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In recent years, methods based on photodissociation in the gas phase have become powerful means in the field of chiral analysis. Among them, infrared multiple photon dissociation (IRMPD) spectroscopy is a very attractive one, since it can provide valuable spectral and structural information of chiral complexes in addition to chiral discrimination. Experimentally, the method can be fulfilled by the isolation of target diastereomeric ions in an ion trap followed by the irradiation of a tunable IR laser. Chiral analysis is performed by comparing the difference existing in the spectra of enantiomers. Combined with theoretical calculations, their structures can be further understood on the molecular scale. By now, lots of chiral molecules, including amino acids and peptides, have been studied with the method combined with theoretical calculations. This review summarizes the relative experimental results obtained, and discusses the limitation and prospects of the method.

Shenkang injection is a traditional Chinese formula with good curative effect on chronic renal failure. In this paper, a novel, rapid and sensitive ultra-high-performance liquid chromatography coupled with Q Exactive hybrid quadrupole Orbitrap high-resolution accurate mass spectrometry was developed and validated for simultaneous determination of seven bioactive constituents of Shenkang injection in rat plasma and tissues after intravenous administration. Acetonitrile was used as a protein precipitation agent in biological samples disposal with carbamazepine as internal standard. The chromatographic separation was carried out on a C 18 column with a gradient mobile phase consisting of acetonitrile and water (containing 0.1% formic acid). The MS analysis was performed in the full-scan positive and negative ion mode. The lower limits of quantification for the seven analytes in rat plasma and tissues were 0.1-10 ng/mL. The validated method was successfully applied to tissue distribution and pharmacokinetic studies of Shenkang injection after intravenous administration. The results of the tissue distribution study showed that the high concentrations of seven constituents were primarily in the kidney tract. This is the first report of the application of Q-Orbitrap with full-scan mass spectrometry in tissue distribution and pharmacokinetic studies of Shenkang injection., (© 2018 John Wiley & Sons, Ltd.)

Anlotinib, as a promising oral small-molecule antitumor drug, its role in glioma has been only reported in a small number of case reports. Therefore, anlotinib has been considered as a promising candidate in glioma. The aim of this study was to investigate the metabolic network of C6 cells after exposure to anlotinib and to identify anti-glioma mechanism from the perspective of metabolic reprogramming. Firstly, CCK8 method was used to evaluate the effects of anlotinib on cell proliferation and apoptosis. Secondly, ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS)-based metabolomic and lipidomic were developed to characterize the metabolite and lipid changes in cell and cell culture medium (CCM) caused by anlotinib in the treatment of glioma. As a result, anlotinib had concentration-dependent inhibitory effect with the concentration range. In total, twenty-four and twenty-three disturbed metabolites in cell and CCM responsible for the intervention effect of anlotinib were screened and annotated using UHPLC-HRMS. Altogether, seventeen differential lipids in cell were identified between anlotinib exposure and untreated groups. Metabolic pathways, including amino acid metabolism, energy metabolism, ceramide metabolism, and glycerophospholipid metabolism, were modulated by anlotinib in glioma cell. Overall, anlotinib has an effective treatment against the development and progression of glioma, and these remarkable pathways can generate the key molecular events in cells treated with anlotinib. Future research into the mechanisms underlying the metabolic changes is expected to provide new strategies for treating glioma. [ABSTRACT FROM AUTHOR]

Garcinia multiflora is a kind of evergreen tree which is widely distributed in the south of China. However, few researches focused on the constituents in different parts of G. multiflora as well as their potential targets and pathways in vivo. To clarify the chemical constituents of G. multiflora rapidly and predict the potential targets as well as pathways in vivo that this plant may have effects on, a feasible and accurate strategy was developed to identify the chemical constituents in fruits, leaves, and branches of G. multiflora by ultra‐high performance liquid chromatography with Q‐Exactive hybrid quadrupole‐orbitrap high‐resolution accurate mass spectrometry. Network pharmacology was then employed and a "compounds‐targets‐diseases" network was established. Sixty‐one compounds including polycyclic polyprenylated acylphloroglucinols, xanthones, and flavonoids were finally identified in different parts of G. multiflora, and the contents of seven constituents were quantified, respectively. On the basis of the network pharmacology analysis results, compounds in this plant were speculated to have potential pharmacodynamic effect on cancer, inflammatory, respiratory diseases, cardiovascular diseases, and metabolic diseases. This research will provide a new method for the advanced study on the pharmacodynamic materials basis of G. multiflora, and offer valuable evidences for medicinal purpose of this plant. [ABSTRACT FROM AUTHOR]

Highlights • Competition between metallization and protonation/reduction exists in MALDI. • The winner of competition might be changed during the whole process. • Covariance mapping shows metalized and protonated species are negatively correlated. Abstract In order to better understand effects of metal cationization on protonation and reduction in MALDI process, mass spectra of riboflavin complexes with different alkali metal ions generated by a series of laser shots at a fixed target spot were consecutively recorded with the matrix of 2,5-dihydroxybenzoic acid (DHB). Progressive changes in the spectra, including the decrease of reduction extent for the metalized molecule ions and the increase of relative intensities of metalized species compared to protonated species, were observed with the increase of laser shots. Covariance mapping analysis was also performed for the data. Results show that different metalized ions are positively correlated each other; while metalized ions and protonated species are negatively correlated. These results not only reflect competition between metalization and protonation/reduction in laser plume, but also show that the winner of it might be changed during the process of sample consumption by laser irradiation. [ABSTRACT FROM AUTHOR]

A novel zwitterionic surfactant N-dodecyl aspartic acid was synthesized with dodecylamine, maleic acid anhydride and sodium hydroxide in ethanol-water as the solvent. The chemical structure of N-dodecyl aspartic acid was characterized by IR, H NMR and MS. The surface properties of the surfactant were studied by measuring the equilibrium surface tensions of the dilute aqueous solutions. The synthesized surfactant can reduce the surface tension of water to 29-32 mN m at temperatures of 298-313 K, the surface activity reaches its highest under mild pH conditions. The water hardness has almost no effect on foam power and foam stability of the surfactant at lower and middle water hardnesses. [ABSTRACT FROM AUTHOR]