Optimization Studies on the Extraction of Flavone Di-C-glycosides from Premna fulva Craib by Deep Eutectic Solvents

Yueyuan Chen,Xiaojie Yan,Dianpeng Li,Jiaoyang Dang,Fenglai Lu

doi:10.1155/2020/7240535

Abstract

Deep eutectic solvents (DESs) are emerging as new extraction solvents for the extraction of bioactive compounds from natural plants. In this work, a total of thirteen choline chloride-based DESs were synthesized and evaluated for the simultaneous extraction of five bioactive flavone di-C-glycosides from Premna fulva Craib. DES-F, which was composed of choline chloride and 1,3-propanediol, showed the best extraction efficiency for the flavone di-C-glycosides, exceeding that of the conventional industrial solvent (40% ethanol). Subsequently, the extraction parameters for ultrasonic-assisted extraction (liquid-solid ratio, water content (%) in the selected DES, and extraction time) were optimized using response surface methodology. Furthermore, the microstructural alterations in the samples after extraction were evaluated using scanning electron microscopy. In addition, we further verified the recovery of flavone di-C-glycosides from the DESs using macroporous resins and evaluated the reusability of the DESs as solvents. The results indicated that DES-F was an efficient and sustainable solvent for the extraction of bioactive flavone di-C-glycosides from Premna fulva Craib. Therefore, this novel strategy may represent a sustainable approach for the extraction of bioactive products and could make phytochemistry more attractive and environmentally friendly.

Highlights

Premna fulva Craib, which is known as the Zhuang medicine “zhangu,” belongs to the Verbenaceae family and is mainly distributed in the Guangxi province in China [1]
We evaluated the effect of Deep eutectic solvents (DESs) as green solvents in the extraction of flavone di-C-glycosides from Premna fulva Craib using ultrasonic-assisted extraction
Good linearity was obtained for each analyte over the concentration range tested (r2 > 0.99) (Table 2). e limit of quantification (LOQ) and limit of detection (LOD) were determined by gradually diluting the individual standard solution with methanol and were calculated for signal-to-noise ratios (S/N) of 10 and 3, respectively. e LOD and LOQ values in the present study were less than 0.06 μg and 0.18 μg, respectively (Table 2), which indicated that the developed method had excellent sensitivity and allowed the direct determination of flavone di-C-glycosides in Premna fulva Craib without any previous enrichment step

Summary

Introduction

Premna fulva Craib, which is known as the Zhuang medicine “zhangu,” belongs to the Verbenaceae family and is mainly distributed in the Guangxi province in China [1]. Jian-Gu injection, a traditional Chinese medicine, is made from the roots and stems of Premna fulva Craib [2]. Clinical studies have shown that Jian-Gu injection has been widely used to treat cervical spondylosis, lumbar sprain, and osteoarthritis [3,4,5,6,7]. The overwhelming majority of flavonoids in Premna fulva Craib are flavone C-glycosides [9]. Jian-Gu injection is obtained from Premna fulva Craib using ultrasonic-assisted extraction, which has replaced conventional techniques such as maceration (40% ethanol) [10, 11], which have drawbacks such as inefficiency and the high vapor pressure of the solvent.

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Conclusion