RESUMO
7-Arylsulfonyl substituted benzofuropiperidine was discovered as a novel scaffold for 5HT(6) receptor antagonists. Optimization by substitution at C-1 position led to identification of selective, orally bioavailable, brain penetrant antagonists with reduced hERG liability. An advanced analog tested in rat social recognition model showed significant activity suggesting potential utility in the enhancement of short-term memory.
Assuntos
Benzofuranos/química , Piperidinas/química , Receptores de Serotonina/química , Antagonistas da Serotonina/farmacologia , Animais , Encéfalo/embriologia , Encéfalo/metabolismo , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go/metabolismo , Humanos , Concentração Inibidora 50 , Cinética , Memória de Curto Prazo/efeitos dos fármacos , Modelos Químicos , Ratos , Esquizofrenia/tratamento farmacológico , Relação Estrutura-AtividadeRESUMO
The purpose of this study was to investigate whether changes in the pH of the gastrointestinal tract can directly affect P-glycoprotein (P-gp) function. The effect of changes in extracellular pH on P-gp functionality was examined by testing colchicine (a nonionizable P-gp substrate) in bidirectional Caco-2 and MDR1-Madine Darby canine kidney (MDCK) cell permeability assays, in which the pH of the apical and basolateral chambers was varied. Reduction of the pH from 7.4 to 5.0 and 4.5 markedly increased the apical-to-basolateral flux of colchicine and reduced the basolateral-to-apical flux. The efflux ratio for colchicine was reduced to 1.2 at pH 4.5, compared with values greater than 20 that were measured in the pH range of 5.5-7.4. A similar result was obtained when MDR1-MDCK cells were used in the bidirectional permeability studies. Other nonionizable P-gp substrates (digoxin, dexamethasone, paclitaxel, and etoposide) responded to acidic pH (4.5) in a manner similar to colchicine. Reduced P-gp ATPase activity is a reason for the diminished P-gp function observed at pH 4.5.
Assuntos
Absorção Intestinal , Mucosa Intestinal/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP/química , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Disponibilidade Biológica , Transporte Biológico , Células CACO-2 , Colchicina/metabolismo , Digoxina/metabolismo , Cães , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Células Madin Darby de Rim Canino , Permeabilidade , Conformação Proteica , Relação Estrutura-Atividade , TransfecçãoRESUMO
Elaboration of the SAR around a series of 2,4-diaminopyrimidines led to a number of c-Met inhibitors in which kinase selectivity was modulated by substituents appended on the C4-aminobenzamide ring and the nature of the C2-aminoaryl ring. Further lead optimization of the C2-aminoaryl group led to benzoxazepine analogs whose pharmaceutical properties were modulated by the nature of the substituent on the benzoxazepine nitrogen. Tumor stasis (with partial regressions) were observed when an orally bioavailable analog was evaluated in a GTL-16 tumor xenograft mouse model. Subsequent PK/PD studies suggested that a metabolite contributed to the overall in vivo response.
