Hunan Province Key Laboratory for Antibody-based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua, 418000, China.
Hunan Provincial Key Laboratory for Synthetic Biology of Traditional Chinese Medicine, Hunan University of Medicine, Huaihua, 418000, China.
Rapid Commun Mass Spectrom. 2020 Oct 15;34(19):e8880. doi: 10.1002/rcm.8880.
Eomecon chionantha Hance (ECH), a traditional folk herb, is commonly used to treat traumatic injuries based on its analgesic and anti-inflammatory properties. Previous studies have reported that alkaloids are the major bioactive components in ECH. Therefore, identification of alkaloids from ECH contributes to the discovery of its potential active ingredients and quality control in clinic treatments.
A four-step screening strategy was performed as follows. (1) Extracting the accurate masses of ions related to different molecules. (2) Screening different types of compounds using their molecular cations, protonated molecules, diagnostic product ions and fragmentation pathways. (3) Comparing the characteristic product ion formulae to obtain the type and number of substituents. (4) Using the biosynthetic pathways of isoquinoline alkaloids to determine the concentration of alkaloids.
Ultrahigh-performance liquid chromatography-tandem quadrupole Exactive Orbitrap mass spectrometry (UHPLC/Q-Exactive Orbitrap MS) analysis combined with the four-step screening strategy was used to profile the alkaloids in ECH. The structures of 95 alkaloids in ECH were unambiguously identified or reasonably assigned, of which 76 were reported in ECH for the first time. Six types of benzylisoquinoline alkaloids were identified in ECH: six benzyltetrahydroisoquinolines, nine protopines, five N-methyltetrahydroprotoberberines, six protoberberines, eight benzophenanthridines and sixty-one dihydrobenzophenanthridines.
This comprehensive study identified the alkaloids in ECH, thus providing a practical reference for further research. The UHPLC/Q-Exactive Orbitrap MS method, combined with the four-step screening strategy, which was developed and successfully applied to identify the alkaloids in ECH, may also be applicable for the efficient screening of other herbal medicines.
峨眉堇菜（ECH）是一种传统的民间草药，具有镇痛和抗炎作用，常用于治疗创伤。先前的研究表明，生物碱是 ECH 的主要生物活性成分。因此，从 ECH 中鉴定生物碱有助于发现其潜在的活性成分，并控制其在临床治疗中的质量。
采用四步筛选策略，具体如下。（1）提取与不同分子相关的离子的精确质量。（2）使用其分子阳离子、质子化分子、诊断产物离子和碎裂途径筛选不同类型的化合物。（3）比较特征产物离子公式，以获得取代基的类型和数量。（4）利用异喹啉生物碱的生物合成途径确定生物碱的浓度。
采用超高效液相色谱-串联四极杆 Exactive Orbitrap 质谱联用（UHPLC/Q-Exactive Orbitrap MS）分析，并结合四步筛选策略，对 ECH 中的生物碱进行了分析。ECH 中的 95 种生物碱结构被明确鉴定或合理归属，其中 76 种生物碱在 ECH 中首次报道。在 ECH 中鉴定出 6 种苯并异喹啉生物碱：6 种苯甲基四氢异喹啉、9 种原小檗碱、5 种 N-甲基四氢原小檗碱、6 种原阿片碱、8 种苯并菲啶和 61 种二氢苯并菲啶。
本研究全面鉴定了 ECH 中的生物碱，为进一步研究提供了实用参考。开发并成功应用于鉴定 ECH 中生物碱的 UHPLC/Q-Exactive Orbitrap MS 方法，结合四步筛选策略，也可能适用于其他草药的高效筛选。
