Green microextraction using deep eutectic solvents: Computer-aided analysis of bioactive components in natural products

An efficient and sustainable deep eutectic solvent-based vortex-simplified matrix solid phase dispersion (DES-VSMSPD) microextraction method was established to extract and detect the bioactive components in natural products (NPs) by ultra high-performance liquid chromatography with photodiode array (UHPLC-PDA). Single-factor optimization and Box-Behnken design combined with response surface methodology (BBD-RSM) were used to obtain the optimal extraction conditions of DES-VSMSPD. The electrostatic potential (ESP) distributions, the independent gradient model (IGMH) and frontier molecular orbitals theory were used to systematically elucidate the molecular mechanism of DES synthesis and its interaction with the target compounds. The analysis indicated that DES composed of betaine and malonic acid exhibited the excellent elution performance. With the optimal extraction conditions, the total extraction yield of five analytes was achieved at 41.92 mg g−1, which was superior to the other conventional extraction methods. Furthermore, the greenness and sustainability of this developed method were confirmed by green analytical procedure index (GAPI) and Analytical Eco-Scale. Additionally, this analytical method possessed excellent linearity with correlation coefficients for the analytes all more than 0.9999. The limits of detection ranged from 0.04 to 0.13 μg mL−1. The recoveries of five analytes ranged from 96.1 % to 102 % (RSD < 2 %). There were significant differences in the contents of five analytes from ten batches of Paeoniae Radix Rubra (PRR), and the content ranges of the gallic acid, catechin, albiflorin, paeoniflorin and paeonol were 0.24–1.33 mg g−1, 0.35–0.94 mg g−1, 0.71–28.93 mg g−1, 15.6–25.79 mg g−1, 0–0.19 mg g−1, respectively. Consequently, the thorough analysis of the extraction mechanism of green solvents by combining theoretical simulation with specific experiments, which provided the new perspective for effective extraction and quantification of bioactive components in NPs. [Display omitted] •DES-VSMSPD method was used for the extraction of active compounds in natural products.•A sustainable deep eutectic solvent was synthesized and used as the elution solvent.•The extraction mechanism was further explained using Density Functional Theory (DFT).•GAPI and Analytical Eco-Scale were used to assess the method's greenness.