New Use Agriculture and Natural Plant Products Program, Department of Plant Biology and Center for Agricultural Food Ecosystems, The New Jersey Institute of Food, Nutrition & Health, Rutgers University, 59 Dudley Road, New Brunswick, NJ, 08901, USA.
Department of Medicinal Chemistry, Rutgers University, 160 Frelinghuysen Road, Piscataway, NJ, 08854, USA.
Rapid Commun Mass Spectrom. 2020 Oct 15;34(19):e8882. doi: 10.1002/rcm.8882.
The safe consumption of Solanum scabrum and S. nigrum berries (SNBs) depends on a reliable and rapid chemical screen for the testing of the fruit and/or final food and industrial products for the presence and level of toxic glycoalkaloids. Such a rapid and sensitive screen could also be used by those involved in food safety and forensics, industry, research labs and those in agriculture production, breeding and food processing. Significant variation in the content and composition of glycoalkaloids across SNBs has been reported. To facilitate high-throughput targeted analysis, this work overcame the slow scan speed of a traditional triple quadruple mass spectrometry (QqQ) method by development of a pseudo-MS method.
In-source fragmentation functioned as a pseudo-MS or pseudo-hydrolysis to trim down the structurally diverse and complex glycosides into five types of aglycone ions, which were then analyzed using multiple reaction monitoring (MRM). Characteristic product ions were selected based on the aglycone skeleton and substitution pattern and associated fragmentation pathway.
A compact method with only 15 MRM transitions were developed for high-throughput screening of very diverse glycoalkaloids. Glycosides of the same aglycone type were readily identified in the same transition window without the need for mass spectra interpretation. Validated using solamargine, the sole available standard, the accuracy was 99.7-101.3%, the intra- and inter-day precision were, respectively, 2.5-5.0% and 8.0-9.2%, and the lower limit of detection and quantification were, respectively, 3.1 and 10.2 ng/mL (with 1 μL injection volume).
The peudo-MS method allowed for high-throughput targeted analysis with compact MRM transitions to address a large number of glycoalkaloids with diverse structures. This method could serve to meet the most heavy-duty demand for rapid inspection of glycoalkaloids in SNBs. This method can be adopted and used by those involved in food safety and forensics, in developing food and industrial products and in genetics and breeding.
安全食用龙葵和黑茄浆果（SNB）取决于对水果和/或最终食品和工业产品进行可靠且快速的化学筛查，以检测有毒糖苷生物碱的存在和水平。食品安全和法医学、工业、研究实验室以及农业生产、育种和食品加工领域的人员也可以使用这种快速灵敏的筛查方法。据报道，SNB 中的糖苷生物碱含量和组成存在显著差异。为了便于高通量靶向分析，本工作通过开发伪-MS 方法克服了传统三重四极杆质谱（QqQ）方法的扫描速度慢的问题。
源内碎裂作为伪-MS 或伪水解，将结构多样且复杂的糖苷切割成五种糖苷配基离子，然后使用多重反应监测（MRM）进行分析。根据糖苷配基骨架和取代模式以及相关的碎裂途径选择特征产物离子。
开发了一种紧凑的方法，仅使用 15 个 MRM 转换，可用于高通量筛选非常多样化的糖苷生物碱。具有相同糖苷配基类型的糖苷很容易在相同的转换窗口中被识别，而无需进行质谱解释。使用唯一可用的标准索马金验证，准确性为 99.7-101.3%，日内和日间精密度分别为 2.5-5.0%和 8.0-9.2%，检测限和定量限分别为 3.1 和 10.2ng/mL（进样量为 1μL）。
伪-MS 方法允许使用紧凑的 MRM 转换进行高通量靶向分析，以解决具有多种结构的大量糖苷生物碱。这种方法可以满足对 SNB 中糖苷生物碱快速检查的最苛刻需求。食品安全和法医学、食品和工业产品开发、遗传学和育种领域的人员都可以采用和使用这种方法。
