and DNA repair in E. Coli pol A +/-. These assays were conducted with and without a metabolic activation system containing Aroclor 1254-induced rat-liver homogenate. Forward gene mutation, sister-chromatid exchange, DNA alkaline elution and chromosome aberration potential were evaluated in mouse lymphoma L5178Y tissue culture cells. The tissue culture assays were performed with and without metabolic activation mixture utilizing uninduced mouse-liver S-9. The use of this enzyme preparation was felt to more closely mimic the actual in vivo situation and to be more compatible with mouse cells employed in the assay. No evidence of gene mutation was observed. However, six of the 12 compounds evaluated demonstrated potential in vitro clastogenic (chromosome damaging) activity.

Animals↗
PubMed1992

Kinetic resolution of organosilicon compounds by stereoselective dehydrogenation with horse liver alcohol dehydrogenase.

Stereoselective dehydrogenation of three isomers of trimethylsilylpropanol was carried out with horse liver alcohol dehydrogenase (HLADH, EC 1.1.1.1.) and optically active organosilicon compounds were obtained in a water-organic solvent two-layer system with coenzyme regeneration. Furthermore, we examined the effects of the silicon atom on stereoselectivity of HLADH compared to the corresponding carbon compounds. Substitution of the silicon atom for the carbon atom was found to improve the stereoselectivity of HLADH. For example, the optical purity of the remaining 1-trimethylsilyl-2-propanol was higher than 99% enantiomeric excess (ee) at 50% conversion, whereas that of the carbon analogue was 84% ee. This phenomenon was probably ascribable to the bulkiness of the organosilicon compounds derived from their longer Si-C bond. Kinetic analysis in an aqueous monolayer system demonstrated that the specific properties of the silicon atom greatly affected the reactivity of these substrate compounds.

1-Propanol↗
PubMed1977

[Effect of some organosilicon compounds (silatranes) on the biosynthesis of collagen in cartilagenous tissue of chick embryo].

Effect of some organosilicon compounds from the class of silatranes on the biosynthesis of collagen in cartilagenous tissue of chick embryos in vitro was studied. The criteria for assessing the intensity of collagen biosynthesis was the formation of peptide bond 14C-hydroxyproline from 14C-proline of incubation medium. All the compounds studied (methylsilatrane, ethoxysilatrane and chloromethylsilatrane) stimulated total protein biosynthesis and collagen biosynthesis in cartilagenous tissue of chick embryos. The most pronounced stimulation of the biosynthesis of collagen was observed at 3-10(-3) M concentration of silatranes within 180 min. of incubation (14C-proline was added to the incubation medium 60 min after the beginning of the incubation). The activity of partly purified collagen prolyl-hydroxylase in the presence of silatranes was also studied.

Animals↗
PubMed1988

Effects of an organosilicon compound on the tubular apparatus of rat kidney. A histological and enzyme histochemical report.

Male adult Wistar rats were treated for 8 weeks with an organosilicone [2,2-dimethyl-4-(chloromethyl)-1,3-dioxa-2-silacyclopentane] employing two different dosages (25 and 50 mg/kg body weight i.p. daily) and the changes in the tubular apparatus of the kidney were investigated employing histological and enzyme-histochemical methods. The effects, more pronounced at the higher dosage, were the following: The brush borders of the proximal tubules were stuck together and disintegrated; only few epithelial cells remained intact showing a decreased activity of nonspecific esterases and the increase of beta-hydroxybutyric acid dehydrogenase. The nuclei of most of the epithelial cells in the distal tubules were dislocated towards the enlarged lumen and the cytoplasma showed a decrease of nonspecific esterases and an increase of beta-hydroxybutyric acid dehydrogenase. The collagen fibers in the walls of the collecting tubules were dislocated and disintegrated with a discontinuous border of Mg2+-ATPase; the nuclei of the epithelial cells were pyknotic, the cytoplasma showed an increase of beta-hydroxybutyric acid dehydrogenase. The induced changes were partially reversible after a recovery period of 8 weeks.

Animals↗
PubMed1987

Hypocholesterolemic action of 1-ethoxysilatrane.

Intraperitoneal administration of the organosilicon compound 1-ethoxysilatrane to the rat caused a 25% decrease in the concentration of cholesterol in serum without affecting that of triacylglycerols. The specific activity of 3-hydroxy-3-methylglutaryl CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis, was depressed in hepatic microsomes of silatrane-treated animals.

Animals↗
PubMed1984

Organosilicone induced malformation of rat sperms, a histochemical study.

The effects of an organosilicon compound SOC, a derivative of 1,3-dioxa-2-sila-cyclopentane, on rat spermiogenesis were studied with the help of histochemical and enzyme histochemical methods. The rats were injected with SOC i.p. daily for 3 weeks (dosage: 25 mg SOC/kg body weight). Two changes were observed: a) formation of a distinct vacuole within the acrosomal cap of spermatids b) the splitting of the tails of mature sperms.

Acrosome↗
PubMed1988

A comparison of the rates of methylation of mercury(II) species in aquatic media by various organotin and organosilicon moieties.

Metals can be methylated in environmental aqueous media by a variety of organotin and organosilicon compounds. Main group metals and metalloids were surveyed for the identification of species that can either donate or accept methyl groups. The methylation of mercury(II) by trimethyltin cation was found to be a bimolecular reaction, the reaction rate of which decreased with increasing chloride concentration. Kinetic investigations using NMR techniques showed that the most important pairs of reactants were (CH3)3Sn+ + HgCl2, (CH3)3SnCl + HgCl2, and (CH3)3SnCl + HgCl-3. Sodium 2,2,3,3-tetradeutero-3-(trimethylsilyl)propionate (TSP) and sodium 2,2-dimethyl-2-silapentane-5-sulfonate (DSS) were found to methylate mercury(II). Organylsilatranes were found to transfer their organic groups readily to mercury(II) to produce organomercury compounds.

Magnetic Resonance Spectroscopy↗
PubMed1983

Cisobitan in treatment of prostatic cancer. A prospective controlled multicentre study.

Cisobitan, an organosilicon compound with estrogenic and antigonadotropic properties has been evaluated clinically in comparison with an estrogen preparation. In a multicenter study a total of 140 patients with well and moderately well differentiated prostatic cancer were randomly allocated to treatment with Cisobitan or Estradurin/Etivex, 70 to each group. Of 34 patients with poorly differentiated prostatic cancer 18 were given Cisobitan--and 16 were given Estracyt-treatment. Among the patients with well and moderately well differentiated prostatic cancer there were, disregarding mortality, no major differences in subjective, objective or laboratory response to the two kinds of treatment. The pattern of side effects was similar, but oedema requiring diuretics occurred more often in the estrogen treated group. There was a significant difference in mortality at 12 months between the groups, two in the Cisobitan group and ten in the estrogen treated group. Cancer was the cause of death in two patients in the estrogen treated group. All other patients succumbed in cardiovascular diseases. At 24 months the difference in mortality rate was less pronounced: Another ten patients had died in the Cisobitan treated group and seven among the estrogen treated patients. Cancer was responsible for the deaths in seven of the Cisobitan patients compared to four of the estrogen treated patients. Within three years one more patient in both groups had died. Of the 34 patients with poorly differentiated cancer, twelve were alive at the 24 months' follow up, six in the Cisobitan group and six in the Estracyt group.

Clinical Trials as Topic↗
PubMedDate not supplied

[Atranes: their ulcerostatic effect and its possible mechanisms].

The ulcerostatic activity of methylethyl (sylathrane-1-ilmethyl) sulfoiodide, 1-(chlormethyl) sylatrane, and 1-(isopropoxy)hermatrane has been revealed at experimental acetate ulcer in rats. The effect of atranes was equal to that of oxyferriscorbone and exceeded that of methyluracil. All the compounds studied inhibited peroxide oxidation of lipids in blood and stomach tissues from ulcer and in model experiments in egg yolk liposomes. The processes of ulcer development and photodynamic effects of lipid peroxidation in biological objects have been summarized. The data obtained allow to conclude that the ulcerostatic mechanism of action effect of atranes and the comparable drugs is based on their antioxidative effect.

Acetates↗