RESUMEN
Escherichia coli O157:H7 is a major foodborne pathogen that poses a significant threat to food safety and human health. Rapid and sensitive detection of viable Escherichia coli O157:H7 can effectively prevent food poisoning. Here, we developed a microwell-confined and propidium monoazide-assisted digital CRISPR microfluidic platform for rapid and sensitive detection of viable Escherichia coli O157:H7 in food samples. The reaction time is significantly reduced by minimizing the microwell volume, yielding qualitative results in 5 min and absolute quantitative results in 15 min. With the assistance of propidium monoazide, this platform can eliminate the interference from 99% of dead Escherichia coli O157:H7. The direct lysis method obviates the need for a complex nucleic acid extraction process, offering a limit of detection of 3.6 × 101 CFU mL-1 within 30 min. Our results demonstrated that the platform provides a powerful tool for rapid detection of Escherichia coli O157:H7 and provides reliable guidance for food safety testing.
Asunto(s)
Azidas , Escherichia coli O157 , Propidio , Escherichia coli O157/aislamiento & purificación , Azidas/química , Propidio/química , Propidio/análogos & derivados , Técnicas Analíticas Microfluídicas/instrumentación , Microbiología de Alimentos/instrumentación , Dispositivos Laboratorio en un Chip , Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Viabilidad Microbiana , Límite de DetecciónRESUMEN
The metabolic oxidation of drug-like small molecules by aldehyde oxidase (AO) has commonly been mitigated through the incorporation of deuterium at the oxidation site. We report that dimethylformamide dimethyl acetal and related compounds undergo rapid CH to CD isotopic exchange upon exposure to methanol-d and similar deuterated alcohols. This isotopic exchange process can be used to synthesize Me2NCD(OMe)2 and has significant implications for the use of Me2NCD(OMe)2 in the synthesis of specifically deuterium-labeled compounds. The application of Me2NCD(OMe)2 to the synthesis of various heterocycles that have been associated with AO metabolism is described, and we report the impact of deuteration on the rate of in vitro AO-mediated metabolism.
RESUMEN
A novel series of quinolinone-based adenosine A(2B) receptor antagonists was identified via high throughput screening of an encoded combinatorial compound collection. Synthesis and assay of a series of analogs highlighted essential structural features of the initial hit. Optimization resulted in an A(2B) antagonist (2i) which exhibited potent activity in a cAMP accumulation assay (5.1 nM) and an IL-8 release assay (0.4 nM).