Quality-controlled LC-ESI-MS food metabolomics of fenugreek (Trigonella foenum-graecum) sprouts: Insights into changes in primary and specialized metabolites

Metabolic profiling and antioxidant activity of fenugreek seeds cultivars 'Giza 2' and 'Giza 30' compared to other geographically-related seeds

This study addresses a comparative comprehensive metabolic profiling of two Egyptian cultivars of fenugreek (Trigonella foenum-graecum L.) seeds 'Giza 2' and 'Giza 30' via RP-HPLC-DAD-QTOF-MS and MS/MS. Briefly, 126 metabolites were detected in the samples under investigation, being classified into hydroxybenzoic acids (8), hydroxycinnamic acids (7), flavonoids (49 with a predominancy of flavones in particular apigenin derivatives), coumarins (1), furostanol saponins (17), alkaloids (2), amino acids (11), peptides (2), jasmonates (6), nucleosides (30), organic acids (16), terpenoids (1), and sugars (3). In addition, the total phenolic content and antioxidant activity were determined and compared with other geographically related seeds (chickpea Giza-1, sesame Giza-32, and linseed, Giza-10), showing slight differences among them but higher values than the other geographically related seeds that were segregated from them upon chemometric analysis. This is the first comprehensive metabolic profiling of these cultivars, presenting an initial account of some metabolites found in Fabaceae, such as apigenin di C pentoside, with a significant occurrence of biologically active furostanol saponins. It gives a prospect of fenugreeks richness of bioactive metabolites as an essential functional food that could add value to the food and nutraceutical industries' sustainability.

Production of Polyphenolic Natural Products by Bract-Derived Tissue Cultures of Three Medicinal Tilia spp.: A Comparative Untargeted Metabolomics Study

Medicinal plant tissue cultures are potential sources of bioactive compounds. In this study, we report the chemical characterization of the callus cultures of three medicinal Tilia spp. (Tilia cordata, Tilia vulgaris and Tilia tomentosa), along with the comparison to bracts and flowers of the same species. Our aim was to show that calli of Tilia spp. are good alternatives to the calli of T. americana for the production of polyphenols and are better sources of a subset of polyphenolic metabolites, compared to the original organs. Calli were initiated from young bracts and grown on woody plant medium containing 1 mg L-1 2,4-D and 0.1 mg L-1 BAP. For chemical characterization, a quality-controlled untargeted metabolomics approach and the quantification of several bioactive compounds was performed with the use of LC-ESI-MS/MS. While bracts and flowers contained flavonoid glycosides (astragalin, isoquercitrin) as major polyphenols, calli of all species contained catechins, coumarins (fraxin, esculin and scopoletin) and flavane aglyca. T. tomentosa calli contained 5397 µg g DW-1 catechin, 201 µg g DW-1 esculin, 218 µg g DW-1 taxifolin and 273 µg g DW-1 eriodictyol, while calli from other species contained lower amounts. T. cordata and T. tomentosa flowers were rich in isoquercitrin, containing 8134 and 6385 µg g DW-1, respectively. The currently tested species contained many of the bioactive metabolites described from T. americana. The production of catechin was shown to be comparable to the most efficient tissue cultures reported. Flowers and bracts contained flavonoid glycosides, including tiliroside, resembling bioactive fractions of T. americana. In addition, untargeted metabolomics has shown fingerprint-like differences among species, highlighting possible chemotaxonomic and quality control applications, especially for bracts.

Deciphering the metabolic signatures of Trigonella microgreens as a function of photoperiod and temperature using targeted compound analysis and non-targeted UHPLC-QTOF-IMS based approach

Trigonella foenum-graecum L. (Fenugreek) is an annual herb that belongs to Fabaceae family. The compositional make-up of microgreens depends on prevailing environmental conditions. So, Trigonella microgreens were cultivated under different photoperiod and temperature conditions and evaluated for plant height, total chlorophyll content (TCC), targeted compound analysis and non-targeted UHPLC-QTOF-IMS based metabolomic profile. The plant height and TCC of Trigonella microgreens increased by approximately 22 % and 20 %, respectively under T1 conditions (longer photoperiod of 22 h with 22 °C in light and 17 °C in dark). The targeted phenolic profile analysis revealed the dominant presence of gallic acid, p-coumaric acid and apigenin in Trigonella microgreens. Also, the concentration of p-coumaric acid concentration raised from 3.51 mg/g to 5.83 mg/g as a response of T1 conditions. The sugar profile revealed augmented concentration of myo-inositol, glucose, fructose, xylose, maltose, and sucrose in longer photoperiod with T1 conditions. The microgreens were also rich in amino acids like aspartic acid, glutamic acid, leucine, isoleucine, and phenylalanine. Notably, the concentration of proline increased from 10.40 mg/g to 16.92 mg/g as a response to T1 growth conditions. The concentration of these metabolites varied significantly under different photoperiod and temperature conditions. The comprehensive non-targeted UHPLC-QTOF-IMS analysis of microgreens revealed different class of metabolites like organic compounds, alkaloids, coumarin-derivatives, phenolic and flavonoid derivatives, terpenoids, sugars, amino acids and few nucleic acid derivatives. The multivariate PLS-DA explained different expression level of metabolites under different growing conditions. The T1 growing condition resulted in the increased biosynthesis of phenolic compounds and various metabolites. The expression level of terpenoid derivatives specifically of Trigonelloside C and Trigoneoside XIIa/b increased under T1 conditions. The substantial alteration in the metabolites due to growing conditions may alter the microgreen's dietary benefits. So, additional research may be warranted.