Development and validation of a new method to quantify vitexin-2-O-rhamnoside on Passiflora L. extracts

The genus Passiflora L. is the most representative of the Passifloraceae family and includes about 500 species. The aim of this work was to analyze three different passion fruit species in relation to vitexin-2´´-O-rhamnoside content by high-performance liquid chromatography coupled to a diode-array ultaviolet detector. Samples were prepared by water infusion (10% w/v), dried by lyophilization, and stored in amber vials at -20°C. The method for quantification of vitexin-2´´-O-rhamnoside was developed and validated using a Shimadzu Class-VP liquid phase chromatograph. Quantification of vitexin-2´´-O-rhamnoside was done with an Ascentis-phenyl supelco column (250 mm x 4.6 mm i.d. x 5 µm), mobile phase composed of ultrapure water (pH = 3.0) (Solvent A)/ acetonitrile (Solvent B), in gradient elution mode, flow rate of 1.4 mL/min, and UV detection at 340 nm. The adopted method showed great linearity, precision, accuracy, detection (LOD), and quantification (LOQ) limits, recovery and robustness. Total analysis time was 16 min. This method has clear advantages when compared to those found in the literature, since the use of a silica-based phenyl column allowed the best chromatographic resolution, resulting in better LOD and LOQ. Vitexin-2''-O-rhamnoside content was higher in P. foetida (7.21%), followed by P. setacea (3.66%), and P. alata (2.89%). Key words: Vitexin-2''-O-rhamnoside quantity, high-performance liquid chromatography (HPLC) new method, passion fruit.