Search results for "HPLC"

Phenoloxidases of different sizes are modulated by LPS inoculation into ciona intestinalis tunic and pharynx

2015

In the present study, to further characterize the pro-phenoloxidase (proPO) and active phenoloxidase (PO) involved in the Ciona intestinalis inflammatory response, tunic and pharynx homogenate supernatants were separated on high pressure liquid chromatography and fractions were assayed for the PO activity before and after LPS inoculation, as well as before and after trypsin treatment which activates proPO. The LPS inoculation per se did not significantly change the basal PO activity of the tunic homogenate supernatant (THS) and pharynx homogenate supernatant (PHS) restricted in two confluent peaks, whereas a significant enhancement was observable after the trypsin treatment. This trypsin ef…

High Performance Liquid Chromatografy-Mass Spectrometry based chemometric characterization of olive oils

2005

In this study the effective discrimination of extra virgin olive oils is described using HPLC-MS, combined with chemometric evaluation. The presented method is simple since the diluted oil sample is directly injected into the system, without any preliminary chemical derivatization or purification step. Separation of diacylglycerols, triacylglycerols and sterols occurs within 20 min and is achieved using an octadecyl-silica column. Detection is performed by positive APCI mass spectrometry which provided sensitivity to detect over 50 compounds in the sample. After extraction of data, stepwise discriminant function analysis is used to select the variables with the highest discriminative power.…

HPLC-UV/Vis-APCI-MS/MS Determination of Major Carotenoids and Their Bioaccessibility from "Delica" (Cucurbita maxina) and "Violina" (Cucurbita moscha…

2018

Carotenoids are a widespread group of fat-soluble pigments, and their major nutritional importance comes from their pro-vitamin A activity and their antioxidant capacity. In this study, two different pumpkin cultivars (Cucurbita maxima, also named `Delica&rsquo

Antioxidant activity and phenolic composition in Pomegranate (Punica granatum, L.) genotypes from south Italy by UHPLC/Orbitrap-MS approach

2018

Background: Pomegranate fruits are a rich source of polyphenols with numerous health-promoting effects. Pomegranate juices of five genotypes (‘Mollar’, ‘Kingdom’, ‘Dente di Cavallo’, and two old populations ‘Francofonte’ and ‘Santa Tecla’) were evaluated regarding anthocyanin and non-anthocyanin phenolic contents using ultrahigh performance liquid chromatography (UHPLC)–Orbitrap-mass spectrometry (MS). Moreover, total antioxidant activity (TAA) was evaluated using a 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay. Results: Twenty-three phenolic compounds were identified. Cyanidin-3,5-O-diglucoside and pelargonidin-3,5-O-diglucoside were the most representa…

γ-irradiation as a methods for decontaminating food: reduction/elimination of mycotoxins in raw unpeeled almond kernels (Prunus dulcis)

2012

Quantification of fluorescent dyes in organ tissue samples via HPLC analysis

2017

Abstract The determination of regional blood flow via the accumulation of fluorescent microspheres is a concept regularly used in medical research. Typically, the microbeads get extracted from the tissue of interest and are then quantified by measuring the absorption or fluorescence of the incorporated dyes without further separation from the medium. However, in that case the absorption spectra of different dyes can overlap when used simultaneously, leading to an overestimation of the concentration. Additionally, background absorption from the medium can be problematic. Therefore, a high performance liquid chromatography method for the simultaneous detection of four dyes (orange, crimson, y…

Review: Applications of HPLC–MS for food analysis

2012

HPLC–MS applications in the agrifood sector are among the fastest developing fields in science and industry. The present tutorial mini-review briefly describes this analytical methodology: HPLC, UHPLC, nano-HPLC on one hand, mass spectrometry (MS) and tandem mass spectrometry (MS/MS) on the other hand. Analytical results are grouped together based on the type of chemicals analyzed (lipids, carbohydrates, glycoproteins, vitamins, flavonoids, mycotoxins, pesticides, allergens and food additives). Results are also shown for various types of food (ham, cheese, milk, cereals, olive oil and wines). Although it is not an exhaustive list, it illustrates the main current directions of applications. …

Magnetic molecularly imprinted polymer for the simultaneous selective extraction of phenoxy acid herbicides from environmental water samples

2022

[EN] A selective magnetic molecularly imprinted polymer (MMIP) was synthetized with 4-chloro-2-methylphenoxyacetic acid as template and 4-vinylpiridine as monomer in presence of vinylized magnetite nanoparticles. Scanning electron microscopy, nitrogen adsorption-desorption isotherms, Fourier transform infrared spectrometry and vibrating sample magnetometry were applied to characterize the resulting material. The synthesized MMIP was applied as sorbent in magnetic molecularly imprinted solid-phase extraction (MMISPE) for selective extraction of a mixture of the five herbicides 4-chloro-2-methylphenoxyacetic acid (MCPA), 4-(4-chloro-2-methylphenoxy)butyric acid (MCPB), mecoprop (MCPP), fenoxa…

Antibacterial activity and HPLC analysis of extracts from Mediterranean brown algae

2020

The antibacterial activity of methanolic extracts of eight Mediterranean brown algae belonging to the genera Cystoseira sensu lato, Dictyopteris and Padina was investigated. Extracts from Sargassaceae showed antibacterial activity. Specifically, Carpodesmia crinita and Carpodesmia brachycarpa extracts inhibited the growth of the Gram-positive strain Kocuria rhizophila whereas Cystoseira compressa and Carpodesmia amentacea extracts showed antibacterial activity against the Gram-positive strains, Kocuria rhizophila and Staphylococcus aureus. None of them inhibited the growth of the Gram-negative bacterium Escherichia coli. The extracts of Cystoseira sp. pl. and Treptacantha ballesterosii did …

Biophysical investigation on therapeutic proteins (Chaperonins, Hsp60 and CCT/TRiC) involved in human diseases

Molecular chaperones are indispensable cellular components that assist folding and assembly of newly synthesized proteins, translocation of proteins across membranes, as well as refolding and degrading of misfolded and aggregated proteins. In the last few years, innovative therapeutic strategies targeting stability and functionality of chaperones have received great attention, particularly in the field of neurodegenerative diseases. Moreover, the growing number of diseases found linked to chaperone mutations, testifies to the importance of their role in the cellular protein-quality control mechanism. The investigation of the biophysical interactions between chaperones and specific proteins …