Search results for "HPLC"
showing 10 items of 201 documents
Non-Thermal Ultrasonic Extraction of Polyphenolic Compounds from Red Wine Lees
2020
This study presents the results of conventional aqueous (CE) and non-conventional ultrasound-assisted (UAE) extractions of polyphenolic compounds from lees extracts of red wine varieties (Merlot and Vranac). The effect of ultrasound extraction time (t, s), and amplitude (A,%) from a 400 W ultrasound processor with different ultrasonic probes diameters (Ds, mm) on the amount and profile of polyphenolic compounds in the obtained extracts was investigated and compared to CE. The optimal conditions resulting in maximum extraction of phenolic compounds were: Probe diameter of 22 mm, amplitude 90% and extraction time for Vranac wine lees 1500 s and for Merlot wine lees extraction time of 1361 s. …
Assessment of metal levels in foodstuffs from the Region of Valencia (Spain).
2017
Graphical abstract
Light-induced Changes in the Dimerization Interface of Bacteriophytochromes
2015
Phytochromes are dimeric photoreceptor proteins that sense red light levels in plants, fungi, and bacteria. The proteins are structurally divided into a light-sensing photosensory module consisting of PAS, GAF, and PHY domains and a signaling output module, which in bacteriophytochromes typically is a histidine kinase (HK) domain. Existing structural data suggest that two dimerization interfaces exist between the GAF and HK domains, but their functional roles remain unclear. Using mutational, biochemical, and computational analyses of the Deinococcus radiodurans phytochrome, we demonstrate that two dimerization interfaces between sister GAF and HK domains stabilize the dimer with approximat…
A new multi analytical approach for the identification of synthetic and natural dyes mixtures. The case of orcein-mauveine mixture in a historical dr…
2017
In this paper, the application of a multi-analytical approach for the characterisation of synthetic and natural dyes in a historical textile is presented. The work is focused on a historical dress of a Sicilian noblewoman, dating from about 1865–1870. Firstly, SERS on fibre was performed, in order to individuate the classes of dyes employed. The SERS spectra suggested the presence of two main dyes: mauveine and orcein. In order to confirm these preliminary results, two different extraction protocols were applied. The extracts obtained were analysed by ESI-MS, MALDI-ToF and UHPCL-MS analyses, confirming the SERS results. In particular, the application of the ammonia mild extraction technique…
Untargeted screening of the bound / free phenolic composition in tomato cultivars for industrial transformation
2019
BACKGROUND Tomato is one of the most important agricultural crops and it is characterized by a wide bioactive compound profile. However, little information is reported on its comprehensive polyphenol profile. In this work, 13 commercial tomato cultivars for industrial transformation were screened by ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS) for both free and bound phenolic profiles. Thereafter, the in vitro antioxidant activity of each cultivar was assessed by ferric reducing antioxidant power (FRAP) and oxygen radical absorbance activity (ORAC) assays. Multivariate statistics, i.e. orthogonal projection to latent struct…
Analytical tools used for the identification and quantification of pectin extracted from plant food matrices, wastes and by-products: A review
2018
Pectin is the methylated ester of polygalacturonic acid and has a wide range of applications. It can be used in food and animal feed as well as in pharmaceutical and cosmetic products. Pectin is traditionally used as a gelling agent in fruit-based products, as a stabilizer in some fruit juices and milk drinks and fruit filling for bakery and confectionary products, but their potential applications differ according to their chemical composition. Therefore, at this stage of development, it is of a great importance to find fast, reliable methods to not only identify and quantify pectin, but also to determine its chemical structure and composition when it is extracted from plant matrices, waste…
Cucumis sativus l. Seeds ameliorate muscular spasm-induced gastrointestinal and respiratory disorders by simultaneously inhibiting calcium mediated s…
2021
Cucumis sativus L. is globally cultivated as an edible vegetable. Besides its nutritional benefits, it is used in traditional medicines against various ailments. The current study was designed to elucidate the multi-target mechanisms of a C. sativus seeds extract against asthma and diarrhea using network pharmacology along with a molecular docking approach. Furthermore, in-vitro and in-vivo experiments were conducted to verify the mechanistic insight of in silico studies. LC-ESI-MS/MS was performed to identify the bioactive compounds in the extract; later, some compounds were quantified by HPLC. C. sativus seed. EtOH has kaempferol in higher concentration 783.02 µg/g, followed by quercetin …
In vitro evaluation of poloxamer in situ forming gels for bedaquiline fumarate salt and pharmacokinetics following intramuscular injection in rats
2019
Graphical abstract
Diels-Alder Reactions ofin situ generated N-benzoylindolo-2,3-quinodimethane with carbodienophiles
1993
The indolo-2,3-quinodimethane (5), generated from 2,3-bis(bromomethyl)indole (4), was trapped with unsymmetrical carbodienophiles or N, N′-p-phenylenedimaleimide to furnish the 1,2,3,4-tetrahydrocarbazoles (6–9). [4 + 2]-Cycloaddition of 5 with tetracyanoethylene gave rise to the tetracyanocarbazole (10) and a subsequent product 11a or 11b. The Diels-Alder reaction of 5 with divinyl sulfone was regiospecific within the detection limits of HPLC analysis. Similarly, the reaction of 5 with N, N′-p-phenylenedimaleimide yielded solely the stereoisomer 9.
Actinins as novel broad-spectrum AMP isolated from the tentacle of Anthozoan Actinia equina (Linnaeus, 1758)
2023
Capturing activities and defense mechanisms of Cnidarian are strongly associated with toxins and peptide with antimicrobial properties. AMP are an important component of many organisms’ innate immune system with a good inhibitory or killing effect against invaders pathogens. We investigated the AMP activity of acid extracts obtained from tentacle and body of Actinia equina (Cnidaria, Anthozoa) against Gram positive (Micrococcus lysodeikticus) and Gram negative (Escherichia coli, Vibrio alginolyticus) bacteria. The peptide fractions showed interesting minimum inhibitory concentrations (MIC) values (concentrations up to 0.125 μg/ml) against tested pathogens. Tentacle acid extracts exhibiting …