Rapid screening of glycoalkaloids in Solanum scabrum and S. nigrum berries using ultra‐high‐performance liquid chromatography with pathway‐specified in‐source fragmentation tandem mass spectrometry

Abstract

Rationale 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‐MS3 method. Methods 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. Results 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). Conclusions The peudo‐MS3 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.

African nightshades (Solanum nigrum complex): The potential contribution to human nutrition and livelihoods in sub‐Saharan Africa

“…The toxic level of matured berries is too low to harm but can harm children (Defelice, 2003; Edmonds & Chweya, 1997). Solanum nigrum accession (USDA PI 381239) contains trace levels of glycoalkaloids (Lyu et al., 2020). However, the glycoalkaloids (solasodine, solanine, and solamargine) are high in berries compared to shoots and leaves of S. nigrum , with solasonine being high in the shoots of S. nigrum (Al‐Ashaal, 2019).…”

“…ANS berries are commonly considered toxic and not consumed in SSA (Lyu et al., 2020). The young berries of S. nigrum contain the highest level of SGA compared with the whole plant or leafy and stem parts (Abbas et al., 1998; Defelice, 2003; Edmonds & Chweya, 1997; Mohy‐Ud‐Din et al., 2010; Ronoh et al., 2017; Yang & Ojiewo, 2013).…”

Chemical, Manufacturing, and Standardization Controls of Grape Polyphenol Dietary Supplements in Support of a Clinical Study: Mass Uniformity, Polyphenol Dosage, and Profiles

“…Even though HPLC-UV/Vis is generally used for the identification and quantification of phenolic compounds from grapes and their products, some compounds are difficult to be effectively separated and accurately identified using the methodology due to their insufficient peak capacity and the accumulation of analytes ( 38 ). UHPLC coupled with triple quadrupole MS (UHPLC-QQQ-MS/MS) based on HPLC using a small particle diameter column and mass spectrometer allows rapid screening of a large number of phytochemicals using the information on the characteristics of molecular ions ( 38 , 39 ). Multiple-reaction monitoring (MRM) mode of QQQ-MS/MS is a highly specific and sensitive MS technique that can selectively quantify the compounds within complex mixtures.…”

“…Multiple-reaction monitoring (MRM) mode of QQQ-MS/MS is a highly specific and sensitive MS technique that can selectively quantify the compounds within complex mixtures. It selects specific analytes and absolute quantitation of proteins, peptides, metabolites, and lipids in the fields of biochemistry, drug metabolism, and plant studies ( 39 , 40 , 44 ). In contrast to the UV chromatograms of GSE capsules, the CGJs are more complicated.…”

Overview of Recent Liquid Chromatography Mass Spectrometry-Based Methods for Natural Toxins Detection in Food Products

“…Another method was proposed by Lyu et al [ 145 ] for the rapid screening of six glycoalkaloids in Solanum scabrum and S. nigrum berries from Kenya and US using UHPLC-MS/MS. Specifically, for the first time, the use of in-source fragmentation prior to the MS/MS analysis was applied as pseudo-MS to transform the GAs glycosides into the relevant aglycones.…”