LC-ESI/LTQOrbitrap/MS Metabolomic Analysis of Fennel Waste (Foeniculum vulgare Mill.) as a Byproduct Rich in Bioactive Compounds

Phytochemical exploration of Neolitsea pallens leaves using UPLC-Q-TOF-MS/MS approach

Neolitsea pallens (D. Don) Momiyama & H. Hara (Family: Lauraceae), commonly known as Pale Litsea, is an evergreen small tree, distributed in India at altitudes of 1500-3000 m. Traditionally utilized for various purposes, its leaves and bark are used as spices, and the plant is valued in preparing a hair tonic from freshly pressed juice. Secondary metabolites of the leaves have not comprehensively been analysed so far. The objective of the study was to determine the chemical composition of the leaves by analysing their 25% aqueous methanol extract with the aid of ultra-performance liquid chromatography quadrupole time of flight tandem mass spectrometry. Overall, 56 compounds were identified in the study. Phenolics represented by phenolic acids, phenolic glycosides, proanthocyanidins, and flavonoids were the main components of the extract.

Metabolite Profiling, through LC-ESI/LTQOrbitrap/MS Analysis, of Antioxidant Extracts from Physalis alkekengi L

Due to the increasing use of Physalis alkekengi L. as a food supplement and starting material for tea preparation, a comprehensive analysis of green extracts was performed. Two different extraction methods were applied to yellow Physalis alkekengi L. fruit and calyx and compared: hydroalcoholic extraction and decoction. Characterization of the metabolome of the calyx and fruit of yellow Physalis alkekengi L. was performed by LC-ESI/LTQOrbitrap/MS followed by LC-ESI/LTQOrbitrap/MS/MS to identify 58 phytocompounds using the two different extraction techniques. Subsequently, through preliminary spectrophotometric assays followed by cell studies, the antioxidant activity of the different Physalis alkekengi L. extracts were evaluated. It was found that Physalis alkekengi L. extracts are a good source of metabolites such as flavonoids, organic acids, phenylpropanoids, physalins and carotenoids, with various biological activities, in particular, antioxidant activity capable of reducing the production of free radicals in intestinal Caco-2 cells. For the first time, an integrated approach (metabolomics approach and antioxidant evaluation) was applied to the study of Physalis alkekengi green extracts and decoctions, the green extraction method mostly used in herbal preparations. An interesting finding was the high antioxidant activity shown by these extracts.

Metabolite Profiling for Typization of "Rucola della Piana del Sele" (PGI), Eruca sativa, through UHPLC-Q-Exactive-Orbitrap-MS/MS Analysis

In August 2020, the Eruca sativa cultivar "Rucola della Piana del Sele" obtained from the European Union the prestigious PGI (protected geographical indication) label, which certifies the uniqueness of its characteristics and increases its prestige both nationally and, above all, internationally. This plant is recognized as a product of excellence, with a unique flavor and unmistakable aroma. Therefore, since there are no methods to characterize the PGI product, a metabolomic approach was applied to characterize E. sativa grown in the Piana del Sele and different geographical areas. As E. sativa has very wide cultivation, this study sought to compare the metabolite profiles of rocket grown in Piana del Sele, Bergamo, and Brescia, as well as in Switzerland, making a comparison also with the metabolite profile of E. sativa grown spontaneously. To determine the best procedure to distinguish "Rucola della Piana del Sele" from the others, different extraction procedures were carried out using different solvents and fresh or freeze-dried plant matrices. The different extracts were analyzed by liquid chromatography coupled with high-resolution mass spectrometry experiments, using chemometric analyses to identify biomarker metabolites that characterize the PGI product. The LC-ESI-Q-Exactive-MS/MS profiles of methanol and hydroalcoholic extracts of different cultivars of E. sativa were found to be rich in bioactive compounds such as glucosinolates, glycosylated flavonoids, fatty acids, and lipids. The LCMS data were analyzed by principal component analysis (PCA); the score scatter plot shows significant separation among Eruca samples grown in different geographical areas. In detail, loading the scatter plot revealed Eruca grown in Piana del Sele to be richer than other cultivars in glycosylated quercetin 3,3',4'-O-triglucoside (7), quercetin-3,4'-O-diglucoside-3'-O-(6-sinapoyl-glucoside) (10), and quercetin diglucoside (30). Finally, considering the biological interest in erucin, the myrosinase product of glucoerucin, the latter was quantified in the extracts by LC-ESI/QTrap/MS/MS using the multiple reaction monitoring (MRM) method; E. sativa from Piana del Sele showed the highest content of glucoerucin.

Exploring fennel (Foeniculum vulgare): Composition, functional properties, potential health benefits, and safety

Fennel (Foeniculum vulgare Mill), a member of the Apiaceae family (Umbelliferaceae), is a hardy and perennial herb, with grooved stems, intermittent leaves, petiole with sheath, usually bisexual flower and yellow umbrella. Although fennel is a typical aromatic plant generally considered native to the Mediterranean shores, it has become widespread in many regions of the world and has long been used as a medicinal and culinary herb. The aim of this review is to collect recent information from the literature on the chemical composition, functional properties and toxicology of fennel. Collected data show the efficacy of this plant in various in vitro and in vivo pharmacological studies including antibacterial, antifungal, antiviral, antioxidant, anti-inflammatory, antimutagenic, antinociceptive, hepatoprotective, bronchodilatory, and memory enhancing activities. It has also been shown to be effective on infantile colic, dysmenorrhea, polycystic ovarian syndrome and milk production. This review also aims to identify gaps in the literature that require to be filled by future research.

A Comparative UHPLC-Q-Trap-MS/MS-Based Metabolomics Analysis to Distinguish Foeniculum vulgare Cultivars' Antioxidant Extracts

Among the environmental factors, seasonality is the one which most affects the metabolome of a plant. Depending on the harvest season, the plant may have a variable content of certain metabolites and thus may have different biological properties. Foeniculum vulgare is an annual plant whose cultivation creates large amounts of waste rich in bioactive compounds. The present investigation was performed with the aim of determining the amount of biologically active compounds in F. vulgare wastes obtained from varieties of different seasonality. Ten polyphenolic compounds were quantified in the little stems and leaves of Tiziano, Pegaso, and Preludio cultivars by ultra performance liquid chromatography (UPLC) hyphenated to QTRAP mass spectrometry by using the MRM (multiple reaction monitoring) method. The antioxidant activity of hydroalcoholic extracts was then evaluated using TEAC and DPPH spectrophotometric assays, followed by a multivariate statistical analysis to determine the correlation between metabolite expression and antioxidant activity. The Preludio variety, grown in summer, showed a higher content of bioactive compounds, which guarantees it a better antioxidant power; kaempferol 3-O-glucuronide, quercetin 3-O-glucuronide, and quercetin 3-O-glucoside are the polyphenolic compounds that could be mainly responsible for the antioxidant effect of fennel. The PLS chemometric model, which correlated quantitative data obtained by a sensitive and selective LC-ESI-QTrap-MS/MS analysis of antioxidant activity, resulted in a selective tool to detect the compounds responsible for the activity shown by the extracts in chemical tests.

Sustainable Extraction Methods Affect Metabolomics and Oxidative Stability of Myrtle Seed Oils Obtained from Myrtle Liqueur By-Products: An Electron Paramagnetic Resonance and Mass Spectrometry Approach

Myrtle liqueur production generates high amounts of by-products that can be employed for the extraction of bioactive compounds. Bio-based, non-toxic and biodegradable solvents (ethyl acetate and 2-methyltetrahydrofuran), and a mechanical extraction were applied to myrtle seeds, by-products of the liqueur production, to extract oils rich in phenolic compounds. The oils obtained were characterized for yield, peroxide value (PV), lipid composition, and total phenolic concentration (TPC). The phenolic profile of the oils, determined by LC-MS, the antioxidant activity, and the oxidative stability were also analyzed. A validated UHPLC-ESI-QTRAP-MS/MS analytical method in multiple reaction monitoring (MRM) mode was applied to quantify myricetin and its main derivatives in myrtle oils. The results pointed out clear differences among extraction methods on myricetin concentration. The oxidative stability of myrtle oils was studied with electron paramagnetic resonance (EPR) spectroscopy highlighting the effect of the extraction method on the oxidation status of the oils and the role of phenolic compounds in the evolution of radical species over time. A principal component analysis applied to LC-MS data highlighted strong differences among phenolic profiles of the oils and highlighted the role of myricetin in the oxidative stability of myrtle oils. Myrtle oil, obtained from the by-products of myrtle liqueur processing industry, extracted with sustainable and green methods might have potential application in food or cosmetic industries.

Metabolomics Approach to Characterize Green Olive Leaf Extracts Classified Based on Variety and Season

The huge interest in the health-related properties of plant polyphenols to be applied in food and health-related sectors has brought about the development of sensitive analytical methods for metabolomic characterization. Olive leaves constitute a valuable waste rich in polyphenols with functional properties. A (HR)LC-ESI-ORBITRAP-MS analysis with a multivariate statistical analysis approach using PCA and/or PLS-DA projection methods were applied to identify polyphenols in olive leaf extracts of five varieties from the Apulia region (Italy) in two different seasonal times. A total of 26 metabolites were identified, further finding that although metabolites are common among the different cultivars, they differ in the relative intensity of each peak and within each cultivar in the two seasonal periods taken into consideration. The results of the total phenol contents showed the highest content in November for Bambina and Cima di Mola varieties (1816 and 1788 mg/100 g, respectively), followed by Coratina, Leccino, and Cima di Melfi; a similar trend was found for the antioxidant activity and RapidOxy evaluations by reaching in Bambina values of 45 mmol TE/100 g and 85 min of induction time.

UPLC-ESI-QTRAP-MS/MS Analysis to Quantify Bioactive Compounds in Fennel (Foeniculum vulgare Mill.) Waste with Potential Anti-Inflammatory Activity

Foeniculum vulgare is a perennial aromatic plant whose cultivation produces large amounts of waste rich in bioactive compounds with promising anti-inflammatory activities. Nine selected metabolites were quantified through Ultra Performance Liquid Chromatography (UPLC) hyphenated to QTRAP mass spectrometry by using MRM (multiple reaction monitoring) was performed on four parts of fennel: bulb, stem, little stem, and leaf. Analysis revealed significant differences in the amount of quantified metabolites, suggesting that little stem and leaf are the most valuable parts of the waste. Phenolic acids and glycosylated flavonoids were quantified for their known possible anti-inflammatory activities; in fact, due to this reason their ability to inhibit COX-1 and COX-2 isoforms was evaluated through a fluorometric assay, resulting in specific inhibitors of COX-2 at certain concentrations. In conclusion, as the leaf of fennel may be beneficial to human health, clinical studies should include it in nutraceuticals or functional foods for human consumption.

Integrated Transcriptomic and Metabolomic Analyses Reveal the Mechanisms Underlying Anthocyanin Coloration and Aroma Formation in Purple Fennel

The color and aroma are the significant traits of vegetables and fruits, but the metabolic and molecular mechanisms underlying anthocyanin accumulation and aroma formation remain almost unknown in fennel (Anethum foeniculum L.), which is a crucial vegetable crop and grown widely for aromatic leaves and bulbs. Here, ten major anthocyanins identified and quantified by ultra-high performance liquid chromatography coupled with quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) were mainly responsible for the coloration of purple fennel leaf. With the application of GC-MS, it was found that the reduced volatile phenylpropanoids including isoeugenol, trans-isoeugenol, and apiol chiefly account for the characteristic aroma changes of the purple fennel. Moreover, the characteristic anthocyanin coloration and aroma formation in purple fennel were systematically studied with the integrated transcriptomics and metabolomics. The critical genes associated with the biosynthesis and regulation of anthocyanins and volatile phenylpropanoids were isolated and studied carefully in transiently transfected tobacco cells and transgenic tomato plants. Together with the results of UHPLC-Q-Orbitrap HRMS, RT-qPCR, and yeast two hybrid (Y2H), it is proved that the metabolic flux redirection of phenylpropanoid pathway primarily regulated by a functional MYB-bHLH-WD40 complex consisting of AfTT8, AfMYB7, and AfTTG1 accounts for the characteristic anthocyanin coloration and aroma formation in purple fennel leaf. The systematic understanding of the anthocyanin accumulation and aroma formation will assist in the improvement of fennel resource utilization and breeding.

In vitro bioactivity evaluation of mulberry leaf extracts as nutraceuticals for the management of diabetes mellitus

There is an increasing need for new options to treat diabetes mellitus at its early stage and natural remedies have been recently reassessed as potential candidates owing to their low-cost and effectiveness. Genus Morus plants contain many active compounds with hypoglycaemic, hypolipidemic, and antioxidant effects. Current research on mulberry chemical composition and bioactivity has been generally carried out only on Asian cultivation, where this plant has been traditionally used in the form of leaf infusion for decades. In this work, twelve Italian mulberry cultivars were fully characterised to fill this gap of knowledge, since a strong correlation among composition, genetics and growing area was proven. Antiglycative and hypoglycaemic effects of leaf extracts were evaluated using different in vitro models. The results indicate that the inhibitory effect on carbohydrate digestive enzymes was likely mediated by 1-deoxynojirimycin, kaempferol, quercetin, and chlorogenic acid, acting in a synergistic way. Besides, the combined antiglycative and carbonyl trapping capacities, tested here for the first time, may help in preventing long-term complications related to AGEs in diabetic patients.