GC/EI-MS method for the determination of phytosterols in vegetable oils

Sterols are a highly complex group of lipophilic compounds present in the unsaponifiable matter of virtually all living organisms. In this study, we developed a novel gas chromatography with mass spectrometry selected ion monitoring (GC/MS-SIM) method for the comprehensive analysis of sterols after saponification and silylation. A new referencing system was introduced by means of a series of saturated fatty acid pyrrolidides (FAPs) as internal standards. Linked with retention time locking (RTL), the resulting FAP retention indices (RIFAP) of the sterols could be determined with high precision. The GC/MS-SIM method was based on the parallel measurement of 17 SIM ions in four time windows. This set included eight molecular ions and seven diagnostic fragment ions of silylated sterols as well as two abundant ions of FAPs. Altogether, twenty molecular ions of C27- to C31-sterols with 0–3 double bonds were included in the final method. Screening of four common vegetable oils (sunflower oil, hemp oil, rapeseed oil, and corn oil) enabled the detection of 30 different sterols and triterpenes most of which could be identified. Graphical abstract

UHPLC-Orbitrap-MS Tentative Identification of 51 Oleraceins (Cyclo-Dopa Amides) in Portulaca oleracea L. Cluster Analysis and MS2 Filtering by Mass Difference

Oleraceins are a class of indoline amide glycosides found in Portulaca oleracea L. (Portulacaceae), or purslane. These compounds are characterized by 5,6-dihydroxyindoline-2-carboxylic acid N-acylated with cinnamic acid derivatives, and many are glucosylated. Herein, hydromethanolic extracts of the aerial parts of purslane were subjected to UHPLC-Orbitrap-MS analysis, in negative ionization mode. Diagnostic ion filtering (DIF), followed by diagnostic difference filtering (DDF), were utilized to automatically filter out MS data and select plausible oleracein structures. After an in-depth MS2 analysis, a total of 51 oleracein compounds were tentatively identified. Of them, 26 had structures, matching one of the already known oleracein, and the other 25 were new, undescribed in the literature compounds, belonging to the oleracein class. Moreover, based on selected diagnostic fragment ions, clustering algorithms and visualizations were utilized. As we demonstrate, clustering methods provide valuable insights into the mass fragmentation elucidation of natural compounds in complex mixtures.

UHPLC-Orbitrap-HRMS Identification of 51 Oleraceins (Cyclo-Dopa Amides) in Portulaca oleracea L. Cluster Analysis and MS2 Filtering by Mass Difference

Oleraceins are a class of indoline amide glycosides found in Portulaca oleracea L. (Portulacaceae), or purslane. These compounds are characterized with 5,6-dihydroxyindoline-2-carboxylic acid N-acylated with cinnamic acid derivatives, and many are glucosylated. Herein, hydromethanolic extracts of the aerial parts of purslane were subjected to UHPLC-Orbitrap-HRMS analysis, conducted in negative ionization mode. Diagnostic ion filtering (DIF), followed by diagnostic difference filtering (DDF), were utilized to automatically filter out MS data and select plausible oleracein structures. After an in-depth MS2 analysis, a total of 51 oleracein compounds were tentatively identified. Of them, 26 had structure matching one of already known oleraceins and the other 25 are new, undescribed in the literature structures, belonging to the oleracein class. Moreover, diagnostic fragment ions were selected, based on which clustering algorithms and visualizations were employed. As we demonstrate, clustering methods can provide valuable insights into the mass fragmentation elucidation of natural compounds in complex mixtures.

Diagnostic Fragment-Ion-Based for Rapid Identification of Chlorogenic Acids Derivatives in Inula cappa Using UHPLC-Q-Exactive Orbitrap Mass Spectrometry

Inula cappa (Buch.-Ham. ex D. Don) DC has been used in traditional Chinese medicine to treat malaria, dysentery, and hepatitis. Previous studies have shown that chlorogenic acid is the effective ingredient of plants in this family. And the research of the chlorogenic acid in Inula cappa will help to further improve the effective resource utilization rate of this plant. Therefore, it is necessary to establish an accurate method to characterize the chlorogenic acid components in Inula cappa. In this study, a simple, fast, and sensitive UHPLC-Q-Exactive Orbitrap mass spectrometry method was established, which can simultaneously analyze known and unknown ingredients in a short time (within 30 minutes) in Inula cappa. According to the diagnosis fragmentation ions, retention time, and bibliography, 68 chlorogenic acid derivatives were identified in Inula cappa. The results of this experiment lay the foundation for the active substances and quality control of Inula cappa and provide a theoretical basis for whether Inula cappa can be an alternative to the endangered wild medicinal materials of the same family.

Structural Identification and Conversion Analysis of Malonyl Isoflavonoid Glycosides in Astragali Radix by HPLC Coupled with ESI-Q TOF/MS

In this study, four malonyl isoflavonoid glycosides (MIGs), a type of isoflavonoid with poor structural stability, were efficiently isolated and purified from Astragali Radix by a medium pressure ODS C18 column chromatography. The structures of the four compounds were determined on the basis of NMR and literature analysis. Their major diagnostic fragment ions and fragmentation pathways were proposed in ESI/Q-TOF/MS positive mode. Using a target precursor ions scan, a total of 26 isoflavonoid compounds, including eleven malonyl isoflavonoid glycosides coupled with eight related isoflavonoid glycosides and seven aglycones were characterized from the methanolic extract of Astragali Radix. To clarify the relationship of MIGs and the ratio of transformation in Astragali Radix under different extraction conditions, two MIGs (calycosin-7-O-glycoside-6″-O-malonate and formononetin-7-O-glycoside-6″-O-malonate) coupled with related glycosides (calycosin-7-O-glycoside and formononetin-7-O-glycoside) and aglycones (calycosin and formononetin) were detected by a comprehensive HPLC-UV method. Results showed that MIGs could convert into related glycosides under elevated temperature conditions, which was further confirmed by the conversion experiment of MIGs reference compounds. Moreover, the total contents of MIGs and related glycosides displayed no obvious change during the long-duration extraction. These findings indicated that the quality of Astragali Radix could be evaluated efficiently and accurately by using the total content of MIGs and related glycosides as the quality index.

Characterization and Identification of Isoflavonoids in the Roots of Millettia speciosa Champ. by UPLC-Q-TOF-MS/MS

Introduction: The root of Millettia speciosa Champ. (Leguminosae) is one of the wellknown traditional Chinese medicines abundant in phenolic compounds and plays important roles in the treatment of pain or numbness of the joints, blood deficiency sallow, chronic bronchitis and chronic hepatitis. Objective: An ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) based chemical profiling approach was established for the separation and characterization of isoflavonoids in the roots of Millettia speciosa Champ. Methods: The roots of Millettia speciosa Champ. were prepared by ethanol extraction followed by further extraction with chloroform. The extracts were analyzed by UPLC-Q-TOF-MS in positive and negative electrospray ion modes at different Collision Energy (CE) values. Results: A total of 48 components were simultaneously detected, of which 38 components, including 21 isoflavones, 4 phenolic acids, 4 isoflavanones, 2 phenolic aldehydes, 2 flavanones, 1 aliphatic acid, 1 chalcone, 1 flavonol, 1 isoflavane and 1 pterocarpan were unambiguously identified or tentatively assigned based on the retention time, UV spectra, characteristic molecular ions, MS/MS fragmentation data and reference standards. The isomers of isoflavonoids were distinguished using accurate mass, the diagnostic fragmentations of C-ring and UV spectra. The major diagnostic fragment ions of isoflavonoids were observed and the corresponding fragmentation pathways were proposed. Conclusion: This investigation provides important analysis data for further quality control, pharmacological and toxicological research on Millettia speciosa Champ.

Surveillance for Adenoviruses in Bats in Italy

Adenoviruses are important pathogens of humans and animals. Bats have been recognized as potential reservoirs of novel viruses, with some viruses being regarded as a possible zoonotic threat to humans. In this study, we report the detection and analysis of adenoviruses from different bat species in northern Italy. Upon sequence and phylogenetic analysis, based on a short diagnostic fragment of the highly-conserved DNA polymerase gene, we identified potential novel candidate adenovirus species, including an avian-like adenovirus strain. An adenovirus isolate was obtained in simian cell lines from the carcass of a Pipistrellus kuhlii, and the complete genome sequence was reconstructed using deep sequencing technologies. The virus displayed high nucleotide identity and virtually the same genome organization as the Pipistrellus pipistrellus strain PPV1, isolated in Germany in 2007. Gathering data on epidemiology and the genetic diversity of bat adenoviruses may be helpful to better understand their evolution in the mammalian and avian hosts.

HighResNPS.com: An Online Crowd-Sourced HR-MS Database for Suspect and Non-targeted Screening of New Psychoactive Substances

The number of new psychoactive substances (NPS) is constantly increasing. However, although the number might be large, most NPS have a low prevalence of use, so keeping screening libraries updated with the relevant analytical targets becomes a challenge. One way to ensure sufficient screening coverage is to use shared high resolution-mass spectrometry (HR-MS) databases, such as HighResNPS.com: a free, online, spreadsheet-format, crowd-sourced HR-MS database for NPS screening. The aims of this study were (i) to present the database to the scientific community and (ii) to verify that the HighResNPS database can be utilized in suspect screening workflows for LC–HR-MS instruments and software from four different instrument vendors. A sample was spiked with 10 NPS, and participating laboratories then analyzed the sample with their respective HR-MS vendor platforms and the HighResNPS database. The HighResNPS data were obtained via a spreadsheet converted to fit the import specifications of the different vendor platforms. Suspect screening was performed using LC–HR-MS vendor platforms from Thermo Fisher, Waters, Bruker and Agilent. All 10 NPS were identified in at least three workflows used for the four different vendor platforms. Multiple users have submitted data to HighResNPS for the same NPS, which resulted in multiple true-positive identifications for these NPS. Suspect screening with LC–HR-MS can be based on diagnostic fragment ions reported by users of different vendor platforms and can support NPS identification in biological samples and/or seizure analyses when no reference standard is available in-house. The present work clearly demonstrates that HighResNPS data is compatible with instruments and screening software from at least four different vendor platforms. The database can thus serve as a useful add-on in LC–HR-MS screening workflows.

Using UPLC-QTOF-MS Method to Analyse the Spot Constituents of the Thin Layer Chromatograms for Chuzhou Stemona sessilifolia (Miq.) Miq.

A simple, rapid, and highly sensitive analytical method was established for identification of constituents in the spot of the thin layer chromatogram of Chuzhou Stemona sessilifolia (Miq.) Miq. (Chuzhou S. sessilifolia) with ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). The technology was applied to systematically analyze and detect the targeted spots. Compared with the fragmentation behaviors of more than thirty reference constituents, the possibly existing compounds of the target spots were identified or tentatively identified by their exact masses and diagnostic fragment ions. Finally, the four clear spots of the thin layer chromatograms of Chuzhou S. sessilifolia were screened and identified of possible molecular formula and structures.