نتایج جستجو برای: pyrimidines

تعداد نتایج: 6345  

Journal: :Journal of bacteriology 2008
Xianxian Liu Rebecca E Parales

Escherichia coli exhibits chemotactic responses to sugars, amino acids, and dipeptides, and the responses are mediated by methyl-accepting chemotaxis proteins (MCPs). Using capillary assays, we demonstrated that Escherichia coli RP437 is attracted to the pyrimidines thymine and uracil and the response was constitutively expressed under all tested growth conditions. All MCP mutants lacking the M...

Journal: :Journal of the American Chemical Society 1921

2,2'-Disubstitutedamino-4-4'-bis-pyrimidines (3a-m) have been prepared by linking 2,4-dichloro-6-methyl-5-nitropyrimidine (1) with several diamines and subsequent reaction with suitable amines. Some of these compounds (3c and 3j) which were reduced catalitically, on treatment with nitrous acid, urea in pyridine, and boiling thionyl chloride gave the corresponding bistriazolopyrimidin (6), ...

Journal: :Acta pharmaceutica 2004
Fathy A Eid Ashraf H F Abd El-Wahab Gameel A M El-Hag Ali Moustafa M Khafagy

Several novel naphtho[2,1-b]pyrano[2,3-d]pyrimidines, pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines and their coumarin-3-yl derivatives were synthesized. Some of these derivatives exhibited pronounced antimicrobial activities.

2011
Dhilli Rao Gorja K Shiva Kumar K Mukkanti Manojit Pal

The Pd/C-CuI-PPh(3) catalytic system facilitated C-C bond formation between 4-chlorothieno[2,3-d]pyrimidines and terminal alkynes in methanol with high selectivity without generating any significant side products arising from C-O bond formation between the chloro compounds and methanol. A variety of novel 4-alkynylthieno[2,3- d]pyrimidines were prepared via alkynylation of 4-chlorothieno[2,3-d]...

Journal: :علوم دامی ایران 0
علی اکبر مسعودی استادیار دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران میثاق مریدی دانشجوی کارشناسی ارشد دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران جواد احمدپناه دانشجوی کارشناسی ارشد دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران رسول واعظ ترشیزی دانشیار، دانشکده کشاورزی، دانشگاه تربیت مدرس، تهران حمیدرضا سید آبادی عضو هیئت علمی موسسة تحقیقات علوم دامی کشور، تهران

heat shock proteins (hsps), are highly important due to their association with such economically important traits in animals as resistance to temperature shock and mastitis. in the current study, to get a comprehensive information on molecular structure and evolution of the hsp70s, and the available hsp70 sequences of the cattle and other animals taken from ncbi and aligned together. then, nucl...

احمدپناه, جواد,

     In the current study, phylogenetic analysis and molecular evolution of the mammalian’s Leptin was investigated. Data was achieved and aligned by searching its genome database, while all examined mammals contained only a single copy of the Leptin. The nucleotide substitution rate of the sequences and molecular evolution of the Leptin were calculated by maximum likelihood and neighbor-joinin...

Journal: :Journal of Heterocyclic Chemistry 2021

Chalcone-derived pyrimidine is a well-known heterocyclic compound that commonly present in ribonucleic acid (RNA) and deoxyribonucleic (DNA) bio-isosteres. Pyrimidine derivatives are effective both the electronic industry drug industries. This review highlights synthesis of pyrimidines, namely mono-pyrimidine, bis-pyrimidine, fused pyrimidine, symmetric, asymmetric via one-pot two-pot methods. ...

Journal: :Nucleosides, nucleotides & nucleic acids 2005
Frank Seela W Lin Z Kazimierczuk H Rosemeyer V Glaron X Peng Y He X Ming M Andrzejewska A Gorska X Zhang H Eickmeier P La Colla

The synthesis of base modified L-nucleosides is described with pyrrolo[2,3-d]pyrimidines, pyrazolo[3,4-d]pyrimidines, benzimidazoles, and imidazo[1,2-a]-s-triazines as nucleobases. The conformation of the nucleosides is studied and the antiviral activity is evaluated.

A practical and new method for the synthesis oxindole substituted pyrrolo[2,3-d]pyrimidines by the condensation of isatin, acetophenone and 6-amino-uracil under ultrasound irradiation conditions at 60 °C was described. The reaction was developed via a sequential tandem process to afford the oxindole substituted pyrrolo[2,3-d]pyrimidines in good to excellent yields. All reactions performed effic...

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