Tag: M.W=100-150

Sun, Chang-Zheng published the artcileCharacterization of the doxorubicin-pluronic F68 conjugate micelles and their effect on doxorubicin resistant human erythroleukemic cancer cells, Recommanded Product: N,N-Dimethylpyrimidin-4-amine, the publication is Journal of Nanomedicine & Nanotechnology (2011), 2(5), 1000114, database is CAplus.

Doxorubicin-pluronic F68 conjugate (DOX-P) was synthesized and its structure was confirmed by FTIR and H-NMR spectra. Using human erythroleukemic cancer cells as model, DOX-P application in chemotherapy was further investigated. Differential scanning calorimetry anal. was applied to compare the fusion and crystallization characterization between pluronic F68 and DOX-P. Morphol. and size assessment were measured using a transmission electron microscopy (TEM) to confirm the capability of forming micelles of DOX-P. Tumor cell lines K562 and K562/AO2 were used to investigate the effect of DOX-P on tumor cell resistance. The Tm and Tc of DOX-P were lower than pluronic F68 resulted from the connection of DOX to pluronic F68. Morphol. images confirmed the existence of DOX-P micelles, with an average size of about 20 nm. Drug release profile showed that the DOX-P conjugate maintained a sustained DOX release. From cell experiment in vitro, DOX-P micelles could circumvent the DOX resistance of K562/AO2 cells. With advantages of EPR effect and reducing tumor resistance, DOX-P micelles might develop as new tumor targeted delivery system for chemotherapy.

Journal of Nanomedicine & Nanotechnology 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 C7H5I2NO3, Recommanded Product: N,N-Dimethylpyrimidin-4-amine.

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

Lemoine, Remy C. published the artcileSynthesis of base-modified dihydropacidamycins, Application In Synthesis of 608-34-4, the publication is Bioorganic & Medicinal Chemistry Letters (2002), 12(7), 1121-1123, database is CAplus and MEDLINE.

The authors describe the synthesis of 1,2-di-O-acetyl-5-azido-3,5-dideoxy-α,β-L-arabinofuranose, a carbohydrate donor that was used for the synthesis of 1-(5′-amino-3′,5′-dideoxy-α-L-arabinofuranosyl)uracil, the nucleoside found in dihydropacidamycin D. The carbohydrate donor was also used for the synthesis of a set of new nucleosides that were introduced in new dihydropacidamycins. These compounds were tested for biol. activity, and the results showed that uracil is the only base recognized by MraY.

Bioorganic & Medicinal Chemistry Letters 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, Application In Synthesis of 608-34-4.

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

Shkurko, O. P. published the artcileNMR spectra of pyrimidines. Effect of substituents on the chemical shift of meta-protons in 2- and 4-substituted pyrimidines, Product Details of C6H9N3, the publication is Khimiya Geterotsiklicheskikh Soedinenii (1978), 673-7, database is CAplus.

NMR chem. shifts were recorded for H-4 in I (R = Me₂N, MeO, Me, Ph, H, halo, CO₂Me, MeSO₂, CN) and for H-2 and H-6 in II (same R), and correlation equations with F and R substituent constants were obtained. The inductive effect of R was weaker when R and the observed H were separated by a ring N.

Khimiya Geterotsiklicheskikh Soedinenii 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 C39H35N5O8, Product Details of C6H9N3.

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

Shkurko, O. P. published the artcileNMR spectra of pyrimidines. Effect of substituents on a chemical shift of amino group protons of p-substituted 2- and 5-aminopyrimidines and anilines, Product Details of C5H4N4, the publication is Khimiya Geterotsiklicheskikh Soedinenii (1979), 1683-6, database is CAplus.

NMR data for 4-substituted anilines, 5-substituted 2-aminopyrimidines, and 2-substituted 5-aminopyrimidines were subjected to correlation anal. The inductive effects were transmitted approx. equally through the benzene and pyrimidine rings. The conjugation effects were transmitted with equal efficiency through the benzene ring and from position 5 to position 2 of the pyrimidine ring; transmission from position 2 to position 5 of the pyrimidine ring was somewhat more efficient.

Khimiya Geterotsiklicheskikh Soedinenii published new progress about 56621-93-3. 56621-93-3 belongs to pyrimidines, auxiliary class Pyrimidine,Nitrile,Amine, name is 5-Aminopyrimidine-2-carbonitrile, and the molecular formula is C40H35N7O8, Product Details of C5H4N4.

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

Kurinovich, Mary Ann published the artcileThe acidity of uracil and uracil analogs in the gas phase: four surprisingly acidic sites and biological implications, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione, the publication is Journal of the American Society for Mass Spectrometry (2002), 13(8), 985-995, database is CAplus and MEDLINE.

The gas phase acidities of a series of uracil derivatives (1-methyluracil, 3-methyluracil, 6-methyluracil, 5,6-dimethyluracil, and 1,3-dimethyluracil) have been bracketed to provide an understanding of the intrinsic reactivity of uracil. The experiments indicate that in the gas phase, uracil has four sites more acidic than water. Among the uracil analogs, the N1-H sites have ΔH_acid values of 331-333 kcal mol^-1; the acidity of the N3 sites fall between 347-352 kcal mol^-1. The vinylic C6 in 1-methyluracil and 3-methyluracil brackets to 363 kcal mol^-1, and 369 kcal mol^-1 in 1,3-dimethyluracil; the C5 of 1,3-dimethyluracil brackets to 384 kcal mol^-1. Calculations conducted at B3LYP/6-31+G are in agreement with the exptl. values. The bracketing of several of these sites involved utilization of an FTMS protocol to measure the less acidic site in a mol. that has more than one acidic site, establishing the generality of this method. In mols. with multiple acidic sites, only the two most acidic sites were bracketable, which is attributable to a kinetic effect. The measured acidities are in direct contrast to solution acidities, where the two most acidic sites of uracil (N1 and N3) are cannot be differentiated. The vinylic C6 site is also particularly acidic, compared to acrolein and pyridine. The biol. implications of these results particularly with respect to enzymes for which uracil is a substrate are discussed.

Journal of the American Society for 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, Recommanded Product: 3-Methylpyrimidine-2,4(1H,3H)-dione.

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

Kurinovich, Mary Ann published the artcileThe Acidity of Uracil from the Gas Phase to Solution: The Coalescence of the N1 and N3 Sites and Implications for Biological Glycosylation, Category: pyrimidines, the publication is Journal of the American Chemical Society (2000), 122(26), 6258-6262, database is CAplus.

The gas-phase acidities of the N1 and N3 sites of uracil have been bracketed to provide an understanding of the intrinsic reactivity of this nucleic base. The experiments indicate that in the gas phase, the N3 site is far less acidic (ΔH_acid = 347 ± 4 kcal mol^-1) than the N1 site (ΔH_acid = 333 ± 4 kcal mol^-1), in direct contrast to in solution, where the two sites are so close in acidity as to be unresolvable. This intrinsic difference and the coalescence in solution is interpreted through gas-phase and dielec.-medium calculations The results point to a possible chem. reason that N1 is the preferred glycosylation site in nature: nature may simply take advantage of the differential N1 and N3 acidities in a nonpolar environment to achieve selectivity.

Journal of the American Chemical Society 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, Category: pyrimidines.

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

Zhachkina, Anna published the artcileUracil and Thymine Reactivity in the Gas Phase: The S_N2 Reaction and Implications for Electron Delocalization in Leaving Groups, SDS of cas: 608-34-4, the publication is Journal of the American Chemical Society (2009), 131(51), 18376-18385, database is CAplus and MEDLINE.

The gas-phase substitution reactions of Me chloride and 1,3-dimethyluracil (at the N1-CH₃) are examined computationally and exptl. It is found that, although hydrochloric acid and 3-methyluracil are similar in acidity, the leaving group abilities of chloride and N1-deprotonated 3-methyluracil are not: chloride is a slightly better leaving group. The reason for this difference is most likely related to the electron delocalization in the N1-deprotonated 3-methyluracil anion, which we explore further herein. The leaving group ability of the N1-deprotonated 3-methyluracil anion relative to the N1-deprotonated 3-methylthymine anion is also examined in the context of an enzymic reaction that cleaves uracil but not thymine from DNA.

Journal of the American Chemical Society 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 C5H5ClO2, SDS of cas: 608-34-4.

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

Yang, Qiang published the artcileDevelopment of a Scalable Process for the Insecticidal Candidate Tyclopyrazoflor. Part 2. Fit-for-Purpose Optimization of the Route to Tyclopyrazoflor Featuring [3 + 2] Cyclization of 3-Hydrazinopyridine·2HCl and Methyl Acrylate, Synthetic Route of 31401-45-3, the publication is Organic Process Research & Development (2019), 23(10), 2133-2141, database is CAplus.

Optimization of the route to the sap-feeding insecticidal candidate tyclopyrazoflor (I) featuring [3 + 2] cyclization of 3-hydrazinopyridine·2HCl and Me acrylate is described. The key impurities in the [3 + 2] cyclization were identified and successfully controlled after optimization. The hazards associated with oxidation of an intermediate pyrazolidin-3-one using the incompatible combination of potassium persulfate and N,N-dimethylformamide (DMF) were avoided by using potassium ferricyanide in the presence of potassium hydroxide in water. The two elimination impurities in the ethylation step to produce tyclopyrazoflor were successfully minimized using Et iodide in the presence of cesium carbonate in DMF at 0 °C. The overall yield for this seven-step synthesis of tyclopyrazoflor was improved from 10% to 41% after the optimization detailed herein.

Organic Process Research & Development 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 C9H7NO3, Synthetic Route of 31401-45-3.

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

Stepanyugin, A. V. published the artcileUV spectra of pyrimidine bases and nucleosides in the context of methyl substitution and interaction with amino acid carboxylic group, Computed Properties of 608-34-4, the publication is Biopolimeri i Klitina (2003), 19(1), 43-63, database is CAplus.

UV spectra of pyrimidine nucleotide bases, nucleosides, a number of their derivatives and analogs were investigated in anhydrous DMSO. Effects of interaction with neutral and deprotonated carboxylic group of amino acids on the UV spectra were traced. It was established that methylation of pyrimidine bases at the positions 1 and S leads to the 5-12 nm bathochromic shift of the absorption bands. The majority of the Cyt derivatives excluding m³ Cyt and isoCyt were shown to interact specifically with neutral carboxylic group. Interactions with deprotonated carboxylic group is characteristic of Ura, Thy and their derivatives, except chx¹Ura, s²Ura and dU. The conclusion was drawn that substitution at the positions 1 and 5 is accompanied by a decrease of a complex formation ability with the both forms of carboxylic groups, but substitution at the position 5 strengthens interaction with neutral carboxylic group but decreases interaction with carboxylate-ion. Biol. significance of the results obtained is discussed.

Biopolimeri i Klitina 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 C4H12ClNO, Computed Properties of 608-34-4.

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

Samijlenko, S. P. published the artcileSpecific interactions of deprotonated carboxylic group with uracil and thymine provoke diketo → keto-enol tautomeric transition in bases., Related Products of pyrimidines, the publication is Ukrains’kii Biokhimichnii Zhurnal (2001), 73(4), 128-131, database is CAplus.

The H¹ NMR and MNDO/H calculation data combined indicate the uracil and thymine tautomeric transitions from the ground diketo tautomeric state to the high-energy keto-enol one stimulated by specific interaction with carboxylate ion in anhydrous DMSO, which is blocked by base methylation at the 1 or 3 positions.

Ukrains’kii Biokhimichnii Zhurnal 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, Related Products of pyrimidines.

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