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.

Scabiosa atropurpurea: A rich source of iridoids with α-glucosidase inhibitory activity evaluated by in vitro and in silico studies.

Scabiosa atropurpurea L. subsp. maritima (L.) Arc. (Caprifoliaceae) is a plant widely distributed in the Mediterranean region and represented by 32 taxa in the flora of Turkey. In the present study, an in-depth phytochemical investigation of S. atropurpurea methanol extract of the whole plant was carried out using a combination of LC-ESI-FT-MS and NMR analysis. This approach allowed the isolation and structural elucidation of 28 compounds: 17 iridoids, 7 flavonoids, and 4 phenolic acids. Among these compounds, three previously unreported iridoids named secologanin-methyl-hemiacetal, atropurpurin A, and atropurpurin B were identified. The methanol extract of S. atropurpurea was assayed for its antioxidant and antihyperglycemic activity, showing a potent α-glucosidase inhibitory activity (IC50 = 100 µg/mL), higher than that exerted by acarbose (IC50 = 196 µg/mL), used as the positive control. Thus, the most abundant iridoids were selected to be tested for their antihyperglycemic activity, and molecular docking experiments were carried out to assess the possibility for selected compounds to form complexes with α-glucosidase enzyme active site.

Effects of bio-fertilizers on the production of specialized metabolites in Salvia officinalis L. leaves: An analytical approach based on LC-ESI/LTQ-Orbitrap/MS and multivariate data analysis.

In recent years, the use of organic substances has been increased to improve the production of specialized metabolites in aromatic and medicinal plants. Salvia officinalis L., known as sage, is an important medicinal and aromatic plant, whose leaves are commonly used as a condiment in food but mainly as a raw material in pharmaceutical and perfumery industries. In this work to define the effects of bio-fertilizers and foliar applications of l-phenylalanine on specialized metabolites production and biochemical characteristics of S. officinalis leaves, an experimental field in 2 years (2016 and 2017) was developed in semiarid climate, South-western, Iran. Experimental treatments included foliar spraying of l-phenylalanine in diverse concentration (0-250 and 500 mg/mL) and different bio-fertilizers [Arbuscular mycorrhizal fungi (AMF), Pseudomonas fluorescens (Pf), both fungi and bacteria (AMF + Pf)]. A metabolomics approach was carried out on the ethanolic extracts of sage leaves obtained by different treatments using Liquid Chromatography coupled with High-Resolution Mass Spectrometry (LC-ESI/LTQ-Orbitrap/MS) followed by multivariate data analysis. A total of 41 specialized metabolites were detected, and 35 of them were identified based on their accurate mass and mass fragmentation, as belonging to organic acids, phenylpropanoids, flavonoids, diterpenes, salvianolic acids and oxylipins. This work highlighted that the foliar application of l-phenylalanine along with the inoculation of Arbuscular mycorrhizal fungi and P. fluorescens can improve the yields of specific metabolites of pharmaceutical interest.

Chemical profiling and biological screening with potential anti-inflammatory activity of Callisia fragrans grown in Egypt.

The ethanolic extract of Callisia fragrans aerial parts showed a significant strong in vivo anti-inflammatory and in vitro antioxidant activities with a high in vivo gastrointestinal safety profile and a very low in vitro cytotoxicity on peripheral blood mononuclear cells (PBMCs) with an IC50 > 1000 µg/ml. The alcoholic extract of C. fragrans has been analysed by HPLC coupled to multiple-stage Linear Ion-Trap and Orbitrap High-Resolution mass spectrometry in negative electrospray ionisation mode (LC-ESI/LTQOrbitrap/MS/MSn). By this approach, it was possible to putatively identify 13 compounds, mainly organic acids, flavonoids, one steroid and one hydroxy-coumarin. Luteolin 6-C-glucopyranosyl-7-O-glucopyranoside, luteolin-8-C-glucopyranosyl-7-O-rhamnopyranoside, luteolin-6-C-glucoside and isoorientin 7-O-[6''-feruloyl]-glucoside were detected for the first time in C. fragrans and family Commelinaceae.[Figure: see text].

LC-ESI-FT-MSn Metabolite Profiling of Symphytum officinale L. Roots Leads to Isolation of Comfreyn A, an Unusual Arylnaphthalene Lignan.

Preparations of comfrey (Symphytum officinale L.) roots are used topically to reduce inflammation. Comfrey anti-inflammatory and analgesic properties have been proven in clinical studies. However, the bioactive compounds associated with these therapeutic activities are yet to be identified. An LC-ESI-Orbitrap-MSn metabolite profile of a hydroalcoholic extract of comfrey root guided the identification of 20 compounds, including a new arylnaphthalene lignan bearing a rare δ-lactone ring, named comfreyn A. Its structure was determined using extensive 2D NMR and ESI-MS experiments. Additionally, the occurrence of malaxinic acid, caffeic acid ethyl ester, along with the lignans ternifoliuslignan D, 3-carboxy-6,7-dihydroxy-1-(3',4'-dihydroxyphenyl) -naphthalene, globoidnan A and B, and rabdosiin was reported in S. officinale for the first time. These results helped to redefine the metabolite profile of this medicinal plant. Finally, caffeic acid ethyl ester and comfreyn A were found to significantly inhibit E-selectin expression in IL-1ß stimulated human umbilical vein endothelial cells (HUVEC), with EC values of 64 and 50 µM, respectively.

Phytochemical investigation of Scabiosa sicula guided by a preliminary HPLC-ESIMSn profiling.

The genus Scabiosa (Caprifoliaceae) is represented by 80 species, widely used as medicinal plants for their positive effects on human diseases. On the basis of the interesting biological activity shown by Scabiosa spp., the phytochemical investigation of Scabiosa sicula L., never investigated before, was carried out. An initial LC-MS profile of the MeOH extract of S. sicula whole plant guided the isolation of 34 compounds, of which the structures were unambiguously elucidated by NMR analysis as phenolic compounds and triterpene saponins, among which eight undescribed compounds. Moreover, the total phenolic content of S. sicula methanol extract has been evaluated. On the basis of the pharmacological activities reported for Scabiosa species the antioxidant activity of the methanol extract was tested by TEAC and DPPH assays. Finally, the α-glucosidase inhibitory activity of the methanol extract was assayed, showing an IC50 value (49 µg/mL) comparable to that exerted by acarbose (90 µg/mL), used as positive control.

Detection and comparison of phenolic compounds in different extracts of black currant leaves by liquid chromatography coupled with high-resolution ESI-LTQ-Orbitrap MS and high-sensitivity ESI-Qtrap MS.

Liquid preparations such as tinctures and infusion derived from Ribes nigrum L. (black currant) leaves are widely used in Europe. Despite the various uses reported for the infusion and hydroalcoholic extracts of the leaves of this species, their chemical profile has not yet been defined. In the present study, the infusion, hydroalcholic and methanolic extracts prepared from R. nigrum leaves were analyzed. LC-MS analyses of these extracts allowed the characterization of 31 phenolic compounds mainly belonging to organic acids, flavonoids, catechins and its oligomers. Quantitative results proved that these preparations are a rich source of polyphenols and flavonoids and among them the infusion presented the highest polyphenol levels. A metabolomics approach was also used for the comparison and evaluation of the chemical composition of the different extracts obtained from R. nigrum leaves.

A Symphytum officinale Root Extract Exerts Anti-inflammatory Properties by Affecting Two Distinct Steps of NF-κB Signaling.

Symphytum officinale, commonly known as comfrey, constitutes a traditional medicinal plant with a long-standing therapeutic history, and preparations thereof have been widely used for the treatment of painful muscle and joint complaints, wound and bone healing, and inflammation. Today, its topical use is based on its analgesic and anti-inflammatory effects, which have been substantiated by modern clinical trials. However, the molecular basis of its action remained elusive. Here, we show that a hydroalcoholic extract of comfrey root impairs the development of a pro-inflammatory scenario in primary human endothelial cells in a dose-dependent manner. The extract, and especially its mucilage-depleted fraction, impair the interleukin-1 (IL-1) induced expression of pro-inflammatory markers including E-selectin, VCAM1, ICAM1, and COX-2. Both preparations inhibit the activation of NF-κB, a transcription factor of central importance for the expression of these and other pro-inflammatory genes. Furthermore, our biochemical studies provide evidence that comfrey inhibits NF-κB signaling at two stages: it dampens not only the activation of IKK1/2 and the subsequent IκBα degradation, but also interferes with NF-κB p65 nucleo-cytoplasmatic shuttling and transactivation. These results provide a first mechanistic insight into the mode of action of a century-old popular herbal medicine.

LC-ESI/LTQOrbitrap/MS/MS and GC-MS profiling of Stachys parviflora L. and evaluation of its biological activities.

The use of some Stachys genus as herbal remedies is known and the aerial parts have a pharmaceutical interest, being used in Anatolia and Iran as wild tea. In this study, chemical composition, antimicrobial, antioxidant, and antiproliferative activities of the methanolic extract and essential oil (EO) of Stachys parviflora L. (S. parviflora) were evaluated. Qualitative analysis of metabolites of S. parviflora methanolic extract was studied using liquid chromatography coupled to high resolution mass spectrometry (LC-ESI/LTQOrbitrap/MS), evidencing the presence of phenolic acids and flavonoids derivatives. The EO was analyzed using gas chromatography coupled to mass spectrometry (GC/MS). Eighty-seven compounds were characterized in the EO of S. parviflora, of which α-terpenyl acetate (23.6%), ß-caryophyllene (16.8%), bicyclogermacrene (9.3%), spathulenol (4.9%) and α-pinene (4.2%) were found to be the major components. The highest antimicrobial effect of EO was found to S. aureus and B. cereus (MIC = 0.01 µg/ml), while the highest activity of extract was against B. cereus (MIC = 125 µg/ml). The methanolic extract exhibited strong antioxidant activity in DPPH (IC50 = 76.87 µg/ml) and ß-carotene/linoleic acid assay (BCB, IC50 = 188.47 µg/ml) methods. Furthermore, in vitro cytotoxicity evaluation against three cell lines namely human ovarian carcinoma (A2780), human colon carcinoma (HCT), and mouse melanoma cell line (B16F10), showed an anti-proliferative activity of the EO ranging from IC50 value 30.95 µg/ml to 16.55 µg/ml. The results from this study have demonstrated the promising cytotoxic, antibacterial, and antifungal properties of S. parviflora, which could have wide potential applications in food and pharmaceutical industries.

In depth chemical investigation of Glycyrrhiza triphylla Fisch roots guided by a preliminary HPLC-ESIMSn profiling.

Chemical investigations on Glycyrrhiza spp. have mostly been focused on G. glabra (typically cultivated in Europe, henceforth called European licorice), G. uralensis and G. inflata (known as Chinese licorice) with little information on the constituents of other Glycyrrhiza species. According to the growing interest in further Glycyrrhiza spp. to be used as sweeteners, the roots of G. triphylla have been investigated. The LC-ESI/LTQOrbitrap/MS profile of the methanolic extract of G. triphylla roots guided the isolation of 21 compounds, of which the structures were elucidated by 1D- and 2D-NMR experiments. Based on this approach, 6 previously unreported compounds including two isoflavones 7,5'-dihydroxy-6,3'-dimethoxy-isoflavone-7-O-ß-d-glucopyranoside (4) and 7,5'-dihydroxy-6,3'-dimethoxy-isoflavone-7-O-(7,8-dihydro-p-hydroxycinnamoyl)-ß-d-glucopyranoside (7) and four saponins, named licoricesaponins M3 (13), N2 (14), O2 (16) and P2 (18), have been characterized. It is to be noted that the accurate masses of some compounds here reported for the first time corresponded to those of compounds previously described in Glycyrrhiza spp. Thus an approach based only on MS analysis could be misleading; only isolation followed by NMR analysis allowed us to unambiguously assign the structures of these previously unreported compounds.

Combination of LC-MS based metabolomics and antioxidant activity for evaluation of bioactive compounds in Fragaria vesca leaves from Italy.

Wild strawberry (Fragaria vesca) is recognized as a traditional food of Campania region (Italy). The vegetative parts have a pharmaceutical interest, being used as decoctions for hypertension treatment due their detoxifying, diuretic, stimulant and dermatological protective properties; leaves, that after collection of fruits are generally thrown away, could be an interesting byproduct, source of bioactive compounds for cosmetic and pharmaceutical industry. In the present work, the metabolite profiles of F. vesca leaves coming from populations spontaneously growing in the underwood (wild) and in crop (cultivated) and from autochthonous and non-autochthonous germplasm of Campania region (Italy) were investigated by LC-ESI/LTQOrbitrap/MS analysis. 27 metabolites mainly belonging to organic acids, flavonoids, catechin and its oligomers, and ellagitannins were putatively identified. Antioxidant activity was tested for each sample, in particular cultivated samples and wild samples with autochthonous germplasm of Campania region showed higher antioxidant activity compared to the non autochthonous ones. Moreover, in this study, it was possible to predict antioxidant metabolites, markers of this species, using LC-MS spectra and multivariate regression data analysis.

Steviol glycosides targeted analysis in leaves of Stevia rebaudiana (Bertoni) from plants cultivated under chilling stress conditions.

Stevia rebaudiana is an important agricultural crop for the production of a high-potency natural sweetener, sensitive to low temperature during the developmental stage. Stimulation of chilling stress with a pre-treatment with endogenous signalling components and in particular with salicylic acid (SA), hydrogen peroxide (H2O2), 6-benzylaminopurine (BAP) and calcium chloride (CaCl2) could induce tolerance to chilling and could constitute a suitable way to maintain quality and quantity of steviol glycosides under controlled artificial environment. In the present work the effects of different putative signalling molecules on the morpho-physiological parameters were evaluated, and a specific method for the quali-quantitative analysis of steviol glycosides in S. rebaudiana plants cultivated under controlled conditions was developed, by using LC-ESI-FT (Orbitrap) MS, LC-ESI-QqQ-MS/MS and multivariate data analysis. This approach underlined that the pre-treatment has influence on the production of secondary metabolites. In particular Stevia plants characterised by higher contents of rebaudioside A and stevioside, were identified.