Rapid chemome profiling of chemical components of Lonicerae Japonicae Flos using DI-MS/MS~(ALL) / 中国中药杂志

A new method of MS/MS~(ALL) was designed to sequentially record a MS~2 spectrum at each unit mass window through gas phase fractionation concept, so as to offer an opportunity for universal MS~2 spectral recording with direct infusion(DI). As a proof-of-concept, DI-MS/MS~(ALL) was applied for rapid chemome profiling of a famous herbal medicine named Lonicerae Japonicae Flos. After each MS~2 spectrum was correlated to its precursor ion, the structural annotation was conducted by applying well-defined mass cracking rules, matching the mass spectral data with literatures and referring to those accessible databases. As a result, a total of 54 components were identified from Lonicerae Japonicae Flos extract, including 21 phenolic acids, 13 flavonoids, 12 iridoids, 4 triterpenoids and 4 other compounds. Therefore, DI-MS/MS~(ALL) is a powerful tool for comprehensive, rapid qualitative analysis of chemical profiles of traditional Chinese medicine and other chemical components of complex systems.

Rapid chemome profiling of Cistanche salsa using DI-MS/MS~(ALL) / 中国中药杂志

The current study aims to rapidly and comprehensively profile the chemical composition of Cistanche salsa using direct infusion coupled with MS/MS~(ALL)(DI-MS/MS~(ALL)). The C. salsa extract was directly imported into electrospray ionization(ESI) source of quadrupole time-of-flight(Q-TOF) mass spectrometer with an infusion pump at a flow rate of 10 μL·min~(-1). Acquisition program was applied under negative ionization polarity to collect one MS~1 spectrum(m/z 50-1 200), followed by 1 150 MS~2 spectra with precursor isolation window(m/z 1) amongst mass range m/z 50-1 200. After each MS~2 spectrum was matched to its precursor ion, putative identification was conducted through matching mass spectral data with literature and database. A total of 31 components were identified from C. salsa, including 9 phenylethanoid glycosides, 2 iridoids, 4 saccharides, 9 organic acids, and 7 other compounds, similar to those from C. tubulosa and C. deserticola. In conclusion, DI-MS/MS~(ALL), a facile and reliable analytical tool, can be employed for qualitative analysis of chemical constituents in C. salsa. The research offers a promising strategy to achieve rapid chemome profiling of herbal medicine and provides an alternative source of Cistanches Herba.

Online energy-resolved MS boosts the potential of LC-MS towards metabolite characterization of salidroside and tyrosol.

Although currently serving as the workhorse for metabolite characterization, one of the most challenging tasks for LC-MS is isomeric differentiation because isomers frequently yield identical quasi-molecular ions and fragmented ion species. Our previous studies have demonstrated that online energy-resolved MS (ER-MS) is an orthogonal technique for MS/MS experiments to facilitate isomeric identification. Herein, attempts were made for the in-depth characterization of the metabolic profiles of an effective natural product named salidroside (SA) in rats using LC coupled with three-dimensional mass spectrometry (LC-3D MS) that was configured by MS1, MS2 and online ER-MS as 1st, 2nd, and 3rd dimensions, respectively. Moreover, the metabolism characterization of its aglycone, namely, tyrosol (Try) was conducted in parallel to aid in proposing metabolic pathways. High-resolution MS1 and MS2 spectra were acquired by IT-TOF-MS, and subsequent data processing provided theoretical formula and sub-structures for each metabolite. Subsequently, online ER-MS was conducted for precursor > product ion transitions-of-interest to offer linkage information among the sub-structures via building breakdown graphs. As a result, ten (M1-10) and nine (M1, M2, and M5-11) metabolites were detected in SA- and Tyr-administrated biological samples, respectively, and their structures were qualitatively identified. Crucial metabolism occurred for either component. SA initially underwent hydrolysis to produce Tyr, and subsequently hydroxylation, oxidation, glucuronidation, and sulfation were observed as the primary metabolic pathways. To summarize, the metabolic fate of SA was understood in depth, and Tyr, as the hydrolytic product, was responsible for the occurrences of most metabolites (M1, M2, and M5-10). More importantly, identification confidences of the metabolites were significantly advanced by LC-3D MS, suggesting that it is eligible to serve as an integral part of the analyst's toolbox.

Chemome profiling and comparison of three Orobanche medicinal plants / 中国中药杂志

Several Orobanche medicinal plants sometimes served as alternative sources of Cistanches Herba, attributing to the benefits such as tonifying kidney, strengthening tendons and bones. Among them, O. coerulescens, O. cernua and O. pycnostachya have been widely utilized in northern China for treatments of pains in the loins and knees, impotence, and spermatorrhea. However, their chemical profiles haven't been elucidated. In the present study, UHPLC-IT-TOF-MS was implemented to conduct in-depth chemome profiling of O. coerulescens, O. cernua and O. pycnostachya, aiming to achieve a comprehensive chemical characterization and to provide pronounced information for the quality control and clinical applications. An ACE Ultra-Core 2.5 Super C_(18)(3.0 mm×150 mm, 2.5 μm) column was deployed for chromatographic separations, and high-resolution MS~n spectra were recorded by IT-TOF-MS. Forty-eight components, in total, were observed, and thirty-eight ones were structurally annotated according to proposing mass fragmentation patterns, matching with relevant databases. Particularly, nine ones were confirmed by reference compounds. Overall, the chemical compositions of O. coerulescens and O. cernua are quite similar, and differences occur between O. pycnostachya and the prior two ones; primary chemical family is phenylethanoid glycosides, and several lignan glycosides as well as iridoid glycosides are also observed; the primary components include acteoside, isoacteoside, crenatoside and 2'-acetylacteoside, etc.

Advance in evolution and biomechanical mechanism for finite element model of human brain / 医用生物力学

Brain and neck injury has become the most severe injury during vehicle collision accident due to its high fatality rate. Finite element (FE) model has been widely used in the study on biomechanical mechanism of traumatic brain injury (TBI). In this paper, recent literatures on biomechanics of skull-brain-neck FE model were reviewed, advance in the evolution and biomechanical studies of TBI in road traffic accidents was elaborated, and protection methods of head and neck injury were explored, so as to provide a theoretical basis for biomechanical research and development of appropriate car safety devices for TBI in the event of vehicle collision accident.