Quantitative determination of daumone in rat plasma by liquid chromatography-mass spectrometry

Hydrophilic Interaction Liquid Chromatography (HILIC): Latest Applications in the Pharmaceutical Researches

Background:

Significant advances have been occurred in analytical research since the 1970s by Liquid Chromatography (LC) as the separation method. Reverse Phase Liquid Chromatography (RPLC) method, using hydrophobic stationary phases and polar mobile phases, is the most commonly used chromatographic method. However, it is difficult to analyze some polar compounds with this method. Another separation method is the Normal Phase Liquid Chromatography (NPLC), which involves polar stationary phases with organic eluents. NPLC presents low-efficiency separations and asymmetric chromatographic peak shapes when analyzing polar compounds. Hydrophilic Interaction Liquid Chromatography (HILIC) is an interesting and promising alternative method for the analysis of polar compounds. HILIC is defined as a separation method that combines stationary phases used in the NPLC method and mobile phases used in the RPLC method. HILIC can be successfully applied to all types of liquid chromatographic separations such as pharmaceutical compounds, small molecules, metabolites, drugs of abuse, carbohydrates, toxins, oligosaccharides, peptides, amino acids and proteins.

Objective:

This paper provides a general overview of the recent application of HILIC in the pharmaceutical research in the different sample matrices such as pharmaceutical dosage form, plasma, serum, environmental samples, animal origin samples, plant origin samples, etc. Also, this review focuses on the most recent and selected papers in the drug research from 2009 to the submission date in 2020, dealing with the analysis of different components using HILIC.

Results and Conclusion:

The literature survey showed that HILIC applications are increasing every year in pharmaceutical research. It was found that HILIC allows simultaneous analysis of many compounds using different detectors.

Ascaroside Profiling of Caenorhabditis elegans Using Gas Chromatography-Electron Ionization Mass Spectrometry

Nematodes such as the model organism Caenorhabditis elegans produce various homologous series of l-ascarylose-derived glycolipids called ascarosides, which include several highly potent signals in intra and interspecies communication as well as cross-kingdom interactions. Given their low concentrations and large number of structurally similar components, mass spectrometric screens based on high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) are commonly employed for ascaroside detection and quantification. Here, we describe a complementary gas chromatography-electron ionization mass spectrometry (GC-EIMS) screen that utilizes an ascarylose-derived K1-fragment ion signal at m/z 130.1 [C₆H₁₄OSi]^+● to highlight known as well as yet unidentified ascaroside components in TMS-derivatized crude nematode exometabolome extracts. GC-EIMS-based ascaroside profiling of wild-type and mutant C. elegans facilitates the analysis of all basic ascarosides using the same ionization technique while providing excellent resolution for the complete homologous series with side chains ranging from 3 to 33 carbons. Combined screening for m/z 130.1 along with side chain-specific J1 [M - 173]⁺ and J2 [M - 291]⁺ fragment ions, as well as additional characteristic marker ions from α-cleavage, enables convenient structure assignment of ca. 200 components from wild-type and peroxisomal β-oxidation mutants including (ω - 1)-linked acyl, enoyl, β-hydroxyacyl, and 2-ketoalkyl ascarosides along with their (ω)-linked or α-methyl isomers and ethanolamide derivatives, as well as 2-hydroxyalkyl ascarosides. Given the widespread availability of GC-MS and its increasing popularity in metabolomics, this method will promote the identification of ascarosides in C. elegans and other nematodes.

Simultaneous determination of 3-O-acetyloleanolic acid and oleanolic acid in rat plasma using liquid chromatography coupled to tandem mass spectrometry

3-O-Acetyloleanolic acid (OAA) is a triterpenoid compound, and exerts an apoptosis in cancer cell lines, an inhibition of both atopic and allergic contact dermatitis in murine model, and a suppression of inflammatory bone loss in mice. OAA can be converted into oleanolic acid (OA) by hydrolysis in vivo, and OA exhibits several pharmacological effects as well. A liquid chromatographic method using tandem mass spectrometry (MS/MS) was developed for the simultaneous determination of OAA and OA in rat plasma. After liquid-liquid extraction with ethylacetate, both substances were chromatographed on a reversed phase column with a mobile phase of 0.1% formic acid aqueous solution and acetonitrile (1:9, v/v). The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of both substances over time following an intravenous administration of OAA in rats.

Daumone fed late in life improves survival and reduces hepatic inflammation and fibrosis in mice

The liver is one of the most susceptible organs to aging, and hepatic inflammation and fibrosis increase with age. Chronic inflammation has been proposed as the major molecular mechanism underlying aging and age-related diseases, whereas calorie restriction has been shown to be the most effective in extending mammalian lifespan and to have anti-aging effects through its anti-inflammatory action. Thus, it is necessary to develop effective calorie restriction mimetics. Daumone [(2)-(6R)-(3,5-dihydroxy-6-methyltetrahydropyran-2-yloxy)heptanoic acid], a pheromone secreted by Caenorhabditis elegans, forces them to enter the dauer stage when facing inadequate conditions. Because Caenorhabditis elegans live longer during the dauer stage under energy deprivation, it was hypothesized that daumone may improve survival in mammals by mimicking calorie restriction. Daumone (2 mg kg(-1) day(-1) ) was administered orally for 5 months to 24-month-old male C57BL/6J mice. Daumone was found to reduce the risk of death by 48% compared with age-matched control mice, and the increased plasma insulin normally presented in old mice was significantly reduced by daumone. The increased hepatic hypertrophy, senescence-associated β-galactosidase activity, insulin resistance, lipid accumulation, inflammation, oxidative stress, and fibrosis in old mice were significantly attenuated by daumone. From a mechanistic view, daumone reduced the phosphorylation of the IκBα and upregulation of Rela and Nfkbia mRNA in the livers of old mice. The anti-inflammatory effect of daumone was confirmed in lipopolysaccharide-induced liver injury model. Oral administration of daumone improves survival in mice and delivers anti-aging effects to the aged liver by modulating chronic inflammation, indicating that daumone could be developed as an anti-aging compound.

Simultaneous determination of 7-O-succinyl macrolactin A and its metabolite macrolactin A in rat plasma using liquid chromatography coupled to tandem mass spectrometry

7-O-Succinyl macrolactin A (SMA) and its major metabolite macrolactin A (MA) are generated from Bacillus polyfermenticus KJS-2. Both substances show inhibitory effects on angiogenesis and cancer cell invasion. SMA in rat plasma is known to be relatively stable at room temperature, but MA was not detected due to its instability. Therefore, a stabilizer is required to accurately measure the substance in biological rat samples. In this study, NaF and eserine were examined to determine whether they could stabilize MA to allow for accurate measurement in rat plasma. We also developed a rapid and simple chromatographic method using tandem mass spectrometry (MS/MS) for the simultaneous determination of these compounds in rat plasma. After simple protein precipitation with acetonitrile including methaqualone (internal standard), the analytes were chromatographed on a Hilic column with a mobile phase of 10mM formic acid aqueous solution, methanol, and acetonitrile (15:15:70, v/v). The accuracy and precision of the assay were in accordance with FDA regulations for the validation of bioanalytical methods. This analytical method was successfully applied to monitor plasma concentrations of both compounds over time following intravenous administration of a salt form of SMA in rats.

Hydrophilic interaction chromatography in drug analysis

Hydrophilic interaction chromatography (HILIC) is an increasingly popular alternative to conventional HPLC for drug analysis. It offers increased selectivity and sensitivity, and improved efficiency when quantifying drugs and related compounds in complex matrices such as biological and environmental samples, pharmaceutical formulations, food, and animal feed. In this review we summarize HILIC methods recently developed for drug analysis (2006–2011). In addition, a list of important applications is provided, including experimental conditions and a brief summary of results. The references provide a comprehensive overview of current HILIC applications in drug analysis.