Accelerated solvent extraction of phenolic compounds exploiting a Box-Behnken design and quantification of five flavonoids by HPLC-DAD in Passiflora species

This work describes the development of a method for the extraction of phenolic compounds, mainly flavonoids, from species of Passiflora by employing accelerated solvent extraction (ASE) and using a Box-Behnken design with desirability functions for optimization. The optimal extraction conditions consisted of an extraction temperature of 80 °C, 64% (w/w) ethanol and five number of extraction cycles. A high-performance liquid chromatography-diode array detection (HPLC-DAD) method for the identification and quantification of orientin, isoorientin, vitexin, isovitexin and rutin flavonoids in the leaves of seventeen Passiflora spp. using gradient elution with acetonitrile (solvent B) and 0.2% (w/w) formic acid in water (solvent A) as the eluent mixture was also developed and validated. These five flavonoids were quantified with good linearity, LOQs, LODs, precision, and accuracy. Higher concentrations of isoorientin, orientin, vitexin, isovitexin and rutin were determinate in P. edulis f. flavicarpa (1.61 mg/g extract and 0.58 mg/g dry plant), P. morifolia (2.10 mg/g extract and 0.90 mg/g dry plant), P. setacea (2.48 mg/g extract and 0.97 mg/g dry plant), P. setacea (8.46 mg/g extract and 3.30 mg/g dry plant) and P. galbana (3.48 mg/g extract and 1.02 mg/g dry plant), respectively.