Untargeted metabolite profiling and phytochemical analysis based on RP-HPLC-DAD-QTOF-MS and MS/MS for discovering new bioactive compounds in Rumex algeriensis flowers and stems.

INTRODUCTION: Natural products with distinctive pharmaceutical activities are considered as the main source of new herbal drugs, functional foods and cosmetic additives. Rumex algeriensis is an endemic medicinal plant with no accessible information about its chemical profile and biological activities. OBJECTIVE: In the quest for new sources of biologically-active compounds, we intended in the present work to undertake a comprehensive characterisation of phytochemical compounds from Rumex algeriensis flowers and stems hydro-methanolic extract. METHODOLOGY: Chemical profiles were evaluated by a rapid analytical method reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to electrospray ionisation-quadrupole-time-of-flight mass spectrometry (ESI-QTOF-MS) and tandem mass spectrometry (MS/MS) using negative and positive ions modes. RESULTS: In this work, 44 bioactive compounds were tentatively identified using high mass accuracy data and confirmed by MS/MS experiments, among which five compounds were reported for the first time in the Polygonaceae family. These compounds were classified as sugars, hydroxybenzoic acids, hydroxycinnamic acids, flavonols, flavanones, flavone, flavanols, condensed tannins, hydrolysable tannins and their conjugated derivatives. CONCLUSIONS: The obtained results highlighted that Rumex algeriensis, even though undervalued and unexplored, contributes to the preclinical knowledge that could be considered as a renewable source of nutraceutical compounds that may be exploited in novel herbal medicinal products, in the food, pharmaceutical and nutraceutical industries.

Use of ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry system as valuable tool for an untargeted metabolomic profiling of Rumex tunetanus flowers and stems and contribution to the antioxidant activity.

Rumex tunetanus is an untapped resource with no available information about their chemical composition. That is why, the present study has conducted comprehensive metabolites profiling of the hydromethanol extracts of the Rumex tunetanus flowers and stems using RP-UHPLC-ESI-QTOF-MS. As results, 60 compounds were characterized for the first time in Rumex tunetanus between them, 18 photochemical were firstly identified in the Polygonaceae family in negative ionization mode. In this regard, quercetin-3-O-glucuronide and (-)-epicatechin gallate were the most abundant phenolic compounds in flowers and stems, respectively. Moreover, positive correlations were found between the antioxidant activity measured by DPPH and FRAP assays with the total phenolic compounds (r = 0.98; r = 0.99, respectively) and the abundance of some phenolic subfamilies such as hydroxycinnamic acids, hydroxybenzoic acids, flavonols and flavones with r > 0.86. The compounds displaying significant (P < 0.01) and good correlations with the antioxidant activity (r > 0.93) were hydroxybenzoic acid, rutin, quercetin-3-O-glucuronide, quercetin-3-O-glucoside, quercetin and luteolin-7-O-rutinoside. In conclusion, Rumex tunetanus flowers and stems showed different bioactive compound profiles and significant antioxidant properties and could be further used in food and nutraceutical industries.

Comparison and characterization of volatile compounds as markers of oils stability during frying by HS-SPME-GC/MS and Chemometric analysis.

The formation and emission of volatile compounds, including the aldehydes and some toxic compounds of oil samples, ROPO pure (100%) and the blended ROPO/RCO (80-20%), were carried out during deep frying at 180°C. The volatile profile of both oil samples was evaluated by an optimized HS-SPME-GC/MS method, before and after 20, 40 and 60 successive sessions of deep-frying. Actually, from 100 detected compounds, aldehydes were found to be the main group formed. In addition, the oil degradation under thermal treatment regarding the volatile compounds were evaluated and compared. Consequently, the blended ROPO/RCO revealed fewer formations of unsaturated aldehydes, including toxic ones, such as acrolein, and showed a greater stability against oxidative thermal degradation compared to ROPO pure.

LC-DAD/ESI-MS/MS characterization of phenolic constituents in Tunisian extra-virgin olive oils: Effect of olive leaves addition on chemical composition.

The aim of the present research is to evaluate the chemical characterization of main compounds from Tunisian monocultivar extra virgin olive oil (EVOO) ('Chemlali', 'Chétoui', 'Zalmati' and 'crossbreeding Chemlali by Zalmati') extracted after the addition of different amounts (0% and 3%) of olive leaves. As expected for extra virgin olive oil, the main sterols found in all analyzed samples were ß-sitosterol, ∆-5-avenasterol, campesterol and clerosterol. Stigmasterol, 24-methylene-cholesterol, cholesterol, campestanol, sitostanol, ∆-7-stigmastenol, ∆-5,24-stigmastadienol, and ∆-7-avenasterol were also found in all samples, but in lower amounts. Most of these compounds were significantly affected by the cultivars but not to be affected by added leaves at 3% to olives prior to the extraction process. The obtained results revealed that 14 phenolic compounds belonging to different phenolic types were characterized and quantified by an effective HPLC-DAD-ESI-MS/MS method. In all the studied olive oil samples, dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA), oleuropein aglycon (3,4-DHPEA-EA), and ligstroside aglycon (p-HPEA-EA) were the most abundant compounds. In addition, EVOO from 'Chétoui' cultivar extracted with 3% of olive leaves presented the highest amount of individual phenolic compounds.

LC-MS phenolic profiling combined with multivariate analysis as an approach for the characterization of extra virgin olive oils of four rare Tunisian cultivars during ripening.

In this work, the phenolic composition of four rare cultivars grown under the same agronomical and environmental conditions was studied. This is to test the effects of cultivars and ripening index essentially on phenolic composition in olive oils as well as tocopherols composition, organoleptic profiling and oxidative properties. Furthermore, some agronomical traits were determined in which a general increase in the size of the fruit and oil contents were recorded for all cultivars. The phenolic fractions were identified and quantified using liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) in multiple reaction monitoring mode (MRM). A total of 13 phenolic compounds belonging to different chemical families were determined. Qualitative and quantitative differences in phenolic composition were observed among cultivars and also among sampling times. On the contrary to the agronomical traits, a general decrease (p<0.05) of total phenolic compounds was observed during maturation. Likewise, a decrease in tocopherols concentrations and oxidative properties was observed.

Urtica dioica attenuates ovalbumin-induced inflammation and lipid peroxidation of lung tissues in rat asthma model.

CONTEXT: To find bioactive medicinal herbs exerting anti-asthmatic activity, we investigated the effect of an aqueous extract of Urtica dioica L. (Urticaceae) leaves (UD), the closest extract to the Algerian traditional use. OBJECTIVE: In this study, we investigated the in vivo anti-asthmatic and antioxidant activities of nettle extract. MATERIALS AND METHODS: Adult male Wistar rats were divided into four groups: Group I: negative control; group II: Ovalbumin sensitized/challenged rats (positive control); group III: received UD extract (1.5 g/kg/day) orally along the experimental protocol; group IV: received UD extract (1.5 g/kg/day) orally along the experimental protocol and sensitized/challenged with ovalbumin. After 25 days, blood and tissue samples were collected for haematological and histopathological analysis, respectively. The oxidative stress parameters were evaluated in the lungs, liver and erythrocytes. Then, correlations between markers of airway inflammation and markers of oxidative stress were explored. RESULTS: UD extract significantly (p < 0.01) inhibited eosinophilia increases in BALF (-60%) and the levels of leucocytes (-32.75%) and lymphocytes (-29.22%) in serum, and effectively suppressed inflammatory cells recruitment in the asthmatic rat model. Besides, the lipid peroxidation generated by allergen administration was significantly (p < 0.05) diminished by UD treatment in lung tissue (-48.58%). The nettle extract was also investigated for the total phenolic content (30.79 ± 0.96 mg gallic acid/g dry extract) and shows DPPH radical scavenging activity with 152.34 ± 0.37 µg/mL IC50 value. CONCLUSIONS: The results confirmed that UD administration might be responsible for the protective effects of this extract against airway inflammation.

HPLC-DAD-QTOF-MS profiling of phenolics from leaf extracts of two Tunisian fig cultivars: Potential as a functional food.

The phenolic constituents of the aqueous-ethanolic extract of two Tunisian Ficus carica leaves cultivars and their hypoglycaemic, hypolipidaemic and antioxidative activities in alloxan-induced diabetic rats were investigated. Our results demonstrated that the treatment with the leaves extracts of F. carica improved lipid profile and reduced blood glucose level as well as thiobarbituric acid-reactive substances content. The antioxidant enzymes activity in the liver and heart tissues of diabetic rats was increased after the treatment. These antihyperglycaemic, antihyperlipidaemic and antioxidant effects of both leaf extracts could be associated with their in vitro scavenging ability and their phenolic composition. The HPLC-DAD-QTOF-MS analysis of both extracts revealed the presence of dihydroxybenzoic acid, dipentoside, rutin, psoralen, methoxypsoralen and oxypeudacin hydrate as relatively the most abundant compounds. These results showed indicated the capacity of the leaves extracts of F. carica to ameliorate hyperglycaemia, hyperlipidaemia and antioxidant status in diabetic rats.

RP-HPLC-DAD-ESI-QTOF-MS based metabolic profiling of the potential Olea europaea by-product "wood" and its comparison with leaf counterpart.

INTRODUCTION: Olea europaea L. organs such as leaves, stems and roots have been associated with numerous in vivo and in vitro biological activities and used for traditional medicinal purposes. However, tree wood is an untapped resource with little information about their chemical composition. OBJECTIVE: That is why, the objective of this study is to increase the knowledge about phytochemicals from 'Chemlali' olive wood by means of mass spectrometry-based analyses. Its comparison with by-products derived from leaves was also studied. METHODOLOGY: Hydromethanol extracts from wood and leaves with stems of 'Chemlali' olive cultivar were analysed using reversed-phase (RP) high-performance liquid chromatography (HPLC) coupled to two detection systems: diode-array detection (DAD) and quadrupole time-of-flight (QTOF) mass spectrometry (MS) in negative ion mode. Tandem MS experiments were performed to establish the chemical structure of olive phytochemicals. RESULTS: A total of 85 compounds were characterised in the studied olive parts and classified as: sugars (3), organic acids (5), one phenolic aldehyde, simple phenolic acids (6), simple phenylethanoids (5), flavonoids (14), coumarins (3), caffeoyl phenylethanoid derivatives (6), iridoids (5), secoiridoids (32), and lignans (5). To our knowledge, the major part of these metabolites was not previously reported in olive tree wood, and 10 olive chemical constituents were identified for the first time in the Oleaceae family. CONCLUSION: The results presented here demonstrated the usefulness of the methodology proposed, based on RP-HPLC-DAD-ESI-QTOF-MS and MS/MS, to develop an exhaustive metabolic profiling and to recover new biologically active compounds in olive wood with pharmacologic and cosmetic potential. Copyright © 2017 John Wiley & Sons, Ltd.

Biosurfactant production by the crude oil degrading Stenotrophomonas sp. B-2: chemical characterization, biological activities and environmental applications.

In this work, biosurfactant-producing microorganisms were isolated from hydrocarbon-contaminated water collected from Tunisian oilfield. After enrichment and isolation, different bacterial strains were preliminary studied for their biosurfactant/bioemulsifier properties when using crude oil as the unique carbon source. In particular, the isolate strain B-2, a Gram-negative, rod-shaped bacterium, efficiently emulsified crude oil. The extracellular biosurfactant product from this strain presented an emulsification activity above 70% and a hydrophobicity of 71%. In addition, a diameter of 6 cm was observed in the oil displacement test. The characterization of B-2 strain using 16S rDNA sequencing enables us to find a high degree of similarity with various members of the genus Stenotrophomonas (with a percentage of similarity of 99%). The emulsification activity of Stenotrophomonas biosurfactant B-2 was maintained in a wide range of pH (2 to 6), temperature (4 to 55 °C), and salinity (0 to 50 g L-1) conditions. It also enhanced the solubility of phenanthrene in water and could be used in the re-mobilization of hydrocarbon-contaminated environment. In addition, this biosurfactant exhibited antimicrobial and antioxidant properties. Infrared spectroscopy suggested potential lipidic and peptidic moieties, and mass spectrometry-based analyses showed that the biosurfactant contains mainly cyclic peptidic structures belonging to the class of diketopiperazines. Therefore, the B-2 strain is a promising biosurfactant-producing microorganism and its derived biosurfactant presents a wide range of industrial applications.

Chemical composition and direct electrochemical oxidation of table olive processing wastewater using high oxidation power anodes.

Table olive processing wastewater (TOW) is a notoriously polluting due to its high organic and phenol content. To reduce them, an electrochemical process has been studied for the treatment of this effluent. Experiments were performed with a cell equipped with lead dioxide (PbO2) or boron-doped diamond (BDD) as anode and platinum as cathode, where Table Olive Wastewater (TOW) were destroyed by hydroxyl radicals formed at the anode surface from water oxidation. The comparative study of both systems shows the performance of the BDD anode compared to PbO2, explained by the large amounts of hydroxyl radicals generated effective at BDD anode and its synthesis characteristics. Using LC/MS analysis, it was possible to determine hydroxytyrosol, as major phenolic compounds, in table olive processing wastewater and its concentration reach 890 mg L-1. A possible reaction mechanism oxidation for hydroxytyrosol was proposed. The kinetics decays for hydroxytyrosol degradation on PbO2 anode follows a pseudo-first order reaction with a rate constant 0.9 h-1 for japp value 20 mA cm-2.

Antimicrobial effect of the Tunisian Nana variety Punica granatum L. extracts against Salmonella enterica (serovars Kentucky and Enteritidis) isolated from chicken meat and phenolic composition of its peel extract.

Punica granatum L. is widely recognized for its potency against a broad spectrum of bacterial pathogens. The purpose of this study was to explore the inhibitory and the bactericidal activities of Punica granatum against Salmonella strains. The effect of extracts obtained from different parts (peels, seeds, juice and flowers) of pomegranate and using different solvents against Salmonella enterica serovars Kentucky and Enteritidis isolated from chicken meat was thus investigated. Salmonella strains were identified with the standard API-20E system and confirmed by real time PCR. The obtained results showed that the highest antibacterial activity against Salmonella strains was observed with the peels ethanolic extract giving MIC values ranging from 10.75 to 12.5mg/mL. The ethanolic extract of P. granatum Nana peels at 0.8 and 1.6mg/g significantly inhibited the growth of Salmonella Kentucky in chicken meat stored at 4°C. The phenolic composition of the ethanolic peel extract was explored by HPLC coupled to both DAD and ESI/TOF-MS detections. The obtained results allowed the detection of 21 phytochemical compounds among which various phenolic compounds have been identified on the basis of their UV and MS spectra as well as with literature data. Among the detected compounds, anthocyanins, ellagitannins, ellagic acid derivatives and flavanols were further characterized through MS-MS analysis. Our results showed thus that the Tunisian variety Nana pomegranate constitutes a good source of bioactive compounds with potent antimicrobial activity on the growth of Salmonella strains suggesting that the studied pomegranate cultivar could be a natural remedy to minimize the emergence of Salmonella enterica strains which is often involved in food borne illness.

Antihyperlipidemic and Antioxidant Activities of Edible Tunisian Ficus carica L. Fruits in High Fat Diet-Induced Hyperlipidemic Rats.

The phenolic constituents of the aqueous-ethanolic extract of Tunisian Ficus carica (F. carica) fruit (FE) and its antihyperlipidemic and antioxidant activities in high-fat diet-induced hyperlipidemic rats (HFD) were evaluated. The obtained results demonstrated that the FE improved the lipid profile by decreasing the total cholesterol, triglyceride, low-density lipoprotein cholesterol and increasing high-density lipoprotein cholesterol levels. It also reduced the content of thiobarbituric acid-reactive substances and increased the antioxidant enzymes in liver, heart and kidney in HFD-fed rats. These antihyperlipidemic effects and in vivo antioxidative effects correlated with the in vitro phenolic content scavenging ability. Thus, the major phenolic compounds were identified using reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled with two detection systems: diode-array detection (DAD) and quadrupole time-of-flight (QTOF) mass spectrometry (MS). Therefore, in the negative ionization mode, 28 phenolic compounds, including hydroxybenzoic acids, hydroxycinnamic acids, flavanoids and hydroxycoumarins were characterized. Dihydroxybenzoic acid di-pentoside, the flavonol quercetin 3-O-rutinoside and the flavone assigned as apigenin 8-C-glucoside were the main representative compounds in 'Tounsi' fruits. This work was complemented by the detection of seven other phenolic compounds in the positive ionization mode, including anthocyanins and furanocoumarins. Overall, these results have shown that the FE has a significant hypocholesterolemic effect and antioxidant activity in HFD-fed rats. This beneficial effect may be partly due to these phenolic constituents, especially vitexin, dihydroxybenzoic acid di-pentoside as well as rutin.

Assessment of the distribution of phenolic compounds and contribution to the antioxidant activity in Tunisian fig leaves, fruits, skins and pulps using mass spectrometry-based analysis.

The phenolic composition of leaves, fruits, skins and pulps from two F. carica cultivars, 'Temri' and 'Soltani', was studied in order to understand its contribution to the antioxidant activity. A total of 116 compounds were characterized based on the results obtained by reversed-phase ultra-high performance liquid chromatography coupled to diode array and mass spectrometry detection. In general, the leaves of both cultivars and the skin of 'Soltani' presented richer qualitative profiles compared to the other plant parts. Using the negative ionization mode, qualitative profiles of the same part of the studied figs were similar. In this regard, rutin was the main compound in fruits, skins and leaves, but with different relative amounts. Alternatively, an isomer of prenylhydroxygenistein was the major compound in the pulps. In the positive ionization mode, 9 anthocyanins were characterized in 'Soltani' skin, only two of them being also present in the green cultivar 'Temri'. The main anthocyanins were cyanidin 3-rutinoside and cyanidin 3,5-diglucoside, depending on the cultivar and fruit part. In this ionization mode, 15 furanocoumarins were also detected in the leaves of both the studied cultivars with methoxypsoralen and psoralen being the most relatively abundant. In addition, our findings showed a good correlation between the antioxidant activity, total phenol content, and abundance of some phenolic subfamilies such as hydroxybenzoic acids, flavonols, flavones, hydroxycoumarins and furanocoumarins with r > 0.97.

Effect of processing systems on the quality and stability of Chemlali olive oils.

The present work has been carried out to ascertain the influence of different processing systems employed in olive process on the chemical composition, quality and stability of three Chemlali olive oils. Among these oils, two were classified as extra-virgin olive oils and the third named repassed olive oil was classified as an ordinary virgin olive oil. The analysis of the effect of the processing (two- and three-phases) on the analytical determinations values, revealed statistically significant differences (p<0.05) in some parameters, mainly in oxidative stability, antioxidant activity, total waxes, total phenols, o-diphenols and α-tocopherol contents as well as phenolic composition. The phenolic composition values were higher in the extra-virgin olive oil obtained from the two-phase system than in that obtained from the three-phase processing because it does not require the addition of water to the olive paste. Nevertheless, they were lower in the ordinary virgin olive oil (repassed olive oil) which was obtained by introducing hot water to the wet residues into the centrifugation processing at two-phases, than those in the extra-virgin olive oils obtained from the two- and three-phase processing.