Valorisation, Green Extraction Development, and Metabolomic Analysis of Wild Artichoke By-Product Using Pressurised Liquid Extraction UPLC-HRMS and Multivariate Data Analysis.

Valorisation of food by-products has recently attracted considerable attention due to the opportunities to improve the economic and environmental sustainability of the food production chain. Large quantities of non-edible parts of the artichoke plant (Cynara cardunculus L.) comprising leaves, stems, roots, bracts, and seeds are discarded annually during industrial processing. These by-products contain many phytochemicals such as dietary fibres, phenolic acids, and flavonoids, whereby the most challenging issue concerns about the recovery of high-added value components from these by-products. The aim of this work is to develop a novel valorisation strategy for the sustainable utilisation of artichoke leaves' waste, combining green pressurised-liquid extraction (PLE), spectrophotometric assays and UPLC-HRMS phytochemical characterization, to obtain bioactive-rich extract with high antioxidant capacity. Multivariate analysis of the major selected metabolites was used to compare different solvent extraction used in PLE.

Anticholesterolemic Activity of Three Vegetal Extracts (Artichoke, Caigua, and Fenugreek) and Their Unique Blend.

Hepatic-related diseases, in particular hyperlipidemia and hypercholesterolemia, are a thorn on the side of the national health institutes around the globe. Indeed, liver lipid and cholesterol dysregulation could lead to atherosclerotic plaque formation and cardiovascular diseases. Currently, statin administration and monacolin K consumption are the main therapies proposed to counter this alarming connection, but relevant side effects are known. To overcome this issue, safe nutraceutical formulations and/or vegetal extracts, endowed with anticholesterolemic activity, could be instrumental in hypercholesterolemia prevention and treatment. In the present work, the anticholesterolemic efficacy of three vegetal extracts used in traditional medicine (artichoke, caigua, and fenugreek), their unique blend (ACFB), and the monacolin K-containing red yeast extract (RYR), was investigated with an in vitro approach based on hepatic cell line HepG2. The impact on cholesterol of the three extracts, their blend, and RYR were investigated by determining hepatocyte total and free cholesterol and bile acids biosynthesis. According to our results, the anticholesterolemic activity of the vegetal extracts was confirmed, and a novel choleretic activity of caigua extract was evidenced. ACFB showed to be safer than RYR while showing a similar effect on total and free cholesterol and bile acids synthesis compared to it. The anticholesterolemic activity of the blend was obtained with lower vegetal extract concentrations compared with the single vegetal extract, potentially indicating an additive effect between the extracts. In conclusion, the vegetal extracts and their blend, ACFB, are safe and are endowed with anticholesterolemic activity, potentially providing complementary therapies to the statin-based ones for hyperlipidemia and hypercholesterolemia-related complications.

Green non-conventional techniques for the extraction of polyphenols from agricultural food by-products: A review.

Food processing industry is accompanied with the generation of a great production of wastes and by-products exceptionally rich in bioactive compounds (especially phenolics), with antioxidant activity. The recovery of these health molecules constitutes a key point for the valorization of by-products, with the possibility of creating new ingredients to be used for the formulation of food and cosmetic products. One of the main limitations to reuse by-products is linked to the high cost to obtain bioactive compounds, consequently in order to exploit these resources commercially valuable it is necessary to develop innovative, economic and environmentally friendly extraction strategies. These extraction methods should be able to reduce petroleum solvents, energy consumption and chemical wastes, protecting both environment and consumers and ensuring safe and high-quality final products. The purpose of this review is to summarize current knowledge and applications of the new extraction techniques such as supercritical fluid extraction, pressurized liquid extraction, ultrasound assisted extraction applied to polyphenols extraction from agricultural food by-products. Particular attention has been paid to theoretical background, highlighting mechanisms and safety precautions. Authors concluded that relevant results of these techniques represent an opportunity to industrial scale-up, improving the extraction yields, minimizing time, costs and environmental impact.

Characterisation of nutraceutical compounds from different parts of particular species of Citrus sinensis 'Ovale Calabrese' by UHPLC-UV-ESI-HRMS.

Consumers are aware of diet causing health problems and therefore there is an increased demand for natural ingredients that are expected to be safe and health-promoting. Many of these compounds belong to the class of flavonoids and can be divided into these five groups: flavanones, flavones, flavonols, flavanols, isoflavones and anthocyanidins. Extracts from citrus fruits are usually used as functional ingredients for several products. The aim of this paper was to develop an UHPLC-UV-ESI-HRMS method to define the metabolite profile of different parts of citrus fruit, of a particular cultivar called 'Ovale Calabrese', and in its main by-products. The high resolution mass spectrometry analysis allowed the identification of 27 compounds belonging to the classes of flavonoids and terpenoids. The high contents of phytochemical compounds, reveal the potential use of the 'Ovale Calabrese' as a rich source of nutraceutical compounds.

Response surface methodology to optimize supercritical carbon dioxide/co-solvent extraction of brown onion skin by-product as source of nutraceutical compounds.

Food industry produces a large amount of onion wastes. Due to the high amount of bioactive compounds in onion by-products an idea for their reuse, could be use them as source of high-value functional and health ingredients. In this study, outer dry layers of coppery onion "Ramata di Montoro" were used as source of bioactive compounds. Firstly, the chemical profile of secondary metabolites of exhaustive extract, obtained by ultrasound assisted extraction was established by UHPLC-UV-HRMS/MS analysis. Subsequently, the supercritical fluid extraction was used as alternative and green method to recover flavonoids from onion skin. Main parameters such as pressure, temperature and composition of solvent modifier were optimized in order to improve the extraction efficiency of SFE technique, by using a response surface Box-Behnken design.

Pressurized hot water extraction of bioactive compounds from artichoke by-products.

Artichoke by-products are a suitable source of health-promoting ingredients for the production of dietary supplements and food additives. A pressurized hot water extraction (PHWE) was developed to recover caffeoylquinic acids (CQAs) and flavone glycosides (FLs) from agro-industrial artichoke by-products. The main factors influencing PHWE efficiency and CQA isomerization (temperature, numbers of cycles, modifier, and extraction time) were carefully studied and optimized by response surface design. The proposed PHWE procedure provides an exhaustive extraction of CQAs and FLs (recoveries: 93-105% and 90-105%) from artichoke external bracts and leaves of different cultivars (p > 0.05), without significant formation of artefacts generated by high temperatures. PHWE extracts showed CQA and FL levels (14-37 mg/g and 3-19 mg/g, respectively) comparable to commercial products and marked antioxidative effects (EC50 11-83 µg/mL) by cellular antioxidant activity assay in human hepatocarcinoma HepG2 cells. These results proved that PHWE is an excellent green technique to recover bioactive compounds from artichoke agro-industrial residues.

Counter-current chromatography with off-line detection by ultra high performance liquid chromatography/high resolution mass spectrometry in the study of the phenolic profile of Lippia origanoides.

Lippia origanoides (Verbenaceae) is an important Brazilian medicinal plant, also used for culinary purposes. Most chemical studies with this plant have been focused on its volatile composition. In this work, we combined High-Speed Counter-current Chromatography (HSCCC) and High Performance Liquid Chromatography coupled to Ultra Violet detection and High Resolution Mass Spectrometry (HPLC-UV-HRMSn) methodologies to access the non-volatile chemical composition of L. origanoides. The crude ethanol extract of L. origanoides (LOEF) was first analyzed by HPLC-UV-HRMSn and allowed the identification of 7 major compounds. Among them, eriodictyol, naringenin and pinocembrin, were determined and are phytochemical markers of this plant. However, owing to the complexity of this plant matrix, LOEF was fractionated by HSCCC (hexane-ethanol-water, 4:3:1) as a tool for preparative pre-purification, affording a flavonoid-rich fraction. A column screening with the chromatographic stationary phases ZIC-HILIC, monolithic and particulate RP18 was performed. The best column separation was achieved with a Purospher STAR RP18e, which was used for HPLC-DAD-HRMSn studies. By this approach 12 compounds were further identified in addition to the major ones identified in the raw extract. Two of them, 6,8-di-C-hexosyl-luteolin and 6,8-di-C-glucosyl-apigenin, are being reported for the first time in the family Verbenaceae. This work shows the integration of HSCCC as a preparative tool for the fractionation and purification of natural products from a complex plant extract with other analytical techniques, with the purpose of showing each technique's potential.

Oil distillation wastewaters from aromatic herbs as new natural source of antioxidant compounds.

Distillation wastewaters (DWWs) are generated during the essential oil steam distillation from aromatic herbs. Despite of growing interest on novel source of natural antioxidant compounds as food additives, studies on DWWs are scarse. Herein, the potential of DWWs produced by the distillation of packaged fresh basil, rosemary and sage wastes was evaluated by chemical and antioxidant characterization. HPLC-DAD-HRMS profiling revealed that DWWs contain water-soluble phenolic compounds, mainly caffeic acid derivatives and flavonoid glycosides, with rosmarinic acid (RA) as predominant components (29-135mg/100mL). DWWs demonstrated high levels of total phenolic compounds (TPC, 152-443mg GAE/100mL) and strong antioxidant capacities, in ORAC, DPPH and ABTS assays (1101-4720, 635-4244 and 571-3145µmol TE/100mL, respectively). Highly significant correlations of TEAC values with TPC and RA contents revealed that phenolic compounds and high RA content were responsible of DWWs antioxidant properties.Thus, DWWs are proposed as a new promising source of natural food additives and/or functional ingredients for cosmetic, nutraceutical and food applications.

Chemical profile and anti-leishmanial activity of three Ecuadorian propolis samples from Quito, Guayaquil and Cotacachi regions.

Three propolis samples were collected from different regions of Ecuador (Quito, Guayaquil and Cotacachi) and their methanolic extracts were prepared. Preliminary information supplied by TLC and NMR data, allowed us to define two main types of propolis: Cotacachi propoli sample (CPS), rich in flavonoids and Quito and Guayaquil samples (QPS and GPS) containing triterpenic alcohols and acetyl triterpenes as the main constituents. Two different approaches based on RP-HPLC preparative procedure and NMR structural determination (CPS) and GC-MS analysis (QPS and GPS) were successfully used for the chemical characterization of their major compounds. All three propolis extracts were able to inhibit Leishmania amazonensis growth but propolis sample rich in flavonoids was the most active (IC50=17.1±1.7µg/mL). In the literature this is the first study on propolis from Ecuador.

HPLC-PDA-MS and NMR characterization of a hydroalcoholic extract of Citrus aurantium L. var. amara peel with antiedematogenic activity.

The phytochemical profile of a hydroalcoholic extract of Citrus aurantium var. amara L. peel, used as herbal medicine, was characterized by HPLC-PDA-MS. Two di-C-glycosyl flavones (vincenin II and diosmetin 6,8-di-C-glucoside), a series of flavones (luteolin 7-O-neohesperidoside, rhoifolin, and neodiosmin), and flavanone (neoeriocitrin, naringin, and neohesperidin) 7-O-neohesperidosides and two methoxyflavones (nobiletin and tangeretin), commonly present in Citrus, were identified. Furthermore, brutieridin and melitidin, two 3-hydroxy-3-methylglutaryl flavanone glycosides, were also characterized along with rhoifolin 4'-glucoside and three coumarins (8,3'-ß-D-glucopyranosyloxy-2'-hydroxy-3'-methylbutyl-7-methoxycoumarin, merazin hydrate, and isomerazin). A preparative isolation procedure followed by NMR spectroscopy confirmed the proposed structures of the major flavonoids and identified the coumarins. The phenolic content was found to be 14.8 mg mL(-1), and naringin and neohesperidin were the compounds present in the highest concentration (3.6 and 2.6 mg mL(-1)). The extract of C. aurantium peel inhibited significantly (p < 0.05) both histamine- and dextran-induced edema in rats in a concentration-dependent manner (IC(50) = 119.6 and 118.3 mg kg(-1), respectively), providing evidence for the therapeutic use of C. aurantium var. amara peel.

Phenolic derivatives from the leaves of Martinella obovata (Bignoniaceae).

A new phenolic derivative, 4-methoxyphenol 1-O-beta-D-apiofuranosyl-(1 --> 6)-O-beta-D-glucopyranoside (1), has been identified together with uncommon 3,4-dimethoxyphenol 1-O-beta-D-apiofuranosyl-(1 --> 6)-O-beta-D-glucopyranoside (2) and 3-hydroxy, 4-methoxyphenol 1-O-beta-D-apiofuranosyl-(1 --> 6)-O-beta-D-glucopyranoside (3) from the leaves of Martinella obovata (Kunth) Bureau & K. Schum., an Honduran species used in folk medicine for the treatment of eyes diseases. Verbascoside, isoverbascoside, leucoceptoside A, vitexin, isovitexin, luteolin 8-C-beta-D-glucopiranoside and spireoside were also found. All structures were elucidated on the basis of mass spectrometry and 2D NMR techniques.

Cuban and Brazilian red propolis: botanical origin and comparative analysis by high-performance liquid chromatography-photodiode array detection/electrospray ionization tandem mass spectrometry.

Chemical composition of propolis depends on the specificity of the local flora at the site of collection and thus on the geographic and climatic characteristics of this place. This paper describes a comparative analysis of Cuban red propolis (CRP), Brazilian red propolis (BRP), and Dalbergia ecastophyllum exudates (DEE) by high-performance liquid chromatography with diode-array detection and tandem mass spectrometry. The aim of this study was to investigate the overall chemical profile and the botanical origin of red propolis and to suggest similarities and differences between samples collected in different tropical regions. Isoliquiritigenin (1), liquiritigenin and naringenin (2 and 17), isoflavones (3-4 and 16), isoflavans (5-7 and 18), and pterocarpans (8-13) were detected in CRP, BRP, and DEE, whereas polyisoprenylated benzophenones (PPBs) guttiferone E/xanthochymol (14a,b) and oblongifolin A (15) were detected only in BRP. Pigments responsible for the red color of DEE and red propolis were also identified as two C30 isoflavans, the new retusapurpurin B (19) and retusapurpurin A (20). PPBs and pigments were isolated and unambiguously characterized by 1D and 2D NMR analysis. These results show that red propolis samples from different tropical zones have a similar chemical composition. DEE is the main red propolis source, but the presence of PPBs in BRP suggests the contribution of different botanical sources for Brazilian samples. This chemical information is important for quality control of red propolis and its commercial products and for biological study.

HPLC-PDA-MS and NMR characterization of C-glycosyl flavones in a hydroalcoholic extract of Citrus aurantifolia leaves with antiplatelet activity.

A hydroalcoholic extract of lime ( Citrus aurantifolia) leaves has been developed in Cuba to be used as a nutritional supplement and phytomedicine in the form of tincture (TLL). A HPLC-PDA-ESI/MS/MS method has been used for the comprehensive analysis of C-glycosyl flavones in TLL. Six C-glycosyl flavones were characterized and, to confirm the proposed structures and to elucidate the nature of the sugar units, a preparative procedure was applied, and isolated compounds were characterized by NMR. Apigenin-6,8-di-C-beta-D-glucopyranoside (vicenin II) (1), diosmetin-6,8-di- C-beta- d-glucopyranoside (2), apigenin-8-C-beta-D-glucopyranoside (vitexin) (3), apigenin-8-C-[alpha-L-arabinopyranosyl-(1-->6)]-O-beta-D-glucopyranoside (4), apigenin-6-C-[alpha-l-arabinopyranosyl-(1-->6)]-O-beta-D-glucopyranoside (5). and apigenin-6-C-beta-D-glucopyranoside (isovitexin) (6) were identified in TLL and quantified by HPLC-PDA. Compounds 4 and 5 were two new arabinosyl derivatives of vitexin and isovitexin. Inhibitor effect of TLL on platelet aggregation induced by physiological agonists of platelets was evaluated in human plasma. TLL inhibited significantly ADP and epinephrine-induced platelet aggregation in a concentration-dependent manner (IC 50=0.40 and 0.32 mg/mL, respectively).