Enhancement of Solasodine Extracted from Fruits of <i>Solanum nigrum</i> L. by Microwave-Assisted Aqueous Two-Phase Extraction and Analysis by High-Performance Liquid Chromatography

• Main Authors: Li Lin, Wen Yang, Xing Wei, Yi Wang, Li Zhang, Yunsong Zhang, Zhiming Zhang, Ying Zhao, Maojun Zhao
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Molecules
• Subjects: microwave-assisted aqueous two-phase extraction; Solasodine; alkaloid; response surface methodology; high-performance liquid chromatography
• Online Access: https://www.mdpi.com/1420-3049/24/12/2294

<b>Background:</b> Solasodine is a major bioactive ingredient in <i>Solanum nigrum</i> L. that has strong pharmacological characteristics. Therefore, the development of a simple and effective extraction method for obtaining solasodine is highly important. This study aims to provide a rapid and effective method for extracting solasodine from <i>Solanum nigrum</i> L. by microwave-assisted aqueous two-phase extraction (MAATPE). <b>Methods:</b> First, the high-performance liquid chromatography (HPLC) conditions were established for the detection of solasodine. Then, the aqueous two-phase system (ATPS) compositions were examined. On the basis of the results of single-factor experiments, for a better yield, response surface methodology (RSM) was used to optimize influential factors including the extraction temperature, extraction time and liquid-to-solid ratio. <b>Results:</b> The maximum extraction yield of 7.11 &#177; 0.08 mg/g was obtained at 44 &#176;C, an extraction time of 15 min, and a liquid-to-solid ratio of 42:1 mL/g in the ATPS consisting of EtOH solvent, (NH₄)₂SO₄, and water (28:16:56, <i>w</i>/<i>w</i>/<i>w</i>). The extraction yield of the alkaloid obtained using this method was markedly higher than those of microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE). <b>Conclusions:</b> In this work, solasodine was extracted by MAATPE for the first time and a high yield was obtained. MAATPE is a simple, rapid, and green technique for extraction from medical plants. Thus, the present study will enable the development of a feasible extraction method of active alkaloids from <i>Solanum nigrum</i> L.