Leaf metabolomics and molecular networking of wild type and mutant genotypes of chia (Salvia hispanica L.)

Salvia hispanica L., commonly named Chia, is a food plant from Central America and Australia, producing seeds whose consumption has been increasing in the last decade. Several articles analysed the seeds metabolite content. However, few is known about Chia leaves. This work is the first report on the whole metabolite profile of chia leaves, determined by spectroscopic methods including NMR, GC-MS and LC-MS coupled with chemometrics analysis. Additionally, molecular networking has been applied to the LC-MS data to determine the flavonoid composition. Different chia sources were compared: one commercial (black) and three early flowering (G3, G8 and G17) mutant genotypes cultivated at two irrigation regimes (50 and 100%). Organic extracts were mainly composed by saturated and mono- and polyunsaturated fatty acids with palmitic being the most abundant followed by oleic and linolenic acids. Aqueous extracts contained glucose, galactose, and fructose as main sugars. Flavonoids were based on vitexin and orientin and their analogues. Chemical composition of early flowering genotypes was quite similar to commercial black chia with the exception of G8 showing significant differences in the polar phase. A generally highest content of omega-9 fatty acids has been found in the early flowering genotypes along with high content of nutraceuticals suggesting them as a potential source of raw materials for the food/feed industry.