RESUMO
Sphingosine-1-phosphate is now emerging as an important player in cancer, inflammation, autoimmune, neurological and cardiovascular disorders. Abundance evidence in animal and humans cancer models has shown that SphK1 is linked to cancer. Thus, there is a great interest in the development new SphK1 inhibitors as a potential new treatment for cancer. In a search for new SphK1 inhibitors we selected the well-known SKI-II inhibitor as the starting structure and we synthesized a new inhibitor structurally related to SKI-II with a significant but moderate inhibitory effect. In a second approach, based on our molecular modeling results, we designed new structures based on the structure of PF-543, the most potent known SphK1 inhibitor. Using this approach, we report the design, synthesis and biological evaluation of a new series of compounds with inhibitory activity against both SphK1 and SphK2. These new inhibitors were obtained incorporating new connecting chains between their polar heads and hydrophobic tails. On the other hand, the combined techniques of molecular dynamics simulations and QTAIM calculations provided complete and detailed information about the molecular interactions that stabilize the different complexes of these new inhibitors with the active sites of the SphK1. This information will be useful in the design of new SphK inhibitors.
Assuntos
Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Pirimidinas/uso terapêutico , Desenho de Fármacos , Humanos , Modelos Moleculares , Pirimidinas/farmacologiaRESUMO
New nitrosopyrimidines were synthesized and evaluated as potential antibacterial agents. Different compounds structurally related with 4,6-bis(alkyl or arylamino)-5-nitrosopyrimidines were evaluated. Some of these nitrosopyrimidines displayed significant antibacterial activity against human pathogenic bacteria. Among them compounds 1c, 2a-c, and 9a-c exhibited remarkable activity against methicillin-sensitive and -resistant Staphylococcus aureus, Escherichia coli, Yersinia enterocolitica, and Salmonella enteritidis. A detailed structure-activity relationship study, supported by theoretical calculations, aided us to identify and understand the minimal structural requirements for the antibacterial action of the nitrosopyrimidines reported here. Thus, our results have led us to identify a topographical template that provides a guide for the design of new nitrosopyrimidines with antibacterial effects.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Desenho de Fármacos , Compostos Nitrosos/síntese química , Compostos Nitrosos/farmacologia , Pirimidinas/síntese química , Pirimidinas/farmacologia , Bactérias/crescimento & desenvolvimento , Desenho Assistido por Computador , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
The design, synthesis, in vitro evaluation, and conformational study of nitrosopyrimidine derivatives acting as antifungal agents are reported. Different compounds structurally related with 4,6-bis(alkyl or arylamino)-5-nitrosopyrimidines were evaluated. Some of these nitrosopyrimidines have displayed a significant antifungal activity against human pathogenic strains. In this paper, we report a new group of nitrosopyrimidines acting as antifungal agents. Among them, compounds 2a, 2b and 15, the latter obtained from a molecular modeling study, exhibited antifungal activity against Candida albicans, Candida tropicalis and Cryptococcus neoformans. We have performed a conformational and electronic analysis on these compounds by using quantum mechanics calculations in conjunction with Molecular Electrostatic Potentials (MEP) obtained from B3LYP/6-31G(d) calculations. Our experimental and theoretical results have led us to identify a topographical template which may provide a guide for the design of new nitrosopyrimidines with antifungal effects.
Assuntos
Antifúngicos/química , Compostos Nitrosos/química , Pirimidinas/química , Antifúngicos/síntese química , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Ligação de Hidrogênio , Testes de Sensibilidade Microbiana , Modelos Moleculares , Compostos Nitrosos/síntese química , Compostos Nitrosos/farmacologia , Pirimidinas/síntese química , Pirimidinas/farmacologia , Teoria Quântica , Relação Estrutura-AtividadeRESUMO
Ten new N(4)-substituted 1H-pyrazolo[3,4-d]pyrimidine-4,6-diamines have been synthesized and the structures of nine of them are reported here, falling into two clear groups, those which are stoichiometric hydrates and those which crystallize in solvent-free forms. In each of N(4)-methyl-N(4)-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C(12)H(12)N(6) (I), N(4)-cyclohexyl-N(4)-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C(12)H(18)N(6) (II), and N(4)-(3-chlorophenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine, C(11)H(9)ClN(6) (III), the molecules are linked into hydrogen-bonded sheets. The molecules of 2-{4-(6-amino-1H-pyrazolo[3,4-d]pyrimidin-4-yl)piperazin-1-yl}ethanol, C(11)H(17)N(7)O (IV), are linked into a three-dimensional framework, while the structure of N(4)-methyl-N(4)-(4-methylphenyl)-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine monohydrate, C(13)H(14)N(6) x H(2)O (V), is only two-dimensional despite the presence of five independent hydrogen bonds. The stoichiometric hemihydrates N(4)-ethyl-N(4)-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine hemihydrate, C(13)H(14)N(6) x 0.5 H(2)O (VI) and N(4)-(4-methoxyphenyl)-N(4)-methyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine hemihydrate, C(13)H(14)N(6)O x 0.5 H(2)O (VII), exhibit remarkably similar sheet structures, despite different space groups and Z' values, Z' = 0.5 in C2/c for (VI) and Z' = 1 in P1 for (VII). N(4)-4-Benzyl-N(4)-phenyl-1H-pyrazolo[3,4-d]pyrimidine-4,6-diamine monohydrate, C(18)H(16)N(6) x H(2)O (VIII), crystallizes with Z' = 2 in P2(1)/n, and the four independent molecular components are linked into sheets by a total of 11 intermolecular hydrogen bonds. The sheet structure in {4-(pyrrolidin-1-yl)-1H-pyrazolo[3,4-d]pyrimidine-6-amine} ethanol hemisolvate hemihydrate, C(9)H(12)N(6).0.5C(2)H(6)O x 0.5 H(2)O (IX), is built from the pyrimidine and water components only; it contains eight independent hydrogen bonds, and it very closely mimics the sheets in (VI) and (VII); the ethanol molecules are pendent from these sheets. The N(4)-alkyl-N(4)-aryl-4-aminopyrazolopyrimidine molecules in (I), (V)-(VIII) all adopt very similar conformations, dominated in each case by an intramolecular C-H...pi(arene) hydrogen bond: this interaction is absent from (III) where the molecular conformation is entirely different and probably dominated by the intermolecular hydrogen bonds.
Assuntos
Diaminas/química , Ligação de Hidrogênio , Pirazóis/química , Pirimidinas/química , Água/química , Modelos Moleculares , Estrutura MolecularRESUMO
The pyrimidine rings in ethyl (E)-3-[2-amino-4,6-bis(dimethylamino)pyrimidin-5-yl]-2-cyanoacrylate, C(14)H(20)N(6)O(2), (I), and 2-[(2-amino-4,6-di-1-piperidylpyrimidin-5-yl)methylene]malononitrile, C(18)H(23)N(7), (II), which crystallizes with Z' = 2 in the P1 space group, are both nonplanar with boat conformations. The molecules of (I) are linked by a combination of N-H...N and N-H...O hydrogen bonds into chains of edge-fused R(2)(2)(8) and R(4)(4)(20) rings, while the two independent molecules in (II) are linked by four N-H...N hydrogen bonds into chains of edge-fused R(2)(2)(8) and R(2)(2)(20) rings. This study illustrates both the readiness with which highly-substituted pyrimidine rings can be distorted from planarity and the significant differences between the supramolecular aggregation in two rather similar compounds.
Assuntos
Cianoacrilatos/química , Nitrilas/química , Pirimidinas/química , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares , Estrutura MolecularRESUMO
The molecules of 2-[6-amino-3-methyl-2-(methylsulfanyl)-4-oxo-3,4-dihydropyrimidin-5-ylcarbonyl]acetonitrile, C(9)H(10)N(4)O(2)S, (I), are linked in pairs by N-H...O hydrogen bonds to form cyclic centrosymmetric R(2)(2)(4) dimers. Similar dimers formed by 2-(6-amino-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-5-ylcarbonyl)acetonitrile, C(9)H(10)N(4)O(3), (II), are reinforced by paired N-H...N hydrogen bonds and linked into chains of rings by C-H...O hydrogen bonds. The molecules of 2-cyano-N-[6-methoxy-2-(methylsulfanyl)pyrimidin-4-yl]acetamide, C(9)H(10)N(4)O(2)S, (III), are linked into simple C(6) chains by an N-H...N hydrogen bond, and the chains are weakly linked into sheets by a pi-pi stacking interaction. A combination of one two-centre N-H...N hydrogen bond and one three-centre C-H...(N,O) hydrogen bond links the molecules of 2-cyano-N-[6-chloro-2-(methylsulfanyl)pyrimidin-4-yl]acetamide, C(8)H(7)ClN(4)OS, (IV), into a chain of alternating edge-fused R(2)(1)(6) and R(1)(2)(6) rings. The crystal structures reported in this study, and those of some related examples from the recent literature, show a wide variation in hydrogen-bonded aggregation consequent upon rather small changes in molecular constitution.