Tag: M.W=100-150

Yang, Zhibo published the artcileInfluence of methylation on the properties of uracil and its noncovalent interactions with alkali metal ions. Threshold collision-induced dissociation and theoretical studies, Application In Synthesis of 608-34-4, the publication is International Journal of Mass Spectrometry (2005), 241(2-3), 225-242, database is CAplus.

The influence of methylation on the properties of uracil and its noncovalent interactions with alkali metal ions is investigated both exptl. and theor. Threshold collision-induced dissociation (CID) of M⁺(xMeU) with Xe is studied in a guided ion beam mass spectrometer. M⁺ include the following alkali metal ions: Li⁺, Na⁺, and K⁺. Five methylated uracils are examined, xMeU = 1-methyluracil, 3-methyluracil, 6-methyluracil, 1,3-dimethyluracil, and 5,6-dimethyluracil. In all cases endothermic loss of the intact nucleobase is the dominant reaction pathway, while ligand exchange to produce MXe⁺ is observed as a minor reaction pathway. The threshold regions of the cross sections are interpreted to extract 0 and 298 K bond dissociation energies (BDEs) for M⁺-xMeU after accounting for the effects of multiple ion-neutral collisions, kinetic and internal energies of the reactants, and dissociation lifetimes. Ab initio calculations at the MP2(full)/6-31G* level of theory are used to determine the structures of these complexes and provide mol. constants required for the thermochem. anal. of the exptl. data. Theor. bond dissociation energies are determined from single point energy calculations at the MP2(full)/6-211+G(2d,2p) level using the MP2(full)/6-31G* geometries. Excellent agreement between theory and experiment is found for the Na⁺ and K⁺ systems, while theory systematically underestimates the strength of binding in the Li⁺ systems. Theor. calculations are also performed to examine the influence of methylation on the acidities, proton affinities, and Watson-Crick base pairing energies. The present results are compared to earlier studies of uracil and 5-methyluracil to more fully elucidate the influence of methylation on the properties of uracil, its noncovalent interactions with alkali metal ions, and nucleic acid stability.

International Journal of Mass Spectrometry published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C20H40O2, Application In Synthesis of 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Grabowski, Zbigniew R. published the artcileTwisted intramolecular charge transfer states (TICT). A new class of excited states with a full charge separation, COA of Formula: C6H9N3, the publication is Nouveau Journal de Chimie (1979), 3(7), 443-54, database is CAplus.

The dual fluorescence of N,N-dialkylanilines as well as the high polarity of the lowest excited singlet states of compounds containing perpendicular donor (D) and acceptor (A) orbitals is explained by a common phenomenon involving 1 electron transfer in this new class of excited states, TICT. The electronic structure, thermodn. and formation kinetics, dipole moments, and radiative and radiationless transitions of the TICT states are discussed. The TICT states are formed by D-A mols. as well as sym. biaryls and I.

Nouveau Journal de Chimie published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, COA of Formula: C6H9N3.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Pizzirani, Daniela published the artcileDiscovery of a New Class of Highly Potent Inhibitors of Acid Ceramidase: Synthesis and Structure-Activity Relationship (SAR), Product Details of C5H6N2O2, the publication is Journal of Medicinal Chemistry (2013), 56(9), 3518-3530, database is CAplus and MEDLINE.

1-(Alkylamino)-2,4-pyrimidinediones such as I [R = H, F, MeO, F₃C, Ph; R¹ = Me(CH₂)_nNH; R² = H, Me, MeO₂C; n = 5, 7] were prepared as inhibitors of acid ceramidase for potential use as antitumor agents. Uracils bearing an electron-withdrawing substituent at position 5, a substituent such as Me at position 3, and an alkylaminocarbonyl moiety with a six- to eight-carbon alkyl group at position 1 were the most effective inhibitors of acid ceramidase of the compounds tested. The acid ceramidase inhibition and stability of an alkylaminopyrimidinedione was correlated with the stabilization of the antibonding orbital of its N1-carbonyl bond. I (R = H, F, Ph; R² = H, Me; n = 5, 7) inhibited a human cancer cell line (SW403) with IC₅₀ values of 20-24 μM. I (R = F, F₃C, MeO; R² = H, MeO₂C; n = 5, 7) inhibited acid ceramidase with single digit-nanomolar IC₅₀ values (IC₅₀ = 4-7 nM).

Journal of Medicinal Chemistry published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Product Details of C5H6N2O2.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Shih, Phoebe published the artcileHydrophobicities of the nucleic acid bases: distribution coefficients from water to cyclohexane, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Journal of Molecular Biology (1998), 280(3), 421-430, database is CAplus and MEDLINE.

To establish an exptl. scale of hydrophobicities for the nucleic acid bases, comparable with a scale developed earlier for amino acid side-chains, these bases and their parent compounds (purine and pyrimidin-2-one) were converted to n-butylated and tetrahydrofurylated derivatives that are appreciably soluble in cyclohexane, a truly non-polar solvent that dissolves negligible water at saturation Distribution measurements between neutral aqueous solution and cyclohexane, at varying solute concentrations, showed no evidence of self-association of the solute in either solvent, and the possibility of specific entrainment of water by solutes entering cyclohexane was ruled out by the results of experiments with tritiated water. In both the Bu and tetrahydrofuryl series, the bases span a range of �.3 kcal mol^-1 in their free energies of transfer from water to cyclohexane, and are arranged in the following rank, in order of decreasing hydrophobicity: purine > thymine > adenine > uracil > pyrimidin-2-one > hypoxanthine �cytosine �guanine. In both series of pyrimidin-2-ones, hydrophobicity decreases with introduction of an amino substituent, but addition of an exocyclic keto group results in a modest enhancement of hydrophobicity; and free energies of transfer are relatively insensitive to the position of N-alkyl substitution. In both series of purines, hydrophobicity decreases with the introduction of exocyclic amino and keto groups, the keto group having the greater effect; and free energies of transfer vary substantially depending on the position of N-alkyl substitution. Several addnl. compounds were examined to test recent predictions based on SM5.4/A, a quantum mech. self-consistent-field solvation model; and that model was found to yield values in reasonable agreement with the exptl. results. (c) 1998 Academic Press.

Journal of Molecular Biology published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C27H39ClN2, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Herbich, Jerzy published the artcileIntramolecular electron transfer in 4-(dialkylamino)pyrimidines. Study in solutions and supersonic jet, Name: N,N-Dimethylpyrimidin-4-amine, the publication is Proceedings – Indian Academy of Sciences, Chemical Sciences (1992), 104(2), 117-31, database is CAplus.

The dual fluorescence (a and b) of 4-(dialkylamino)pyrimidines (4-DAAP) in solutions is explained in terms of the twisted intramol. charge transfer (TICT) state model. 4-DAAP form complexes with protic solvents: efficient radiationless depopulation is switched on by H-bonding (HB). The photoinduced electron transfer is modified by HB or by coordination to the metal ion. In nitriles, 2 emitting states of 4-(N,N-dimethylamino)pyrimidine (I) and 4-(N,N-diethylamino)pyrimidine (II) reach equilibrium In protic solvents, the fluorescences a and b are not kinetically coupled: the different ground state complexes are responsible for each band. Jet-cooled 4-DAAP show only primary excited fluorescence b. Microsolvation of pretwisted o-methylated compounds, by small polar mols., contrary to more planar I and II, gives rise to the long-wave (probably TICT) fluorescence.

Proceedings – Indian Academy of Sciences, Chemical Sciences published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, Name: N,N-Dimethylpyrimidin-4-amine.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Herbich, Jerzy published the artcile“Twisted” intramolecular charge-transfer states in supercooled molecules: structural effects and clustering with polar molecules, Formula: C6H9N3, the publication is Journal of Physical Chemistry (1991), 95(9), 3491-7, database is CAplus.

A study of laser-induced fluorescence and excitation spectra of jet-cooled 4-(dimethylamino)benzonitriles and 4-(dialkylamino)pyrimidines and their complexes with small polar mols. (methanol and acetonitrile). Various ground-state forms (monomers, dimers, and larger clusters) have been observed The bare mols. [except Me₂NC₆H₂Me₂(CN)-2,6,4] do not exhibit any distinct long-wave fluorescence that can be assigned to a twisted intramol. charge-transfer (TICT) state. Microsolvation of pretwisted compounds by small polar mols. gives rise to a long-wave fluorescence, which is interpreted as emission from a TICT state.

Journal of Physical Chemistry published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is C6H9N3, Formula: C6H9N3.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Sparatore, Anna published the artcilePharmacological profile of a novel H₂S-releasing aspirin, Recommanded Product: N,N-Dimethylpyrimidin-4-amine, the publication is Free Radical Biology & Medicine (2009), 46(5), 586-592, database is CAplus and MEDLINE.

The pharmacol. profile of a new, safe, and effective hydrogen sulfide (H₂S)-releasing derivative of aspirin (ACS14) is described. We report the synthesis of ACS14, and of its deacetylated metabolite (ACS21), the preliminary pharmacokinetics, and its in vivo metabolism, with the H₂S blood plasma levels after i.v. administration in the rat. ACS14 maintains the thromboxane-suppressing activity of the parent compound, but seems to spare the gastric mucosa, by affecting redox imbalance through increased H₂S/glutathione formation, heme oxygenase-1 promoter activity, and isoprostane suppression.

Free Radical Biology & Medicine published new progress about 31401-45-3. 31401-45-3 belongs to pyrimidines, auxiliary class Pyrimidine,Amine, name is N,N-Dimethylpyrimidin-4-amine, and the molecular formula is Al2H32O28S3, Recommanded Product: N,N-Dimethylpyrimidin-4-amine.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Szczepaniak, K. published the artcileMatrix isolation and DFT quantum mechanical studies of vibrational spectra of uracil and its methylated derivatives, Application In Synthesis of 608-34-4, the publication is Polish Journal of Chemistry (1998), 72(2), 402-420, database is CAplus.

The IR spectra of uracil and its derivatives in the carbonyl region are strikingly complex, and extremely sensitive to substitution, particularly at ring nitrogens. The IR spectra of uracil, 1,3-di-deuterouracil, 1-methyluracil, 3-methyluracil and 1,3-dimethyluracil were studied exptl. by low temperature (12 K) matrix isolation IR spectroscopic techniques, and theor. by DFT/B3LYP/6-31G(d,p) quantum mech. methods. Particular attention is focused on the carbonyl region and on the mech. coupling of the C2= and C4=O stretching vibrations with each other, with the N1H and N3H bending motions, and with other motions. This coupling plays a crucial role in determining the frequencies and intensities of the normal modes that determine the spectral patterns in the IR spectrum in the carbonyl region. The extreme sensitivity of the frequencies, intensities and spectral pattern in the carbonyl region to isotopic substitution and methylation (and to the intermol. interactions, particularly H bonding) is attributed, to a large extent, to changes in this coupling. The DFT calculations appear to give quite accurate values for the force constants and allow separation of simple mass effects and chem. substituent effects on the coupling. Fermi resonance in the carbonyl region is an important factor contributing to the observed complexity of this spectral region. Examination of this effect making use of the visualization of normal modes of vibration provides rules for when it may be expected to be important.

Polish Journal of Chemistry published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C13H18N2, Application In Synthesis of 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Brunetti, Bruno published the artcileSublimation Enthalpies of Some Methyl Derivatives of Uracil from Vapor Pressure Measurements, Safety of 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Journal of Chemical and Engineering Data (2000), 45(2), 242-246, database is CAplus.

The standard sublimation enthalpies for uracil, 1-methyluracil, 3-methyluracil, and 1,3-dimethyluracil, Δ_subH°(298 K) = (128 ± 2), (124 ± 5), (121 ± 4), and (118 ± 4) kJ mol^-1, resp., were determined from their vapor pressures measured by the torsion method. The results of vapor pressure measurements were fit to the following linear equations: uracil, log(p/kPa) = (12.29 ± 0.15) – (6634 ± 100) K/T (from 384 K to 494 K); 1-methyluracil, log(p/kPa) = (13.75 ± 0.15) – (6357 ± 150) K/T (from 343 K to 428 K); 3-methyluracil, log(p/kPa) = (13.59 ± 0.10) – (6210 ± 100) K/T (from 344 K to 419 K); 1,3-dimethyluracil, log(p/kPa) = (15.10 ± 0.10) – (6049 ± 100) K/T (from 311 K to 364 K). The different sublimation behavior of some compounds can be due to the presence of hydrogen bonds in their solid state.

Journal of Chemical and Engineering Data published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, Safety of 3-Methylpyrimidine-2,4(1H,3H)-dione.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia

Colasurdo, Diego D. published the artcileTautomerism of uracil and related compounds and mass spectrometry study, SDS of cas: 608-34-4, the publication is European Journal of Mass Spectrometry (2018), 24(2), 214-224, database is CAplus and MEDLINE.

It has been demonstrated that uracil has a preponderant tautomeric form, but it is also known that different tautomers co-exist in this equilibrium In this work, mass spectrometry is used as a helpful tool to analyze the equilibrium, using derivative compounds to forbid the presence of some tautomers and ion trap mass spectrometry to follow relevant fragmentation pathways. Theor. calculations were performed to confirm tautomers abundance by energy minimization in gas phase. Anal. of mass spectra of uracil, three methyl-substituted uracils, 2-thiouracil and three benzouracils suggest that uracil exists mainly as three tautomers in gas phase and one major structure that corresponds to the classical structure of uracil (pyrimidine-2,4(1H,3H)-dione) bearing two carbonyls and two NH moieties, and two minor enolic forms (4-hydroxypyrimidin-2(1H)-one and 2-hydroxypyrimidin-4(1H)-one). Such tautomeric distribution is supported by theor. calculations, which show that they are the three most stable tautomers.

European Journal of Mass Spectrometry published new progress about 608-34-4. 608-34-4 belongs to pyrimidines, auxiliary class Pyrimidine,Amide, name is 3-Methylpyrimidine-2,4(1H,3H)-dione, and the molecular formula is C5H6N2O2, SDS of cas: 608-34-4.

Referemce:
https://pubchem.ncbi.nlm.nih.gov/compound/Pyrimidine,
Pyrimidine – Wikipedia