Exploring geographic variations in quinoa grains: Unveiling anti-Alzheimer activity via GC-MS, LC-QTOF-MS/MS, molecular networking, and chemometric analysis.

Quinoa is an ancient Andean crop with a significant interest due to its nutritional and health benefits. This work provides a comprehensive metabolite profiling of five commercially available quinoa grains from diverse geographical origins. GC-MS analysis of primary metabolites identified sugars, sugar derivatives, and lipids as the predominant classes. LC-QTOF-MS/MS metabolomics and molecular networking facilitated the identification of 151 secondary metabolites, including 20 flavonoids, 14 saponins, and 20 lipids, which were reported for the first time in quinoa. In the AChE inhibition assay, USA white quinoa exhibited the highest activity. Chemometric analyses indicated that flavonoids and saponins were crucial for distinguishing quinoa grains. Notably, flavonoid glycosides and saponins were positively correlated with AChE inhibition. This study represents the first MS-based metabolomics investigation using molecular networking and chemometrics to explore the metabolome heterogeneity of commercial quinoa grains, underscoring their potential as a promising natural source for combating Alzheimer's disease.