Electrospray ionization mass spectrometry fingerprinting of essential oils: Spices from the Labiatae family

Lipophilized rosmarinic acid: Impact of alkyl type and food matrix on antioxidant activity, and optimized enzymatic production

In this study, the initial focus was on exploring the simultaneous impact of the oil-based food matrix and the polarity of rosmarinic acid derivatives on the antioxidant properties. Rosmarinic acid (RA) showed remarkable DPPH, FRAP, and ABTS radical scavenging activities, followed by methyl rosmarinate (MR) and ethyl rosmarinate (ER). In bulk oil, both conjugated dienes and p-AnV values reached a peak in the following order after 30 days: ER > MR > RA = BHT > control (no antioxidant). In the oil structured using monoacylglycerol, MR was more effective than ER and RA. For ethyl cellulose oleogel, emulsion, and gelled emulsion systems, RA was more effective. Additionally, after confirming the importance of the food matrix on the antioxidant activity of RA derivatives, the lipophilization of RA with ethanol was optimized as a model with Lipozyme 435 in hexane. A conversion yield of as high as 85.59% for ER was achieved, as quantified by HPLC-UV and confirmed by HPLC-DAD-ESI-qTOFMS.

Targeted UHPLC-QTOF-IMS based metabolite profiling for bioactive compounds in Rosa webbiana wallich ex royle: An unexploited native from western himalayas

The current study focused on the tissues of wild Rosa webbiana from different altitudes of Indian Western Himalayas for vitamin C content, total phenolics, flavonoids, total sugars, and antioxidant potential. To date, there are very few studies on underutilized tissues viz. fruits, leaves and stem of Rosa webbiana growing in the higher altitudes. The targeted UHPLC-QTOF-IMS illustrated the phenolics fingerprinting of tissue extracts. Twelve bioactive compounds were detected with quercetin, kaempferol, and their derivatives dominantly in stem and leaves. The results have revealed that fruits possessed the highest vitamin C, and sugar contents (960, and 191.6 mg/100 g, respectively). Compared to other tissues, leaves showed the highest total phenolics as well as best results in vitro assays employed to assess antioxidant potential. The antioxidant activity showed a positive correlation with total phenolics. A significant variation in total phenolics, total flavonoids, and antioxidant potential was mainly attributed to oxidative stress on plants due to altitude difference, and secondary metabolite production. Taken together, the underutilized tissues of Rosa webbiana could be exploited as a promising, low-cost resource of phenolic compounds in food, cosmetic, and pharmaceutical industries. Our study will pave the way to developing food products from Rosa webbiana, a natural source for health-conscious people.

Distribution profile of iridoid glycosides and phenolic compounds in two Barleria species and their correlation with antioxidant and antibacterial activity

INTRODUCTION

Barleria prionitis is known for its medicinal properties from ancient times. Bioactive iridoid glycosides and phenolic compounds have been isolated from leaves of this plant. However, other parts of a medicinal plants are also important, especially roots. Therefore, it is important to screen all organs for complete chemical characterization.

METHOD

All parts of B. prionitis, including leaf, root, stem and inflorescence in search of bioactive compounds, with a rapid and effective metabolomic method. X500R QTOF system with information dependent acquisition (IDA) method was used to collect high resolution accurate mass data (HRMS) on both the parent (MS signal) and their fragment ions (MS/MS signal). ESI spectra was obtained in positive ion mode from all parts of the plant. A comparative analysis of antioxidant and antibacterial activity was done and their correlation study with the identified compounds was demonstrated. Principal component analysis was performed.

RESULT

Iridoid glycosides and phenolic compounds were identified from all parts of the showing variability in presence and abundance. Many of the compounds are reported first time in B. prionitis. Antioxidant and antibacterial activity was revealed in all organs, root being the most effective one. Some of the iridoid glycoside and phenolic compounds found to be positively correlated with the tested biological activity. Principal component analysis of the chemical profiles showed variability in distribution of the compounds.

CONCLUSION

All parts of B. prionitis are rich source of bioactive iridoid glycosides and phenolic compounds.

Neuroprotective Potential of Tamarillo (Cyphomandra betacea) Epicarp Extracts Obtained by Sustainable Extraction Process

Tamarillo (Cyphomandra betacea (Cav.) Sendt.), or tree tomato, is a tropical fruit from the Andean region of South America; it is highly rich in vitamins, minerals, and polyphenolic compounds. In this study, extracts from tamarillo epicarp (TE) were obtained by pressurized liquid extraction (PLE), and their in-vitro neuroprotective potential was assessed. A central composite design with response surface methodology was performed to optimize PLE as a function of solvent composition and temperature. Selected response variables were extraction yield, total phenolic content (TPC), total flavonoid content (TFC), total carotenoid content (TCC), antioxidant (ABTS), and anti-inflammatory (LOX) activities, and anti-acetylcholinesterase (AChE) inhibitory capacity. According to the desirability function, the optimal conditions were 100% ethanol and 180°C with a 0.87 desirability value. Next, the anti-butyrylcholinesterase enzyme (BChE), reactive oxygen species (ROS), and reactive nitrogen species (RNS) inhibition as well as cytotoxicity in HK-2, THP-1 monocytes, and SH-5YSY neuroblastoma cell lines were studied for the TE extract obtained under optimized conditions. The optimum TE extract provided the following results: extraction yield (36.25%), TPC (92.09 mg GAE/g extract), TFC (4.4 mg QE/g extract), TCC (107.15 mg CE/g extract), antioxidant capacity (ABTS, IC₅₀ = 6.33 mg/ml extract), LOX (IC₅₀ = 48.3 mg/ml extract), and AChE (IC₅₀ = 97.46 mg/ml extract), and showed no toxicity at concentration up to 120 μg/ml extract for all the tested cell lines. Finally, chemical characterization by liquid chromatography-tandem mass spectrometry (UHPLC-q-TOF-MS/MS) of the optimum TE extract exhibited an important presence of hydroxycinnamic acid derivatives and other phenolic acids as well as quercetin hexoside and rutin, as main metabolites responsible for the observed biological properties. All these results suggested that TE, which represents between 8 and 15% of the total fruit, could become a promising natural by-product with a potential "multitarget" activity against Alzheimer's disease.

Analysis of Erythroxylum coca Leaves by Imaging Mass Spectrometry (MALDI-FT-ICR IMS)

Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) can determine the chemical identity and spatial distribution of several molecules in a single analysis, conserving its natural histology. However, there are no specific studies on the spatial distribution of alkaloids in Erythroxylum coca leaves by MALDI IMS, preserving the histology of the monitored compounds. Therefore, in this work, positive-ion mode MALDI Fourier-transform ion cyclotron resonance imaging mass spectrometry (MALDI(+)FT-ICR IMS) was applied to identify and analyze the distribution of alkaloids on the surface of coca leaves, evaluating the ionization efficiency of three matrices (α-cyano-4-hydroxycinnamic acid (CHCA), 2-mercaptobenzothiazole (MBT), and 2,5-dihydroxybenzoic acid (DHB)). The last was chosen as the best matrix in this study, and it was studied in five concentrations (0.5, 1.0, 2.0, 4.0, and 8.0 mg·mL^-1), where 2 mg·mL^-1 was the most efficient. The washing of coca leaves with the organic solvents (acetonitrile, methanol, toluene, and dichloromethane) tested did not improve the performance of the ionization process. Finally, a tissue section, 50 μm thick, was used to study the inner part of the leaf tissue, where alkaloids and flavonoid molecules were detected.

LC-MS Analysis and Antioxidant Activity of the Hydro-alcoholic Extract of Melissa Officinalis L. From Algeria

The present work focuses on evaluation of the chemical composition and antioxidant activity of the hydro-methanolic extract of Melissa officinalis from Algeria. The liquid chromatography-mass spectrometry analysis allowed the identification of six compounds: caffeic acid, caftaric acid, hydroxyjasmonic acid glucoside, caftaric acid glucoside, rosmarinic acid and sagerinic acid. The in-vitro antioxidant activity of the hydro-methanolic extract was evaluated by using four different methods including: radical scavenging assay (DPPH), scavenging activity (ABTS), cupric reducing antioxidant capacity, and ferric reducing power assay. The extract exhibited a relatively strong antioxidant activity compared to the synthetic antioxidants. The highest radical scavenging activity was registered using DPPH and ABTS methods, IC50= 20.53±2.64 μg/mL and 22.50±0.67 μg/mL, respectively. These results suggest that Melissa officinalis L. could be considered a potential source of natural antioxidants with potential interest in the agrochemical and pharmaceutical industries.

Finding solutions for agricultural wastes: antioxidant and antitumor properties of pomegranate Akko peel extracts and β-glucan recovery

Pomegranate peels are the major by-products of the processing of pomegranate juice. Scientific research studies have shown that pomegranate peels are an extraordinary source of bioactive compounds, most of which can be converted into value added products. From this point of view, the present study was carried out with the aim of providing a solid basis for the use of whole pomegranate peels (Akko variety) as a source of nutraceutical compounds, such as β-glucans. Moreover, acetone (S1) and methanolic (S2) extracts, obtained in the preliminary stage of the β-glucan isolation procedure, have been tested for their antioxidant and antitumor activities. The total phenolic content and phenolic profile of S1 and S2 were determined. S1 and S2 exhibited a significant DPPH scavenging activity, with an IC50 value for S1 1.5-fold lower than that for the standard Trolox. Both S1 and S2 extracts possess in vitro ROS scavenging activity toward 3T3-L1 murine fibroblasts and Hek-293 human embryonic kidney epithelial cells and antiproliferative activity towards human breast MCF-7 and uterine HeLa cancer cells.

Qualitative and quantitative analysis on the chemical constituents in Orthosiphon stamineus Benth. using ultra high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

A sensitive and efficient method was established and validated for qualitative and quantitative analysis on the chemical constituents in Orthosiphon stamineus Benth. (O. stamineus) using ultra high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Based on the retention time and MS spectra, 61 compounds were detected by using ultra high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry. 52 chemical structures in the O. stamineus extracts including 26 phenolic acids, 11 flavonoids, 6 diterpenoids, 4 fatty acids and 5 tanshinones were tentatively identified without the time-consuming process of isolation. Moreover, five chemical constituents (Danshensu, Caffeic acid, Rosmarinic acid, Sinensetin and Eupatorin) were quantified in three different batches of O. stamineus samples by the developed ultra high-performance liquid chromatography coupled with electrospray ionization triple-quadrupole mass spectrometry method in 10 min. The method validation of the five compounds was performed with acceptable linearity (R², 0.9930-0.9997), precision (RSD, 1.87-10.36%), repeatability (RSD, 0.59-4.87%) and recovery (105.30-110.53%, RSD ≤ 13.90%).

Flavonoid Constituents of Phlomis (Lamiaceae) Species Using Liquid Chromatography Mass Spectrometry

INTRODUCTION

Phlomis is one of the medicinal genera of Lamiaceae. This genus has unique medicinal properties. Consequently, appropriate methods need to be described for the identification of the chemical compounds.

OBJECTIVE

A liquid chromatography tandem mass spectrometry (LC-MS/MS) technique on a triple quadrupole mass spectrometer (TQMS) was used for separation and identification of leaf flavonoid compounds for seven Phlomis species including Phlomis kurdia, Ph. aucheri, Ph. olivieri, Ph. bruguieri, Ph. persica, Ph. anisodonta and Ph. elliptica.

METHODOLOGY

The flavonoid solution of air-dried leaves (10.5 g) was extracted using 85% methanol. The chromatogram was treated with three systems: methanol-water, chloroform-methanol and acetic acid. The extracts were analysed using LC-MS/MS. The MS² detection was performed under negative mode electrospray ionisation (ESI). The identification of constituents was based on authentic references used in the identification process.

RESULTS

A total of 35 chemical compounds were detected from which 32 were identified as flavonoids through comparison with published literature and reference standards. These compounds were distributed in four flavonoid classes. Flavones (12), flavonols (11), flavanones (8) and flavane (1) were the main groups appearing in almost all of the studied samples. The flavonoids such as naringenin, chrysoeriol, eriodictyol, dimethoxyflavanone, apigenin, luteolin, kaempferol and rhamnetin were in high proportions. Moreover, 22 flavonoid compounds were first reported in this study for Phlomis species.

CONCLUSION

The fragmentation patterns of the compounds during collision induced dissociation (CID) clarified information of the compounds analysed. The detailed flavonoid compositions of Phlomis species provide the appropriate context from phytochemical and phytotherapeutics points of view. Copyright © 2017 John Wiley & Sons, Ltd.

Phytochemical Characterization and Biological Evaluation of the Aqueous and Supercritical Fluid Extracts from Salvia sclareoides Brot

Plants belonging to the genus Salvia (Lamiaceae) are known to have a wide range of biological properties. In this work, extracts obtained from the aerial parts of Salvia sclareoides Brot. were evaluated to investigate their chemical composition, toxicity, bioactivity, and stability under in vitro gastrointestinal conditions. The composition of the supercritical fluid extract was determined by GC and GC-MS, while the identification of the infusion constituents was performed by HPLC-DAD and LC-MS. The in vitro cytotoxicity of both extracts (0-2 mg/mL) was evaluated in Caco-2 cell lines by the MTT assay. The anti-inflammatory and anticholinesterase activities were determined through the inhibition of cyclooxygenase-1 and acetylcholinesterase enzymes, while β-carotene/linoleic acid bleaching test and the DPPH assays were used to evaluate the antioxidant activity. The infusion inhibited cyclooxygenase-1 (IC50 = 271.0 μg/mL), and acetylcholinesterase (IC50 = 487.7 μg/ mL) enzymes, also demonstrated significant antioxidant properties, as evaluated by the DPPH (IC50 = 10.4 μg/mL) and β-carotene/linoleic acid (IC50 = 30.0 μg/mL) assays. No remarkable alterations in the composition or in the bioactivities of the infusion were observed after in vitro digestion, which supports the potential of S. sclareoides as a source of bioactive ingredients with neuroprotective, anti-inflammatory and antioxidant properties.

Antioxidant activity guided separation of major polyphenols of marjoram (Origanum majorana L.) using flash chromatography and their identification by liquid chromatography coupled with electrospray ionization tandem mass spectrometry

Marjoram extracts have been separated into polar and nonpolar parts using liquid-liquid extraction. Both polar and nonpolar parts of the extracts were further fractionated by flash chromatography. The obtained fractions (90 polar and 45 nonpolar fractions) were investigated for their antioxidant activities by 2,2-diphenylpicrylhydrazyl and ferric ion reducing antioxidant power assays. A direct, positive, and linear relationship between antioxidant activity and total phenolic content of the fractions was observed. Based on antioxidant and total phenolic content data, the three fractions with the high antioxidant activities from polar and nonpolar part of the extract were analyzed for their constituent polyphenols by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. Compounds were identified by matching the mass spectral data and retention time with those of authentic standards. Identification of the compounds for which there were no "in-house" standards available was carried out by accurate mass measurement of the precursor ions and product ions generated from collision-induced dissociation. Rosmarinic acid was found to be the strongest antioxidant polyphenol conferring the highest antioxidant activity to fractions 47 and 17 of polar and nonpolar part of the extract, respectively. The identification of the rosmarinic acid was further confirmed by (1) H NMR spectroscopy.

Electrospray ionization mass spectrometry and partial least squares discriminant analysis applied to the quality control of olive oil

Direct infusion electrospray ionization mass spectrometry in the positive ion mode [ESI(+)-MS] is used to obtain fingerprints of aqueous-methanolic extracts of two types of olive oils, extra virgin (EV) and ordinary (OR), as well as of samples of EV olive oil adulterated by the addition of OR olive oil and other edible oils: corn (CO), sunflower (SF), soybean (SO) and canola (CA). The MS data is treated by the partial least squares discriminant analysis (PLS-DA) protocol aiming at discriminating the above-mentioned classes formed by the genuine olive oils, EV (1) and OR (2), as well as the EV adulterated samples, i.e. EV/SO (3), EV/CO (4), EV/SF (5), EV/CA (6) and EV/OR (7). The PLS-DA model employed is built with 190 and 70 samples for the training and test sets, respectively. For all classes (1-7), EV and OR olive oils as well as the adulterated samples (in a proportion varying from 0.5 to 20.0% w/w) are properly classified. The developed methodology required no ions identification and demonstrated to be fast, as each measurement lasted about 3 min including the extraction step and MS analysis, and reliable, because high sensitivities (rate of true positives) and specificities (rate of true negatives) were achieved. Finally, it can be envisaged that this approach has potential to be applied in quality control of EV olive oils.

Molecular recognition of rosmarinic acid from Salvia sclareoides extracts by acetylcholinesterase: a new binding site detected by NMR spectroscopy

Acetylcholinesterase (AChE) inhibition is one of the most currently available therapies for the management of Alzheimer's disease (AD) symptoms. In this context, NMR spectroscopy binding studies were accomplished to explain the inhibition of AChE activity by Salvia sclareoides extracts. HPLC-MS analyses of the acetone, butanol and water extracts eluted with methanol and acidified water showed that rosmarinic acid is present in all the studied samples and is a major constituent of butanol and water extracts. Moreover, luteolin 4'-O-glucoside, luteolin 3',7-di-O-glucoside and luteolin 7-O-(6''-O-acetylglucoside) were identified by MS(2) and MS(3) data acquired during the LC-MS(n) runs. Quantification of rosmarinic acid by HPLC with diode-array detection (DAD) showed that the butanol extract is the richest one in this component (134 μg mg(-1) extract). Saturation transfer difference (STD) NMR spectroscopy binding experiments of S. sclareoides crude extracts in the presence of AChE in buffer solution determined rosmarinic acid as the only explicit binder for AChE. Furthermore, the binding epitope and the AChE-bound conformation of rosmarinic acid were further elucidated by STD and transferred NOE effect (trNOESY) experiments. As a control, NMR spectroscopy binding experiments were also carried out with pure rosmarinic acid, thus confirming the specific interaction and inhibition of this compound against AChE. The binding site of AChE for rosmarinic acid was also investigated by STD-based competition binding experiments using Donepezil, a drug currently used to treat AD, as a reference. These competition experiments demonstrated that rosmarinic acid does not compete with Donepezil for the same binding site. A 3D model of the molecular complex has been proposed. Therefore, the combination of the NMR spectroscopy based data with molecular modelling has permitted us to detect a new binding site in AChE, which could be used for future drug development.

Iberian ham typification by direct infusion electrospray and photospray ionization mass spectrometry fingerprinting

RATIONALE

Iberian ham is a product of high commercial value whose quality mainly depends on breeding and feeding of pigs in an authorized way. Simple, fast, simple, reliable and high-throughput analytical methods are necessary to assure the quality of ham and for fraud prevention. Tandem mass spectrometry (MS/MS) is proposed as an advantageous alternative over other analytical techniques commonly used in this industry for product authentication.

METHODS

The analytical approach is based on direct infusion electrospray mass spectrometry (ESI(+)-MS) of dichloromethane/methanol (60:40) extracts of ham intramuscular fat. Similarly, atmospheric pressure photoionization ionization mass spectrometry (APPI(+)-MS) was used with a flow injection analysis system for sample introduction with methanol/water (50%) as the mobile phase and toluene as the dopant. All experiments were performed on an API QSTAR® XL Hybrid system using both ESI and APPI sources.

RESULTS

The ESI(+)-MS mass spectra present several clusters of peaks attributed to ammonium adducts [M + NH(4) (+) ] of lipid compounds (mono-, di- and triacylglycerols - MGs, DGs, TGs, and free fatty acids - FFAs), that can be identified by MS/MS spectra. On the other hand, the APPI(+)-MS spectra present [M + H(+) ] ions and reflect a higher fragmentation of the sample. Five different types of Iberian ham samples were successfully classified using partial least-squares discriminant analysis (PLS-DA) of data from these samples.

CONCLUSIONS

The application of direct infusion tandem mass spectrometry to dichloromethane/methanol extracts from intramuscular fat ham allows the simple, fast and reliable fingerprinting typification of different Iberian ham samples from pigs with different diets. With the proposed method, sample handling is minimal and chromatographic separation is not necessary, which represents an evident advantage over other analytical procedures usually used for this purpose.

Antioxidant Capacity and Phenolic Content of four Myrtaceae Plants of the South of Brazil

Antioxidant compounds can be useful to prevent several degenerative diseases or as preservative in food and toiletries. Species of the Myrtaceae family are able to accumulate phenolic substances and those are closely related to the antioxidant activity due to their capacity to scavenge free radicals, protect against lipid peroxidation and quench reactive oxygen species. These facts prompted us to investigate the antioxidant capacity of the ethanolic extracts of the leaves of four Myrtaceae plants collected of the south of Brazil: Eugenia chlorophylla O. Berg., Eugenia pyriformis Cambess, Myrcia laruotteana Cambess and Myrcia obtecta (Berg) Kiacrsk. The antioxidant potential was performed using the DPPH (a single electron transfer reaction based assay) and ORAC (Oxygen Radical Absorbance Capacity, a hydrogen atom transfer reaction based assay) assays. Moreover, the total soluble phenolic content was also measured using the Folin-Ciocalteu reagent. A preliminary evaluation of the ethanolic extracts of these Myrtaceae plants revealed high levels of phenolic compounds (343.7-429.3 mg GAE) as well as high antioxidant activity according to both methods (1338 a 3785 μmol of TE/g of extract in ORAC and SC50 in the range of 1.70 and 33.7 μg/mL in the DPPH). The highest antioxidant activity obtained by DPPH assay was exhibited by ethanol extract of the leaves of E. pyriformis (1.70 μg/mL), followed by extracts of M. laruotteana (3.38 μg/mL) and M. obtecta (6.66 μg/mL). In comparison with controls, in the DPPH assay, the extract of E. pyriformis was more active than trolox (SC50 = 2.55 μg/mL), while the extracts of M. laruotteana and M. obtecta were more actives than quercetin (SC50 = 7.80 μg/mL). In the ORAC assay, all species also show good antioxidant capacity (>1000 μmol of TE/g). Initial HPLC-UV/DAD and ESIMS confirmed the presence of phenolic acids constituents in the ethanol extracts. The results indicate the presence of compounds possessing promising antioxidant/free-radical scavenging activity in the analyzed extracts of Myrcia and Eugenia plants of the south of Brazil.

Discrimination of n-3 rich oils by gas chromatography

Exploring the capabilities of instrumental techniques for discriminating n-3 rich oils derived from animals is a very important though much neglected area that was emphasized more than 100 years ago. In this study the potential of gas chromatography (GC) for discriminating full fatty acid methyl ester (FAME) profiles from fish (cod liver and salmon) and marine mammal (seal and whale) oils is evaluated by means of principal component analysis (PCA). The FAME profiles from plant oils such as rapeseed, linseed and soy oils and seven different brands of n-3 supplements are also used in the discrimination process. The results from the PCA plots can reliably distinguish between plant, n-3 supplements, fish and marine mammal oils. By removing the contribution of the n-3 supplements and plant oils it is possible to discriminate between types of fish and marine animal oils. GC offers a rapid, simple and convenient means of discriminating oils from different species, brands and grades.

Characterization of phenolic composition in Lamiaceae spices by LC-ESI-MS/MS

A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices, rosemary, oregano, sage, basil, and thyme, were identified in the present study using LC-ESI-MS/MS. These compounds were distributed in four major categories, namely, hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, flavonoids, and phenolic terpenes. Among them, the category of flavonoids was the largest, with 17 compounds. Identification of the phenolic compounds was carried out by comparing retention times and mass spectra with those of authentic standards. If standards were unavailable, phenolic compounds were identified on the basis of accurate mass of pseudomolecular [M - H](-) ions and tandem mass spectrometry (MS/MS) data. The results of accurate mass measurements fit well with the elemental composition of the compounds. The diagnostic fragmentation patterns of the compounds during collision-induced dissociation (CID) elucidated the structural information of the compounds analyzed.

Extra virgin (EV) and ordinary (ON) olive oils: distinction and detection of adulteration (EV with ON) as determined by direct infusion electrospray ionization mass spectrometry and chemometric approaches

Extra virgin (EV), the finest and most expensive among all the olive oil grades, is often adulterated by the cheapest and lowest quality ordinary (ON) olive oil. A new methodology is described herein that provides a simple, rapid, and accurate way not only to detect such type of adulteration, but also to distinguish between these olive oil grades (EV and ON). This approach is based on the application of direct infusion electrospray ionization mass spectrometry in the positive ion mode, ESI(+)-MS, followed by the treatment of the MS data via exploratory statistical approaches, PCA (principal component analysis) and HCA (hierarchical clustering analysis). Ten distinct brands of each EV and ON olive oil, acquired at local stores, were analyzed by ESI(+)-MS and the results from HCA and PCA clearly indicated the formation of two distinct groups related to these two categories. For the adulteration study, one brand of each olive oil grade (EV and ON) was selected. The counterfeit samples (a total of 20) were then prepared by adding assorted proportions, from 1 to 20% w/w, with increments of 1% w/w, of the ON to the EV olive oil. The PCA and HCA methodologies, applied to the ESI(+)-MS data from the counterfeit (20) and authentic (10) EV samples, were able to readily detect adulteration, even at levels as low as 1% w/w.

Fingerprinting of yogurt products by laser desorption spray post-ionization mass spectrometry

Yogurt and related products have been directly analyzed using laser desorption spray post-ionization mass spectrometry (LDSPI-MS) in positive ion mode. Assignments are made for some of the abundant diagnostic peaks through LDSPI-MS/MS analysis in comparison with authentic compounds. It is demonstrated that different yogurt products can be reliably differentiated according to their LDSPI-MS spectra. Principal component analysis (PCA) is further used to clearly show the capability of LDSPI-MS fingerprinting for rapid sorting of yogurt products. We believe that this sample-preparation-free technique can be a very useful product screening tool in the dairy industry because of its simplicity, reliability and high throughput.

RAPD-based method for the quality control of Mediterranean oregano and its contribution to pharmacognostic techniques

A pharmacognostic survey of 84 commercial samples of Mediterranean oregano, obtained from wholesale traders between 2001 and 2007, pinpointed the presence of extraneous plant material in 90.5% of the samples. In 59% of them extraneous material of plant origin was above 20%. Two major groups of botanical foreign matter were identified: oregano-like flavored plants ( Satureja montana L., Origanum majorana L.) and plants lacking a clearly detectable essential oil profile ( Rubus sp., Cistus incanus L., Rhus coriaria L.), added as bulk extraneous material. A random amplified polymorphic DNA (RAPD) method was developed to make the detection of the second group of adulterants easier and speed pharmacognostic analysis of large batches of samples. Thirteen primers discriminating between Origanum spp. and Rubus caesius , R.coriaria, and C. incanus were individuated, allowing their detection in oregano samples with a limit of detection of 1%. The utilization of RAPD as a reliable test to probe the authenticity of Mediterranean oregano or previously screen the presence of specific contaminants is proposed as a complementary approach to pharmacognostic and phytochemical screening.

Antioxidant activity and ultra-performance LC-electrospray ionization-quadrupole time-of-flight mass spectrometry for phenolics-based fingerprinting of Rose species: Rosa damascena, Rosa bourboniana and Rosa brunonii

Roses are one of the most important groups of ornamental plants and their fruits and flowers are used in a wide variety of food, nutritional products and different traditional medicines. The antioxidant activity of methanolic extracts from fresh flowers of three rose species (Rosa damascena, Rosa bourboniana and Rosa brunonii) was evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical method. The ability to scavenge DPPH radical was measured by the discoloration of the solution. The methanolic extract from R. brunonii exhibited maximum free-radical-scavenging activity (64.5+/-0.38%) followed by R. bourboniana (51.8+/-0.46%) and R. damascena (43.6+/-0.25%) at 100 microg/ml. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study phenolic composition in the methanolic extracts from the fresh flowers of rose species. The phenolic constituents were further investigated by direct infusion-ESI-QTOF-MS/MS in negative ion mode. Characteristic Electrospray ionization tandem mass spectrometry (ESI-MS/MS) spectra with other diagnostic fragment ions generated by retro Diels-Alder (RDA) fragmentation pathways were recorded for the flavonoids. Distinct similarities were observed in the relative distribution of polyphenolic compounds among the three species. The dominance of quercetin, kaempferol and their glycosides was observed in all the three species.

Electrospray ionization mass spectrometry fingerprinting of perfumes: Rapid classification and counterfeit detection

A fast procedure to classify perfumes and identify counterfeit samples is described. Dilution of a few microL of the sample in a 1:1 methanol/water solution is followed by detection of its major polar components via direct infusion electrospray ionization mass spectrometry (ESI-MS) in the positive ion mode. As proof-of-principle cases, three famous brands of perfumes were used. The ESI+-MS fingerprints of authentic samples were very characteristic, showing distinctive sets of polar markers for each sample. Principal component analysis (PCA) placed samples of the three perfume brands in well-defined groups. Counterfeit samples were also clearly detected owing to contrasting ESI-MS fingerprints, with PCA placing these samples far away from the authentic samples.