Utility Of High-performance Liquid Chromatography Research Articles

UPLC-Q-TOF-MS, network analysis, and molecular docking to investigate the effect and active ingredients of tea-seed oil against bacterial pathogens.

Object: This research intended to probe the antibacterial effect and pharmacodynamic substances of Tea-Seed Oil (TSO) through the use of ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) analysis, network analysis, and molecular docking. Methods: The major chemical components in the methanol-extracted fractions of TSO were subjected to UPLC-Q-TOF-MS. Network pharmacology and molecular docking techniques were integrated to investigate the core components, targets, and potential mechanisms of action through which the TSO exert their antibacterial properties. To evaluate the inhibitory effects, the minimum inhibitory concentration and diameter of the bacteriostatic circle were calculated for the potential active ingredients and their equal ratios of combinatorial components (ERCC) against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Moreover, the quantification of the active constituents within TSO was achieved through the utilization of high-performance liquid chromatography (HPLC). Results: The methanol-extracted fractions contained a total of 47 chemical components, predominantly consisting of unsaturated fatty acids and phenolic compounds. The network pharmacology analysis and molecular docking analysis revealed that various components, including gallocatechin, gallic acid, epigallocatechin, theophylline, chlorogenic acid, puerarin, and phlorizin, have the ability to interact with critical core targets such as serine/threonine protein kinase 1 (AKT1), epidermal growth factor receptor (EGFR), a monoclonal antibody to mitogen-activated protein kinase 14 (MAPK14), HSP90AA1, and estrogen receptor 1 (ESR1). Furthermore, these components can modulate the phosphatidylinositol-3-kinase protein kinase B (PI3K-AKT), estrogen, MAPK and interleukin 17 (IL-17) signaling pathways, hereby exerting antibacterial effects. In vitro validation trials have found that seven components, namely gallocatechin, gallic acid, epigallocatechin, theophylline, chlorogenic acid, puerarin, and phloretin, displayed substantial inhibitory effects on E. coli, S. aureus, P. aeruginosa, and C. albicans, and are typically present in tea oil, with a total content ranging from 15.87∼24.91 μg·g-1. Conclusion: The outcomes of this investigation possess the possibility to expand our knowledge base concerning the utilization of TSO, furnish a theoretical framework for the exploration of antibacterial drugs and cosmetics derived from inherently occurring TSO, and establish a robust groundwork for the advancement and implementations of TOS products within clinical settings.

Highly Sensitive Detection of Multiple MicroRNAs by High-Performance Liquid Chromatography Coupled with Long and Short Probe-Based Recycling Amplification.

This report demonstrated the utility of high-performance liquid chromatography (HPLC)-fluorescence detection for selective separation and sensitive quantification of multiple microRNAs (miRNAs). A duplex specific nuclease (DSN)-assisted target recycling amplification strategy was developed to enhance the signals of miRNAs, which alleviates the low sensitivity of conventional HPLC to nucleic acids. To separate the signals of different miRNAs, DNA probes with different lengths and base sequences were immobilized on magnetic beads. The application of an effective magnetic separation minimized the background signal and extended the dynamic range. This assay achieved a limit of detection of 0.39 fM for miRNA-122, 0.30 fM for miRNA-155, and 0.26 fM for miRNA-21, respectively. The proposed assay was successfully applied to detect simultaneously miRNA-122, miRNA-155, and miRNA-21 in serum samples from healthy persons and cervical cancer patients, and the results were then compared with those of quantitative real-time-polymerase chain reaction amplification.

Carbohydrate-Deficient Transferrin Determination in a Clinical Setting: Consistency Between Capillary Electrophoresis Assays and Utility of HPLC as a Confirmatory Test.

Carbohydrate-deficient transferrin (CDT) is used to assess chronic alcohol consumption in administrative and forensic context. The aim of the present study was the optimization of the diagnostic strategy for CDT determination in a clinical laboratory setting. Two capillary zone electrophoresis (CZE) assays, the CEofix CDT (Analis, Suarlée, Belgium) run on single capillary MDQ instrument and the muticapillary (Sebia, Lisses, France), were compared as screening methods and a commercial high-performance liquid chromatography (HPLC) assay (Recipe, Munich, Germany) was used for confirmation. In total, 367 serum samples were analyzed by both CZE assays with concordant classification in 92% of cases. All discordant samples were classified as negative by HPLC, as did 2/3 of those that could not be classified by either CZE assay. Classification of samples with CDT values close to cut-off by CZE was confirmed by HPLC in 95-100% of negative samples but only in 28.6-33.3% of positive samples. Both CZE assays proved suitable for CDT screening. HPLC was useful for discriminating CDT value in most of samples that could not be interpreted by CZE due to analytical interferences. Considering the implication of CDT testing, HPLC assay may also be helpful for the confirmation of positive results close to the cut-off value of CZE assays.

Phytochemical and analytical studies of Panax notoginseng (Burk.) F.H. Chen

Panax notoginseng (Burk.) F.H. Chen is distributed throughout the southwest of China, Burma and Nepal. The root of this plant, called notoginseng or sanchi, has a long history of use as a remedy in Oriental traditional medicine. Modern studies have found that extracts and compounds from notoginseng exert various physiological effects. The active constituents are mainly recognized as saponins. In this review, we summarized the discovery and analysis of chemical constituents in notoginseng. Fifty-six saponins from notoginseng were isolated and elucidated. All of them are dammarane saponins, 35 of which can be classified as belonging to the protopanaxadiols group, and 21 as belonging to the protopanaxatriols group. Evidence from phytochemical studies on notoginseng demonstrated that no oleanane-type saponin, which exists in Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius), was found. Other types of compounds such as non-protein amino acids, polyacetylenes, phytosterols, flavonoids, and polysaccharides, many of which have pharmacological activities, were also isolated from notoginseng. Analytical studies on notoginseng were carried out based on botanical and phytochemical advances. In the qualitative studies, identification of the herbal materials and extracts was the main objective. The utilization of high-performance liquid chromatography (HPLC) fingerprint and molecular biological methods made the identification accurate and efficient. Spectral, chromatographic and immunoassay methods were used for the quantitative analysis. HPLC methods are the main authority regarding the determination of saponins and other types of constituents. The chromatographic conditions and detectors employed in the HPLC are discussed.

Utility of high-performance liquid chromatography for identification of mycobacterial species rarely encountered in clinical laboratories.

High-performance liquid chromatography (HPLC) has been demonstrated to be a suitable technique for determining the species of mycobacteria on the basis of their mycolic acid pattern. Representative HPLC profiles, which are needed for the visual recognition of chromatograms, have been published for the most frequently encountered mycobacterial species. No extensive study has been reported for less common species, and only a few, scattered chromatographic patterns are available in literature. This study evaluates the utility of this technique for the identification of several rare species. Mycobacterium celatum, Mycobacterium genavense and Mycobacterium simiae chromatographic profiles have been verified, and previously unreported profiles of other species investigated. The chromatographic pattern of Mycobacterium malmoense is presented for the first time.

Utilization of high-performance liquid chromatography as an enrichment step for the determination of cyclic fatty acid monomers in heated fats and biological samples

A method was developed to determine traces of cyclic fatty acid monomers (CFAM) in oils and animal tissues. This method is a combination of some techniques developed earlier but with the enrichment step being achieved by high-performance liquid chromatography (HPLC) instead of urea inclusion. After transformation of the lipids into methyl esters, the latter were hydrogenated after addition of an internal standard (methyl heptadecanoate or ethyl hexadecanoate). The mixture was enriched in CFAM by HPLC on a semi-preparative C 18 reversed-phase column using acetonitrile-acetone (90:10, v/v) at 4 ml/min. The enriched fraction containing the CFAM and the internal standard was then analysed by gas chromatography on a polar column (cyanosilicone phase). This method was developed using known mixtures of CFAM isolated from both heated sunflower and linseed oils. Small amounts of CFAM (50 μg/g of sample) were determined with good reproducibility without any loss during the HPLC enrichment step and with no modification of the relative proportions of the CFAM in the mixture. This method can be applied to either heated fats and oils or biological samples (heart cell culture) that contain only traces of CFAM. Ethyl hexadecanoate (16:0 ethyl ester) can be used as an internal standard for samples containing small amounts of 17:0.

G1- and S-phase syntheses of histones H1 and H1o in mitotically selected CHO cells: utilization of high-performance liquid chromatography.

We have employed high-performance liquid chromatography (HPLC) to investigate the syntheses of histones H1 and H1o as synchronized cells traverse from mitosis to S phase. Chinese hamster (line CHO) cells were synchronized by mitotic selection, and, at appropriate times, they were pulse labeled for 1 h with [3H]lysine. Histones H1 and H1o were extracted by blending radiolabeled and carrier cells directly in 0.83 M HC1O4; the total HC1O4-soluble, Cl3CCO2H-precipitable proteins were then separated by a modification of an HPLC system employing three mu Bondapak reversed-phase columns [Gurley, L. R., D'Anna, J. A., Blumenfeld, M., Valdez, J. G., Sebring, R. J., Donahue, D. K., Prentice, D. A., & Spall, W. D. (1984) J. Chromatogr. 297, 147-165]. These procedures (1) produce minimally perturbed populations of synchronized proliferating cells and (2) maximize the recovery of radiolabeled histones during isolation and analysis. Measurements of rates of synthesis indicate that the rate of H1 synthesis increases (3.6 +/- 0.5)-fold as cells traverse from early to mid G1; as cells enter S phase, the rate of H1 synthesis increases an additional congruent to 22-fold and is proportional to the number of S-phase cells. In contrast to H1, the rate of H1o synthesis is nearly constant throughout G1. As cells progress into S phase, the rate of H1o synthesis increases (3.1 +/- 0.2)-fold so that it also appears to be proportional to the number of S-phase cells. Except for the first 1-2 h after mitotic selection, these results are similar to those obtained when cells are synchronized in G1 with the isoleucine deprivation procedure.

Purification of human interleukin 1 by high-performance liquid chromatography

The utility of high-performance liquid chromatography (HPLC) in the purification of Interleukin 1 (IL 1, lymphocyte-activating factor) has been investigated Human IL 1-containing supernatants were concentrated by lyophilization and desalted using Bio-Gel P-6 DG desalting gel. Subsequently, the sample containing IL 1 activity was subjected to HPLC with a novel HPHT hydroxylapatite column. Using a sodium phosphate gradient, IL 1 was eluted as a single peak of activity separated from the major protein contaminant, yielding 90% recovery and a specific activity of 6.3 · 10 4 U/mg. Pooled fractions from Bio-Gel HPHT were concentrated and subjected either to Bio-Sil IEX 540 DEAE anion-exchange or Bio-Sil TSK 125 size exclusion chromatography. From DEAE the IL 1 activity was eluted before a linear sodium chloride gradient was started, whereas the protein contaminant was eluted at 110 m M Nacl. When TSK was used IL 1 activity was eluted within a molecular weight range of 20, 000–10,000. Fractions from the DEAE or TSK columns that were positive for IL 1 activity did not contain detectable protein, suggesting a good resolution. Furthermore, the recovery from DEAE was 26% whereas TSK 125 yielded 119% of the original activity. The specific activities were 6 · 10 7 and 2.5 · 10 8 U/mg, respectively. Thus, this method provides a rapid and reproducible procedure for the purification if IL 1 for further biological characterization.

Isolation of denatured proteins and peptides by high-performance liquid chromatography: Effect of different perfluorinated acids, column length and large-pore supports

The utilization of high-performance liquid chromatography for the isolation of peptides and proteins is extended by the demonstration that trifluoroacetic acid, pentafluoropropionic acid and heptafluorobutyric acid are effective peptide and protein solvents and as components of a mobile phase alter both the absolute and relative retention times of eluting peptides. In addition, studies related to stationary-phase performance indicate that: (1) column length (55–25 cm) does not significantly influence large peptide or protein retention times or resolution; (2) 300 A pore supports are ideal for the isolation of both large peptides and proteins; (3) peptide and protein conformation, even in the presence of denaturants, alters the steric interaction with the support; and (4) large peptides and proteins probably interact with the support by virtue of multi-site binding, not partitioning between the stationary and mobile phases.