RESUMO
The convenient and efficient synthesis of two macrocyclic ligands (15- and 18-membered) based on a dipyrido-6,7,8,9-tetrahydrophenazine (dpqc) or 2,2':6',2''-terpyridine (tpy) heterocycle and a DTTA (diethylenetriaminetriacetic acid) skeleton is described. In these ligands the DTTA skeleton contains an additional extracyclic functionality (NH(2) group) suitable for covalent attachment to bioactive molecules. These octa- and nonadentate ligands form very stable and luminescent neutral lanthanide complexes in aqueous solutions at physiological pH. The corresponding Eu(III) and Tb(III) complexes are characterized by a maximum absorption wavelength compatible with nitrogen laser excitation (337 nm) and attractive lifetimes and quantum yields. Further introduction of a maleimide bioconjugatable handle in the Eu(III) complexes was investigated and a valuable luminescence brightness above 1500 dm(3) mol(-1) cm(-1) at 337 nm was obtained with the corresponding Eu(III) tpy-derivative. Finally, these two luminescent chelates were grafted onto thiol residues of a model antibody (Mab GSS11) without loss of their luminescent properties.
Assuntos
Quelantes/química , Elementos da Série dos Lantanídeos/química , Substâncias Luminescentes/química , Compostos Macrocíclicos/química , Anticorpos Monoclonais/química , Quelantes/síntese química , Elementos da Série dos Lantanídeos/síntese química , Substâncias Luminescentes/síntese química , Compostos Macrocíclicos/síntese química , Maleimidas/síntese química , Maleimidas/química , Ácido Pentético/análogos & derivados , Ácido Pentético/síntese química , Ácido Pentético/química , Fenazinas/síntese química , Fenazinas/química , Piridinas/síntese química , Piridinas/químicaRESUMO
Our docking program, Fitted, implemented in our computational platform, Forecaster, has been modified to carry out automated virtual screening of covalent inhibitors. With this modified version of the program, virtual screening and further docking-based optimization of a selected hit led to the identification of potential covalent reversible inhibitors of prolyl oligopeptidase activity. After visual inspection, a virtual hit molecule together with four analogues were selected for synthesis and made in one-five chemical steps. Biological evaluations on recombinant POP and FAPα enzymes, cell extracts, and living cells demonstrated high potency and selectivity for POP over FAPα and DPPIV. Three compounds even exhibited high nanomolar inhibitory activities in intact living human cells and acceptable metabolic stability. This small set of molecules also demonstrated that covalent binding and/or geometrical constraints to the ligand/protein complex may lead to an increase in bioactivity.
Assuntos
Inibidores de Proteases/farmacologia , Serina Endopeptidases/metabolismo , Interface Usuário-Computador , Animais , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos , Estabilidade de Medicamentos , Humanos , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Prolil Oligopeptidases , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Conformação Proteica , Ratos , Serina Endopeptidases/química , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
A series of pyrrolic analogs and two series of regioisomeric pyrazolic analogs of the marine alkaloids granulatimide and isogranulatimide were prepared. The synthesis of the two first ones was based on the condensation reaction of diversely 5-substituted 3-bromoindoles with pyrrole or pyrazole followed by addition of the intermediates on maleimide or dibromomaleimide, respectively, the so-obtained acyclic adducts being finally photocyclized to the desired analogs. Compounds of the last series were obtained by reacting different 5-substituted-indole-3-glyoxylates with N-Boc-pyrazole-3-acetamide and subsequent photochemical cyclization of the adducts. All the compounds were evaluated for their in vitro growth inhibitory properties toward eight cancer cell lines. Several compounds were also assayed for their ability to abrogate the G2-cell cycle checkpoint or to inhibit a panel of Ser/Thr kinases. Lastly, computer-assisted phase-contrast microscopy (quantitative videomicroscopy) revealed that the three most potent compounds (4a, 9a, 9e), with IC(50) growth inhibitory concentrations ranging between 10 and 20 µM, displayed cytostatic, not cytotoxic, anticancer effects.
Assuntos
Alcaloides/síntese química , Alcaloides/farmacologia , Organismos Aquáticos/química , Imidazóis/síntese química , Imidazóis/farmacologia , Indóis/síntese química , Indóis/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas de Química Sintética , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Camundongos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Granulatimide and isogranulatimide are alkaloids obtained from marine sources which have been shown to inhibit cell-cycle G2-checkpoint, targeting more particularly checkpoint 1 kinase (Chk1). At a structural level, they possess a characteristic pyrrolocarbazole framework also shared by the well-known rebeccamycin and staurosporine microbial metabolites which have been described to inhibit topoisomerase I and diverse kinases, respectively. This review reports precisely on the synthesis and kinase inhibitory activities of pyrrolocarbazole-based analogues of granulatimide.