RESUMO
Invasive fungal infections (IFIs) are fatal infections, but treatment options are limited. The clinical efficacies of existing drugs are unsatisfactory because of side effects, drug-drug interaction, unfavorable pharmacokinetic profiles, and emerging drug-resistant fungi. Therefore, the development of antifungal drugs with a new mechanism is an urgent issue. Herein, we report novel aryl guanidine antifungal agents, which inhibit a novel target enzyme in the ergosterol biosynthesis pathway. Structure-activity relationship development and property optimization by reducing lipophilicity led to the discovery of 6h, which showed potent antifungal activity against Aspergillus fumigatus in the presence of serum, improved metabolic stability, and PK properties. In the murine systemic A. fumigatus infection model, 6h exhibited antifungal efficacy equivalent to voriconazole (1e). Furthermore, owing to the inhibition of a novel target in the ergosterol biosynthesis pathway, 6h showed antifungal activity against azole-resistant A. fumigatus.
Assuntos
Antifúngicos/farmacologia , Ergosterol/antagonistas & inibidores , Guanidina/farmacologia , Infecções Fúngicas Invasivas/tratamento farmacológico , Tiazóis/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Aspergillus fumigatus/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ergosterol/biossíntese , Guanidina/análogos & derivados , Guanidina/química , Humanos , Infecções Fúngicas Invasivas/metabolismo , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/químicaRESUMO
Cohesion is essential for the identification of sister chromatids and for the biorientation of chromosomes until their segregation. Here, we have demonstrated that an RNA-binding motif protein encoded on the X chromosome (RBMX) plays an essential role in chromosome morphogenesis through its association with chromatin, but not with RNA. Depletion of RBMX by RNA interference (RNAi) causes the loss of cohesin from the centromeric regions before anaphase, resulting in premature chromatid separation accompanied by delocalization of the shugoshin complex and outer kinetochore proteins. Cohesion defects caused by RBMX depletion can be detected as early as the G2 phase. Moreover, RBMX associates with the cohesin subunits, Scc1 and Smc3, and with the cohesion regulator, Wapl. RBMX is required for cohesion only in the presence of Wapl, suggesting that RBMX is an inhibitor of Wapl. We propose that RBMX is a cohesion regulator that maintains the proper cohesion of sister chromatids.
