- Thiation of heterocycles using silica gel supported P2S5 under microwave irradiation in solventless system
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The efficient and environmentally friendly thiation of heterocycles using P2S5 under microwave irradiation in solvent free condition is described.
- Heravi,Rajabzadeh,Rahimizadeh,Bakavoli,Ghassemzadeh
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- Chalcogen containing heterocyclic scaffolds: New hybrids with antitumoral activity
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In this work, 27 novel hybrid derivatives containing diverse substituents with chalcogen atoms (selenium or sulfur) and several active heterocyclic scaffolds have been synthesized. Compounds were tested against two human cancer cells lines (MCF7 and PC-3) and a normal human mammary epithelial cell line (184B5) in order to determine their activity and selectivity against malignant cells. Ten compounds showed GI50values below 10?μM in at least one of the cancer cell lines and six of them exhibited a selectivity index higher than 9. In general, selenium-containing compounds were more active than their corresponding sulfur analogs but we found some thiocyanate derivatives with comparable or higher activity and selectivity. Among the different substituents, the seleno- and thio-cyanate groups showed the most promising results. On the basis of their potent activity and high selectivity index, compounds 7e and 8f (containing a thiocyanate and a selenocyanate group, respectively) were selected for further biological evaluation. Both the compounds induced caspase-dependent cell death and cell cycle arrest in G2/M phase. In addition, these compounds do not violate any of the Lipinski's Rule of Five and thus possess good potential to become drugs, compound 7e being particularly promising.
- Alcolea, Verónica,Plano, Daniel,Encío, Ignacio,Palop, Juan Antonio,Sharma, Arun K.,Sanmartín, Carmen
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p. 407 - 418
(2016/08/04)
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- Spectroscopic identification of 2,4-pyrimidinedithiol; an experimental matrix isolation and ab initio Hartree-Fock and density functional theory study
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2,4-Pyrimidinedithiol (the dithiol form of 2,4-dithiouracil) was generated by UV (λ > 335 nm) irradiation of the dithione form of 2,4-dithiouracil isolated in low-temperature argon or nitrogen matrices. The IR and UV spectra of the photoproduct are reported. The dithiol form of 2,4-dithiouracil was identified by comparison of the experimental spectrum with the spectrum theoretically predicted for this form at the HF/6-31 (d,p) and DFT(B-3LYP)/6-31 (d,p) levels. This comparison resulted also in assignment of the bands observed in the IR spectrum of 2,4-pyrimidinedithiol to the theoretically predicted normal modes.
- Lapinski, Leszek,Nowak, Maciej J.,Kolos, Robert,Kwiatkowski, Jozef S.,Leszczynski, Jerzy
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p. 685 - 693
(2007/10/03)
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- Artificial DNA base pair analogues
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The present invention is directed to new artificial base pairs comprising complementary artificial purines and pyrimidines and methods of using artificial complementary base pairs.
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- The Tautomeric Equilibria of Thio Analogues of Nucleic Acid Bases. Part 1. 2-Thiouracil: Background, Preparation of Model Compounds, and Gas-phase Proton Affinities
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The preparation is reported of all four the monoalkyl derivatives of 2-thiouracil and four of the six possible dialkyl derivatives required as models for a study of the tautomeric equilibria by physical methods.Gas-phase proton affinities are determined using ion cyclotron resonance mass spectrometry, and are used to provide quantitative estimates of individual tautomer stabilities in the vapour state.These quantitative results agree well with qualitative deductions of predominant structures for the monoalkyl derivatives from i.r. spectroscopy.
- Katritzky, Alan R.,Baykut, Gokhan,Rachwal, Stanislaw,Szafran, Miroslaw,Caster, Kenneth C.,Eyler, John
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p. 1499 - 1506
(2007/10/02)
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- Lubricating composition containing anti-wear/extreme pressure additives
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Compounds suitable for use as extreme pressure (EP)/anti-wear (AW) agents in lubricating oil compositions, which compounds have the formula:-, R1 - S - X - S - S - R (I), wherein R1 is either R-S- or hydrogen, R is independently either hydrocarbyl or substituted hydrocarbyl, and, X comprises a heterocyclic ring having six atoms of which two are nitrogen atoms.
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- A Rapid and Efficient Synthesis of Sulfur Analogues of Pyrimidine Bases
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An improved procedure for thionation of some natural pyrimidine bases with tetraphosphorus decasulfide/sodium hydrogen carbonate is reported.Some substituted uracils and 2-thiouracils were converted into a series of analogues in which the oxygen at position 4 was replaced by sulfur atom.The advantage of this method of thionation over the older procedures is based on the tetraphosphorus decasulfide/sodium hydrogen carbonate mixture giving rise to excellent yields and simplified isolation of the desired pure products.
- Lapucha, Andrzej R.
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p. 256 - 258
(2007/10/02)
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