RESUMO
Conjugated microporous polymers (CMPs) have unique characteristics and have been used in a range of fascinating applications in separation sciences. In this study, a CMP, designated as CMP-1, was synthesized via the Sonogashira-Hagihara coupling reaction using 1,3,5-triphenylbenzene and 1,4-dibromobenzene as building blocks. CMP-1 features a large surface area, abundant micropore structures, and excellent stability, making it a promising solid-phase extraction adsorbent for the efficient enrichment of neonicotinoid insecticides (NEOs). Under the optimized conditions, CMP-1 was combined with high-performance liquid chromatography and diode array detection to enable the detection of NEOs with a wide linear range (0.5-200 µg·L-1), a low detection limit (0.26-0.58 µg·L-1), and acceptable precision. The developed method was applied to determine spiked NEOs in three types of environmental water samples, with recoveries of 73.7%-112.0% and relative standard deviations of 0.6%-9.4%.
Assuntos
Inseticidas , Limite de Detecção , Neonicotinoides , Polímeros , Extração em Fase Sólida , Poluentes Químicos da Água , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/química , Inseticidas/análise , Inseticidas/isolamento & purificação , Inseticidas/química , Cromatografia Líquida de Alta Pressão/métodos , Neonicotinoides/análise , Neonicotinoides/isolamento & purificação , Neonicotinoides/química , Polímeros/química , Porosidade , AdsorçãoRESUMO
The SCUEC4 strain of Ochrobactrum intermedium is a newly isolated bacterium that degrades nicotine can use nicotine as the sole carbon source via a series of enzymatic catalytic processes. The mechanisms underlying nicotine degradation in this bacterium and the corresponding functional genes remain unclear. Here, we analyzed the function and biological properties of the ocnE gene involved in the nicotine-degradation pathways in strain SCUEC4. The ocnE gene was cloned by PCR with total DNA of strain SCUEC4 and used to construct the recombinant plasmid pET28a-ocnE. The overexpression of the OcnE protein was detected by SDS-PAGE analysis, and study of the function of this protein was spectrophotometrically carried out by monitoring the changes of 2,5-dihydroxypyridine. Moreover, the effects of temperature, pH, and metal ions on the biological activities of the OcnE protein were analyzed. The optimal conditions for the biological activities of OcnE, a protein of approximately 37.6 kDa, were determined to be 25 °C, pH 7.0, and 25 µmol/L Fe2+, and the suitable storage conditions for the OcnE protein were 0 °C and pH 7.0. In conclusion, the ocnE gene is responsible for the ability of 2,5-dihydroxypyridine dioxygenase. These findings will be beneficial in clarifying the mechanisms of nicotine degradation in O. intermedium SCUEC4.
Assuntos
Proteínas de Bactérias/metabolismo , Genes Bacterianos , Nicotina/metabolismo , Ochrobactrum/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Concentração de Íons de Hidrogênio , Ferro/metabolismo , Peso Molecular , Ochrobactrum/genética , Piridinas/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , TemperaturaRESUMO
Chemotherapy induced neuropathy causes excruciating pain to cancer patients. Wen-Luo-Tong (WLT), a traditional Chinese medicinal compound, has been used to alleviate anti-cancer drug such as oxaliplatin-induced neuropathic pain for many years. However, the current route of administration of WLT is inconvenient and the active ingredients and mechanism of action of WLT are still unclear. To address these issues, we developed a novel formulation of WLT (W/O microemulsion) for the ease of application. New ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) methods were employed for analysis of the ingredients. We identified seven ingredients that penetrated through the skin into the Franz cell receptor solution and four of those ingredients were retained in skin tissue when WLT microemulsion was applied. We tested the microemulsion formulation on an oxaliplatin-induced neuropathy rat model and showed that this formulation significantly decreased oxaliplatin-induced mechanical hyperalgesia responses. Schwann cells (SCs) viability experiment in vitro was studied to test the protective effect of the identified seven ingredients. The result showed that Hydroxysafflor Yellow A, icariin, epimedin B and 4-dihydroxybenzoic acid significantly increased the viability of SCs after injured by Oxaliplatin. Our report presents the first novel formulation of WLT with neuroprotective effect and ease of use, which has potential for clinical applications.