RESUMO
This study presents the development and validation of a fast and simple bioanalytical ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method intended for quantifying the anti-inflammatory candidate 5'-methoxynobiletin (5'-MeONB) in rat plasma. Standard of 5'-MeONB was purified from A. conyzoides extract by using preparative HPLC. After a pretreatment of plasma samples with acetonitrile, chromatographic separations were efficiently achieved with a C18 column using a 9 min gradient system of 0.1% aqueous formic acid and acetonitrile as eluent. Drug candidate 5'-MeONB and chrysin (internal standard, IS) detection were carried out using ESI+ through the extracted ion chromatograms approach, monitored at m/z 433.1494 (for 5'-MeONB, tR:1.78 min) and m/z 255.0657 (for IS, tR:1.57 min). Method was validated according to US FDA guidelines, presenting linearity (R2 > 0.999) over concentration range of 30-750 ng/mL. Relative standard deviation (RSD) of repeatability and intermediary precision respectively ranged between 1.93-3.65% and 2.16-7.54%, considering lower limit of quantitation (30 ng/mL) and quality control (90, 360 and 600 ng/mL) samples, while accuracy was between 82.51 and 109.44%. Moreover, no interference from plasma endogenous substances, no carryover effect, and no influence of extraction method even in hemolyzed blood samples were observed. Sample stability in auto-sampler and long-term -80 °C storage, as well as matrix effect were within acceptable limits. For the first time, using the validated UPLC-MS bioanalytical method, the plasma pharmacokinetics of 5'-MeONB following 2 mg/kg intravenous bolus dosing to Wistar rats was characterized allowing the determination of the parameters describing drug distribution and elimination.
Assuntos
Anti-Inflamatórios/sangue , Cromatografia Líquida de Alta Pressão/métodos , Flavonas/sangue , Espectrometria de Massas em Tandem/métodos , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacocinética , Flavonas/química , Flavonas/farmacocinética , Limite de Detecção , Modelos Lineares , Masculino , Ratos , Ratos Wistar , Reprodutibilidade dos TestesRESUMO
Ageratum conyzoides L. is a plant widely used in traditional medicine of tropical and subtropical regions for its anti-inflammatory and antinociceptive properties. Nevertheless, the chemical composition of its medicinal preparation has not been yet accurately established. In this study, chromatographic methods were developed for the simultaneous identification and quantification of the main compounds in A. conyzoides aqueous extract, using UPLC-PDA-ESI-QToF-MS. The qualitative analyses defined by MS/MS analysis allowed the identification of 27 compounds in the aqueous extract, including the toxic pyrrolizidine alkaloids, phenolic acids, coumarin and polymethoxyflavones. Among the metabolites, twelve were detected for the first time in the species. The quantitative method was validated according to the official guidelines, demonstrating to be specific, linear, precise, accurate and sensitive for the quantification of chlorogenic acid, coumaric acid, coumarin (1,2-benzopyranone), 5,6,7,3',4',5'-hexamethoxyflavone, nobiletin, 5'-methoxynobiletin and eupalestin.
Assuntos
Ageratum/química , Cromatografia Líquida de Alta Pressão/métodos , Cumarínicos/análise , Flavonas/análise , Hidroxibenzoatos/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/instrumentação , Extratos Vegetais/análise , Extratos Vegetais/química , Folhas de Planta/químicaRESUMO
A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (¹HNMR, {¹H}-13C NMR, and APT-13C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the structural elucidation and the complete ¹H and 13C chemical shift assignments of these natural compounds. In addition, the antifungal activity of these compounds against phytopathogenic and human pathogenic fungi was investigated.
Os flavonóis 8-hidroxi-3, 4', 5, 6, 7-pentametoxiflavona (1) e 8-hidroxi-3, 3', 4', 5, 6, 7-hexametoxiflavona (2) foram isolados em mistura a partir de uma amostra comercial de Citrus aurantifolia. A determinação estrutural e a inequívoca atribuição dos sinais de deslocamento químico dos átomos de hidrogênio e carbono destes compostos naturais foram realizadas através da análise dos espectros de RMN 1D e 2D, incluindo COSY, NOESY, HMQC e HMBC. Em adição, a atividade antifúngica destes compostos contra fungos patogênicos também foiinvestigada.