RESUMO
Secondary drying is the final step of lyophilization before stoppering, during which water is desorbed from the product to yield the final moisture content. We studied how chamber pressure and partial pressure of water vapor during this step affected the time course of water content of aqueous solutions of polyvinylpyrrolidone (PVP) in glass vials. The total chamber pressure had no effect when the partial pressure of water vapor was very low. However, when the vapor phase contained a substantial fraction of water vapor, the PVP moisture content was much higher. We carried out dynamic vapor sorption experiments (DVS) to demonstrate that the higher PVP moisture content was a straightforward result of the higher water vapor content in the lyophilizer. The results highlight that the partial pressure of water vapor is extremely important during secondary drying in lyophilization, and that lower chamber pressure set points for secondary drying may sometimes be justified as a strategy for ensuring low partial pressure of water vapor, especially for lyophilizers that do not inject dry gas to control pressure. These findings have direct application for process transfers/scale ups from freeze-dryers that do not inject dry gas for pressure control to those that do, and vice versa.
Assuntos
Liofilização/métodos , Pressão Parcial , Pressão , VaporRESUMO
Elevated levels of human lipoprotein-associated phospholipase A2 (Lp-PLA2) are associated with cardiovascular disease and dementia. A fragment screen was conducted against Lp-PLA2 in order to identify novel inhibitors. Multiple fragment hits were observed in different regions of the active site, including some hits that bound in a pocket created by movement of a protein side chain (approximately 13 Å from the catalytic residue Ser273). Using structure guided design, we optimized a fragment that bound in this pocket to generate a novel low nanomolar chemotype, which did not interact with the catalytic residues.
Assuntos
1-Alquil-2-acetilglicerofosfocolina Esterase/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Pirazóis/farmacologia , Tiazóis/farmacologia , 1-Alquil-2-acetilglicerofosfocolina Esterase/metabolismo , Sítios de Ligação/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/químicaRESUMO
The design, synthesis, and in vitro evaluation of the first macrocyclic inhibitor of 3C and 3C-like proteases of picornavirus, norovirus, and coronavirus are reported. The in vitro inhibitory activity (50% effective concentration) of the macrocyclic inhibitor toward enterovirus 3C protease (CVB3 Nancy strain), and coronavirus (SARS-CoV) and norovirus 3C-like proteases, was determined to be 1.8, 15.5 and 5.1 µM, respectively.
Assuntos
Coronavirus/enzimologia , Compostos Macrocíclicos/farmacologia , Norovirus/enzimologia , Peptídeo Hidrolases/metabolismo , Picornaviridae/enzimologia , Inibidores de Proteases/farmacologia , Relação Dose-Resposta a Droga , Desenho de Fármacos , Compostos Macrocíclicos/síntese química , Compostos Macrocíclicos/química , Modelos Moleculares , Conformação Molecular , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , Relação Estrutura-AtividadeRESUMO
1,2-Benzisothiazol-3(2H)-ones and 1,3,4-oxadiazoles individually have recently attracted considerable interest in drug discovery, including as antibacterial and antifungal agents. In this study, a series of functionalized 1,2-benzisothiazol-3(2H)-one-1,3,4-oxadiazole hybrid derivatives were synthesized and subsequently screened against Dengue and West Nile virus proteases. Ten out of twenty-four compounds showed greater than 50% inhibition against DENV2 and WNV proteases ([I] = 10 µM). The IC(50) values of compound 7n against DENV2 and WNV NS2B/NS3 were found to be 3.75 ± 0.06 and 4.22 ± 0.07 µM, respectively. The kinetics data support a competitive mode of inhibition by compound 7n. Molecular modeling studies were performed to delineate the putative binding mode of this series of compounds. This study reveals that the hybrid series arising from the linking of the two scaffolds provides a suitable platform for conducting a hit-to-lead optimization campaign via iterative structure-activity relationship studies, in vitro screening and X-ray crystallography.
Assuntos
Antivirais/química , Vírus da Dengue/enzimologia , Oxidiazóis/química , Peptídeo Hidrolases/metabolismo , Inibidores de Proteases/química , Triazóis/química , Vírus do Nilo Ocidental/enzimologia , Animais , Antivirais/farmacologia , Dengue/tratamento farmacológico , Vírus da Dengue/efeitos dos fármacos , Desenho de Fármacos , Humanos , Modelos Moleculares , Oxidiazóis/farmacologia , Inibidores de Proteases/farmacologia , Triazóis/farmacologia , Febre do Nilo Ocidental/tratamento farmacológico , Vírus do Nilo Ocidental/efeitos dos fármacosRESUMO
Dengue and West Nile viruses (WNV) are mosquito-borne members of flaviviruses that cause significant morbidity and mortality. There is no approved vaccine or antiviral drugs for human use to date. In this study, a series of functionalized meta and para aminobenzamide derivatives were synthesized and subsequently screened in vitro against Dengue virus and West Nile virus proteases. Four active compounds were identified which showed comparable activity toward the two proteases and shared in common a meta or para(phenoxy)phenyl group. The inhibition constants (K(i)) for the most potent compound 7n against Dengue and West Nile virus proteases were 8.77 and 5.55 µM, respectively. The kinetics data support a competitive mode of inhibition of both proteases by compound 7n. This conclusion is further supported by molecular modeling. This study reveals a new chemical scaffold which is amenable to further optimization to yield potent inhibitors of the viral proteases via the combined utilization of iterative medicinal chemistry/structure-activity relationship studies and in vitro screening.
Assuntos
Antivirais/química , Benzamidas/química , Vírus da Dengue/enzimologia , Peptídeo Hidrolases/química , Inibidores de Proteases/química , Vírus do Nilo Ocidental/enzimologia , Antivirais/síntese química , Antivirais/farmacologia , Sítios de Ligação , Domínio Catalítico , Simulação por Computador , Vírus da Dengue/efeitos dos fármacos , Cinética , Peptídeo Hidrolases/metabolismo , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Inibidores de Proteases/síntese química , Inibidores de Proteases/farmacologia , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Triazóis/farmacologia , Vírus do Nilo Ocidental/efeitos dos fármacosRESUMO
There is currently an unmet need for the development of small-molecule therapeutics for norovirus infection. The piperazine scaffold, a privileged structure embodied in many pharmacological agents, was used to synthesize an array of structurally-diverse derivatives which were screened for anti-norovius activity in a cell-based replicon system. The studies described herein demonstrate for the first time that functionalized piperazine derivatives possess anti-norovirus activity. Furthermore, these studies have led to the identification of two promising compounds (6a and 9l) that can be used as a launching pad for the optimization of potency, cytotoxicity, and drug-like characteristics.
Assuntos
Antivirais/farmacologia , Infecções por Caliciviridae/tratamento farmacológico , Norovirus/metabolismo , Piperazinas/farmacologia , Motivos de Aminoácidos , Linhagem Celular , Química Farmacêutica/métodos , Desenho de Fármacos , Humanos , Modelos Químicos , Norovirus/efeitos dos fármacos , Piperazinas/química , Ligação Proteica , Conformação Proteica , Relação Estrutura-AtividadeRESUMO
A series of broad-spectrum antifungal agents based on the 1,2-benzisothiazol-3(2H)-one scaffold is reported. Preliminary structure-activity relationship studies have established the importance of the presence of the heterocyclic ring, a methyl group, and a phenyl ring for optimal manifestation of antifungal activity.
Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Tiazóis/química , Tiazóis/farmacologia , Antifúngicos/síntese química , Compostos Heterocíclicos/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Tiazóis/síntese químicaRESUMO
A new class of compounds that exhibit anti-norovirus activity in a cell-based system and embody in their structure a cyclosulfamide scaffold has been identified. The structure of the initial hit (compound 2a, ED(50) 4 µM, TD(50) 50 µM) has been prospected by exploiting multiple points of diversity and generating appropriate structure-activity relationships.
Assuntos
Amidas/química , Amidas/farmacologia , Vírus Norwalk/efeitos dos fármacos , Ácidos Sulfônicos/química , Ácidos Sulfônicos/farmacologia , Linhagem Celular Tumoral , Humanos , Estrutura Molecular , Vírus Norwalk/química , Relação Estrutura-AtividadeRESUMO
The first series of peptidyl aldehyde inhibitors that incorporate in their structure a glutamine surrogate has been designed and synthesized based on the known substrate specificity of Norwalk virus 3C protease. The inhibitory activity of the compounds with the protease and with a norovirus cell-based replicon system was investigated. Members of this class of compounds exhibited noteworthy activity both in vitro and in a cell-based replicon system.