RESUMO
Aberrant activation of the Hedgehog (Hh) signalling pathway has been associated with the development and progression of pancreatic cancer. For this reason, blockade of Hh pathway by inhibitors targeting the G protein-coupled receptor Smoothened (SMO) has been considered as a therapeutic target for the treatment of this cancer. In our previous work, we obtained a new SMO ligand based on a purine scaffold (compound I), which showed interesting antitumor activity in several cancer cell lines. In this work, we report the design and synthesis of 17 new purine derivatives, some of which showed high cytotoxic effect on Mia-PaCa-2 (Hh-dependent pancreatic cancer cell lines) and low toxicity on non-neoplastic HEK-293 cells compared with gemcitabine, such as 8f, 8g and 8h (IC50 = 4.56, 4.11 and 3.08 µM, respectively). Two of these purines also showed their ability to bind to SMO through NanoBRET assays (pKi = 5.17 for 8f and 5.01 for 8h), with higher affinities to compound I (pKi = 1.51). In addition, docking studies provided insight the purine substitution pattern is related to the affinity on SMO. Finally, studies of Hh inhibition for selected purines, using a transcriptional functional assay based on luciferase activity in NIH3T3 Shh-Light II cells, demonstrated that 8g reduced GLI activity with a IC50 = 6.4 µM as well as diminished the expression of Hh target genes in two specific Hh-dependent cell models, Med1 cells and Ptch1-/- mouse embryonic fibroblasts. Therefore, our results provide a platform for the design of SMO ligands that could be potential selective cytotoxic agents for the treatment of pancreatic cancer.
Assuntos
Antineoplásicos , Neoplasias Pancreáticas , Purinas , Receptor Smoothened , Humanos , Receptor Smoothened/antagonistas & inibidores , Receptor Smoothened/metabolismo , Purinas/química , Purinas/farmacologia , Purinas/síntese química , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/metabolismo , Ligantes , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Animais , Camundongos , Relação Estrutura-Atividade , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HEK293 , Linhagem Celular Tumoral , Células NIH 3T3 , Simulação de Acoplamento Molecular , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/antagonistas & inibidoresRESUMO
We designed, synthesized, and evaluated novel 2,6,9-trisubstituted purine derivatives for their prospective role as antitumor compounds. Using simple and efficient methodologies, 31 compounds were obtained. We tested these compounds in vitro to draw conclusions about their cell toxicity on seven cancer cells lines and one non-neoplastic cell line. Structural requirements for antitumor activity on two different cancer cell lines were analyzed with SAR and 3D-QSAR. The 3D-QSAR models showed that steric properties could better explain the cytotoxicity of compounds than electronic properties (70% and 30% of contribution, respectively). From this analysis, we concluded that an arylpiperazinyl system connected at position 6 of the purine ring is beneficial for cytotoxic activity, while the use of bulky systems at position C-2 of the purine is not favorable. Compound 7h was found to be an effective potential agent when compared with a currently marketed drug, cisplatin, in four out of the seven cancer cell lines tested. Compound 7h showed the highest potency, unprecedented selectivity, and complied with all the Lipinski rules. Finally, it was demonstrated that 7h induced apoptosis and caused cell cycle arrest at the S-phase on HL-60 cells. Our study suggests that substitution in the purine core by arylpiperidine moiety is essential to obtain derivatives with potential anticancer activity.
Assuntos
Antineoplásicos/síntese química , Purinas/química , Relação Quantitativa Estrutura-Atividade , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Conformação Molecular , Purinas/síntese química , Purinas/farmacologia , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacosRESUMO
A series of 2,6,9-trisubstituted purine derivatives have been synthesized and investigated for their potential role as antitumor agents. Twelve compounds were obtained by a three step synthetic procedure using microwave irradiation in a pivotal step. All compounds were evaluated in vitro to determine their potential effect on cell toxicity by the MTT method and flow cytometry analysis on four cancer cells lines and Vero cells. Three out of twelve compounds were found to be promising agents compared to a known and effective anticancer drug, etoposide, in three out of four cancer cell lines assayed with considerable selectivity. Preliminary flow cytometry data suggests that compounds mentioned above induce apoptosis on these cells. The main structural requirements for their activity for each cancer cell line were characterized with a preliminary pharmacophore model, which identified aromatic centers, hydrogen acceptor/donor center and a hydrophobic area. These features were consistent with the cytotoxic activity of the assayed compounds.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Modelos Moleculares , Purinas/química , Purinas/farmacologia , Animais , Antineoplásicos/síntese química , Linhagem Celular Tumoral , Chlorocebus aethiops , Humanos , Estrutura Molecular , Purinas/síntese química , Relação Estrutura-Atividade , Células VeroRESUMO
We report on the synthesis of two series of 1,4-naphthohydroquinone derivatives conjugated with amino acids (Gly, Ala, Phe, and Glu) and with substituted purines linked by an aliphatic chain. The compounds were obtained through Diels-Alder cycloaddition between myrcene and 1,4-benzoquinone and evaluated in vitro for their cytotoxicity (GI50 ) against cultured human cancer cells of A-549 lung carcinoma, HT-29 colon adenocarcinoma, and MCF-7 breast carcinoma. The GI50 values found for some hydroquinone-amino acid and hydroquinone-purine hybrids against MCF-7 are in an activity range comparable to that of the reference drug doxorubicin.
Assuntos
Aminoácidos/síntese química , Aminoácidos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Hidroquinonas/síntese química , Hidroquinonas/farmacologia , Purinas/síntese química , Purinas/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/farmacologia , Células HT29 , Humanos , Concentração Inibidora 50 , Células MCF-7 , Estrutura MolecularRESUMO
This study aimed to evaluate the 4-(6'-thiopurine)-7-chloroquinoline, a novel quinoline/6-thiopurine conjugate, for the treatment of Gallus gallus experimentally infected with Plasmodium juxtanucleare, an avian malaria agent. The avian group treated with 4-(6'-thiopurine)-7-chloroquinoline showed a significative parasite clearance and maintained a low level of parasitaemia, when compared with the untreated control group and to the chloroquine treated avian group.
Assuntos
Antimaláricos/farmacologia , Plasmodium/efeitos dos fármacos , Purinas/farmacologia , Quinolinas/farmacologia , Animais , Antimaláricos/síntese química , Antimaláricos/química , Galinhas , Cloroquina/química , Cloroquina/farmacologia , Modelos Animais de Doenças , Malária Aviária/tratamento farmacológico , Parasitemia/tratamento farmacológico , Purinas/síntese química , Purinas/química , Quinolinas/síntese química , Quinolinas/químicaRESUMO
The 5-[2-ethoxy-5-(4-methylpiperazin-1-ylsulfonyl)phenyl]-1-methyl-3-propyl-1,6-dihydro-7 H-pyrazolo[4,3-d]pyrimidin-7-one, sildenafil, is a cGMP-specific phosphodiesterase-5 (PDE5) inhibitor used for penile erectile dysfunction. In the search for more potent and selective PDE5 inhibitors, new sildenafil analogues (6a-v), characterized by the presence on the sulfonyl group in the 5' position of novel N-4-substituted piperazines or ethylenediamine moiety, were prepared by traditional and microwave-assisted synthesis and tested in rabbit isolated aorta and corpus cavernosum. Similarly to sildenafil, several analogues showed IC50 values in the nanomolar range. In the in vitro studies, all the tested compounds caused concentration-dependent relaxations in both rabbit isolated aorta and corpus cavernosum. All sildenafil analogues potentiated the nitric oxide-dependent vasodilation in endothelium-intact rabbit aorta. Compound 6f exhibited great pEC50 value in corpus cavernosum, and compounds 6r and 6u in isolated aorta were found as potent as sildenafil for inhibiting PDE5. Because several analogues were significantly more lipophilic than sildenafil, these compounds may offer a new lead for development of new sildenafil analogues.
Assuntos
Disfunção Erétil/tratamento farmacológico , Inibidores da Fosfodiesterase 5 , Piperazinas/síntese química , Pirimidinas/síntese química , Sulfonas/síntese química , Animais , Aorta/efeitos dos fármacos , Aorta/fisiologia , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Endotélio Vascular/fisiologia , Humanos , Técnicas In Vitro , Espectroscopia de Ressonância Magnética , Masculino , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Pênis/efeitos dos fármacos , Pênis/fisiologia , Piperazinas/química , Piperazinas/farmacologia , Purinas/síntese química , Purinas/química , Purinas/farmacologia , Pirimidinas/química , Pirimidinas/farmacologia , Coelhos , Ratos , Citrato de Sildenafila , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade , Sulfonas/química , Sulfonas/farmacologiaRESUMO
We report herein the synthesis and the in vitro antileishmanial evaluation of a series of 6-substituted purines. The most active compounds against Leishmania amazonensis promastigotes were 6-(3'-chloropropylthio)purine 2 [11,12] [corrected] 6-(3'-(thioethylamine)propylthio)purine 5, 6-(alpha-aceticacidthio)purine 7 and 6-(6'-deoxy-1'-O-methyl-beta-D-ribofuranose)purine 14 with an IC(50)=50, 50, 39 and 29 microM, respectively.
Assuntos
Etilaminas/síntese química , Etilaminas/farmacologia , Leishmania/efeitos dos fármacos , Purinas/síntese química , Purinas/farmacologia , Animais , Etilaminas/química , Concentração Inibidora 50 , Macrófagos/efeitos dos fármacos , Camundongos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Purinas/químicaRESUMO
Steroidal nucleoside analogs were synthesized starting from testosterone. By reduction of the oxime of 17 beta-hydroxy-androst-4-en-3-one (testosterone), a mixture of the two amino epimers of C-3 were obtained. The 3 alpha-amino-androst-4-en-17 beta-ol was crystallized in 73% yield and coupled with 5-amino-4,6-dichloropyrimidine to give 3 alpha-(5'-amino-4'-chloro-pyrimidin-6'-yl)amino-androst-4-en-17 beta-ol. This compound was treated with triethyl orthoformate in acid media to give the corresponding purinyl steroid adduct 3 alpha-(6'-chloro-purin-9'-yl)-androst-4-en-17 beta-ol in 98% yield. This substance, in turn, was converted with good yield into the 6'-thio, 6'-methylamino, and 6'-diethyl aminopurinyl derivatives through nucleophilic reactions at C-6 of the purine nucleus.
Assuntos
Androstenóis/síntese química , Nucleosídeos/síntese química , Cristalização , Ciclização , Temperatura Alta , Hidroxilamina/química , Oxirredução , Oximas/química , Purinas/síntese química , Pirimidinas/síntese química , Testosterona/análogos & derivados , Testosterona/químicaRESUMO
A series of six potential plant hormones, 6-alky- and arylamino-9-(tetrahydro-2-pyranyl)purines were prepared in three steps in 35 to 45% overall yield from 6-methylthiopurine via 6-methylsulfonylpurine.
Assuntos
Reguladores de Crescimento de Plantas/síntese química , Purinas/química , Purinas/síntese química , Piranos/síntese química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Reguladores de Crescimento de Plantas/química , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
The design of more effective therapies for metastatic disease involves development of new compounds able to specifically block the malignant process. We demonstrated previously that a new synthetic nitrogenated compound 3'-1-chloroethyl-2,3-dihydro-1H-imidazo-(2, 1-i)-purine-4-ium-7-yl-3'-deoxy-1',5', 6'-tri-O-(methylsulfonyl)-muco-inositol chloride (DIC) had an anti-proliferative activity on tumor cells in vitro. In the present work we demonstrate that DIC induces apoptosis on the LM3 murine mammary adenocarcinoma cell line in vitro and has anti-angiogenic activity in vivo. We also evaluated toxicity, biodistribution and anti-neoplastic properties of DIC in vivo. Toxicity studies allowed us to establish the LD50 (750 mg/kg body weight). Administration of 250 mg/kg/day (LD10) for 6 days did not cause overt toxic effects. Biodistribution assays revealed that DIC was rapidly eliminated (60% at t=10 min), although it accumulated in tumor tissue at higher concentrations than in other tissues. Daily s.c. treatment with DIC (LD10) for 24 days significantly reduced the number of spontaneous lung metastases. These results suggest that DIC has the ability of impairing the metastatic development by inhibiting angiogenesis and inducing apoptosis on tumor cells.