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Molecules (Basel, Switzerland) Feb 2017Vitamin E is recognized as an essential vitamin since its discovery in 1922. Most vegetable oils contain a mixture of tocopherols and tocotrienols in the vitamin E... (Review)
Review
Vitamin E is recognized as an essential vitamin since its discovery in 1922. Most vegetable oils contain a mixture of tocopherols and tocotrienols in the vitamin E composition. Structurally, tocopherols and tocotrienols share a similar chromanol ring and a side chain at the C-2 position. Owing to the three chiral centers in tocopherols, they can appear as eight different stereoisomers. Plant sources of tocopherol are naturally occurring in the form of while synthetic tocopherols are usually in the form of all-racemic mixture. Similarly, with only one chiral center, natural tocotrienols occur as the -isoform. In this review, we aim to discuss a few chromatographic methods that had been used to separate the stereoisomers of tocopherols and tocotrienols. These methods include high performance liquid chromatography, gas chromatography and combination of both. The review will focus on method development including selection of chiral columns, detection method and choice of elution solvent in the context of separation efficiency, resolution and chiral purity. The applications for separation of enantiomers in vitamin E will also be discussed especially in terms of the distinctive biological potency among the stereoisoforms.
Topics: Chromatography; Chromatography, Gas; Chromatography, High Pressure Liquid; Molecular Structure; Stereoisomerism; Tocopherols; Tocotrienols; Vitamin E
PubMed: 28165404
DOI: 10.3390/molecules22020233 -
Molecular & Cellular Proteomics : MCP 2021Glycosylation is a prevalent, yet heterogeneous modification with a broad range of implications in molecular biology. This heterogeneity precludes enrichment strategies... (Review)
Review
Glycosylation is a prevalent, yet heterogeneous modification with a broad range of implications in molecular biology. This heterogeneity precludes enrichment strategies that can be universally beneficial for all glycan classes. Thus, choice of enrichment strategy has profound implications on experimental outcomes. Here we review common enrichment strategies used in modern mass spectrometry-based glycoproteomic experiments, including lectins and other affinity chromatographies, hydrophilic interaction chromatography and its derivatives, porous graphitic carbon, reversible and irreversible chemical coupling strategies, and chemical biology tools that often leverage bioorthogonal handles. Interest in glycoproteomics continues to surge as mass spectrometry instrumentation and software improve, so this review aims to help equip researchers with the necessary information to choose appropriate enrichment strategies that best complement these efforts.
Topics: Animals; Chromatography; Glycomics; Glycopeptides; Glycoproteins; Glycoside Hydrolases; Graphite; Humans; Lectins; Mass Spectrometry; Proteomics
PubMed: 33583771
DOI: 10.1074/mcp.R120.002277 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Dec 2020Bile acids facilitate the absorption of lipids, and affect the development of various diseases by regulating intestinal flora structure and modulating immunity and... (Review)
Review
Bile acids facilitate the absorption of lipids, and affect the development of various diseases by regulating intestinal flora structure and modulating immunity and metabolism. It is therefore important to quantitatively detect bile acids. Current analytical methods are still immature due to constituent complexity, structural heterogeneity and bioactive variability of bile acids. Detection of individual bile acids is of significance for pharmacological research, clinical diagnosis and disease prevention. Advances have been made in bile acid analysis from multiple sources including serum, bile, urine and feces, although several limitations still exist for bile acid quantification. Here we review research progress in conventional bile acid assays, including spectrophotometry, thin-layer chromatography, liquid/gas chromatography and liquid/gas chromatography-mass spectrometry. Moreover, we emphasize the development of bile acid biosensors that may have promising prospects.
Topics: Bile; Bile Acids and Salts; Biosensing Techniques; Chromatography, Thin Layer; Gas Chromatography-Mass Spectrometry
PubMed: 33398972
DOI: 10.13345/j.cjb.200196 -
Analytical and Bioanalytical Chemistry May 2018RNA is becoming more important as an increasing number of functions, both regulatory and enzymatic, are being discovered on a daily basis. As the RNA boom has just... (Review)
Review
RNA is becoming more important as an increasing number of functions, both regulatory and enzymatic, are being discovered on a daily basis. As the RNA boom has just begun, most techniques are still in development and changes occur frequently. To understand RNA functions, revealing the structure of RNA is of utmost importance, which requires sample preparation. We review the latest methods to produce and purify a variation of RNA molecules for different purposes with the main focus on structural biology and biophysics. We present a guide aimed at identifying the most suitable method for your RNA and your biological question and highlighting the advantages of different methods. Graphical abstract In this review we present different methods for large-scale production and purification of RNAs for structural and biophysical studies.
Topics: Animals; Chromatography, Affinity; Chromatography, Gel; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Chromatography, Reverse-Phase; Humans; RNA; Transcription, Genetic
PubMed: 29546546
DOI: 10.1007/s00216-018-0943-8 -
Molecules (Basel, Switzerland) Jan 2018Many substances of forensic interest are chiral and available either as racemates or pure enantiomers. Application of chiral analysis in biological samples can be useful... (Review)
Review
Many substances of forensic interest are chiral and available either as racemates or pure enantiomers. Application of chiral analysis in biological samples can be useful for the determination of legal or illicit drugs consumption or interpretation of unexpected toxicological effects. Chiral substances can also be found in environmental samples and revealed to be useful for determination of community drug usage (sewage epidemiology), identification of illicit drug manufacturing locations, illegal discharge of sewage and in environmental risk assessment. Thus, the purpose of this paper is to provide an overview of the application of chiral analysis in biological and environmental samples and their relevance in the forensic field. Most frequently analytical methods used to quantify the enantiomers are liquid and gas chromatography using both indirect, with enantiomerically pure derivatizing reagents, and direct methods recurring to chiral stationary phases.
Topics: Chromatography, Gas; Chromatography, Liquid; Forensic Sciences; Pharmaceutical Preparations
PubMed: 29382109
DOI: 10.3390/molecules23020262 -
Journal of Chromatography. A Jan 2021Extracellular vesicles (EVs) are heterogenous membrane-bound vesicles released from various origins. EVs play a crucial role in cellular communication and mediate... (Review)
Review
Extracellular vesicles (EVs) are heterogenous membrane-bound vesicles released from various origins. EVs play a crucial role in cellular communication and mediate several physiological and pathological processes, highlighting their potential therapeutic and diagnostic applications. Due to the rapid increase in interests and needs to elucidate EV properties and functions, numerous isolation and separation approaches for EVs have been developed to overcome limitations of conventional techniques, such as ultracentrifugation. This review focuses on recently emerging and modern EV isolation and separation techniques, including size-, charge-, and affinity-based techniques while excluding ultracentrifugation and precipitation-based techniques due to their multiple limitations. The advantages and drawbacks of each technique are discussed together with insights into their applications. Emerging approaches all share similar features in terms of being time-effective, easy-to-operate, and capable of providing EVs with suitable and desirable purity and integrity for applications of interest. Combination and hyphenation of techniques have been used for EV isolation and separation to yield EVs with the best quality. The most recent development using an automated on-line system including selective affinity-based trapping unit and asymmetrical flow field-flow fractionation allows reliable isolation and fractionation of EV subpopulations from human plasma.
Topics: Chromatography, Affinity; Chromatography, Gel; Chromatography, Ion Exchange; Electrophoresis; Extracellular Vesicles; Fractionation, Field Flow; Humans; Ultracentrifugation
PubMed: 33316564
DOI: 10.1016/j.chroma.2020.461773 -
Analytical and Bioanalytical Chemistry Mar 2022This work presents a comparative study for the analysis of carbohydrates for four common chromatographic methods, each coupled to mass spectrometry. Supercritical fluid...
This work presents a comparative study for the analysis of carbohydrates for four common chromatographic methods, each coupled to mass spectrometry. Supercritical fluid chromatography (SFC), hydrophilic interaction liquid chromatography (HILIC), reversed-phase liquid chromatography (RP-LC) and gas chromatography (GC) with detection by triple quadrupole mass spectrometer (QqQ-MS) are compared. It is shown that gas chromatography and reversed-phase liquid chromatography, each after derivatisation, are superior to the other two methods in terms of separation performance. Furthermore, comparing the different working modes of the mass spectrometer, it can be determined that a targeted analysis, i.e. moving from full scan to single ion monitoring (SIM) and multiple reaction monitoring (MRM), results in an improvement in the sensitivity as well as the repeatability of the method, which has deficiencies especially in the analysis using HILIC. Overall, RP-LC-MS in MRM after derivatisation with 1-phenyl-3-methyl-5-pyrazolone (PMP) proved to be the most suitable method in terms of separation performance, sensitivity and repeatability for the analysis of monosaccharides. Detection limits in the nanomolar range were achieved, which corresponds to a mass concentration in the low µg/L range. The applicability of this method to different biological samples was investigated with various herbal liquors, pectins and a human glycoprotein.
Topics: Carbohydrates; Chromatography, Liquid; Chromatography, Reverse-Phase; Gas Chromatography-Mass Spectrometry; Humans; Mass Spectrometry
PubMed: 34928405
DOI: 10.1007/s00216-021-03845-z -
Methods in Molecular Biology (Clifton,... 2023The compositional and structural analysis of GAGs is challenging due to their heterogenous structures. Strong anion exchange (SAX) HPLC can aid in the compositional...
The compositional and structural analysis of GAGs is challenging due to their heterogenous structures. Strong anion exchange (SAX) HPLC can aid in the compositional analysis of GAGs and can separate complex mixtures based on charge and degree of sulfation. Herein we describe the digestion and release of GAGs from tissue, and the compositional analysis using SAX-HPLC.
Topics: Glycosaminoglycans; Chromatography, Ion Exchange; Chromatography, High Pressure Liquid; Anions
PubMed: 36374422
DOI: 10.1007/978-1-0716-2835-5_14 -
Journal of Chromatography. A Aug 2022The aim of this study was to evaluate the potential of ultra-high performance supercritical fluid chromatography (UHPSFC) for peptide analysis by comparing its...
The aim of this study was to evaluate the potential of ultra-high performance supercritical fluid chromatography (UHPSFC) for peptide analysis by comparing its analytical performance to several chromatographic approaches based on reversed-phase liquid chromatography (RPLC), hydrophilic interaction liquid chromatography (HILIC) and mixed-mode liquid chromatography. First, the retention behavior of synthetic peptides with 3 to 30 amino acids and different isoelectric points (acid, neutral, and basic) was evaluated. For all the tested conditions (13 peptides in 8 conditions), only 4 results were not exploitable (not retained or not eluted), confirming that all the tested chromatographic conditions can be successfully applied when analyzing a wide range of diverse peptides. Average tailing factor were quite comparable across all chromatographic modes, while the best peak capacity values were obtained under mixed-mode LC conditions. Selectivity for each chromatographic mode was also evaluated for six closely related peptides having minor modifications on their structures. The LC-based chromatographic modes confirmed their superior selectivity over UHPSFC. By contrast, when analyzing short peptides (di- or tripetides), UHPSFC was the only technique allowing to simultaneously separate highly polar and less polar peptides within the same run confirming its unique versatility. In addition, the sensitivity of each chromatographic approach was accessed by for two representative peptides by both UV and MS detection. With UV detection, limit of detection (LOD) values were comparable among the different chromatographic modes, ranging from 0.5 to 2 µg mL. However, major differences were found when employing MS detection (LOD values ranged from 0.05 to 5 µg mL). The best results were obtained under HILIC conditions, followed by SFC, and finally mixed-mode LC and RPLC modes.
Topics: Chromatography, Liquid; Chromatography, Reverse-Phase; Chromatography, Supercritical Fluid; Hydrophobic and Hydrophilic Interactions; Peptides
PubMed: 35785673
DOI: 10.1016/j.chroma.2022.463282 -
Journal of Chromatography. A Apr 2021Mass spectrometry is now in widespread use for the detection of the analytes separated by chromatography. Electron ionization is the most frequently used method in mass... (Review)
Review
Mass spectrometry is now in widespread use for the detection of the analytes separated by chromatography. Electron ionization is the most frequently used method in mass spectrometry. However, this ionization technique sometimes suffers from extensive fragmentation of analytes, which makes identification difficult. A photoionization technique has been developed for suppressing this fragmentation and for subsequently observing a molecular ion. A variety of lasers have been employed for the sensitive and selective ionization of organic compounds. A femtosecond laser has a high peak power and is preferential for efficient ionization as well as for suppressing fragmentation, providing valuable information concerning molecular weight and chemical structure as well. In this review, we report on applications of femtosecond ionization mass spectrometry combined with gas chromatography.
Topics: Chromatography; Gas Chromatography-Mass Spectrometry; Mass Spectrometry; Polycyclic Aromatic Hydrocarbons; Spectrum Analysis, Raman; Thermodynamics
PubMed: 33714081
DOI: 10.1016/j.chroma.2021.462023