1,721,025 research outputs found
Produzione di resveratrolo in colture cellulari di vite. Un approccio biotecnologico per l’ottenimento di resveratrolo, molecola di grande interesse farmaceutico e cosmetico
No full textIl resveratrolo (3,5,4’-triidrossistilbene) è un fitopolifenolo sintetizzato da numerose specie di piante in risposta ad infezioni fungine e microbiche e a stimoli abiotici. Le fonti naturali di maggior rilevanza per la dieta umana sono gli acini di vite (Vitis vinifera).
Il forte interesse per il resveratrolo è legato al suo potenziale farmacologico: sono stati documentati suoi effetti antiossidanti e contro patologie tumorali e cardiovascolari.
Essendo un metabolita secondario, la sua sintesi in vivo ed in vitro è stimolata da elicitori biotici e stress abiotici.
Sospensioni cellulari ottenute da piccioli della cultivar Barbera sono state trattate con diversi elicitori biotici quali N-acetil-D-glucosammina, D-glucosammina, chitosano e alcuni antibiotici. Le colture liquide sono state monitorate per 15 giorni misurando numero di cellule, vitalità cellulare, pH e peso fresco; il contenuto di resveratrolo in cellule e terreno è stato quantificato tramite analisi HPLC.
I risultati migliori sono stati ottenuti nei trattamenti con D-glucosammina 50 μg/mL e chitosano 50 μg/mL. Entrambi accrescono il contenuto intracellulare dei due isomeri del resveratrolo rispetto alle colture controllo, ma il monomero ne inibisce il rilascio. Nel caso dell’isomero trans l’elicitazione più forte e duratura è dovuta alla D-glucosammina, mentre nel caso del cis al chitosano.
I buoni risultati ottenuti in laboratorio hanno incoraggiato prove su larga scala in bioreattori da 2,5 e 16 litri.
Mediante immunolocalizzazione in protoplasti e analisi al microscopio confocale è stata individuata la localizzazione intracellulare dell’enzima biosintetico stilbene sintasi: i siti di sintesi del resveratrolo sembrano essere sul lato citoplasmatico di tonoplasto e membrana cellulare
Winery by-products: pomace as source of high value phenols
No full textGrape pomace, the main by-product from winemaking industry, accounts for 20-30% of processed grape weight and still contains valuable compounds. Valorization of pomace by extracting phenols can be a further step towards a “near zero-waste socie-ty” direction. The present work aimed at the selection of the best extraction condi-tions for phenol recovery from Sangiovese and Montepulciano (Vitis vinifera L.) mixed winery pomace. Different solvents were screened in 2h incubation at 30°C and 50°C, with 1:10 and 1:5 solid/liquid ratios, with or without ultrasound pre-treatment. Total phenol yields were measured in all extracts and best extracts were characterized for flavonoid, flavanol and anthocyanin contents and for total antioxidant activity. In conclusion, 75% acetone led to the highest compound extractions, followed by 50% acetonitrile and 50% ethanol. Higher yields were obtained with 1:5 solid/liquid ratio. The ultrasound pre-treatment did not significantly affect compound recovery, while better extractions were achieved with temperature increase
Ethnobotanical survey of wild food plants traditionally collected and consumed in the Middle Agri Valley (Basilicata region, southern Italy)
Full text linkAbstract Background This research was carried out in a scarcely populated area of the Middle Agri Valley (Basilicata region, southern Italy). The aim of the study was to record local knowledge on the traditional uses of wild food plants, as well as to collect information regarding the practices (gathering, processing and cooking) and the medicinal uses related to these plants. Methods Fifty-eight people still possessing traditional local knowledge (TLK), 74% women and 26% men, were interviewed between May–August 2012 and January 2013, using open and semi-structured ethnobotanical interviews. For each described plant species, the botanical family, the Italian common and folk names, the plant parts used, the culinary preparation and, when present, the medicinal use, were recorded and the relative frequency of citation index (RFC) was determined. Results The 52 plant species mentioned by the respondents belong to 23 botanical families, with Asteraceae (12 plants) and Rosaceae (7 plants) being most frequently cited. The species with the highest RFC index is Cichorium intybus L. (0.95), followed by Sonchus spp. (S. oleraceus L., S. asper L. and S. arvensis L.) (0.76). The plant parts preferably used are leaves (22 plants), fruits (12) and stems (7). Only six wild plants were indicated as having both food use and therapeutic effect. Conclusions The survey conducted on the traditional use of wild food plants in the Middle Agri Valley revealed that this cultural heritage is only partially retained by the population. Over the last few decades, this knowledge has been in fact quickly disappearing along with the people and, even in the rural context of the study area, is less and less handed down to younger generations. Nevertheless, data also revealed that the use of wild plants is recently being revaluated in a way closely related to local habits and traditions
Capsicum spp in vitro liquid cell suspensions: A useful system for the production of capsaicinoids and polyphenols
No full textCapsicum are among the most extensively cultivated and consumed plant species in the world, because of their unique pungency, aroma and colour. The typical burning sensation caused by chili peppers is due to the occurrence of a group of alkaloids named capsaicinoids. In the present study, the production of solid callus and cell suspensions from hypocotyl explants of three different chili pepper cultivars (Capsicum annuum L. cv. Mazzolino, Capsicum chinense Jacq. cv. Naga Morich and Pimenta de Neyde), was optimised. In addition, C. chinense cv. Naga Morich cell suspensions were supplemented with biotic elicitors (methyl-jasmonate and chitosan) and with precursors and intermediates of capsaicin biosynthesis (vanillin, phenylalanine and valine), and both cells and media were analysed for capsaicinoid, polyphenol, flavonoid contents and for antioxidant activity. This is the first report regarding capsaicinoid elicitation with pure chitosan and with a combination of precursors of both phenylpropanoid and valine pathways. Overall, the highest capsaicinoid levels were detected in cell extracts from cultures treated with 10 μM methyl-jasmonate and with a combination of phenylalanine and valine amino acids (100 μM each). The present results confirm the possibility of using hypocotyl chili pepper cell suspensions to produce high amounts of health beneficial metabolites
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Improving the functional and sensorial profile of cereal-based fermented foods by selecting Lactobacillus plantarum strains via a metabolomics approach
Full text linkMetabolomics was recently applied in food science for monitoring the quality, processing, safety, and microbiology of both raw materials and final products to improve the consumer's health and confidence.The present work aimed at using a metabolomics approach to detect the flavour and antioxidant profiles characteristic of different . Lactobacillus plantarum strains in sourdoughs of durum wheat and KAMUT® khorasan wheat. The study was developed to improve sensorial and functional properties of cereal-fermented foods through the selection of optimal flour-microbial strain combinations. A large set of metabolites, including volatile compounds, polyphenols and flavonoids, was taken into consideration and the antioxidant activity was determined. The metabolic profiles were combined by using heat maps to visualise the result of a hierarchical clustering of profile data. In KAMUT® khorasan wheat-fermented dough, a high correlation was found between a group of volatiles (5 alcohols, 6 carbonils, dodecanoic acid and 1,3-hexadiene) and the polyphenolic compounds gallic acid (GA), epigallocatechin-gallate (EGCG), epigallocatechin (EGC), flavonoids (Flav), protocathecuic acid (Prot ac) and total polyphenols (Polyp). In durum wheat dough a different pattern of volatile molecules (10 alcohols, 5 carbonils, 3 acids and 3 hydrocarbons) resulted highly correlated with EGC, EGCG, Flav and Polyp. The results also evidenced a simultaneous increase of sensorial and health promoting compounds when using . L. plantarum strains 98A and 6BHI in fermented durum wheat dough, while 94A and 206 strains had their highest performance with KAMUT® khorasan wheat dough. Our data show that metabolomics may represent an important tool for the rapid selection of strain/substrate combinations to simultaneously increase sensorial and health beneficial characteristics
Advances in combined enzymatic extraction of ferulic acid from wheat bran
No full textWheat bran could be utilised as feedstock for innovative and sustainable biorefinery processes. Here, an enzymatic hydrolysis process for ferulic acid (FA) extraction was optimised step by step for total wheat bran (Tritello) and then also applied to the outer bran layer (Bran 1). Proteins, reducing sugars, total phenols and FA were quantified. The highest FA yields (0.82–1.05 g/kg bran) were obtained either by rehydrating the bran by autoclaving (Tritello) or by steam explosion (Bran 1) using a bran/water ratio of 1:20, followed by enzymatic pretreatment with Alcalase and Termamyl, to remove protein and sugars, and a final enzymatic hydrolysis with Pentopan and feruloyl esterase to solubilise phenol. FA was recovered from the final digestate via solid phase extraction. A 40-fold scale-up was also performed and the release of compounds along all the process steps and at increasing incubation times was monitored. Results showed that FA was initially present at a minimum level while it was specifically released during the enzymatic treatment. In the final optimized process, the FA extraction yield was higher than that obtained with NaOH control hydrolysis while, in comparison with other FA enzymatic extraction methods, fewer process steps were required and no buffers, strong acid/alkali nor toxic compounds were used. Furthermore, the proposed process may be easily scaled-up, confirming the feasibility of wheat bran valorisation by biorefinery processes to obtain valuable compounds having several areas of potential industrial exploitation
Novel bioassays based on 3D-printed device for sensing of hypoxia and p53 pathway in 3D cell models
No full textCell-based assays are widely exploited for drug screening and biosensing, providing useful information about bioactivity of target analytes and complex biological samples. It is well recognized that 3D cell models are required to achieve highly valuable information, also from the perspective of replacing animal models. However, bioassays relying on 3D cell models are generally highly demanding in terms of facilities, equipment, and skilled personnel requirements. To reduce cost, increase sustainability, and provide a flexible 3D cell-based platform for bioassays, we here report a novel approach based on a 3D-printed microtissue device. To assess the suitability of this strategy for reporter gene technology, we selected to monitor two molecular pathways which were of interest in several applications, hypoxia signaling and the p53 pathway. The investigation of such pathways is highly relevant in fields spanning from drug screening to bioactivity monitoring for industrial by-product valorization. Microtissues of human hepatocarcinoma (HepG2) and human embryonic kidney (Hek293T) cell lines were obtained with a low-cost and sustainable chip platform and bioassays were developed to monitor the hypoxia-inducible factors (HIFs) and the p53 tumor suppressor pathway. HepG2 and Hek293T 3D cell models were genetically engineered to express the Luc2P from Photinus pyralis firefly either under the regulation of p53 or HIF response elements. The bioassays allowed quantitative assessment of hypoxia and tumoral activity with 1,10-phenanthroline for HIF and with doxorubicin for p53 pathway activation, respectively, showing good potential for applications of this sustainable and low-cost 3D-printed microfluidic platform for bioactivity analyses, drug screening, and precision medicine. Graphical Abstract: (Figure presented.
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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