Free radicals and oxidants are involved in physiological signaling pathways, although an imbalance between pro-oxidant and anti-oxidant systems in favor of the former leads to major biomolecular ...damage. This is the so-called oxidative stress, a complex process that affects us all and is responsible for the development of many diseases. Lipids are very sensitive to oxidant attack and to-date, malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE) and F2-isoprostane are the main biomarkers for lipid peroxidation assessment. They all derive from polyunsaturated fatty acids (PUFAs) either by enzyme-catalyzed reactions (physiological) or by non-enzyme reactions (pathological). The profile of PUFAs present in the tissue will determine the proportion of each biomarker. In this review we aim to discuss the proper method for MDA determination using HPLC. We also offer reference MDA values in humans in physiological and pathological conditions.
This article presents the development of a reversed-phase (RP) high-performance liquid chromatographic (HPLC) method for determination of process-related impurities in a celecoxib drug substance ...following Analytical Quality by Design (AQbD) principles. The method from European Pharmacopeia (EP) for celecoxib drug substance does not sufficiently separate celecoxib from its EP impurity B because the system suitability criterion is not achieved (resolution NLT 1.8). The same issue was observed with the proposed method from United States Pharmacopeia (USP) for celecoxib capsules, where EP impurity A elutes under the main peak. A new HPLC method was developed that eliminates the disadvantages of the two pharmacopeial methods and is capable of efficiently separating and determining all seven impurities listed in EP and the proposed USP monographs. The development of a new HPLC method started with method scouting, in which various C18 and phenyl stationary phases were tested. Improved selectivity was obtained only with a chiral stationary phase. An immobilized Chiralpak IA-3 column used in RP mode turned out to be the most appropriate for method optimization. The ratio of acetonitrile in the mobile phase, flow rate, and column temperature were recognized as critical method parameters (CMPs) and were further investigated using a central composite face response-surface design. A multiple linear regression (MLR) method was applied to fit the mathematical models on the experimental data to determine factor-response relationships. The models created show adequate fit and good prediction abilities. The Monte Carlo simulation method was used to establish the design space. The method developed was verified in terms of precision, sensitivity, accuracy, and linearity, and the results showed that the new method is suitable for determination of seven process-related impurities of celecoxib.
The pollution caused by the abuse of antibiotics has posed a serious threat to the ecological environment and human health, so development of effective strategies for degradation and disposal of ...antibiotic residues is urgently needed. In this work, penicillinase, a kind of β-lactamase, was immobilized into zeolitic imidazolate framework-8 (ZIF-8) by self-assembly method and the catalytic performance of the β-lactamase@ZIF-8 porous materials for degradation of penicillins has been investigated by high performance liquid chromatography coupled with mass spectrometry. The results illustrated that the catalytic activity of the encapsulated enzyme was significantly enhanced comparing with that of free enzyme. Meanwhile, the β-lactamase@ZIF-8 exhibited excellent stability under denaturing conditions including high temperature, organic solvent and the enzyme inhibitor. The catalytic degradation mechanism of the β-lactamase@ZIF-8 for penicillins has been probed and verified, and it has been found that the Zn (II) ion on ZIF-8 frameworks could form the complex with the target molecule, which weakened the bond of the four-membered β-lactam ring in the penicillin molecule, and thus enhanced the degradation efficiency of the enzyme. This work provided a promising strategy for eliminating the penicillin residues in water environment.
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•The β-lactamase has been encapsulated into ZIF-8 MOFs by a self-assembly method.•The β-lactamase@ZIF-8 MOFs possessed excellent stability under denaturing conditions.•Catalytic activity of enzyme encapsulated into ZIF-8 MOFs was significantly enhanced.•The catalytic degradation pathway of penicillins was proposed and verified.
In the hereby paper, we have undertaken a study on buffalo milk proteins, employing high performance liquid chromatography (HPLC). This RP-HPLC technique is commonly employed in the separation and ...assessment of caseins K, and in the fresh, as well as processed milk. These methods are also successfully applied in the authenticity and origin assessment of certain cheese products and the qualitative analysis of milk in bubalines, ovines, caprines and bovines (Ferreira şi Cacote, 2003; Veloso şi colab., 2002). In order to identify the main protein types, we found support in literature data (Miranda şi colab., 2004), and thus achieved the chromatographic separation on whole milk, lactoserum and casein samples.
Algal mass productions are widespread events throughout the world. Most research deals with the environmental impact, ecology and toxicity of these phenomena, but the algae are also promising sources ...of bioactive natural products, and also are potential food additives. In the current study, we aimed to characterize the carotenoid composition of three non-toxic algal isolates with distinct taxonomical position, namely Dunaliella salina, Euglena sanguinea and a Nostoc strain.
The strains were screened for carotenoid composition with HPLC–UV–APCI-MS with comparison with authentic standards. Carotenoids were purified with open column chromatography, and characterized by LC–UV–MS and NMR.
All three species contained a high amount of carotenoids. The composition of the carotenoid pattern was somewhat different compared to literature data. The Dunaliella carotenoid fraction contained lutein (52.1% of total carotenoid), β-carotene (13.1%), violaxanthin (11.5%) and neoxanthin (6.2%) as chief compounds. The chief carotenoids in the Nostoc strain was echinenone (34.9%), while the main components of the Euglena isolate were diatoxanthin (39.0%), lutein (23.7%), an unidentified carotenoid (9.6%) and β-carotene (5.4%). Diatoxanthin is identified by NMR spectroscopy.
The carotenoid patterns of the examined strains are somewhat different from the patterns described in the literature. This can be the results of genetic or environmental differences, or combinations thereof. Despite these differences, our study shows the potency of these algae in production of carotenoids, and possibly, usage as food additives.
•Characterization of the carotenoids of a lutein-rich Dunaliella salina strain•Characterization of the carotenoids of an echinenone-rich Nostoc strain•Characterization of the carotenoids of a diatoxanthin-rich Euglena sanguinea strain•Three non-toxic algae were shown to be excellent natural sources of carotenoids.
Schizophrenia is a chronic disabling disease affecting 1 % of the population. Current antipsychotics have limited efficacy in mitigating the severity of the symptoms of the disease. Therefore, ...searching for new therapeutic targets is essential. Previous studies have shown that α2C-adrenoceptor antagonists may have antipsychotic and pro-cognitive effects. Therefore, the current study evaluates the behavioral and neurochemical effects of JP-1302, a selective α2C-adrenoceptor antagonist, in a model of schizophrenia-like deficits induced by sub-chronic ketamine (KET) administration.
Here, we administered ketamine (25 mg/kg, i.p.) to male and female Wistar rats for eight consecutive days. On the last two days of ketamine administration, rats were pretreated with either JP-1302 (1-3-10 μmol/kg, i.p.), chlorpromazine (0.1 mg/kg, i.p.), or saline, and the behavioral tests were performed. Behaviors related to positive (locomotor activity), negative (social interaction), and cognitive (novel object recognition) symptoms of schizophrenia were assessed. Glutamate, glutamine, GABA levels, and α2C-adrenoceptor expression were measured in the frontal cortex and the hippocampus. Tyrosine hydroxylase immunocytochemical reactivity was also shown in the midbrain regions.
Sub-chronic ketamine administration increased locomotor activity and produced robust social interaction and object recognition deficits, and JP-1302 significantly ameliorated ketamine-induced cognitive deficits. Ketamine induced a hyperdopaminergic activity in the striatum, which was reversed by the treatment with JP-1302. Also, the α2C-adrenoceptor expression was higher in the frontal cortex and hippocampus in the ketamine-treated rats.
Our findings confirm that α2C-adrenoceptor antagonism may be a potential drug target for treating cognitive disorders related to schizophrenia.
•α2C-adrenoceptor antagonists like JP-1302 may have antipsychotic and pro-cognitive effects.•JP-1302 significantly ameliorated ketamine-induced cognitive deficits and hyperdopaminergic activity in the striatum.•The α2C-adrenoceptor expression increased in the frontal cortex and hippocampus in the ketamine-treated rats.
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•Conventional solid–liquid and ultrasound-assisted extraction methods were performed.•Folin–Ciocalteu assay was used to determine the content of phenolic ...compounds.•Ultrasound-assisted extraction (ethanol:water 50:50) was the best extraction method.•Bioactive compounds from Moringa leaves were characterized by HPLC–ESI–QTOF–MS.•30 bioactive compounds were characterized for the first time in M. oleifera leaves.
Moringa oleifera Lam is considered one of the most useful tree in the world because every part of the Moringa tree can be used such as nutritional supplement, for medication, and industrial purposes.
Conventional solid–liquid extraction and ultrasound-assisted extraction (UAE) were performed using different solvents and mixtures of solvents with water. The total phenolic content was determined using Folin–Ciocalteu assay. UAE using ethanol:water (50:50) was the best extraction procedure, which allowed 47±4mg gallic acid equivalents (GAE)/g dry leaf to be obtained. In addition, high-performance liquid chromatography coupled to electrospray ionization quadropole-time of flight mass spectrometry (HPLC–ESI–QTOF–MS) was used to characterize the bioactive compounds in the resulting extract. Consequently, 59 compounds were tentatively characterized, phenolic acid derivatives and flavonoids being the most abundant. Furthermore, 30 of these compounds were tentatively identified for the first time in M. oleifera leaves.
This study shows that leaves from M. oleifera are a good nutritional resource used as a nutritional supplement and may carry additional opportunities for food ingredient innovations, pharmaceutical and cosmetics products.
The aim of the study was observed selected and compared chemical components in commercial and raw chocolates. HPLC was used to determine Galic acid, Theobromin, Catechin, Caffeine, Epicatechin and ...Epigallocatechin 3 gallate in 17 commercial chocolates. Result shows very strong inverse correlation between Epigallocatechin 3 gallate and Galic acid. There was also observed strong positive correlation between Theobromin and Caffeine, Epicatechin and Galic acid, Epigallocatechin 3 gallate and Theobromin, Caffeine and Epigallocatechin 3 gallate. The PCA revealed that 78.83 % of the total variation embodied in five variables could be effectively condensed into and explained by first two principal components (PCs), with eigenvalues of 3.00 and 1.72, respectively. The PC1, accounting for 50.05 % of the inertia, contrasted Galic acid and Caffeine, Epigallocatechin 3 gallate and Theobromin whereas PC2, explaining 28.77 % of the inertia, clearly reflected the different content of Epigallocatechin 3 gallate and Epicatechin. The total variability depends on the tested chemical parameters. The tested raw chocolates were characterized in particular by the caffeine parameters Epigallocatechin 3 gallate.
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•First determination of changes in bioactive compounds during postharvest and processing of cocoa from Peru.•Postharvest processing impact on the reduction of the phenolic and ...alkaloids content.•High concentrations of phenolic compounds were characteristic of CFA cocoa variety.•The refining process facilitates the release of the bioactive compounds and consequently an increase in their content is observed.
From cocoa harvest to chocolate, different physical and chemical transformation processes take place. In addition to changes in the main components (lipids and proteins), the content and nature of other compounds of nutritional importance, such as bioactive compounds, which are mainly responsible for chocolate being considered a superfood, are also modified. The objective of this research was to evaluate the behavior of bioactive compounds during postharvest processing of three varieties of cocoa harvested in the Amazonas region of Peru. A batch of cocoa was sampled during five stages of postharvest processing (fresh bean, fermented bean, dry bean, roasted bean and cocoa paste), and the content of phenolic compounds (catechin, epicatechin, gallic acid and caffeic acid) and alkaloids (theobromine, caffeine and theophylline) was quantified by ultra high performance liquid chromatography (U-HPLC). The total phenolic content and antioxidant capacity were determined using spectrophotometric techniques; Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical capture. Except for roasting processing, the content of phenolic compounds increased. Theobromine is reduced with fermentation, drying and roasting. Cocoa liquor had a higher content of bioactive compounds, probably because it facilitates availability. Although a slight increase in total phenolic compounds was evident, antioxidant activity decreased to the same degree during postharvest processing of the cocoa bean. In conclusion, postharvest processing of cocoa beans affects their bioactive composition.
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