Chromatography-diode Array Detection-mass Spectrometry Research Articles

Andean Prumnopitys Andina (Podocarpacae) Fruit Extracts: Characterization of Secondary Metabolites and Potential Cytoprotective Effect.

The fruits from the Chilean Podocarpaceae Prumnopitys andina have been consumed since pre-Hispanic times. Little is known about the composition and biological properties of this fruit. The aim of this work was to identify the secondary metabolites of the edible part of P. andina fruits and to assess their antioxidant activity by means of chemical and cell-based assays. Methanol extracts from P. andina fruits were fractionated on a XAD7 resin and the main compounds were isolated by chromatographic means. Antioxidant activity was determined by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing power (FRAP), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. The cytoprotective activity of the extract against oxidative and dicarbonyl stress was evaluated in human gastric epithelial cells (AGS). The total intracellular antioxidant activity (TAA) of the extract was determined in AGS cells. The inhibition of meat lipoperoxidation was evaluated under simulated gastric digestion conditions. Rutin, caffeic acid β-glucoside and 20-hydroxyecdysone were identified as major components of the fruit extract. Additional compounds were identified by high-performance liquid chromatography diode-array detector mass spectrometry (HPLC-DAD-MSn) and/or co-injection with standards. Extracts showed dose-dependent cytoprotective effects against oxidative and dicarbonyl-induced damage in AGS cells. The TAA increased with the pre-incubation of AGS cells with the extract. This is the first report on the composition and biological activity of this Andean fruit.

Qualitative identification of impurities and principal component quantitative analysis of zearalanone on purity certified reference material

A liquid chromatography method was established for the determination of zearalanone (ZAN) raw material. The qualitative analysis of ZAN and its trace impurities was performed by ultra performance liquid chromatography-diode array detector (UPLC-DAD) and ultra performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), and the response factors of each impurity were calculated. The three main organic impurities in the ZAN raw material were identified as β -zearalanol, α -zearalanol and a dehydration product of zearalanol with relative response factors of 0.5352, 0.8594 and 0.6973, respectively. The main component of the ZAN raw material was determined by the calibration factor normalization method. The purity of zearalanone was determined to be 99.6% with a standard deviation of 0.01%. This method can provide a technical support for the development of ZAN standard materials.

In vitro Antioxidant and Enzymatic Approaches to Evaluate Neuroprotector Potential of Blechnum Extracts without Cytotoxicity to Human Stem Cells.

Background:Investigation of selected plant extracts on multi-targets related to neurodegeneration, such as monoamine oxidases (MAO), cholinesterase enzymes, and antioxidant activities (AOA) is a useful tool for identification of new scaffolds.Objective:This work investigated biological effects of three Blechnum methanol extracts from Brazil and chemical profile of the most active sample.Materials and Methods:AOA included scavenging of hydroxyl and nitric oxide radicals, also lipid peroxidation inhibition. Enzymatic modulation of Blechnum binervatum, Blechnum brasiliense, and Blechnum occidentale extracts on MAO and cholinesterases was conducted. Moreover, total phenol content was performed with all samples, and high-performance liquid chromatography-diode array detection mass spectrometry HPLC-DAD-MS analysis was carried out with B. brasiliense. Possible toxic effects were evaluated on Wistar rats polymorphonuclear cells (PMN) and human stem cells.Results:B. brasiliense extract presented the highest phenolic amount (9.25 g gallic acid equivalent/100 g extract) and lowest IC50 values (112.3 ± 2.61 and 176.1 ± 1.19 μg/mL) against hydroxyl radicals and on lipid peroxidation, respectively, showing strong AO effects. On nitric oxide assay and cholinesterase inhibition, all extracts were considered inactive. MAO-A selective action was evidenced, being B. brasiliense powerful against this enzyme (IC50: 72.7 μg/mL), followed by B. occidentale and B. binervatum (IC50: 130.85 and 165.2 μg/mL). No cytotoxic effects were observed on PMN and human stem cells treated with Blechnum extracts. HPLC-DAD-MS analysis of B. brasiliense allowed the identification of chlorogenic and rosmarinic acids.Conclusion:Our results especially highlight B. brasiliense, with pronounced phenols content and strong effects on selected targets related to neurodegeneration, being characterized as a natural safe source of bioactive hydroxycinnamic acids.SUMMARY Blechnum crude extracts showed high phenolic amounts and valuable IC50 values on targets related with neurodegenerative disordersBlechnum brasiliense was the most active sample, with strong radical scavenging and lipid peroxidation inhibition, also with monoamine oxidases: A selective modulationNo cytotoxic effects were observed on polymorphonuclear cells rat cells and human stem cells treated with Blechnum extractsHigh-performance liquid chromatography-diode array detection-mass spectrometry analysis of Blechnum brasiliense allowed the identification of hydroxycinnamic derivatives: Chlorogenic and rosmarinic acids. Abbreviations used: IC50: half maximal inhibitory concentration; MAO: monoamine oxidase; MAO-A: monoamine oxidase isoform A; MAO-B: monoamine oxidase isoform B; HO•: hydroxyl radical.

Metabolite identification of a new tyrosine kinase inhibitor, HM781‐36B, and a pharmacokinetic study by liquid chromatography/tandem mass spectrometry

HM781-36B (1-[4-[4-(3,4-dichloro-2-fluorophenylamino)-7-methoxyquinazolin-6-yloxy]-piperidin-1-yl]prop-2-en-1-one hydrochloride) is a new anticancer drug to treat advanced solid tumors in clinical trial. In order to understand the behavior of HM781-36B in vitro and in vivo we validated an analytical method for HM781-36B and its major metabolites in plasma. In vivo and in vitro metabolism of HM781-36B was studied in dog plasma, urine and feces as well as using human and dog liver microsomes with extraction by ethyl acetate or methyl tert-butyl ether, respectively, and successfully separated by high-performance liquid chromatography diode-array detection mass spectrometry (HPLC-DAD/MS). Ten metabolites were identified by LC/ESI-ion trap mass spectrometry (MS, MS(2) , MS(3) and MRM) and LC/Q-TOF-MS/MS for exact mass measurement. For accurate characterization of the major metabolites, authentic standards (M1, M2, M4, and M10) were synthesized. Ten metabolites of HM781-36B in an in vitro mixture were separated and identified by LC/ESI-MS(n) . The MS/MS spectral patterns of the parent drug and metabolites exhibited two characteristic ions (A- and B-type ions) attributed to the cleavage of the ether bond between the piperidine ring and the quinazoline ring, providing important information on the site of chemical conversion during the metabolism. Six hydroxylated derivatives including dehalogenation and demethylation, two N-oxide forms, a demethylated form and de-acryloylpiperideine metabolites were observed. The LC/ESI-ion trap MS(n) technique was effective in obtaining structural information and yielded diagnostic ions for the identification of diverse metabolites. The multiple metabolic pathways of HM781-36B were suggested in in vitro and in vivo samples and the dihydroxylation (M1) and demethylation (M2) appeared to be the major metabolites.

Evaluation of antioxidative capability of the tomato (Solanum lycopersicum) skin constituents by capillary electrophoresis and high‐performance liquid chromatography

In the current study, phenolic compounds of the tomato (Solanum lycopersicum) skin extract were separated and their composition was determined by capillary electrophoresis and tandem high-performance liquid chromatography diode array detection-mass spectrometry (HPLC-DAD-MS/MS). Both the total phenolic and flavonoid contents of the extract were determined. The antioxidative capability of the extract was measured using a stable free radical 2,2-diphenyl-1-picrylhydrazyl assay. The monitoring of the radical scavenging capability of specific phenolic compounds was carried out both by capillary electrophoresis and HPLC-MS/MS.

Analysis of environmental samples by application of multivariate curve resolution on fused high-performance liquid chromatography–diode array detection mass spectrometry data

Multivariate curve resolution-alternating least squares (MCR-ALS) is applied to solve coelution problems in liquid chromatograpy with diode array detection (DAD) and mass spectrometry (MS). Fusion of DAD and MS detector signals improved results versus those obtained using only one of the two detector signals. Application of wavelet transform to MS data before its fusion with DAD data, further help to facilitate the resolution and quantitation of the coeluted compounds under study, besides a decrease of time of analysis. Mixtures of biocide compounds in standard mixtures and in environmental samples (sediment and wastewater samples) were analyzed with estimated quantitation errors below 12%.

Identification of Anthocyanins in Rhamnus alaternus L. Berries

Anthocyanin composition in berries of Rhamnus alaternus L., a perennial wild shrub typical of the Mediterranean area, was determined for the first time. The pigments were extracted from the berries with 0.1% HCl in methanol and purified using a C-18 solid-phase cartridge. High-performance liquid chromatography diode array detection-mass spectrometry analysis showed that delphinidin 3-O-rutinoside represented about 62.4% of the total pigments. Other anthocyanins were 3-O-rutinoside derivatives of cyanidin (8.4%), petunidin (15.8%), pelargonidin (4.7%), and peonidin and malvidin (8.7%). The concomitant presence of the six most common anthocyanidins suggested that R. alaternus berries, besides being a good pigment source, could also be a useful tool for anthocyanin identification.