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Silica functionalized sulfonic acid catalyzed one-pot synthesis of 4,5,8a-triarylhex-ahydropyrimido[4,5-d]pyrimidine-2,7(1H,3 H)-diones under liquid phase catalysis

Gupta,Princy; Kumar,Vineet; Paul,Satya
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 Português
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135.97%
SiO2-SO3H catalyzed one-pot synthesis of 4,5,8a-triarylhexahydropyrimido[4,5-d]pyrimidine-2,7(1H,3 H)-diones (4a-k) is reported under liquid phase catalysis. The catalyst is easily prepared, highly stable, very simple to handle and recycled for five times without loss of significant activity.

Structural mimicry of adenosine by the antitumor agents 4-methoxy- and 4-amino-8-(beta-D-ribofuranosylamino)pyrimido[5,4-d]pyrimidine as viewed by a molecular modeling method.

Ghose, A K; Viswanadhan, V N; Sanghvi, Y S; Nord, L D; Willis, R C; Revankar, G R; Robins, R K
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /11/1989 Português
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56.13%
A rationale for the antitumor activity of 4-methoxy- and 4-amino-8-(beta-D-ribofuranosylamino)pyrimido-[5,4-d]pyrimidine (beta-MRPP and beta-ARPP, respectively) was studied by a molecular modeling method. Although these nucleoside analogues are structurally different from adenosine, they act as substrates for adenosine kinase. The molecular modeling method, which considered the three-dimensional structure and atom-based physicochemical properties of the nucleosides to quantify the molecular similarities, showed that certain low-energy conformations of the beta anomers of a series of nucleosides including beta-MRPP, beta-ARPP, and their 4-hydroxy, 4-amino-6-chloro, 4-methylthio-2,6-dichloro, 4,6-diamino, 4-dimethylamino, 4-methylamino, and 4-hydroxy-2,6-dichloro analogues have remarkable structural similarity to adenosine. The method also suggested that the selection of the reference compound adenosine in the structural comparison is of primary importance to gain insight into the observed antitumor activity. The success of the present method led to AM1 (Austin model 1) molecular orbital calculations and experimental studies indicating that the antitumor activity of the alpha anomer of ARPP is probably due to equilibration to the beta anomer. The AM1 calculation of the protonation energy of N5 of pyrimido[5...

The effect of dipyridamole on platelet function: correlation with blood levels in man.

Rajah, S M; Crow, M J; Penny, A F; Ahmad, R; Watson, D A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1977 Português
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25.76%
1 The effect on platelet functions of dipyridamole (a pyrimido-pyrimidine compound) was compared with a control group of patients taking warfarin. 2 Adhesion, aggregation and platelet factor 4 availability showed a significant decrease in the dypyridamole group. 3 Aggregation and platelet factor 4 showed a significant correlation with blood dipyridamole level. 4 Adhesion, aggregation and platelet factor 4 were reduced below the lower limit of normal at blood dipyridamole levels above 3.5 micronmol/1.

Synthesis, Flow Cytometric Evaluation and Identification of Highly Potent Dipyridamole Analogs as Equilibrative Nucleoside Transporter 1 (ENT1a) Inhibitors

Lin, Wenwei; Buolamwini, John K.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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25.74%
Dipyridamole (Persantine) is a clinically used vasodilator with equilibrative nucleoside transporters 1, and 2 (ENT1 and ENT2) inhibitory activity albeit less potent than the prototype ENT1 inhibitor nitrobenzylmercaptopurine riboside (NBMPR). Dipyridamole is a good candidate for further exploration because it is a non-nucleoside and has a proven record of safe use in humans. A series of dipyridamole analogs were synthesized with systematic modification, and evaluated as ENT1 inhibitors by flow cytometry. Compounds with much higher potency were identified, the best being 2,6-bis(diethanolamino)-4,8-diheptamethyleneimino-pyrimido[5,4-d]pyrimidine (13), with a Ki of 0.49 nM, compared to a Ki of 308 nM for dipyridamole. Compound 13 is similar in potency to the prototype potent ENT1 inhibitor NBMPR (0.43 nM). For the first time, a dipyridamole analog has been identified that is equipotent with NBMPR. The SAR indicated that diethanolamine substituted analogs were more active than monoethanolamine compounds. Also, free hydroxyl groups are not essential for activity.

7-(Benzyl­sulfan­yl)-5-(2-methoxy­phen­yl)-1,3-dimethyl-5,6-dihydro­pyrimido[4,5-d]pyrimidine-2,4(1H,3H)-dione

Bazgir, Ayoob; Faraji, Fereshteh
Fonte: International Union of Crystallography Publicador: International Union of Crystallography
Tipo: Artigo de Revista Científica
Publicado em 06/08/2008 Português
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65.79%
In the mol­ecule of the title compound, C22H22N4O3S, the benzene and phenyl rings are oriented at a dihedral angle of 88.72 (4)°. The other two rings have flattened-boat conformations. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the mol­ecules.

4,5,8a-Triphenyl­perhydro­pyrimido[4,5-d]pyrimidine-2,7-dione monohydrate

Zhu, Yulin; Qiu, Wanhong; Yang, Fufen; Li, Guichan
Fonte: International Union of Crystallography Publicador: International Union of Crystallography
Tipo: Artigo de Revista Científica
Publicado em 29/05/2010 Português
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106.04%
The title compound, C24H22N4O2·H2O, was synthesized by the trimethyl­chloro­silane-catalysed reaction between urea, benzaldehyde and acetophenone. The organic mol­ecule comprises two fused tetra­hydro­pyrimidinone rings with phenyl substituents at the 4- and 5-positions on the tetra­hydro­pyrimidinone rings and a third phenyl substituent at the ring junction 8-position. The 4- and 5-substituted phenyl rings are inclined at a dihedral angle of 22.72 (11)° to one another and make angles of 47.95 (7) and 65.76 (7)° with the third phenyl substituent. In the crystal structure, inter­molecular N—H⋯O contacts link pyrimido[4,5-d]pyrimidine mol­ecules into centrosymmetric dimers. Additional N—H⋯O and O—H⋯O hydrogen bonds involving the water mol­ecule generate a three-dimensional network.

7-(4-Methoxy­phen­yl)-5-methyl-9-phenyl-7H-pyrrolo[2′,3′:4,5]pyrimido[1,6-d]tetrazole

Jotani, Mukesh M.; Shah, Rina D.; Jasinski, Jerry P.
Fonte: International Union of Crystallography Publicador: International Union of Crystallography
Tipo: Artigo de Revista Científica
Publicado em 19/12/2009 Português
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45.92%
The title compound, C20H16N6O, is composed of a tetra­zolo ring and a 4-methoxy­phenyl and a benzene-substituted pyrrole ring at the 7 and 9 positions fused to a pyrimidine ring in a nearly planar fashion [maximum deviation of 0.018 (1) Å for the fused ring system]. A methyl group at the 5 position is also in the plane of the hetero cyclic system. The dihedral angle between the mean planes of the benzene and 4-methoxy­phenyl rings is 40.4 (2)°. The dihedral angles between the mean planes of the pyrimidine and the benzene and 4-methoxy­phenyl rings are 15.6 (5)° and 52.6 (7)°, respectively. A weak intra­molecular C—H⋯N hydrogen bond inter­action, which forms an S(7) graph-set motif, helps to establish the relative conformations of the tetrazolo and benzene rings. In the crystal, weak inter­molecular C—H⋯O, C—H⋯π and π–π stacking inter­actions [centroid–centroid distances = 3.5270 (16), 3.5113 (16), 3.7275 (17) and 3.7866 (17) Å] link the mol­ecules into a two-dimensional array obliquely parallel to (101) and propagating along the b axis.

Design, Synthesis and Biological Evaluation of Novel Pyrimido[4,5-d]pyrimidine CDK2 Inhibitors as Anti-Tumor Agents

El-Moghazy, Samir M.; Ibrahim, Diaa A.; Abdelgawad, Nagwa M.; Farag, Nahla A. H.; El-Khouly, Ahmad S.
Fonte: Österreichische Apotheker-Verlagsgesellschaft Publicador: Österreichische Apotheker-Verlagsgesellschaft
Tipo: Artigo de Revista Científica
Português
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106.1%
A series of 2,5,7-trisubstituted pyrimido[4,5-d]pyrimidine cyclin-dependent kinase (CDK2) inhibitors is designed and synthesized. 6-Amino-2-thiouracil is reacted with an aldehyde and thiourea to prepare the pyrimido[4,5-d]-pyrimidines. Alkylation and amination of the latter ones give different amino derivatives. These compounds show potent and selective CDK inhibitory activities and inhibit in vitro cellular proliferation in cultured human tumor cells.

7′-Amino-1′H-spiro­[cyclo­heptane-1,2′-pyrimido[4,5-d]pyrimidin]-4′(3′H)-one

Chen, Shu; Shi, Daxin; Liu, Mingxing; Li, Jiarong
Fonte: International Union of Crystallography Publicador: International Union of Crystallography
Tipo: Artigo de Revista Científica
Publicado em 25/07/2012 Português
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55.86%
The title compound, C12H17N5O, was obtained by cyclo­condensation of 2,4-diamino­pyrimidine-5-carbonitrile with cyclo­hepta­none. The tetra­hydro­pyrimidine ring has a dis­torted boat conformation and the cyclo­heptane ring adopts a chair conformation. In the crystal, molecules are linked via N—H⋯O and N—H⋯N hydrogen bonds generating a three-dimensional network.

Synthesis and anticancer activity of some fused pyrimidines and related heterocycles

Al-Issa, S.A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.08%
On account of the reported anticancer of pyrimidine and condensed pyrimidine, a new pyrimido [3,2-b]-1,2,4,5-tetrazine 3a,b, 5c,d, 6, 9, pyrimido [3,2-b]-1,2,4-triazine 10, 11, pyrimido [3,2-b]-1,2,4-triazole 12 and pyrimidine derivatives 1,2a,b, 4c,d, 8, 13, 14, 15 and 16 were synthesized through different chemical reactions. Structures of all synthesized compounds were supported by spectral and elemental analyses. The obtained compounds were evaluated for their in vitro antitumor activity against human liver cancer cell line (HEPG2).

Dipyridamole analogues as pharmacological inhibitors of equilibrative nucleoside transporters. Identification of novel potent and selective inhibitors of the adenosine transporter function of human equilibrative nucleoside transporter 4 (hENT4)

Wang, Chunmei; Lin, Wenwei; Playa, Hilaire; Sun, Shan; Cameron, Kenyuna; Buolamwini, John
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
35.77%
To identify needed human equilibrative nucleoside transporter 4 (hENT4) inhibitors, we cloned and stably expressed the recombinant protein in PK15NTD (nucleoside transporter deficient) cells, and, investigated its interaction with a series of dipyridamole analogues synthesized in our laboratory. Compounds were tested in this newly established hENT4 expressing system as well in previous stably expressed hENT1 and hENT2 expressing systems. Of the dipyridamole analogues evaluated, about one fourth of the compounds inhibited hENT4 with higher potencies than dipyridamole. The most potent of them, Compound 30 displayed an IC50 of 74.4 nM, making it about 38 times more potent than dipyridamole (IC50 = 2.8 μM), and selectivities of about 80-fold and 20-fold relative to ENT1 and ENT2, respectively. Structure-activity relationship showed nitrogen-containing monocyclic rings and noncyclic substituents at the 4-and 8-positions of the pyrimido[5,4-d]pyrimidine were important for the inhibitory activity against hENT4. The most potent and selective hENT4 inhibitors tended to have a 2,6-di(N-monohydroxyethyl) substitution on the pyrimidopyrimidine ring system. The inhibitors of hENT4 identified in this study are the most selective and potent inhibitors of hENT4 adenosine transporter function to date...

Complex self-assembly of pyrimido[4,5-d]pyrimidine nucleoside supramolecular structures

Zhao, Hang; Guo, Xiurong; He, Shiliang; Zeng, Xin; Zhou, Xinglong; Zhang, Chaoliang; Hu, Jing; Wu, Xiaohua; Xing, Zhihua; Chu, Liangyin; He, Yang; Chen, Qianming
Fonte: Nature Pub. Group Publicador: Nature Pub. Group
Tipo: Artigo de Revista Científica
Publicado em 24/01/2014 Português
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105.99%
Supramolecular self-assembly is not only one of the chemical roots of biological structure but is also drawing attention in different industrial fields. Here we study the mechanism of the formation of a complex flower-shaped supramolecular structure of pyrimido[4,5-d]pyrimidine nucleosides by dynamic light scattering, scanning electron microscopy, differential scanning calorimetry, nuclear magnetic resonance and X-ray analysis. Upon removing the hydroxyl group of sugars, different flower-shaped superstructures can be produced. These works demonstrate that complex self-assembly can indeed be attained through hierarchical non-covalent interactions of single molecules. Furthermore, chimerical structures built from molecular recognition by these monomers indicate their potential in other fields if combined with other chemical entities.

Design, Synthesis and Evaluation of New 2, 6-Dihydroimidazo[1, 2-c]Pyrimido[5, 4-e]-Pyrimidine-5(3H)-thiones as Possible Antihistaminic/Antiasthmatic Agents§

Sirisha, K.; Achaiah, G.; Ram Rao, A. Raghu
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em //2014 Português
Relevância na Pesquisa
25.99%
A series of new 10-(alkylamino)-8-methyl-2, 6-dihydroimidazo[1, 2-c]pyrimido[5, 4-e]pyrimidine-5(3H)-thiones (4a-g) were subjected to molecular property prediction (drug-likeness, lipophilicity and solubility parameters) using Osiris Property Explorer, ALOGPS 2.1, Molinspiration and ACD/Chemsketch 12.0 software programmes. The calculated drug-related properties of the designed molecules were similar to those found in most marketed drugs. Amongst the proposed analogues, four promising candidates were chosen (4a-d) for synthesis on the basis of Lipinski's ‘Rule of Five’ and drug-likeness scores. The significant biological activity of the test compounds in two in vitro modes (isolated guinea pig tracheal chain preparation, isolated guinea pig ileum) supports the promise and accuracy of the prediction. Among them, 4a was the most potent antihistaminic (IC50 value of 30.2 μM; standard, chlorpheniramine maleate showed an IC50 of 14.1 μM).

NSC96654; Pyrimido[5,4-d]pyrimidine, tetrachloro- (9CI); Pyrimido[5, 4-d]pyrimidine, 2,4,6,8-tetrachloro- (8CI); 2,4,6, 8-Tetrachloropyrimido[5,4-d]pyrimidine

US National Cancer Institute
Fonte: Unilever Center for Molecular Informatics, Cambridge University Publicador: Unilever Center for Molecular Informatics, Cambridge University
Tipo: Outros Formato: 2512 bytes; 3274 bytes; chemical/x-cml; chemical/x-cml
Português
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NSC268562; Azinepurine; Pteridine (8CI9CI); Pyrazino[2,3-d]pyrimidine; Pyrimido[4,5-b]pyrazine; 1,3,5,8-Tetraazanaphthalene

US National Cancer Institute
Fonte: Unilever Center for Molecular Informatics, Cambridge University Publicador: Unilever Center for Molecular Informatics, Cambridge University
Tipo: Outros Formato: 2466 bytes; 3235 bytes; chemical/x-cml; chemical/x-cml
Português
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35.74%

Synthesis of quaternised 2-aminopyrimido[4,5- d ]pyrimidin-4(3 H )-ones and their biological activity with dihydrofolate reductase

Gebauer, Markus; McKinlay, Carolyn; Gready, Jill
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
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85.89%
In a program to design and develop mechanism-based compounds active as substrates and inhibitors of dihydrofolate reductase (DHFR), we report the synthesis and physical properties of the 6-methyl- (7), 8-methyl- (8a), and 8-ethyl- (8b) derivatives of the