Comparative assessment of extraction methods and quantitative estimation of luteolin in the leaves of Vitex negundo Linn. by HPLC

Abstract

ObjectiveTo find out the ideal organic solvent and extraction technique for the isolation of luteolin from the leaves of Vitex negundo Linn. (V. negundo) by quantitative estimation of luteolin through high performance liquid chromatography (HPLC) method. MethodsThe leaves of V. negundo were identified by a botanist, cleaned, dried under shade and powdered. Maceration, reflux, Soxhlet and ultrasound assisted extraction techniques were used for the extraction of luteolin from the leaves by using four different solvents of varying polarity such as methanol, ethanol, chloroform, and dichloromethane. A simple HPLC method was used to determine the quantity of luteolin in each sample extract. ResultsThe calibration plot of standard luteolin showed a linear relationship in the concentration range of 100-500 μg/mL with a correlation coefficient, r2 of 0.998. The methanolic extract was found to contain highest amount of luteolin and among various techniques employed for extraction and isolation of luteolin, reflux technique was observed to be the most efficient. ConclusionBased on the HPLC results, it can be concluded that reflux technique using methanol is better than the other extraction techniques and should be preferred for the extraction and isolation of luteolin from V. negundo leaves extract in research labs or industries.