Search results for "CHROMATOGRAPHY"
showing 10 items of 5037 documents
Interactive effects of aging and aerobic capacity on energy metabolism-related metabolites of serum, skeletal muscle, and white adipose tissue
2021
ABSTRACTAerobic capacity is a strong predictor of longevity. With aging, aerobic capacity decreases concomitantly with changes in whole body metabolism leading to increased disease risk. To address the role of aerobic capacity, aging and their interaction on metabolism, we utilized rat models of low and high intrinsic aerobic capacity (LCRs/HCRs) and assessed the metabolomics of serum, muscle, and white adipose tissue (WAT). We compared LCRs and HCRs at two time points: Young rats were sacrificed at 9 months, and old rats were sacrificed at 21 months. Targeted and semi-quantitative metabolomics analysis was performed on ultra-pressure Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS)…
Reliable determination of new lipid peroxidation compounds as potential early Alzheimer Disease biomarkers.
2018
Lipid peroxidation plays an important role in Alzheimer Disease, so corresponding metabolites found in urine samples could be potential biomarkers. The aim of this work is to develop a reliable ultra-performance liquid chromatography-tandem mass spectrometry analytical method to determine a new set of lipid peroxidation compounds in urine samples. Excellent sensitivity was achieved with limits of detection between 0.08 and 17 nmol L-1, which renders this method suitable to monitor analytes concentrations in real samples. The method's precision was satisfactory with coefficients of variation around 5-17% (infra-day) and 8-19% (inter-day). The accuracy of the method was assessed by analysis o…
Biological activities of polyphenols-enriched propolis from Argentina arid regions
2015
Background: Propolis is a bioactive natural product collected by honeybees (Apis mellifera) fromplant sources. Purpose: This studywas undertaken to determine the effect of propolis extracts from arid region of Argentina, on the activity/expression of pro-inflammatory enzymes, and as potential free radical scavenger, antifungal and anthelmintic agent as well as to get a first insight into the polyphenolic profile of the active fractions.Study design/methods: Two propolis samples were collected in different time from hives located in Tucumán, Argentina. They are representative of the collection time of the raw material for phytotherapeutical purposes. Ethanolic extracts from both propolis wer…
The Bioactive Compounds and Antioxidant Activity of Food Products of Rhizophora stylosa Fruit (Coffee and Tea Mangrove)
2018
The objective of this study is to investigate the bioactive compounds and antioxidant activity of coffee and tea mangrove (locally known in Indonesia) produced from the fruit of Rhizophora stylosa. Furthermore, three raw materials of coffee mangrove were also investigated to clarify their potencies. The crude extracts of five samples were subjected to antioxidant assay using DPPH. The results show that the extract of tea mangrove has the strongest activity; then, it was successfully fractionated using different polarity of solvents and yielded acetone and methanol fractions that had high antioxidant activity. The acetone fraction was purified and gave fractions A1, A2, A3, A4, A5, and A6, b…
Ferric-bipyridine assay: A novel spectrophotometric method for measurement of antioxidant capacity
2020
Measurement of the antioxidant potential using in vitro assays is paramount in the assessment of various food products and nutraceuticals. Researchers always attempt to develop more accurate assays which can be performed in unsophisticated conditions. This novel method, Ferric-Bipyridine reducing capacity of total antioxidants (FBRC) is a very simple, accurate assay performed based on the reduction of Fe (III) to Fe (II) by antioxidants with the formation of a colored complex with bipyridine (Bp) i.e, Fe(II)-Bp. The FBRC method thus developed was assessed under carefully adjusted parameters of oxidant concentration, pH, temperature, solvent, light and time in order to fix the optimum condit…
Guava: phytochemical composition of a potential source of antioxidants for cosmetic and/or dermatological applications
2017
Made available in DSpace on 2018-11-28T14:21:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01. Added 1 bitstream(s) on 2019-10-09T18:26:25Z : No. of bitstreams: 1 S1984-82502017000200612.pdf: 803011 bytes, checksum: 199524e8d40cccb25490594ec61b3ed8 (MD5) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) PADC-FCF-UNESP Fundação para o Desenvolvimento da UNESP (FUNDUNESP) Guava (Psidium guajava L.) is a native fruit of the American tropics with commercial applications for its taste, flavor and aroma. Numerous pharmacological uses have been described for it, such as the antiseptic effect of it…
Characterization of Active Compounds of Different Garlic (Allium sativum L.) Cultivars
2018
Garlic (Allium sativum L.) has a reputation as a therapeutic agent for many different diseases such as microbial infections, hypertension, hypercholesterolaemia, diabetes, atherosclerosis and cancer. Health benefits of garlic depend on its content of biologically-active compounds, which differs between cultivars and geographical regions. The aim of this study was to evaluate and compare the biological activity of aqueous extracts from nine garlic varieties from different countries (Poland, Spain, China, Portugal, Burma, Thailand and Uzbekistan). Antioxidant properties were evaluated through free radical scavenging (DPPH•, ABTS•+) and ion chelation (Fe2+, Cu2+) activities. The cytotoxicity o…
Lipid peroxidation as measured by chromatographic determination of malondialdehyde. Human plasma reference values in health and disease
2021
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 p…
Comparing Targeted vs. Untargeted MS2 Data-Dependent Acquisition for Peak Annotation in LC-MS Metabolomics
2020
One of the most widely used strategies for metabolite annotation in untargeted LCMS is based on the analysis of MSn spectra acquired using data-dependent acquisition (DDA), where precursor ions are sequentially selected from MS scans based on user-selected criteria. However, the number of MSn spectra that can be acquired during a chromatogram is limited and a trade-off between analytical speed, sensitivity and coverage must be ensured. In this research, we compare four different strategies for automated MS2 DDA, which can be easily implemented in the frame of standard QA/QC workflows for untargeted LC&ndash
Impact of plant sterols enrichment dose on gut microbiota from lean and obese subjects using TIM-2 in vitro fermentation model
2019
There are scarce data on plant sterols (PS) and gut microbiota relationship. The purpose of this study is to compare the interaction between PS and gut microbiota through in vitro colonic fermentation studies using a validated system (TIM-2) with a PS-enriched dose (similar to 2 g/day) from two sources (food PS-source ingredient and commercial standard) using microbiota from lean and obese populations. Fecal sterols, short chain fatty acids (SCFA) and microbiota composition were determined by GC/MS, IEC, and 16S-sequencing, respectively.PS-feeding decreased coprostanol and ethylcoprostanol concentration and increased the production of acetate and butyrate (mainly with lean microbiota). In a…