ABSTRACT
The aim of this work was to evaluate the spectrophotometric methodology for determining the total flavonoid content (TFC) in herbal drug and derived products from Bauhinia monandra Kurz. Several analytical parameters from this method grounded on the complex formed between flavonoids and AlCl3 were evaluated such as herbal amount (0.25 to 1.25 g); solvent composition (ethanol 40 to 80%, v/v); as well as the reaction time and AlCl3 concentration (2 to 9%, w/v). The method was adjusted to aqueous extractives and its performance studied through precision, linearity and preliminary robustness. The results showed an important dependence of the method response from reaction time, AlCl3 concentration, sample amount, and solvent mixture. After choosing the optimized condition, the method was applied for the matrixes (herbal material and extractives), showing precision lower than 5% (for both parameters repeatability and intermediate precision), coefficient of determination higher than 0.99, and no important influence could be observed for slight variations from wavelength or AlCl3 concentration. Thus, it could be concluded that the evaluated analytical procedure was suitable to quantify the total flavonoid content in raw material and aqueous extractives from leaves of B. monandra.
Subject(s)
Bauhinia/chemistry , Flavonoids/analysis , Flavonoids/chemistry , Plant Extracts/chemistry , Water/chemistryABSTRACT
The purpose of this study was to evaluate the influences from variables of preparation on dry residue and total tannins from macerates of Astronium urundeuva barks. Thus, a 3 ² factorial design was used to study the importance of plant proportion (10, 15 and 20 percent, w/v) and the ethanol concentration (40, 60 and 80 percent, v/v) on the selected response. Mathematical models were fitted according to experimental data. The validated equations were used to generate response surfaces. The analysis of the surfaces showed that the optimum conditions to obtain extractive preparations with high extractive efficiency for tannins were: 10 percent (w/v) of plant with ethanol 40 percent (v/v) as solvent.
O objetivo deste trabalho foi avaliar as influências de variáveis de preparação de macerados das cascas de Astronium urundeuva sobre resíduo seco e teor de taninos totais. Desta forma, um desenho fatorial do tipo 3² foi empregado para avaliar a importância da proporção de planta (10, 15 e 20 por cento; m/v) e da concentração de etanol (40, 60 e 80 por cento; v/v) sobre as respostas eleitas. Modelos matemáticos foram ajustados aos dados experimentais. As equações validadas foram usadas para gerar superfícies de respostas. A análise das superfícies demonstrou que as condições ótimas para obtenção de preparações extrativas com elevada eficiência extrativa de taninos foram: 10 por cento (m/v) para planta e etanol 40 por cento (v/v) como solvente.
