Phytochemical evaluation and exploration of some biological activities of aqueous and ethanolic extracts of two species of the genus Plantago L.

Plantago major L. and Plantago lagopus L. are cosmopolitan species, belonging to the Plantaginaceae family, used in traditional and modern medicine. In this study, a phytochemical evaluation of different aqueous and ethanolic extracts of leaves and roots of both species from the region of Beja in Tunisia was performed. Some biological activities, including antioxidant, anticancer and antibacterial were also done. LC-MS qualitative analysis revealed that the aqueous extracts of the roots of P. lagopus were richer in polyphenols, mainly flavonoids (Luteoline 7-rutinoside, Luteoline 7-rhamnoside) and hydroxycinnamic acids including caffeic acid, than the hydro-ethanolic extracts. Additionally, we identified for the first time the presence of salicylic acid in the hot aqueous extracts of roots of P. lagopus and its absence in the roots of P. major. The antioxidant activity of the extracts was assessed using cyclic voltammetry (CV), revealing that the voltammograms of leaf and root extracts from P. lagopus exhibited a higher antioxidant capacity compared to those of P. major. Antiproliferative activity, was determined against two-colon cancer cell lines, demonstrated that only the 12 h treatments with P. lagopus leaf and root aqueous and hydro-ethanolic extracts at low concentration were able to significantly reduce the colon carcinoma coli-2 (CaCo-2) cells proliferation. The antibacterial /antibiofilm activity was performed on yeast, Gram- negative and +positive bacterial strains. We demonstrated for the first time that ethanolic extracts of leaves and roots of P. lagopus have an inhibitory activity against Escherichia coli and Klebsiella pneumonia at MIC = 2 µg/mL for leaves and 4 µg/mL for roots.

Heavy metals in biological samples of cancer patients: a systematic literature review.

The majority of the so-called heavy metals are suspected to be involved in a number of pathologies and play a role in human carcinogenesis. Some of them (i.e. arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), mercury (Hg) and nickel (Ni)) have been defined as carcinogens, increasing the susceptibility of tumor development and progression in humans. Moreover, Ni, Cr, Cd, Hg, and Pb together with zinc (Zn) and iron (Fe), may be capable of stimulating the progression of breast cancer and reducing a patient's sensitivity to treatment through alterations to DNA methylation. In patients with gastric cancers, levels of various heavy metals are augmented and hypothesized to amplify the expression of the human epidermal growth factor receptor type 2 gene. Cd may increase the risk of lung cancer development and have a negative impact on the overall survival of lung cancer patients. To investigate the relation between heavy metals in biological samples and risk, occurrence and survival cancer individuals, a comprehensive review work was performed, with a focus on breast, lung, prostate and gastric cancers. An extensive search strategy was devised to ensure relevant literature could be identified, with the PECO framework being adopted to facilitate this and identify key search terms. As evidenced in this review, there is substantial data to support the hypothesis that heavy metals influence tumor development and progression. Unluckily the number of papers dealing with the determination of metals directly in samples from cancer tissues is still rather limited, so we decided to expand the scope of this review also to analyses carried out on other biological samples, as urine, plasma, hair, nail, etc. The studies reviewed showed that several limitations and current knowledge gaps are present in the literature that require further investigation to improve our comprehension of the impact of different heavy metals on tumorigenesis.

Decoding the Microbiome's Influence on Rheumatoid Arthritis.

The aim is better to understand and critically explore and present the available data from observational studies on the pathogenetic role of the microbiome in the development of rheumatoid arthritis (RA). The electronic databases PubMed, Scopus, and Web of Science were screened for the relevant literature published in the last ten years. The primary outcomes investigated included the influence of the gut microbiome on the pathogenesis and development of rheumatoid arthritis, exploring the changes in microbiota diversity and relative abundance of microbial taxa in individuals with RA and healthy controls (HCs). The risk of bias in the included literature was assessed using the GRADE criteria. Ten observational studies were identified and included in the qualitative assessment. A total of 647 individuals with RA were represented in the literature, in addition to 16 individuals with psoriatic arthritis (PsA) and 247 HCs. The biospecimens comprised fecal samples across all the included literature, with 16S rDNA sequencing representing the primary method of biological analyses. Significant differences were observed in the RA microbiome compared to that of HCs: a decrease in Faecalibacterium, Fusicatenibacter, Enterococcus, and Megamonas and increases in Eggerthellales, Collinsella, Prevotella copri, Klebsiella, Escherichia, Eisenbergiella, and Flavobacterium. There are significant alterations in the microbiome of individuals with RA compared to HCs. This includes an increase in Prevotella copri and Lactobacillus and reductions in Collinsella. Collectively, these alterations are proposed to induce inflammatory responses and degrade the integrity of the intestinal barrier; however, further studies are needed to confirm this relationship.

Low concentrations of Ambrosia maritima L. phenolic extract protect endothelial cells from oxidative cell death induced by H2O2 and sera from Crohn's disease patients.

ETHNOPHARMACOLOGICAL RELEVANCE: A rising resort to herbal therapies in Crohn's disease (CD) alternative treatments has been recently observed due to their remarkable natural efficiency. In this context, the weed plant Ambrosia maritima L., traditionally known as Hachich el Aouinet in Algeria and as Damsissa in Egypt and Sudan, is widely used in North African folk medicine to treat infections, inflammatory diseases, gastrointestinal and urinary tract disturbances, rheumatic pain, respiratory problems, diabetes, hypertension and cancer. AIM OF THE STUDY: To assess an Ambrosia maritima L. phenolic extract for its phenolic profile composition, its potential antioxidant activity in vitro, and its cytoprotective effect on cultured primary human endothelial cells (ECs) stressed with H2O2 and sera from CD patients. MATERIALS AND METHODS: Phenolic compound extraction was performed with a low-temperature method. Extract chemical profile was attained by HPLC-DAD/ESI-MS. The extract in vitro antioxidant activity was assessed using several methods including cupric ion reducing power, DPPH radical scavenging assay, O-Phenanthroline free radical reducing activity, ABTS cation radical decolourisation assay, Galvinoxyl free radicals scavenging assay. Intracellular reactive oxygen species levels were evaluated in human endothelial cells by H2DCFDA, while cell viability was assessed by MTT. RESULTS: The phenolic compounds extraction showed a yield of 17.66% with three di-caffeoylquinic acid isomers detected for the first time in Ambrosia maritima L. Using different analytical methods, a significant in vitro antioxidant activity was reported for the Ambrosia maritima L. extract, with an IC50 value of 14.33 ± 3.86 µg/mL for the Galvinoxyl antioxidant activity method. Challenged with ECs the Ambrosia maritima L. extract showed a biphasic dose-dependent effect on H2O2-treated cells, cytoprotective and antioxidant at low doses, and cytotoxic and prooxidant at high doses, respectively. Viability and ROS levels data also demonstrated a prooxidant and cytotoxic effect of CD sera on cultured ECs. Interestingly, 10 µg/mL of Ambrosia maritima L. extract was able to counteract both CD sera-induced oxidative stress and ECs death. CONCLUSION: Our data indicated Ambrosia maritima L. as a source of bioactive phenolics potentially employable as a natural alternative for CD treatment.

Role of Polyamines as Biomarkers in Lymphoma Patients: A Pilot Study.

Lymphomas represent a heterogeneous and widely diversified group of neoplastic diseases rising from a variety of lymphoid subsets at heterogeneous differentiation stages. These lymphoproliferative disorders lead to the clinicopathological complexity of the classification of lymphoid neoplasms, describing to date more than 40 categories of non-Hodgkin's lymphoma (NHL) and 5 categories of Hodgkin's lymphoma (HL). Inflammation has been shown to play a key role in the evolution of cancer diseases, and it might be interesting to understand their role also in the context of lymphoid neoplasms. Among circulating biomarkers, the role of polyamines belonging to the arginine and lysine metabolism is relevant. Through modern analytical methods, such as mass spectrometry (MS), we are enabled to increase knowledge and improve our understanding of cancer metabolism. In this study, high-resolution mass spectrometry was used in combination with high-performance liquid chromatography (LC-HRMS) to measure serum levels of polyamines and identify possible diagnostic circulating biomarkers, potentially allowing a more accurate assessment of the diagnostic stratification of lymphoma patients and robust comparisons between different patient groups.

miRNAs as Molecular Biomarkers for Prostate Cancer.

miRNAs are short noncoding RNAs able to regulate specific mRNA stability, thus influencing target gene expression. Disrupted levels of several miRNAs have been associated with prostate cancer (PC), the leading cause of cancer death among men and the fifth leading cause of death worldwide. Herein, we investigated whether miR-145, miR-148, and miR-185 circulating levels in plasma could be used as molecular biomarkers, to allow distinguishing between individuals with benign prostatic hyperplasia, precancerous lesions, and PC. One-hundred and seventy urological clinic patients with suspected PC who underwent prostate biopsy were recruited. Total RNA was isolated from plasma, and TaqMan MicroRNA assays were used to analyze miR-145, miR-185, and miR-148 expression. First, differential miRNA expression among patient groups was evaluated. Then, miRNA levels were combined with clinical assessment outcomes, including results from invasive tests, using multivariate analysis to examine their ability in discriminating among the three patient groups. Our results suggest that miRNA is a promising molecular tool for clinical management of at-risk patients.

Plasma Polyamine Biomarker Panels: Agmatine in Support of Prostate Cancer Diagnosis.

Prostate cancer is the most frequent malignant tumour among males (19%), often clinically silent and of difficult prognosis. Although several studies have highlighted the diagnostic and prognostic role of circulating biomarkers, such as PSA, their measurement does not necessarily allow the detection of the disease. Within this context, many authors suggest that the evaluation of circulating polyamines could represent a valuable tool, although several analytical problems still counteract their clinical practice. In particular, agmatine seems particularly intriguing, being a potential inhibitor of polyamines commonly derived from arginine. The aim of the present work was to evaluate the potential role of agmatine as a suitable biomarker for the identification of different classes of patients with prostate cancer (PC). For this reason, three groups of human patients-benign prostatic hyperplasia (BPH), precancerous lesion (PL), and prostate cancer (PC)-were recruited from a cohort of patients with suspected prostate cancer (n = 170), and obtained plasma was tested using the LC-HRMS method. Statistics on the receiver operating characteristics curve (ROC), and multivariate analysis were used to examine the predictive value of markers for discrimination among the three patient groups. Statistical analysis models revealed good discrimination using polyamine levels to distinguish the three classes of patients. AUC above 0.8, sensitivity ranging from 67% to 89%, specificity ranging from 74% to 89% and accuracy from 73% to 86%, considering the validation set, were achieved. Agmatine plasma levels were measured in PC (39.9 ± 12.06 ng/mL), BPH (77.62 ± 15.05 ng/mL), and PL (53.31 ± 15.27 ng/mL) patients. ROC analysis of the agmatine panel showed an AUC of 0.959 and p ≤ 0.001. These results could represent a future tool able to discriminate patients belonging to the three different clinical groups.

Quantitative Metabolomics to Explore the Role of Plasma Polyamines in Colorectal Cancer.

Colorectal cancer (CRC) is one of the major public health and socio-economic problems, which management demands the development of non-invasive screening tests. Assessment of circulating polyamines could be a valuable tool, although analytical problems still preclude its clinical practice. We exploited ultra-high-resolution liquid chromatography and mass spectrometry, as a highly sensitive and innovative method, to profile eleven polyamines, including spermine and spermidine with their acetylated forms. These data together with an evaluation of the inflammatory indexes might represent suitable biomarkers for the identification of CRC patients. The statistical models revealed good discrimination in distinguishing CRC patients from healthy subjects. The plasma assessment of ornithine and acetylspermine, as well as lymphocyte/platelet ratio, revealed helpful information on the progression of CRC. The combined profiles of circulating polyamines and inflammatory indexes, together with the application of an innovative technology, could represent a valuable tool for discriminating patients from different clinical groups.

Molecular Docking and Comparative Inhibitory Efficacy of Naturally Occurring Compounds on Vegetative Growth and Deoxynivalenol Biosynthesis in Fusarium culmorum.

The fungal pathogen Fusarium culmorum causes Fusarium head blight in cereals, resulting in yield loss and contamination of the grain by type B trichothecene mycotoxins such as deoxynivalenol (DON), and its acetylated derivatives. Synthesis of trichothecenes is driven by a trichodiene synthase (TRI5) that converts farnesyl pyrophosphate (FPP) to trichodiene. In this work, 15 naturally occurring compounds that belong to the structural phenol and hydroxylated biphenyl classes were tested in vitro and in planta (durum wheat) to determine their inhibitory activity towards TRI5. In vitro analysis highlighted the fungicidal effect of these compounds when applied at 0.25 mM. Greenhouse assays showed a strong inhibitory activity of octyl gallate 5, honokiol 13 and the combination propyl gallate 4 + thymol 7 on trichothecene biosynthesis. Docking analyses were run on the 3D model of F. culmorum TRI5 containing the inorganic pyrophosphate (PPi) or FPP. Significant ligand affinities with TRI-PPi and TRI-FPP were observed for the same sites for almost all compounds, with 1 and 2 as privileged sites. Octyl gallate 5 and honokiol 13 interacted almost exclusively with sites 1 and 2, by concurrently activating strong H-bonds with common sets of amino acids. These results open new perspectives for the targeted search of naturally occurring compounds that may find practical application in the eco-friendly control of FHB in wheat.

Adipose-Derived Stem Cell Features and MCF-7.

Human adipose tissue-derived stem cells (hADSCs) are highly suitable for regeneration therapies being easily collected and propagated in vitro. The effects of different external factors and culturing conditions are able to affect hADSC proliferation, senescence, differentiation, and migration, even at the molecular level. In the present paper, we exposed hADSCs to an exhausted medium from the breast cancer cell line (MCF-7) to evaluate whether the soluble factors released by these cells may be able to induce changes in stem cell behavior. In particular, we investigated the expression of stemness-related genes (OCT4; Sox 2; Nanog), the cell-cycle regulators p21 (WAF1/CIP1) p53, epigenetic markers (DNMT1 and Sirt1), and autophagy-related proteins. From our results, we can infer that the exhausted medium from MCF-7 is able to influence the hADSCs behavior increasing the expression of stemness-related genes, cell proliferation, and autophagy. Polyamines detectable in MCF-7 exhausted medium could be related to the higher proliferation capability observed in hADSCs, suggesting direct crosstalk between these molecules and the observed changes in stem cell potency.

A preliminary study procedure for detection of polyamines in plasma samples as a potential diagnostic tool in prostate cancer.

BACKGROUND: Many scientific contributions recognize polyamines as important biomarkers for the diagnosis and treatment of cancer. Several authors have suggested the use of LC/MS instruments as an elective method for their measurement, providing good detection limits and specificity; however, many of these procedures suffer from long chromatographic run times, high detection limits and lengthy and expensive sample pre-treatment steps. METHODS: UHPLC coupled with high-resolution Orbitrap mass spectrometry (UHPLC/Orbitrap) was set up for the identification and separation ofpolyamines, together with some of their metabolites and catabolites, in the plasma of healthy and prostate cancer human patients. Thirteen metabolites were measured in deproteinized plasma samples through a new analytical approach known as the parallel reaction monitoring (PRM) for targeted quantitative analysis. RESULTS: The calibration curves were linear and R2 ranged from 0.9913 to 0.9995 for all analytes. LOQ values are between 0.382 and 25 ng mL-1 and LOD values are between 0.109 and 7.421 ng mL-1. The method shows an accuracy and precision for intra-day and inter-day < 15% RSD and R.E.% for all the QC samples. The matrix effect calculated at different concentration levels did not exceed 15%. CONCLUSIONS: The method developed provides rapid, easy and robust identification and measurement of a wide range of polyamines, and some of their metabolites that can be evaluated as biomarkers to predict the clinical features of prostate cancer patients, avoiding invasive diagnostic procedures.

Naturally Occurring Phenols Modulate Vegetative Growth and Deoxynivalenol Biosynthesis in Fusarium graminearum.

To assess the in vitro activity of five naturally occurring phenolic compounds (ferulic acid, apocynin, magnolol, honokiol, and thymol) on mycelial growth and type B trichothecene mycotoxin accumulation by Fusarium graminearum, three complementary approaches were adopted. First, a high-throughput photometric continuous reading array allowed a parallel quantification of F. graminearum hyphal growth and reporter TRI5 gene expression directly on solid medium. Second, RT-qPCR confirmed the regulation of TRI5 expression by the tested compounds. Third, liquid chromatography-tandem mass spectrometry analysis allowed quantification of deoxynivalenol (DON) and its acetylated forms released upon treatment with the phenolic compounds. Altogether, the results confirmed the activity of thymol and an equimolar mixture of thymol-magnolol at 0.5 mM, respectively, in inhibiting DON production without affecting vegetative growth. The medium pH buffering capacity after 72-96 h of incubation is proposed as a further element to highlight compounds displaying trichothecene inhibitory capacity with no significant fungicidal effect.

Antioxidant, Antimicrobial, and Other Biological Properties of Pompia Juice.

Pompia is a Citrus species belonging to Sardinian endemic biodiversity. Health benefits were attributed to its flavedo rind extracts and essential oils while the juice qualities have never been investigated. In this paper, the antioxidant, antimicrobial, and other biological properties of Pompia juice were studied. A combined LCMS/electrochemical/biological approach was used to clarify a still debated phylogeny of this species and to explain the role of its juice phenolic compounds. A closer phylogenetic relationship with lemon and citron, rather than oranges was suggested. Sensors-based electrochemical measures, together with LCMS qualitative and quantitative analyses, revealed a high contribution of ascorbic acid and phenolics with low redox potential, isorhamnetin 3-O-rutinoside, diosmin, and diosmetin 6,8-diglucoside, to antioxidant capacity. The biological assays demonstrated a marked effect of low concentration of Pompia juice against reactive oxygen species (ROS) starting from 50 µg mL-1, and a moderate capacity to reduce ROS damages on cell membrane. Treatments with Pompia juice also resulted in a significant reduction (20%) of the metabolic activity of SW48 colon cancer cells. Lastly, MIC, MBC, and MBIC antimicrobial assays demonstrated that Pompia and lemon juices have inhibitory and antibiofilm effects against the pathogenic bacteria Pseudomonas aeruginosa, Streptococcus aureus, and Enterococcus faecalis.

Effect of modified atmosphere packaging on overall appearance and nutraceutical quality of pot marigold held at 5 °C.

The effectiveness of passive modified atmosphere packaging (MAP) on chemical and quality properties of calendula flowers was studied during ten days of storage at 5 °C. Weight loss of flowers wrapped with continuous and micro-perforated-films (2-3%), was significantly lower than control (unwrapped flowers) (about 30%) and those wrapped with macro-perforated film (about 7%). At the end of storage unwrapped flowers were judged unmarketable being severely wilted and shriveled, while all packaged ones were still fresh and marketable. On day 10, the fructose concentration of control flowers decreased by 74%. Continuous and micro-perforated films delayed the decline of fructose concentration over storage. Sucrose concentration decreased with storage in control flowers, while in continuous film wrapped flowers it increased. After 10 d of storage, the total phenols' concentration of all packaged flowers was significantly higher than control and similar to the initial value (2.58 ± 0.02 g 100 g-1 d.w.). Thirteen carotenoids were identified by HPLC-MS. The initial ß carotene concentration (65.72 ± 0.09 mg 100 g-1 d.w.) did not change in flowers wrapped with macro- and micro-perforated films, in contrast to the other treatments. Lycopene concentration strongly decreased in control flowers, while minor losses occurred in packaged ones. Laser micro-perforated film, being a good compromise between humidity retention inside the packages and the permeability of the film, seems to be the best choice to extend the storage life of calendula flowers.

SUMOylation Protects FASN Against Proteasomal Degradation in Breast Cancer Cells Treated with Grape Leaf Extract.

Existing therapeutic strategies for breast cancer are limited by tumor recurrence and drug-resistance. Antioxidant plant-derived compounds such as flavonoids reduce adverse outcomes and have been identified as a potential source of antineoplastic agent with less undesirable side effects. Here, we describe the novel regulation of fatty-acid synthase (FASN), the key enzyme in de novo fatty-acid synthesis, whereby Vitis vinifera L. cv Vermentino leaf hydroalcoholic extract lowers its protein stability that is regulated by small ubiquitin-like modifier (SUMO)ylation. The phenolic compounds characterization was performed by liquid chromatography-mass spectrometry (LC-MS), whereas mass spectrometry (LC-MS/MS), Western blotting/co-immunoprecipitation (Co-IP) and RT-PCR, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), clonogenicity assays, and FACS analysis were used to measure the expression of targets and tumorigenicity. Vermentino extract exhibits antitumorigenic effects, and we went on to determine that FASN and ubiquitin-conjugating enzyme 9 (UBC9), the sole E2 enzyme required for SUMOylation, were significantly reduced. Moreover, FASN was found SUMOylated in human breast cancer tissues and cell lines, and lack of SUMOylation caused by SUMO2 silencing reduced FASN protein stability. These results suggest that SUMOylation protects FASN against proteasomal degradation and may exert oncogenic activity through alteration of lipid metabolism, whereas Vermentino extract inhibits these effects which supports the additional validation of the therapeutic value of this compound in breast cancer.

Effects of alternative cropping systems on globe artichoke qualitative traits.

BACKGROUND: Traditionally, globe artichoke cultivation in the Mediterranean basin is based on monoculture and on use of high amounts of nitrogen fertiliser. This raises issues regarding its compatibility with sustainable agriculture. We studied the effect of one typical conventional (CONV) and two alternative cropping systems [globe artichoke in sequence with French bean (NCV1), or in biannual rotation (NCV2) with cauliflower and with a leguminous cover crop in inter-row spaces] on yield, polyphenol and mineral content of globe artichoke heads over two consecutive growing seasons. RESULTS: NCV2 showed statistical differences in terms of fresh product yield with respect to the monoculture systems. In addition, the dihydroxycinnamic acids and dicaffeoylquinic acids of non-conventional samples were one-fold significantly higher than the conventional one. All the samples reported good mineral content, although NCV2 achieved a higher Fe content than conventional throughout the two seasons. After two and three dates of sampling, the CONV samples showed the highest levels of K content. CONCLUSION: In our study, an acceptable commercial yield and quality of 'Spinoso sardo' were achieved by shifting the common conventional agronomic management to more sustainable ones, by means of an accurate choice of cover crop species and rotations introduced in the systems. © 2017 Society of Chemical Industry.

Natural Phenolic Inhibitors of Trichothecene Biosynthesis by the Wheat Fungal Pathogen Fusarium culmorum: A Computational Insight into the Structure-Activity Relationship.

A model of the trichodiene synthase (TRI5) of the wheat fungal pathogen and type-B trichothecene producer Fusarium culmorum was developed based on homology modelling with the crystallized protein of F. sporotrichioides. Eight phenolic molecules, namely ferulic acid 1, apocynin 2, propyl gallate 3, eugenol 4, Me-dehydrozingerone 5, eugenol dimer 6, magnolol 7, and ellagic acid 8, were selected for their ability to inhibit trichothecene production and/or fungal vegetative growth in F. culmorum. The chemical structures of phenols were constructed and partially optimised based on Molecular Mechanics (MM) studies and energy minimisation by Density Functional Theory (DFT). Docking analysis of the phenolic molecules was run on the 3D model of F. culmorum TRI5. Experimental biological activity, molecular descriptors and interacting-structures obtained from computational analysis were compared. Besides the catalytic domain, three privileged sites in the interaction with the inhibitory molecules were identified on the protein surface. The TRI5-ligand interactions highlighted in this study represent a powerful tool to the identification of new Fusarium-targeted molecules with potential as trichothecene inhibitors.

Relationship Between Soil and Essential Oil Profiles in Salvia desoleana Populations: Preliminary Results.

Salvia desoleana is a herbaceous perennial shrub endemic of Sardinia (Italy). The leaves are a source of essential oil, used in pharmaceutical and cosmetic industries. The therapeutic function of this species has been associated to the presence of essential oils rich in α/ß-pinene, p-cimene, linalool, linalyl acetate and 1,8-cineole. Today.the industrial request of Salvia essential oils is increasing and most of the biomass is exploited from the natural populations which are under severe risk of genetic erosion. In order to improve the essential oil production, the study of the environmental parameters that influence composition, quality and quantity of the essential oils, turns out to be necessary. Soil physical and chemical structure represents one of the determinant factors in secondary metabolites production, and could also be involved in volatiles fraction composition in the same species. The main aim of this research was to explore the relationship between essential oil profiles and soil characteristics in S. desoleana populations. GC/MS analysis performed on the essential oil extracts identified 22 principal compounds, which were extremely variable among the five S. desoleana populations studied. The analysis of the essential oils revealed different compositions in the terpenes fractions: 68.2% of monoterpenes, 27.3% of sesquiterpenes and 4.5% of diterpenes. Analysis of chemical and physical soil parameters at the collection sites revealed that silt and sand contents were correlated with α-pinene and sclareol fractions and the total K20 was significantly correlated to several compounds belonging to the three terpene fractions identified. These results will provide guidelines for the in site conservation and for the improvement of the commercial value of the species.

Simultaneous amperometric detection of ascorbic acid and antioxidant capacity in orange, blueberry and kiwi juice, by a telemetric system coupled with a fullerene- or nanotubes-modified ascorbate subtractive biosensor.

Four fullerenes- or nanotubes-modified graphite sensor-biosensor systems (SBs), coupled with a dual-channel telemetric device, based on an ascorbate oxidase (AOx) biosensor, were developed for on line simultaneous amperometric detection of ascorbic acid (AA) and antioxidant capacity in blueberry, kiwi and orange juice. Fullerene C60 (FC60), fullerene C70 (FC70), single-walled carbon nanotubes (SWCN) and multi-walled carbon nanotubes (MWCN) increased the sensitivity of graphite toward AA and phenols 1.2, 1.5, 5.1 and 5.1 times respectively. Fullerenes combined with AOx improved the selectivity toward AA more than nanotubes, being able to hold a higher number of AOx molecules on the biosensor surface. The SBs work at an applied potential of +500 mV, in a concentration range between the LOD and 20 µM, with a response time of two minutes. The LOD is 0.10, 0.13, 0.20 and 0.22 µM for SBs modified with FC60, FC70, SWCN and MWCN respectively. Biosensors register lower AA currents than the sensors due to the enzyme capability to oxidize AA before it reaches the transductor surface. Phenols currents registered by sensors and biosensors did not differ. Based on the difference between sensor and biosensor recorded currents a AA selectivity index was developed as an indicator of specificity toward AA and of the capacity to distinguish between AA and phenols contribution to the antioxidant capacity. This value is almost zero for fullerene-modified SBs, 0.13 and 0.22 for SWCN- and MWCN-modified SBs respectively. The results of juices analysis performed with SBs were in accordance with reference methods.

Development and characterization of an ascorbate oxidase-based sensor-biosensor system for telemetric detection of AA and antioxidant capacity in fresh orange juice.

A new carbon ascorbate oxidase-based sensor-biosensor system (SB) was coupled to a dual-channel telemetric device for online simultaneous electrochemical detection of ascorbic acid (AA) and antioxidant capacity in Hamlin, Sanguinello, and Moro orange varieties. The electrocatalytic performances of the SB were investigated by cyclic voltammetry and amperometric techniques. The phenol composition of orange juice of each variety, and the cyclic voltammetries of the most represented phenols, were provided. The in vitro calibrations were performed in PBS (pH 5.6), applying a constant potential of +500 mV. A standard mixture of phenols, based on orange juice composition, was used as reference material for studying SB behavior. SB works at an applied potential of +500 mV, in a concentration range comprised between the LOD 0.26 µM and 20 µM. In this concentration range, limiting the data acquisition time to 2 min, the problems of electrode passivation due to phenols polymerization were overcome. AA calibration showed that the biosensor registered statistically lower currents than the sensor since the enzyme oxidized AA before it reached the electrode surface. Standard mixture calibration showed that currents registered by sensor and biosensor did not statistically differ. The difference between sensor and biosensor AA registered currents was used to calculate an AA selectivity index and, consequently, to determine the AA content and the antioxidant capacity in the juices. The novelty of the SB is its ability to distinguish between AA and phenols contribution to antioxidant capacity. The obtained results were in accordance with reference methods.