Inula viscosa (L.) Aiton leaves and flower buds: Effect of extraction solvent/technique on their antioxidant ability, antimicrobial properties and phenolic profile.

This study was designed to establish the most effective solvent/technique for extracting antioxidant phytoconstituents from leaves and flower buds of Inula viscosa (L.) Aiton (Asteraceae) grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. The antioxidant potential was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. I. viscosa leaf and flower bud extracts displayed the strongest effect in the DPPH test, being the Soxhlet ethanol the most active ones (IC50 = 54.24 ± 0.21 µg/mL and 39.77 ± 0.23 µg/mL); thus, they were selected for further investigations. The antimicrobial efficacy of the Soxhlet ethanol extracts against ATCC and food isolates strains was assayed; the leaf extract showed the best activity, and Candida albicans was the most sensitive strain (MIC = 125 µg/mL). The extracts resulted non-toxic against Artemia salina. Among the phenolics characterised by HPLC-PDA-ESI-MS, hispidulin hexoside, patuletin and spinacetin were identified for the first time.

Ionic liquids as stationary phases for fatty acid analysis by gas chromatography.

The present paper provides an overview of the application of ionic liquid (IL) columns for GC analysis of fatty acid methyl esters (FAMEs). Although their separation can be carried out utilizing GC columns containing polar stationary phases, some ILs have been employed as stationary phases, either commercial or laboratory made, in GC analysis. Monodimensional and bidimensional GC methods have been optimized in order to achieve the best separation especially considering the geometric and positional isomers of unsaturated fatty acids. Several methods for the analysis of trans-fatty acids have also been reported. The use of GC-GC, using either the same IL columns or different columns in the first and second dimensions, allowed the separation of a large number of FAMEs. The application of the IL columns for GC analysis of FAMEs in different types of real samples is described, e.g., oil of different nature (fish, flaxseed, and olive), margarine and butter, biodiesel, milk, bacteria etc.

Electronic nose and GC-MS analysis of volatile compounds in Tuber magnatum Pico: evaluation of different storage conditions.

The characteristic aromatic composition of white truffles (Tuber magnatum Pico) determines its culinary and commercial value. However modifications of truffle organoleptic proprieties occur during preservation. A study of headspace of white truffles by using Electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS) and sensory analyses was performed. Truffles were stored at different conditions for 7 days: +4 and +8°C wrapped in blotting paper or covered by rice or none of the above. Headspace E-nose measurements and sensory analyses were performed each day. Statistical multivariate analysis of the data showed the capability of E-nose to predict sensorial analysis scores and to monitor aroma profile changes during storage. Truffle's volatile molecules were also extracted by headspace solid phase microextraction technique and separated and identified by GC-MS. Partial Components Analysis of data was performed. E-nose and GC-MS results were in agreement and showed that truffle storage in paper at +8°C seemed to be the best storage condition.

Betula pendula leaves: polyphenolic characterization and potential innovative use in skin whitening products.

The research of new tyrosinase inhibitors is currently important for the development of skin whitening agents; particularly, birch leaves extracts are included in many skin cosmetic products. In this study, the potential ability of Betula pendula leaves ethanolic extract (BE) was evaluated on mushroom tyrosinase activity. Results showed that BE was capable to inhibit dose-dependently l-DOPA oxidation catalyzed by tyrosinase. The inhibition kinetics, analyzed by Lineweaver-Burk plots, showed a noncompetitive inhibition of BE towards the enzyme, using l-DOPA as substrate. The inhibitory mechanism of BE as studied by spectrophotometric analysis, demonstrated its ability to chelate copper ion in the active site of tyrosinase. In addition, BE exhibited Fe(2+)-chelating ability (IC(50)=614.12±2.14 µg/mL), reducing power and radical-scavenging properties (IC(50)=137.22±1.98 µg/mL). These results suggest the usefulness of birch leaves extracts in cosmetic and pharmaceutical industries for their skin-whitening and antioxidant effects. Determination of the polyphenolic compounds in BE extracts was afterward achieved by means of high-performance liquid chromatography (HPLC) with photodiode array (PDA) and mass spectrometry (MS) detection. A total of 25 compounds were positively identified, through the complementary analytical information, and are reported in such a matrix for the first time. Knowledge on the qualitative composition and contents of these natural sources in fact represents mandatory information, for rational consumption and correlation of the beneficial effects to the specific amounts.

Phenolic composition and biological activities of Juniperus drupacea Labill. berries from Turkey.

The present study was designed to define the phenolic profile and the biological potential of berries methanol extract of Juniperus drupacea Labill. from Turkey. The total phenolic content (Folin-Ciocalteau assay) was 48.06±0.99mgGAE/g extract. The HPLC-DAD-ESI-MS analysis allowed the determination of the complete phenolic profile of J. drupacea berries. Phenolic acids represented more than 60% of the total phenolics, and tyrosol was the major one (1324±0.64µg/g extract); within the flavonoids amentoflavone was detected as the main constituent (927±0.35µg/g extract). The extract exhibited good antioxidant properties, as determined by different in vitro models: DPPH test (IC(50) 0.38±0.02mg/mL), reducing power (12.63±0.14ASE/mL), Fe(2+) chelating ability (IC(50) 2.26±0.06mg/mL), and TBA test (IC(50) 2.47±1.13µg/mL). Cytotoxicity against Artemia salina was highlighted (LC(50) 489.47±27.8µg/mL), and a significant decrease (p⩽0.05; p⩽0.01) in HepG2 cells viability was observed at the higher concentrations (5-10µg/mL). The extract displayed good antibacterial activity towards Gram-positive bacteria and in particular Staphylococcus aureus was the most susceptible strain (MIC 78.12µg/mL).

Comprehensive chromatographic separations in proteomics.

In such a complicated field as proteomic analysis, scientists are more and more challenged in implementing separation systems capable to provide enhanced separation power, as well as sensitivity of detection for adequate identification and, to a lesser extent, quantification of the separated compounds. To address such issues, several combinations of different separation modes have been investigated in comprehensive liquid chromatographic platforms, in which the entire sample eluted from the first dimension is subjected to a secondary chromatographic separation. The different applications exploited for comprehensive LC analysis of intact or digested proteins are the focus of this review, in which advantages and disadvantages of the different columns combinations, interfaces, and operating modes are pointed out. The combination with mass spectrometry as part of the total system is stressed, and illustrated in more detail. Theoretical concerns and practical requirements will be briefly discussed, as well.

Volatiles from steam-distilled leaves of some plant species from Madagascar and New Zealand and evaluation of their biological activity.

Steam-distilled aerial parts of Ravensara aromatica and Cinnamomum camphora from Madagascar and Leptospermum scoparium from New Zealand have been subjected to qualitative and quantitative analysis by means of GC techniques. This allowed the elucidation of conflicting data present in the available literature for these species. Also, the biological activity in vitro was evaluated by measuring MICs and GIZs.

Comprehensive normal-phase x reversed-phase liquid chromatography coupled to photodiode array and mass spectrometry detection for the analysis of free carotenoids and carotenoid esters from mandarin.

In the present work, a novel strategy including the use of two different comprehensive HPLC methods has been employed to study the whole carotenoid composition of mandarin essential oil. Thus, two different fully orthogonal two-dimensional HPLC methods have been used. A silica microbore column was coupled to a C(18) monolithic column to study the mandarin saponified extract, while the coupling of a cyano microbore column to a C(18) monolithic column was employed to study the intact mandarin essential oil sample in order to characterize the native carotenoid esters composition. Detection was performed by connecting a photodiode array detection (DAD) system in parallel with a MS detection system operated with an atmospheric pressure chemical ionization (APCI) interface. Thus, the carotenoid identification was carried out by combining the information provided by the DAD and MS systems and the peaks relative position in the two-dimensional chromatograms.

Antifungal activity of essential oils against filamentous fungi determined by broth microdilution and vapour contact methods.

AIMS: The in vitro activity of some essential oils (EO) (thyme red, fennel, clove, pine, sage, lemon balm and lavender) against clinical and environmental fungal strains was determined. METHODS AND RESULTS: The minimal inhibitory concentrations were determined by a microdilution method in RPMI 1640 and by a vapour contact assay. The composition of oils was analysed by gas chromatography (GC) and GC/mass spectrometry. The results indicated that the oils antifungal activity depended on the experimental assay used. The inhibiting effects of EO in vapour phase were generally higher than those in liquid state. According to both methods thyme red and clove were found to be the oils with the widest spectrum of activity against all fungi tested. CONCLUSIONS: Despite the differences between the two methods, our results demonstrate that some EO are very active on dermatophytes and dematiaceous fungi. However, more data will be necessary to confirm this good in vitro efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: This study could identify candidates of EO for developing alternative methods to control environmental and clinically undesirable filamentous fungi.

Comprehensive two-dimensional liquid chromatography combined with mass spectrometric detection in the analyses of triacylglycerols in natural lipidic matrixes.

Triacylglycerols (TAGs), the major components in fats and oils, are a good example of natural complex mixtures. The best technique for the separation of such samples is certainly high performance liquid chromatography (HPLC). Monodimensional HPLC separations are often not sufficient to resolve all the components of interest. The present investigation reports the employment of a comprehensive LC system, based on the different separation mechanisms of silver ion (Ag) and non-aqueous reversed phase (RP) HPLC, used respectively in the first and second dimension, and applied to the analysis of plant-derived natural lipidic matrixes. The results obtained show that the approach enables both the separation of a high number of components and the attainment of structural information due to the formation of group-type patterns on the bidimensional (2D) plane. The employment of atmospheric pressure chemical ionisation (APCI) mass spectrometry as detection system was of substantial support for reliable TAG assignment, thus increasing the identification power of this comprehensive chromatographic approach.

Silver-ion reversed-phase comprehensive two-dimensional liquid chromatography combined with mass spectrometric detection in lipidic food analysis.

The triacylglycerol (TAG) profiles present in real world lipidic samples are usually quite complex and, as such, monodimensional high-performance liquid chromatographic (HPLC) techniques are inadequate when challenged with such matrices. In this respect, the complementary use of silver-ion (Ag) and non-aqueous (NA) reversed-phase (RP) HPLC can be exploited if thorough TAG separations are required. The present investigation reports the employment of a newly developed comprehensive LC (LC x LC) system, based on the different separation mechanisms of the aforementioned techniques, and applied to a rice oil sample. The approach was successful in the separation of a high number of solutes, otherwise unachievable through monodimensional LC. Furthermore, the use of atmospheric pressure chemical ionization mass spectrometry (APCI-MS), as detection system, provided a third analytical dimension boosting the identification power of the comprehensive chromatographic method.

Antioxidants in Sicilian wines: analytic and compositive aspects.

The beneficial effects of wine are associated with the physiological protection conferred by phenolic compounds such as anthocyanins and resveratrol. Levels of these phenolic compounds were quantified in 19 monovarietal wines produced in Sicily. Resveratrol and resveratrol-glucosides were detected by high-performance liquid chromatography (HPLC) with an ultraviolet detector, while anthocyanins were determined by micro-HPLC-Electron Spray Ionization-Mass Spectroscopy (ESI-MS) analysis. The amount of cis- and trans-resveratrol and of cis- and trans-piceid varied in the different types of wine, depending on the grape variety. Red wines presented higher contents of resveratrol and resveratrol-glucosides, whereas lower concentrations were present in white wines. In Merlot wine, the concentration of trans-piceid (5.04 mg/l) was significantly greater than in the other wines and represented the highest concentration among all the resveratrol isomers. Fourteen components were identified and dosed in the anthocyanin fraction. The highest concentration of total anthocyanins (417 mg/l) was found in the Cabernet Sauvignon wine, while the highest value among the wines made from the autochthonous grapes was found in Nero d'Avola. Antioxidant capacity was also studied. The results show that the antioxidant capacity of wines is strictly related to the amount of phenolic compounds.

Identification of anthocyanins in berries by narrow-bore high-performance liquid chromatography with electrospray ionization detection.

Qualitative determination of anthocyanins in extracts of red fruits by narrow-bore HPLC/ESI-MS was carried out. This method was used to investigate anthocyanin contents of black bilberry (Vaccinium myrtillus L.), blackberry (Rubus sp.), and mulberry (Morus nigra). An ultraviolet diode array and a mass spectrometer with ESI source were used for detection. Anthocyanin identifications were made by using retention time data and UV-vis and mass spectra and comparing them with those of commercially available standard compounds. The method allowed the identification of fourteen anthocyanins in black bilberry extract, six anthocyanins in blackberry extract, and five anthocyanins in mulberry extract.

LC-MS for the identification of oxygen heterocyclic compounds in citrus essential oils.

The oxygen heterocyclic compounds (coumarins, psoralens and polymethoxylated flavones) present in the nonvolatile residue of the essential oils of Mandarin, Sweet Orange, Bitter Orange, Bergamot and Grapefruit were analysed with an HPLC/API/MS system equipped with an APcI probe in positive mode. The use of hyphenated techniques, such as LC/MS provides a great information about the content and nature of constituents of natural complex matrices, such as essential oils. In this work, MS spectra were recorded at different voltages, to obtain structural information in addition to molecular weight information. The different response of the compounds identified has been also evaluated. The method allowed the confirmation of the identification of the main components of the fraction, previously reported for the different oils. MS characteristics of coumarins, psoralens and polymethoxylated flavones with different substitution patterns were determined on the basis of the response obtained with the APcI interface. Interface parameters were optimised to obtain a contemporaneous response for all the three classes of components.

Determination of anthocyanins in blood orange juices by HPLC analysis.

Determination of anthocyanins in fresh and concentrated juices can be a parameter for the assessment of authenticity and quality of blood orange juices. This work reports an HPLC/UV-Vis method developed for quantitative determination of anthocyanins in blood orange juices, by using a calibration curve obtained for standard cyanidin-3-glucoside. Samples analysed have been obtained from fruits of different trees (one for each of the varieties: 'Moro', 'Tarocco', 'Sanguinello' and 'Sanguinello nocellare') harvested about every 15 days during the 1998 productive season. Seasonal variation has been also evaluated. HPLC results were compared with spectrophotometric measurements, using a calibration curve obtained for cyanidin-3-glucoside solutions. The two methods showed good agreement, but the results obtained greatly differed with the data reported in the literature.

Fast HPLC for the analysis of oxygen heterocyclic compounds of citrus essential oils.

A fast HPLC method for the determination of the oxygen heterocyclic compounds of citrus essential oils was developed. Five different oils were analyzed under identical conditions, by reversed-phase HPLC with photodiode array detector, for a direct comparison of the composition of their oxygen heterocyclic fraction. Analysis time was 7 min. The oils analyzed were lemon, bergamot, mandarin, sweet orange, and bitter orange. The method developed is good for rapid screening or fingerprinting of these essential oils; a slightly slower method is recommended for higher resolution and better quantitative results.