RESUMO
A new method for the selective extraction of p-aminosalicylic acid from aqueous and urine samples has been developed using magnetic molecularly imprinted polymer nanoparticles before determination by high-performance liquid chromatography. The Fe3 O4 nanoparticles were first prepared through the chemical coprecipitation of Fe2+ and Fe3+ and then coated with a vinyl shell. Subsequently, a layer of molecularly imprinted polymers was grafted onto the vinyl-modified magnetic nanoparticles by precipitation polymerization. FTIR spectroscopy, scanning electron microscopy, vibrating sample magnetometry, and thermogravimetric analysis were applied to characterize the sorbent properties. Moreover, the predominant parameters affecting the magnetic solid phase extraction such as sample pH, sorption and elution times, the amount of sorbent, and composition and volume of eluent were investigated thoroughly. The maximum sorption capacity of the imprinted polymer toward p-aminosalicylic acid was 70.9 mg/g, which is 4.5 times higher than that of the magnetic nonimprinted polymer. The magnetic molecularly imprinted polymer nanoparticles were applied for the selective extraction of p-aminosalicylic acid from aqueous and urine samples and satisfactory results were achieved. The results illustrate that magnetic molecularly imprinted polymer nanoparticles have a great potential in the extraction of p-aminosalicylic acid from environmental and biological matrices.
Assuntos
Ácido Aminossalicílico/isolamento & purificação , Impressão Molecular , Ácido Aminossalicílico/urina , Cromatografia Líquida de Alta Pressão , Magnetismo , Polímeros , Extração em Fase SólidaRESUMO
Mycobacterium tuberculosis arylamine N-acetyltransferase (TBNAT) is able to acetylate para-aminosalicylic acid (PAS) both in vitro and in vivo as determined by high-performance liquid chromatography (HPLC) and electrospray ionization-mass spectrometry (ESI-MS) techniques. The antituberculosis activity of the acetylated PAS is significantly reduced. As a result, overexpression of TBNAT in M. tuberculosis results in PAS resistance, as determined by MIC tests and drug exposure experiments. Taken together, our results suggest that TBNAT from M. tuberculosis is able to inactivate PAS by acetylating the compound.
Assuntos
Ácido Aminossalicílico/metabolismo , Antituberculosos/metabolismo , Arilamina N-Acetiltransferase/metabolismo , Proteínas de Bactérias/metabolismo , Mycobacterium tuberculosis/enzimologia , Acetilação , Ácido Aminossalicílico/química , Ácido Aminossalicílico/isolamento & purificação , Ácido Aminossalicílico/farmacologia , Antituberculosos/química , Antituberculosos/isolamento & purificação , Antituberculosos/farmacologia , Arilamina N-Acetiltransferase/genética , Proteínas de Bactérias/genética , Cromatografia Líquida de Alta Pressão , Expressão Gênica , Inativação Metabólica , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Espectrometria de Massas por Ionização por ElectrosprayRESUMO
We have developed an interface that allows the specific detection of nitrogen-containing compounds by using a chemiluminescence nitrogen detector. The feasibility of using this interface was demonstrated by separating and detecting two nitrogen-containing compounds, p-aminosalicylic acid and L-phenylalanine. Although baseline separation was achieved, the theoretical plates were lower when compared to UV detection (25000 vs. approximately 85000). A sensitivity of 75 ng (approximately 500 pmol) per injection was achieved with this system which is adequate for pharmaceutical and biotech applications.
