RESUMEN
Syntheses under shock in nitrogen bubbled samples of the water - formamide - bicarbonate - sodium hydroxide system at pH 8.63, 9.46 and 10.44 were performed in the stainless steel preservation capsules. The maximum temperature and pressure in the capsules reached 545 K and 12.5 GPa respectively. Using the LC-MS-MS analysis, the 21 synthesis products have been identified, including amines and polyamines, carboxamide, acetamide and urea derivatives, compounds containing aniline, pyrrolidine, pyrrole, imidazole, as well as alcohol groups. It was found that the Fischer-Tropsch-type syntheses with catalysis on the surface of the stainless steel of the conservation capsule associated with the adsorbed hydrogen cyanide reactions and transamidation processes play the main role in the shock syntheses. Formation reactions of all the above-mentioned compounds have been suggested. It was proposed that hydrogen cyanide, ammonia, isocyanic acid, aminonitrile, aminoacetonitrile, as well as adsorbed species H(a), CH(a), CH2(a), CHOH(a), NH2(a) and H2CNH(a) are especially important for the formation of the products. A reduction reaction of adsorbed bicarbonate with hydrogen to formaldehyde has been first postulated. In the studied system also classical reactions take place - Wöhler's synthesis of urea and Butlerov's synthesis of methenamine. It was suggest that material of meteorites may be an effective catalyst in the Fischer-Tropsch-type syntheses at falling of the iron-nickel meteorites in the water - formamide regions on the early Earth. It was concluded that life could have originated due to the impact of meteorites on alkaline water-formamide lakes located near volcanoes on the early Earth.
Asunto(s)
Bicarbonatos/química , Evolución Química , Formamidas/química , Origen de la Vida , Compuestos de Potasio/química , Hidróxido de Sodio/química , Cromatografía Liquida , Planeta Tierra , Concentración de Iones de Hidrógeno , Meteoroides , Espectrometría de Masas en Tándem , Agua/químicaRESUMEN
The principal cause of death in cancer involves tumor progression and metastasis. Since only a small proportion of the primary tumor cells, cancer stem cells (CSCs), which are the most aggressive, have the capacity to metastasize and display properties of stem cells, it is imperative to characterize the gene expression of diagnostic markers and to evaluate the drug sensitivity in the CSCs themselves. Here, we have examined the key genes that are involved in the progression of colorectal cancer and are expressed in cancer stem cells. Primary cultures of colorectal cancer cells from a patient's tumors were studied using the flow cytometry and cytological methods. We have evaluated the clinical and stem cell marker expression in these cells, their resistance to 5-fluorouracil and irinotecan, and the ability of cells to form tumors in mice. The data shows the role of stem cell marker Oct4 in the resistance of primary colorectal cancer tumor cells to 5-fluorouracil.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias del Colon/genética , Resistencia a Antineoplásicos/genética , Células Madre Neoplásicas/metabolismo , Animales , Antineoplásicos/farmacología , Biomarcadores de Tumor/metabolismo , Camptotecina/análogos & derivados , Camptotecina/farmacología , Línea Celular Tumoral , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/metabolismo , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Fluorouracilo/farmacología , Regulación Neoplásica de la Expresión Génica , Humanos , Inmunohistoquímica , Irinotecán , Ratones , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
A novel phosphonium salt based on pyridoxine was synthesized. Conformational analysis of the compound in solution was performed using dynamic NMR experiments and calculations. The obtained results revealed some differences in the conformational transitions and the energy parameters of the conformational exchange of the studied compound in comparison to previously reported data for other phosphorus-containing pyridoxine derivatives. It was shown that increasing the substituent at the C-11 carbon leads to greater differences in the populations of stable states and the corresponding equilibrium energies. Copyright © 2015 John Wiley & Sons, Ltd.
Asunto(s)
Ciclohexanoles/síntesis química , Espectroscopía de Resonancia Magnética/métodos , Teoría Cuántica , Ciclohexanoles/química , Modelos Moleculares , EstereoisomerismoRESUMEN
A series of 26 quaternary ammonium pyridoxine derivatives were synthesized and their cytotoxicity and antibacterial activities against clinically relevant bacterial strains were tested in vitro. The antibacterial activity of mono-ammonium salts increased with the rise of the lipophilicity and compound 3,3,5-trimethyl-8,8-dioctyl-1,7,8,9-tetrahydro-[1,3]dioxino[5,4-d]pyrrolo[3,4-b]pyridin-8-ium chloride (2d) reaches a maximum among them. Bis-ammonium salt of pyridoxine 4 with two dimethyloctylamine groups also demonstrated high antibacterial activity despite lower lipophilicity. The results of MTT assay indicated that HEK 293 cells were more sensitive than HSF to quaternary ammonium pyridoxine derivatives. Compounds 2d and 4 did not induce the damage of the DNA and might be of interest in the development of new antimicrobials.