Lipid Profiling of Synechococcus sp. PCC7002 and Two Related Strains by HPLC Coupled to ESI-(Ion Trap)-MS/MS

2011 ◽  
Vol 66 (3-4) ◽  
pp. 149-158 ◽  
Author(s):  
Olimpio Montero
Keyword(s):  
High Performance ◽  
Ion Trap ◽  
Fatty Acyl ◽  
Lipid Profiling ◽  
Lipid Species ◽  
Negative Ionization Mode ◽  
Ionization Mode ◽  
Synechococcus Sp ◽  
Negative Ionization ◽  
Fragmentation Patterns

The lipid profiles of Synechococcus sp. PCC7002 and two related 16S rDNA (99% identity) strains were established by a new method of high-performance liquid chromatography coupled to electrospray-mass spectrometry (HPLC-MS). Lipids were analysed in the positive and negative ionization mode, and fragmentation patterns are reported. No differences in the lipid profi le between the three strains could be observed, but the relative content of some species differed. Major lipid species were found to be 1-octadecatrienoyl- 2-hexadecanoyl-3-(6’-sulfo-α-D-quinovosyl)-sn-glycerol [SQDG (18:3/16:0)] and 1-octadecatrienoyl-2-hexadecenoyl-3-β-D-monogalactosyl-sn-glycerol [MGDG (18:3/16:1)]. Ten species of SQDG, six species of PG (phosphatidyl-glycerol), seven species of MGDG, and two species of DGDG (digalactosyl-diacyl-glycerol) were detected. A PG species (m/z 761) containing hydroxylinolenic acid or oxophytodienoic acid acyl ester (C18H32O3), and SQDG species containing C17:1 and C17:3 fatty acyl esters are reported for the first time in cyanobacteria. The method also allowed the separation of two pairs of closely related isobaric MGDG species (m/z 770 and m/z 772 in positive ionization)

scholarly journals Untargeted Metabolomic Profiling of Early Diet Energy Intake in C57BL/6 N Mice Reveals Differences Associated with Diet and Aberrant Crypt Foci

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1249-1249
Author(s):  
Haley Chatelaine ◽  
Spencer Kyle ◽  
Cynthia Ramazani ◽  
Susan Olivo-Marston ◽  
Emmanuel Hatzakis ◽  
...  
Keyword(s):  
High Performance ◽  
Linear Models ◽  
High Resolution Mass Spectrometry ◽  
Control Diet ◽  
Aberrant Crypt Foci ◽  
Funding Sources ◽  
Negative Ionization Mode ◽  
Ionization Mode ◽  
Negative Ionization ◽  
Polar Extracts

Abstract Objectives A high-fat (H) diet leads to obesity, a known risk factor for colorectal cancer (CRC). In contrast, calorie restriction (E) is associated with reduced CRC risk. However, the metabolome associated with H vs. E-associated CRC risk has never been directly compared. The different influences of these diets on the proximal (PC), medial (MC), and distal (DC) colon metabolome has also not been studied. Thus, the objective is to elucidate metabolites associated with abberant crypt foci (ACF) number, a marker of CRC risk, in each colon region after consumption of H, E, or a normocaloric control diet (C). Methods 3-week-old C57BL/6 N mice were fed a C, E, or H initiation diet for 13 weeks. In weeks 16–21, animals were injected with azoxymethane to initiate ACF formation, and switched to a C, E, or H progression diet (for a total of 9 diet groups: CC, CH, CE, HH, HC, HE, EE, EC, EH). Polar extracts of the colon regions (i.e., PC, MC, and DC) were analyzed using ultra-high performance liquid chromatography-high resolution mass spectrometry method (HRMS) and 1H NMR metabolomics methods. Linear models assessed the main effects of ACF, initiation diet, progression diet, as well as the diet * ACF interaction, on relative metabolite concentration in each colon region. Results Following HILIC-HRMS analysis of extracts in positive and negative ionization mode, 492 and 415 metabolites were detected, respectively. Linear models revealed 21 metabolites were significantly associated with initiation E diet * ACF (8 unique to MC, 13 unique to PC), 14 with initiation H diet * ACF (only in DC), 27 with progression H diet * ACF (14 unique to DC, 2 to MC, 11 to PC) and 20 with progression E diet * ACF (17 unique to DC, 1 to PC, and 1 common to both). Pathway integration and authentication of tentative metabolite identities with chemical standards is underway. Conclusions Diet * ACF interaction significantly influences multiple metabolite concentrations. Little to no overlap is observed between metabolites associated with ACF in a given colon region and the other regions tested, revealing that the diet * ACF interaction is region-specific. Future studies in humans will determine if these metabolites may serve as early biomarkers for CRC diagnosis. Funding Sources Sample analyses were supported by NIH Award Number Grant P30 CA016058, OSU, and OSUCCC.

scholarly journals Determination of Ten Corticosteroids in Illegal Cosmetic Products by a Simple, Rapid, and High-Performance LC-MS/MS Method

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Vita Giaccone ◽  
Giuseppe Polizzotto ◽  
Andrea Macaluso ◽  
Gaetano Cammilleri ◽  
Vincenzo Ferrantelli
Keyword(s):  
High Performance ◽  
Skin Diseases ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Cosmetic Products ◽  
Chromatography Method ◽  
Esi Ms ◽  
Negative Ionization Mode ◽  
Negative Ionization

The aim of our present work was the development of a rapid high-performance liquid chromatography method with electrospray ionization and tandem mass spectrometry detection (LC-ESI-MS/MS) for the determination of several corticosteroids in cosmetic products. Corticosteroids are suspected to be illegally added in cosmetic preparations in order to enhance the curative effect against some skin diseases. Sample preparation step consists in a single extraction with acetonitrile followed by centrifugation and filtration. The compounds were separated by reversed-phase chromatography with water and acetonitrile (both with 0.1% formic acid) gradient elution and detected by ESI-MS positive and negative ionization mode. The method was validated at the validation level of 0.1 mg kg−1. Linearity was studied in the 5–250 μg L−1 range and linear coefficients (r2) were all over 0.99. The accuracy and precision of the method were satisfactory. The LOD ranged from 0.085 to 0.109 mg kg−1 and the LOQ from 0.102 to 0.121 mg kg−1. Mean recoveries for all the analytes were within the range 91.9–99.2%. The developed method is sensitive and useful for detection, quantification, and confirmation of these corticosteroids in cosmetic preparations and can be applied in the analysis of the suspected samples under investigation.

scholarly journals Improved Small Molecule Identification through Learning Combinations of Kernel Regression Models

Metabolites ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 160 ◽  
Author(s):  
Céline Brouard ◽  
Antoine Bassé ◽  
Florence d’Alché-Buc ◽  
Juho Rousu
Keyword(s):  
Small Molecule ◽  
Kernel Regression ◽  
Feature Space ◽  
Molecular Structures ◽  
Subgradient Optimization ◽  
Hinge Loss ◽  
Fast Training ◽  
Negative Ionization Mode ◽  
Ionization Mode ◽  
Negative Ionization

In small molecule identification from tandem mass (MS/MS) spectra, input–output kernel regression (IOKR) currently provides the state-of-the-art combination of fast training and prediction and high identification rates. The IOKR approach can be simply understood as predicting a fingerprint vector from the MS/MS spectrum of the unknown molecule, and solving a pre-image problem to find the molecule with the most similar fingerprint. In this paper, we bring forward the following improvements to the IOKR framework: firstly, we formulate the IOKRreverse model that can be understood as mapping molecular structures into the MS/MS feature space and solving a pre-image problem to find the molecule whose predicted spectrum is the closest to the input MS/MS spectrum. Secondly, we introduce an approach to combine several IOKR and IOKRreverse models computed from different input and output kernels, called IOKRfusion. The method is based on minimizing structured Hinge loss of the combined model using a mini-batch stochastic subgradient optimization. Our experiments show a consistent improvement of top-k accuracy both in positive and negative ionization mode data.

Rapid determination of canagliflozin in rat plasma by UHPLC–MS/MS using negative ionization mode to avoid adduct-ions formation

Talanta ◽  
2015 ◽  
Vol 132 ◽  
pp. 29-36 ◽  
Author(s):  
Muzaffar Iqbal ◽  
Essam Ezzeldin ◽  
Khalid A. Al-Rashood ◽  
Yousif A. Asiri ◽  
Naser L. Rezk
Keyword(s):  
Rapid Determination ◽  
Rat Plasma ◽  
Negative Ionization Mode ◽  
Ionization Mode ◽  
Negative Ionization

scholarly journals Studies on Positive and Negative ionization mode of ESI-LC-MS/ MS for screening of Phytochemicals on Cassia auriculata (Aavaram Poo)

2018 ◽  
Vol 10 (3) ◽  
pp. 457-462
Author(s):  
Paranthaman Ramakrishnan ◽  
Sureshkumar Kalakandan ◽  
Muthukumaran Pakkirisamy
Keyword(s):  
Cassia Auriculata ◽  
Negative Ionization Mode ◽  
Ionization Mode ◽  
Negative Ionization

Validated Chiral LC-ESI-MS/MS Method for the Simultaneous Quantification of Darolutamide Diastereomers and Its Active Metabolite in Mice Plasma: Application to a Pharmacokinetic Study

Drug Research ◽  
2018 ◽  
Vol 68 (11) ◽  
pp. 615-624
Author(s):  
Narayan Balaji ◽  
Suresh Sulochana ◽  
Neeraj Saini ◽  
Siva A. ◽  
Ramesh Mullangi
Keyword(s):  
Pharmacokinetic Study ◽  
Active Metabolite ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Triple Quadrupole Mass Spectrometer ◽  
Liquid Liquid Extraction ◽  
Regulatory Guidelines ◽  
Negative Ionization Mode ◽  
Ionization Mode ◽  
Negative Ionization

AbstractA simple, selective and reliable LC-MS/MS method was developed and validated for the simultaneous quantitation of darolutamide diastereomers (diastereomer-1 and diastereomer-2) and its active metabolite i. e. ORM-15341 in mice plasma using warfarin as an internal standard (IS) as per the regulatory guidelines. Plasma samples were extracted by liquid-liquid extraction and the chromatographic separation was achieved on a Chiralpak IA column with an isocratic mobile phase 5 mM ammonium acetate:absolute alcohol (20:80, v/v) at a flow rate of 1.0 mL/min. Detection and quantitation was done by multiple reaction monitoring on a triple quadrupole mass spectrometer following the transitions: m/z 397→202, 395→202 and 307→250 for darolutamide diastereomers, ORM-15341 and the IS, respectively in the negative ionization mode. The calibration curves were linear (r>0.992) in the range of 100–2400 ng/mL for all the analytes. The intra- and inter-day precisions were in the range of 1.25–10.2 and 1.58-12.3; 2.85-5.68 and 1.85-9.58; 2.34-12.1 and 2.58-7.38 for diastereomer-1, diastereomer-2 and ORM-15341, respectively. Both diastereomers and ORM-15341 were found to be stable under different stability conditions. The validated method was applied to a pharmacokinetic study in mice.

scholarly journals Metabolite Profiling and Quantitation of Cucurbitacins in Cucurbitaceae Plants by Liquid Chromatography coupled to Tandem Mass Spectrometry

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Faraz Ul Haq ◽  
Arslan Ali ◽  
Muhammad Noman Khan ◽  
Syed Muhammad Zaki Shah ◽  
Ram Chandra Kandel ◽  
...  
Keyword(s):  
Natural Products ◽  
Ion Trap ◽  
Biological Activities ◽  
Multiple Reaction Monitoring ◽  
Herbal Medicines ◽  
Distribution Profile ◽  
Anti Cancer ◽  
Negative Ionization ◽  
Fragmentation Patterns ◽  
Cucurbitaceae Family

Abstract Cucurbitaceae is an important plant family because many of its species are consumed as food, and used in herbal medicines, cosmetics, etc. It comprises annual vines and is rich in various bioactive principles which include the cucurbitacins. These steroidal natural products, derived from the triterpene cucurbitane, are mainly the bitter principles of the family Cucurbitaceae. Their biological activities include anti-inflammatory, hepatoprotective, and anti-cancer activities. A total of 10 species belonging to 6 genera of the Cucurbitaceae family along with Cissampelos pareira (Menispermaceae) were included in this study. A comprehensive profiling of certain natural products was developed using HPLC-QTOF-MS/MS analysis and a distribution profile of several major natural products in this family was obtained. A total of 51 natural products were detected in both positive and negative ionization modes, based on accurate masses and fragmentation patterns. Along with this, quantitation of four bioactive cucurbitacins, found in various important plants of the Cucurbitaceae family, was carried out using multiple reaction monitoring (MRM) approach on an ion trap mass spectrometer. Cucurbitacin Q was found to be the most abundant in C. pareira, while Citrullus colocynthis contained all four cucurbitacins in abundant quantities. The developed quantitation method is simple, rapid, and reproducible.

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