Optimizing ultrasonication-assisted comprehensive extraction of bioactive flavonoids from Pterocarpus santalinus leaves using response surface methodology

Abstract

The leaves of Pterocarpus santalinus have been identified as a good source of health-beneficial flavonoids through the amalgamation of untargeted metabolomics using UHPLC-ESI-MSⁿ leading to the identification of flavone-glycosides bearing isorhamnetin and quercetin skeletons. To unveil the optimum ultrasonication extraction conditions required for the comprehensive extraction of major flavone-glycosides, isorhamnetin-3-O-β-d-(2-O-α-L-rhamnopyranosyl)glucopyranoside and isorhamnetin-3-O-β-d-glucopyranoside, the response surface methodology based on Box-Behnken design was adopted. The influence of input extraction parameters extraction time (X₁): 15-45 min, temperature (X₂): 40-60 °C and biomass-solvent ratio (X₃): 60-100 on the extractive yield and comprehensive flavonoid content resulted in the optimal conditions as 19.09 min, 48.65 ^oC, and 72.15, respectively. The investigation provides a sustainable approach for recovering health-beneficial flavone-glycosides for utilization in various industries.

Keywords: Flavonoids; Isorhamnetin; P. santalinus leaves; Quercetin; Response surface methodology; Ultrasonication.