Chemometric analysis of Tunisian durum wheat metabolites using UPLC-ESI-QTOF-MS/MS.

Bioactive compounds in wheat have received a great interest in the last few years due to their nutritional and health benefits. Various analytical procedures were used to identify these compounds in wheat kernels. An ultra-performance liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS/MS) was used for the screening of bioactive compounds in seven Tunisian durum wheat extracts. The aim of this study was to realize a screening of several classes of bioactive compounds in the same analysis and to identify specific metabolite markers for discriminating the durum wheat varieties. The UPLC-ESI-QTOF-MS/MS allows the detection of 81 metabolites, belonging to different chemical families such as sugars, organic acids, amino acids, fatty acids, and phenolic compounds represented by benzoic and cinnamic acid derivatives, phenolic alcohols, flavones, lignans, and condensed tannins. Chemical profiles identified varied greatly between different wheat genotypes. As far as the authors know, this is the first time that different chemical classes were detected at the same time in durum wheat kernels using UPLC-ESI-QTOF-MS/MS. This study gives the most complete map of metabolites in Tunisian durum wheat and proves that UPLC-QTOF-MS/MS coupled with chemometric analysis is a great tool for discrimination between durum wheat cultivars.

In vivo evaluation and molecular docking studies of Schinus molle L. fruit extract protective effect against isoproterenol-induced infarction in rats.

The aim of the current study was to assess the potential cardiopreventive effect of the methanolic extract of S. molle L. (MESM) on isoproterenol-induced infarction in rats. The biomolecules content was evaluated using HPLC-DAD-ESI-QTOF-MS/MS analysis. On the 29th and 30th days, two successive injections of isoproterenol (ISO) were given to Wistar rats to provoke myocardial infarction following pretreatment with either MESM (60 mg/kg b.w) or Pidogrel (Pid; 2 mg/kg b.w.). A total of sixteen phenolics were identified with masazino-flavanone as the most prevalent compound (1726.12 µg/g dm). Results showed that MESM offered cardioprevention by normalizing the ST segment and reducing the elevated cardiac risk parameters. The altered lipid biomarkers together with the plasma ionic levels were improved. Additionally, MESM inhibited the cardiac oxidative stress generated by ISO injection though enhancing antioxidant enzymes (GSH, CAT, SOD and GPX) which reduced lipid peroxidation and protein oxidation. MESM reduced myocardial apoptosis by significantly repressing mRNA expressions of Caspase-3 and Bax, with an upregulated Bcl-2 expression. Moreover, MESM reduced DNA fragmentation as well as the infarct size observed by TTC staining. In addition, MESM exhibited an antifibrotic effect by downregulating TGF-1ß expression and reducing collagen deposition in myocardial tissue, as confirmed by Trichrom Masson analysis. The histopathological findings revealed less muscle separation and fewer inflammatory cells in the ISO + MESM-treated rats. Results of the docking simulation indicated that catechin in MESM was inhibitory mainly due to hydrogen bonding interactions with PDI, ACE and TGF-ß1 proteins which could highlight the antithrombotic and antifibrotic capacity of MESM.

Influence of Drying Temperature and Harvesting Season on Phenolic Content and Antioxidant and Antiproliferative Activities of Olive (Olea europaea) Leaf Extracts.

Interest in plant compounds has increased, given recent evidence regarding their role in human health due to their pleiotropic effects. For example, plant bioactive compounds present in food products, including polyphenols, are associated with preventive effects in various diseases, such as cancer or inflammation. Breast and colorectal cancers are among the most commonly diagnosed cancers globally. Although appreciable advances have been made in treatments, new therapeutic approaches are still needed. Thus, in this study, up to 28 olive leaf extracts were obtained during different seasons and using different drying temperatures. The influence of these conditions on total polyphenolic content (measured using Folin-Ciocalteu assays), antioxidant activity (using Trolox Equivalent Antioxidant Capacity and Ferric Reducing Ability of Plasma assays) and antiproliferative capacity (using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT assays) was tested in breast and colorectal cancer cells. Increased phenolic composition and antioxidant and antiproliferative capacity are noted in the extracts obtained from leaves harvested in autumn, followed by summer, spring and winter. Regarding drying conditions, although there is not a general trend, conditions using the highest temperatures lead to the optimal phenolic content and antioxidant and antiproliferative activities in most cases. These results confirm previously published studies and provide evidence in support of the influence of both harvesting and drying conditions on the biological activity of olive leaf extracts.

HPLC-ESI-QTOF-MS/MS profiling and therapeutic effects of Schinus terebinthifolius and Schinus molle fruits: investigation of their antioxidant, antidiabetic, anti-inflammatory and antinociceptive properties.

The aim of the current work was to study the phytochemical variability among Schinus terebinthifolius (STE) and Schinus molle (SME) fruit extracts. The in vitro antioxidant, antihemolytic, antidiabetic, and macromolecule damage protective activities, as well as, the in vivo anti-inflammatory and antinociceptive capacities were assessed. Using the HPLC-ESI-QTOF/MS analysis, the chemical profile of fruit extract varied between S. terebinthifolius (30 compounds) and S. molle (16 compounds). The major compound was masazino-flavanone (5774.98 and 1177.65 µg/g sample for STE and SME, respectively). The investigations highlighted significant antioxidant proprieties when using ABTS radical (IC50; 0.12 and 0.14 mg/ml for STE and SME, respectively), superoxide (IC50; 0.17 and 0.22 mg/ml for STE and SME, respectively) and hydrogen peroxide (IC50; 014 and 0.17 mg/ml for STE and SME, respectively). In addition, STE and SME proved preventive effects against H2O2-induced hemolysis (IC50; 0.22 and 0.14 mg/ml for STE and SME, respectively). The in vitro antidiabetic effect revealed that STE and SME exhibited important inhibitory effects against α-amylase (IC50; 0.13 and 0.19 mg/ml for STE and SME, respectively) and α-glycosidase (IC50; 0.21 and 0.18 mg/ml for STE and SME, respectively) when compared with acarbose. Furthermore, the extracts showed potent inhibitory activity against AAPH-induced plasmid DNA damage, and protein oxidation. In vivo study revealed that STE and SME presented interesting antinociceptive and anti-inflammatory capacities. All observed effects highlighted the potential application of Schinus fruit extract in food and pharmaceutical industries against ROS-induced damage.

Schinus terebinthifolius fruits intake ameliorates metabolic disorders, inflammation, oxidative stress, and related vascular dysfunction, in atherogenic diet-induced obese rats. Insight of their chemical characterization using HPLC-ESI-QTOF-MS/MS.

ETHNOPHARMACOLOGY RELEVANCE: Schinus terebinthifolius is traditionally used for its anti inflammatory capacity, and indicated as a cardioprotective agent, whereas, its preventive effect against atherogenic diet fed (AD) induced metabolic disorders and the underlying mechanisms has not yet been explored. AIM OF THE STUDY: This study was undertaken to investigate the ameliorative role of Schinus terebinthifolius fruits extract (STFE) against cardiovascular problem, oxidative and inflammatory status related to obesity in rats fed an atherogenic diet. MATERIALS AND METHODS: The metabolites profile in STFE was evaluated using HPLC-DAD-ESI-QTOF-MS/MS analysis. In Wistar rats, atherogenic diet was added for 9 weeks to induce lipid accumulation simultaneously with STFE (50 mg/kg b. w) or saline treatment. Biochemical, oxidant, and inflammatory criteria together with hepatic and arterial integrity examination were assessed. RESULTS: A total of thirty three metabolites were identified using HPLC-DAD-ESI-QTOF-MS, among them masazino-flavanone was the major compound (2645.50 µg/g DW). The results indicated that STFE supplementation during 9 weeks (50 mg/kg b. w.) significantly attenuated the altered lipid profile by decreasing the levels of TC, TG, LDL-C and increasing the HDL-C content both in plasma and liver, when compared with the AD-group. The histological analysis using ORO staining revealed a decrease in the lipid droplet deposit in the cytoplasm of hepatocytes of STFE + AD group. The addition of STFE could improve the glycemic status of AD-treated rats by decreasing the glucose and insulin secretion, and ameliorating the hepatic glycogen synthesis. The harmful effects of atherogenic diet on hepatic oxidative stress indicators (MDA, PC, GSH, SOD, CAT, and GPx), biochemical markers (AST, ALT, LDH and ALP), and liver function, were found to be decreased by the addition of STFE. Moreover, the reduction of inflammatory markers (CRP, IL-6 and TNF-α), associated to alleviating of aortic oxidative stress and integrity, highlighted the positive anti-atherogenic effect of STFE. CONCLUSION: Overall, the pleiotropic protective effect observed with S. terebinthifolius fruits might be related to the presence of various bioactive compounds.

Tunisian Olea europaea L. leaf extract suppresses Freund's complete adjuvant-induced rheumatoid arthritis and lipopolysaccharide-induced inflammatory responses.

ETHNOPHARMACOLOGICAL RELEVANCE: Olea europaea L. (olive) is traditionally used as a folk remedy and functional food in Europe and Mediterranean countries to treat inflammatory diseases. O. europaea contains phenolic compounds and have been reported to prevent cartilage degradation. However, the function and mechanism of O. europaea in rheumatoid arthritis are not known. AIM OF THE STUDY: In this study, we aimed to examine anti-inflammatory and anti-arthritic effects of Tunisian O. europaea L. leaf ethanol extract (Oe-EE). MATERIALS AND METHODS: To do this, we employed an in vitro macrophage-like cell line and an in vivo Freund's complete adjuvant (AIA)-induced arthritis model. Levels of inflammatory genes and mediators were determined from in vivo samples. RESULTS: The Oe-EE clearly reduced the production of the lipopolysaccharide-mediated inflammatory mediators, nitric oxide (NO) and prostaglandin E2 (PGE2), in RAW264.7 cells. The results of HPLC showed that Oe-EE contained many active compounds such as oleuropein and flavonoids. In AIA-treated rats, swelling of paws, pain, and cartilage degeneration were alleviated by oral Oe-EE administration. Correlating with in vitro data, PGE2 production was significantly reduced in paw samples. Furthermore, the molecular mechanism of Oe-EE was dissected, and Oe-EE regulated the gene expression of interleukin (IL)-6, inducible NO synthase (iNOS), and MMPs and inflammatory signaling activation. CONCLUSION: Consequently, Oe-EE possesses anti-inflammatory and anti-rheumatic effects and is a potential effective treatment for rheumatoid arthritis.

Anti-Inflammatory and Photoaging-Protective Effects of Olea europaea through Inhibition of AP-1 and NF-[Formula: see text] B Pathways.

Olea europaea is a beneficial edible plant with a number of biological activities like anti-inflammatory, anti-oxidant, antithrombic, antihyperglycemic, and anti-ischemic activities. The mechanisms behind the antiphotoaging and anti-inflammatory effects of Olea europaea are not fully understood. To investigate how an ethanol extract of Olea europaea (Oe-EE) exerts these effects, we explored its activities in human keratinocytes and dermal fibroblasts. We assessed the anti-oxidant effects of Oe-EE via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2[Formula: see text]-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assays and measured the expression levels of matrix metalloproteinases (MMPs), cyclooxygenase-2, interleukin (IL)-6, tumor necrosis factor (TNF)-[Formula: see text], and moisturizing factors. Antiphotoaging and anti-inflammatory mechanisms of Oe-EE were explored by assessing signaling molecule activation via immunoblotting. Oe-EE treatment decreased the mRNA expression level of MMPs, cyclooxygenase-2, IL-6, and TNF-[Formula: see text] and restored type I collagen, filaggrin, and sirtuin 1 expression in UVB-irradiated cells. Furthermore, Oe-EE inhibited the activities of several activator protein 1 regulatory enzymes, including extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK), and inhibited nuclear factor (NF)-[Formula: see text]B pathway signaling proteins. Therefore, our results indicate that Oe-EE has photoaging-protective and anti-inflammatory effects.

Zygophyllum album leaves extract prevented hepatic fibrosis in rats, by reducing liver injury and suppressing oxidative stress, inflammation, apoptosis and the TGF-ß1/Smads signaling pathways. Exploring of bioactive compounds using HPLC-DAD-ESI-QTOF-MS/MS.

Zygophyllum album is traditionally used against many illnesses, such as liver disease. The present study investigated the bioactive compounds in methanol extract of Z. album (MEZA) using HPLC-DAD-ESI-QTOF-MS/MS and explored its possible antioxidative, anti-inflammatory, anti-apoptotic, and hepatoprotective effect. Twelve phenolic compounds were identified; isorhamnetin-3-O-rutinoside being the main one was the main composite (144.6 mg/100 g dm). Results showed that MEZA reduced significantly the biochemical markers (AST, ALT, LDH and ALP), and the hepatic oxidative stress indicators (MDA, PC, SOD, CAT, and GPx) in deltamethrin (DLM)-treated rats. Moreover, MEZA limited the inflammatory responses through downregulation of NF-κB gene, which suppressed the production of proinflammatory cytokines (TNF-α, IL-1ß, IL-6). Furthermore, Z. album reduced DLM-induced apoptosis by attenuating caspase 3 and p53 mRNA activation. MEZA treatment also alleviated upregulation of α-SMA, type I collagen, and TGF-ß1 mRNA in the liver. The possible antifibrotic effect of MEZA was clearly demonstrated by the histopathology examination, using Masson's Trichrome and Sirius Red stainings. Therefore, the current study suggested that the bioactive compounds of Z. album possessed antifibrotic effect against DLM-induced hepatic fibrosis, by protecting liver tissue, and inhibiting oxidative stress, inflammation, apoptosis and the TGF-ß1/Smads signaling pathways.

HPLC-DAD-ESI-QTOF-MS/MS profiling of Zygophyllum album roots extract and assessment of its cardioprotective effect against deltamethrin-induced myocardial injuries in rat, by suppression of oxidative stress-related inflammation and apoptosis via NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Zygophyllum album is widely used to treat many cardiovascular diseases (CVDs) and as anti-inflammatory plant. AIM OF THE STUDY: This study aimed to investigate the mechanism of the potential protective effects of Zygophyllum album roots extract (ZARE) against myocardial damage and fibrosis induced by a chronic exposure to deltamethrin (DLM) in rats. MATERIALS AND METHODS: Bioactive compounds present in ZARE were analyzed by HPLC-DAD-ESI-QTOF-MS/MS. In vivo, DLM (4 mg/kg body weight), ZARE (400 mg/kg body weight) and DLM with ZARE were administered to rats orally for 60 days. Biochemical markers (LDH, ALT, CK, CK-MB and cTn-I) were assessed in the plasma by an auto-analyzer. Pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) were evaluated by a sandwich ELISA. NF-κB was quantified at mRNA levels by real time PCR. Heart tissue was used to determine cardiac oxidative stress markers (MDA, PC, SOD, CAT, and GPx). Masson's Trichrome (MT) and Sirius Red (SR) stainings were used for explored fibrosis statues. RESULTS: Phytochemical analysis using HPLC-DAD-ESI-QTOF-MS/MS revealed the presence of twenty six molecules including phenolic compounds and saponins. ZARE significantly improved the heart injury markers (LDH, ALT, CK, CK-MB and cTn-I), lipid peroxidation (MDA), protein oxidation (PC), antioxidant capacity (SOD, CAT, and GPx), and DNA structure, which were altered by DLM exposure. Moreover, ZARE cotreatment reduced the expressions of NF-κB, decreased plasmatic pro-inflammatory cytokines concentration (TNF-α, IL-1ß and IL-6), and suppressed the myocardial collagen deposition, as observed by Sirius Red and Masson's Trichrome staining. CONCLUSION: ZARE ameliorated the severity of DLM-induced myocardial injuries through improving the oxidative status and reducing profibrotic cytokines production. The ZARE actions could be mediated by downregulation of NF-κB mRNA.

Suppression of Src and Syk in the NF-κB signaling pathway by Olea europaea methanol extract is leading to its anti-inflammatory effects.

ETHNOPHARMACOLOGICAL RELEVANCE: Olea europaea L., (Oleaceae) has been used widely in folk medicine in the European Mediterranean islands, India, Asia, and other parts of the world. Although this plant has high ethnopharmacological value for treating inflammatory diseases, the molecular mechanisms of how it inhibits the inflammatory response are not fully understood. In this study, we sought to identify the anti-inflammatory mechanisms of this plant. MATERIALS AND METHODS: Using macrophages, we investigated the effects of O. europaea L. methanol extract (Oe-ME) and ethanol extract (Oe-EE) on the production of inflammatory mediator nitric oxide (NO) and prostaglandin E2 (PGE2), the expression levels of pro-inflammatory genes and intracellular inflammatory signaling activities. RESULTS: Oe-ME and Oe-EE suppressed the production of NO in lipopolysaccharide-(LPS-), Pam3CSK4-, and poly (I:C)-stimulated RAW264.7 cells; importantly, no cytotoxicity was observed. Oe-ME and Oe-EE reduced production of PGE2 without exhibiting cytotoxicity. The mRNA expression levels of cyclooxygenase-2 (COX-2), inducible NO synthase (iNOS), IL-6, IL-1ß, and tumor necrosis factor (TNF)-α were down-regulated by Oe-ME and Oe-EE. Nuclear fraction and whole lysate immunoblotting analyses and overexpression experiments strongly suggested that Oe-ME decreased the translocation of p65 and p50 (nuclear factors of the NF-κB subunit) as well as Src and Syk. CONCLUSION: These results suggest that Oe-ME exerts its anti-inflammatory effects by targeting Src and Syk in the NF-κB signaling pathway.

Changes in phenolic composition in olive tree parts according to development stage.

The aim of this study was to investigate the changes in the phenolic profile in different organs (buds, flowers, fruits and leaves) from Chemlali olive variety cultivated in the Center of Tunisia according to development stage. Phenolics recovery was carried out using aqueous methanol from freeze-dried powdered tissues. The extracts were then analyzed by using high performance liquid chromatography coupled to time of flight and ion trap mass spectrometry detectors. Qualitatively, secoiridoids, flavonoids, simple phenols, cinnamic acid derivatives and lignans were identified in the analyzed extracts. Quantitatively, floral buds showed the highest phenolic contents compared to the other tissues under study. The highest content of secoiridoids was observed for unripe fruit extract, whereas the highest content of flavonoids was registered for floral buds.

LC-MS-based metabolite profiling of methanolic extracts from the medicinal and aromatic species Mentha pulegium and Origanum majorana.

INTRODUCTION: There has been increasing interest dedicated to the phenolic compounds with a view to their antioxidant and healthy properties. Recent studies have focused on plants from the Lamiaceae family with special interest in phenolic compounds antioxidant potential. OBJECTIVE: The metabolite profile of methanolic extracts from two Lamiacea medicinal plants was investigated. MATERIALS AND METHODS: Mentha pulegium and Origanum majorana methanolic extracts were analysed using reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled to electrospray ionisation quadrupole time-of-flight mass spectrometry (ESI-QTOF-MS) detection in the negative ion mode. RESULTS: A total of 85 metabolites were characterised from different families, such as organic acids and derivatives, amino acids and derivatives, nucleosides, phenolic compounds as well as other polar metabolites, by using the MS and MS/MS information provided by the QTOF-MS. However, the total phenols and flavonoids were also quantified spectrophotometrically and they registered higher amounts in Mentha pulegium than in Origanum majorana extract. Gallocatechin was the major compound in M. pulegium extract whereas quercetin dimethyl ether, jaceidin and dihydrokaempferide were the major ones in O. majorana extract. CONCLUSION: The distribution of phenolic compounds in the methanolic extract showed a variation among studied plants. Mentha pulegium can be considered as a source of gallocatechin.

Differential metabolomic analysis of the potential antiproliferative mechanism of olive leaf extract on the JIMT-1 breast cancer cell line.

A new differential metabolomic approach has been developed to identify the phenolic cellular metabolites derived from breast cancer cells treated with a supercritical fluid extracted (SFE) olive leaf extract. The SFE extract was previously shown to have significant antiproliferative activity relative to several other olive leaf extracts examined in the same model. Upon SFE extract incubation of JIMT-1 human breast cancer cells, major metabolites were identified by using HPLC coupled to electrospray ionization quadrupole-time-of-flight mass spectrometry (ESI-Q-TOF-MS). After treatment, diosmetin was the most abundant intracellular metabolite, and it was accompanied by minor quantities of apigenin and luteolin. To identify the putative antiproliferative mechanism, the major metabolites and the complete extract were assayed for cell cycle, MAPK and PI3K proliferation pathways modulation. Incubation with only luteolin showed a significant effect in cell survival. Luteolin induced apoptosis, whereas the whole olive leaf extract incubation led to a significant cell cycle arrest at the G1 phase. The antiproliferative activity of both pure luteolin and olive leaf extract was mediated by the inactivation of the MAPK-proliferation pathway at the extracellular signal-related kinase (ERK1/2). However, the flavone concentration of the olive leaf extract did not fully explain the strong antiproliferative activity of the extract. Therefore, the effects of other compounds in the extract, probably at the membrane level, must be considered. The potential synergistic effects of the extract also deserve further attention. Our differential metabolomics approach identified the putative intracellular metabolites from a botanical extract that have antiproliferative effects, and this metabolomics approach can be expanded to other herbal extracts or pharmacological complex mixtures.

UPLC-QTOF/MS for a rapid characterisation of phenolic compounds from leaves of Myrtus communis L.

INTRODUCTION: Although continuous research has been conducted on the biological activities of myrtle and the characterisation of its essential oil, few studies have focused on its phenolic composition despite major beneficial properties. OBJECTIVE: To carry out a comprehensive characterisation of infusion and methanolic extract from myrtle leaves by UPLC-QTOF/MS. METHODS: Myrtle-leaf infusions, prepared using deionised water, and the methanolic extracts were analysed by reversed-phase ultra-performance liquid chromatography (UPLC) coupled to electrospray ionisation quadrupole time-of-flight mass spectrometry (ESI/QTOF/MS). The MS and MS/MS experiments were conducted using the negative-ionisation mode, in order to provide molecular-mass information and production spectra of the compounds for structural elucidation. RESULTS: The analytical method applied enabled the characterisation of several compounds such as gallic acid and galloyl derivatives, ellagic acid and derivatives, hexahydroxydiphenolyl and derivatives, flavonoids, lignans and gallomyrtucommulones. Flavonoids, ellagic acid and its derivatives and gallic acid and its derivatives formed the major fractions. CONCLUSION: UPLC combined with QTOF/MS is a powerful analytical method for characterising infusions and alcoholic extracts from myrtle leaves.

Use of advanced techniques for the extraction of phenolic compounds from Tunisian olive leaves: phenolic composition and cytotoxicity against human breast cancer cells.

A comparison among different advanced extraction techniques such as microwave-assisted extraction (MAE), supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE), together with traditional solid-liquid extraction, was performed to test their efficiency towards the extraction of phenolic compounds from leaves of six Tunisian olive varieties. Extractions were carried out at the best selected conditions for each technique; the obtained extracts were chemically characterized using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap tandem mass spectrometry (ESI-IT-MS(2)). As expected, higher extraction yields were obtained for PLE while phenolic profiles were mainly influenced by the solvent used as optimum in the different extraction methods. A larger number of phenolic compounds, mostly of a polar character, were found in the extracts obtained by using MAE. Best extraction yields do not correlate with highest cytotoxic activity against breast cancer cells, indicating that cytotoxicity is highly dependent on the presence of certain compounds in the extracts, although not exclusively on a single compound. Therefore, a multifactorial behavior is proposed for the anticancer activity of olive leaf compounds.

The occurrence and bioactivity of polyphenols in Tunisian olive products and by-products: a review.

Polyphenols have become a subject of intense research because of their perceived beneficial effects on health due to their anticarcinogenic, antiatherogenic, anti-inflammatory, and antimicrobial activities. It is well known that olives and their derivatives are rich in phenolic substances with pharmaceutical properties, some of which exert important antioxidant effects. The characterization and quantification of their polyphenol composition is one of the first steps to be taken in any evaluation of the putative contribution of the olive to human health. This review is concerned with polyphenols in Tunisian olive (Olea europaea L.) products (fruit and oil) and some by-products (leaves and olive-mill wastewater) with an emphasis on the analytical methods used, as well as the biological activities described in recent years.

Classification of 'Chemlali' accessions according to the geographical area using chemometric methods of phenolic profiles analysed by HPLC-ESI-TOF-MS.

The present work describes a classification method of Tunisian 'Chemlali' olive oils based on their phenolic composition and geographical area. For this purpose, the data obtained by HPLC-ESI-TOF-MS from 13 samples of extra virgin olive oils, obtained from different production area throughout the country, were used for this study focusing in 23 phenolics compounds detected. The quantitative results showed a significant variability among the analysed oil samples. Factor analysis method using principal component was applied to the data in order to reduce the number of factors which explain the variability of the selected compounds. The data matrix constructed was subjected to a canonical discriminant analysis (CDA) in order to classify the oil samples. These results showed that 100% of cross-validated original group cases were correctly classified, which proves the usefulness of the selected variables.

Optimization of microwave-assisted extraction for the characterization of olive leaf phenolic compounds by using HPLC-ESI-TOF-MS/IT-MS(2).

In the present work, a simple and rapid method for the extraction of phenolic compounds from olive leaves, using microwave-assisted extraction (MAE) technique, has been developed. The experimental variables that affect the MAE process, such as the solvent type and composition, microwave temperature, and extraction time, were optimized using a univariate method. The obtained extracts were analyzed by using high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap tandem mass spectrometry (ESI-IT-MS(2)) to prove the MAE extraction efficiency. The optimal MAE conditions were methanol:water (80:20, v/v) as extracting solvent, at a temperature equal to 80 °C for 6 min. Under these conditions, several phenolic compounds could be characterized by HPLC-ESI-MS/MS(2). As compared to the conventional method, MAE can be used as an alternative extraction method for the characterization of phenolic compounds from olive leaves due to its efficiency and speed.