Optimization of an ultrasonic-assisted aqueous two-phase extraction method for four flavonoids from Lysionotus pauciflorus

Abstract

An effective approach to extracting four flavonoids (lysioside C, nevadensin-7-sambubioside, ikarisoside B, and nevadensin) from Lysionotus pauciflorus using ultrasonic-assisted aqueous two-phase extraction (UAATPE) technology was studied. Ethanol/K₂HPO₄ system was selected and the influence of several important parameters, including composition of the aqueous two-phase system (ATPS), extraction temperature and time, particle size, and solvent to material ratio, were investigated by single factor experimentss. Then three key parameters (ethanol concentration, solvent to material ratio and extraction temperature) were further optimized by response surface methodology (RSM). The optimal process was that 1 g 120 mesh herb powders were extracted with 45 g ATPS (made of 30% ethanol/18% K₂HPO₄) in 43 °C for 30 min, and yields of four flavonoids could reach 2.56, 2.06, 3.62, and 6.28 mg/g, respectively. Compared with ultrasonic-assisted extraction (UAE) in three conventional solvents (water, ethanol and 60% ethanol), the UAATPE displayed comparatively higher extraction capability. Therefore, UAATPE in ethanol/K₂HPO₄ system could be an alternative technology for integrated extraction of the flavonoids from L. pauciflorus.

Keywords:

• Aqueous two-phase system
• flavonoids
• Lysionotus pauciflorus
• response surface methodology
• ultrasonic-assisted extraction

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Sichuan University and Office of Science and Technology of Luzhou under Grant [number 2017CDLZ-S33].