Cao Xiaoji, Lin Xupin, Wu Congcong, Zhang Minghua, Wang Mingwei
Research Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou 310014, China.
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
Foods. 2022 Apr 6;11(7):1056. doi: 10.3390/foods11071056.
Lotus seed epicarp, a byproduct of lotus, is commonly discarded directly or burned in the cropland, resulting in waste of resources and environmental pollution. In this work, a green ultrasonic-assisted extraction method with ethyl lactate as the extraction solvent was established to extract alkaloids from lotus seed epicarp. The extraction conditions were optimized by response surface methodology. Under the optimal extraction conditions, the extraction of alkaloids from 1 g lotus seed epicarp was accomplished with only 10 mL of extraction solvent within 15 min. Combined with ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry with information-dependent acquisition mode, a total of 42 alkaloids were annotated in the lotus seed epicarp extracts. Among them, 39 alkaloids were reported in lotus seed epicarp for the first time. According to quantitative analysis, the distributions and trends of alkaloids in the lotus seed epicarp were found to be similar to those of lotus leaves. The five growth stages of lotus seed epicarp could be successfully distinguished based on the ten representative alkaloids. This study demonstrates that ultrasonic-assisted extraction with ethyl lactate as extractant solvent was efficient in the extraction of alkaloids from lotus seed epicarp, which is a potential renewable resource of bioactive ingredients.
莲子外果皮是莲子的一种副产品，通常被直接丢弃或在农田中焚烧，导致资源浪费和环境污染。在这项工作中，建立了一种以乳酸乙酯为萃取溶剂的绿色超声辅助萃取方法，用于从莲子外果皮中提取生物碱。采用响应面法对萃取条件进行了优化。在最佳萃取条件下，仅用10 mL萃取溶剂在15分钟内即可完成从1 g莲子外果皮中提取生物碱。结合超高效液相色谱-四极杆飞行时间串联质谱联用仪和信息依赖采集模式，在莲子外果皮提取物中总共鉴定出42种生物碱。其中，有39种生物碱首次在莲子外果皮中被报道。通过定量分析发现，莲子外果皮中生物碱的分布和趋势与荷叶中的相似。基于十种代表性生物碱能够成功区分莲子外果皮的五个生长阶段。本研究表明，以乳酸乙酯为萃取溶剂的超声辅助萃取法能高效地从莲子外果皮中提取生物碱，莲子外果皮是一种潜在的生物活性成分可再生资源。
