Plants for Human Health Institute, North Carolina State University, North Carolina Research Campus, Kannapolis, NC 28081, USA.
J Chromatogr B Analyt Technol Biomed Life Sci. 2012 Feb 15;885-886:83-9. doi: 10.1016/j.jchromb.2011.12.018. Epub 2011 Dec 26.
Alkaloids from the stem bark of Geissospermum vellosii possess a variety of therapeutic properties including antimalarial activities, activity as a sexual stimulant and inhibition of the proliferation of HIV and herpes viruses. Methods currently used to isolate the active components from G. vellosii are time-consuming, labor intensive, and result in low recovery. In addition, there is a lack of sensitive and accurate analytical methods for the structural characterization and identification of alkaloid components in minor quantities. A combination of high performance counter-current chromatography and ESI tandem mass spectrometry (MS(n)) was established to isolate alkaloids from the stem bark of G. vellosii, and study their electrospray ionization mass spectrometry fragmentation behavior. Five indole alkaloids were successfully isolated and identified by nuclear magnetic resonance and mass spectrometry. The multi-stage tandem mass spectrometric data were used to study their fragmentation pattern and set a model for detailed structure characterization of related indole alkaloids. The presence of the even mass fragment ion suggestive of an odd number of nitrogen at m/z 144 corresponding to C(10)H(9)N was characteristic to indole alkaloids. The results of the experiments demonstrated that the combination of high performance counter current chromatography and ESI-MS(n) is a sensitive, selective and effective approach for rapid isolation and characterization of alkaloids from G. vellosii.
从 G. vellosii 茎皮中分离出的生物碱具有多种治疗特性，包括抗疟活性、作为性刺激物的活性以及抑制 HIV 和疱疹病毒的增殖。目前用于从 G. vellosii 中分离活性成分的方法既耗时又费力，且回收率低。此外，对于数量较少的生物碱成分的结构特征和鉴定，缺乏灵敏且准确的分析方法。建立了高效逆流色谱与电喷雾串联质谱（MS(n)）联用的方法，从 G. vellosii 的茎皮中分离生物碱，并研究其电喷雾电离质谱的裂解行为。通过核磁共振和质谱成功分离并鉴定了 5 种吲哚生物碱。多级串联质谱数据可用于研究其裂解模式，并建立相关吲哚生物碱的详细结构特征模型。质荷比 m/z 144 处出现偶数质量碎片离子，提示存在奇数氮原子，这是吲哚生物碱的特征。实验结果表明，高效逆流色谱与 ESI-MS(n)联用是一种灵敏、选择性和有效的方法，可用于从 G. vellosii 中快速分离和鉴定生物碱。
