An available strategy for elemental composition determination of organic impurities in commercial preparations based on accurate mass and peak ratio of isotopic fine structures (IFSs) by dual mode combined-FT-ICR-MS and fraction collection technology

Quality evaluation of natural monomer flavors for Chinese tobacco industry based on dual mode combined Fourier transform ion cyclotron resonance mass spectrometry and isotopic fine structures

RATIONALE

Natural monomer flavors can modify the taste of cigarettes. However, no report was published to establish the quality control method for their chemical compositions.

METHODS

In this study, licorice, a traditional natural monomer flavor used in tobacco aroma processing, was selected, and the fingerprint was developed by high-performance liquid chromatography (HPLC). Next, the chemical markers of samples from different places of origin were discovered by multivariate statistical analysis. Then, its chemical constituents were identified by combination of HPLC-Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), direct infusion FT-ICR-MS (DI-FT-ICR-MS), and the technology of isotopic fine structures (IFSs). Moreover, its characteristic constituents were quantitatively analyzed using HPLC.

RESULTS

The 14 common peaks were assigned in the fingerprint, and 8 of them were considered as qualitative markers by multivariate statistical analysis. A total of 42 chemical constituents were detected using HPLC-FT-ICR-MS, and 13 of them were unambiguously identified by references. Meanwhile, the elemental compositions of other eight unknown chemical components were decisively determined using IFSs. Subsequently, the contents of five characteristic constituents in 11 batches of samples were determined.

CONCLUSIONS

The integration strategy established here can discover and quantify the chemical markers for improving the quality control standard of natural monomer flavor of licorice. It is expected that the strategy will be valuable for further quality control of other natural monomer flavors in Chinese tobacco industry.

Advances in Ultra-High-Resolution Mass Spectrometry for Pharmaceutical Analysis

Pharmaceutical analysis refers to an area of analytical chemistry that deals with active compounds either by themselves (drug substance) or when formulated with excipients (drug product). In a less simplistic way, it can be defined as a complex science involving various disciplines, e.g., drug development, pharmacokinetics, drug metabolism, tissue distribution studies, and environmental contamination analyses. As such, the pharmaceutical analysis covers drug development to its impact on health and the environment. Moreover, due to the need for safe and effective medications, the pharmaceutical industry is one of the most heavily regulated sectors of the global economy. For this reason, powerful analytical instrumentation and efficient methods are required. In the last decades, mass spectrometry has been increasingly used in pharmaceutical analysis both for research aims and routine quality controls. Among different instrumental setups, ultra-high-resolution mass spectrometry with Fourier transform instruments, i.e., Fourier transform ion cyclotron resonance (FTICR) and Orbitrap, gives access to valuable molecular information for pharmaceutical analysis. In fact, thanks to their high resolving power, mass accuracy, and dynamic range, reliable molecular formula assignments or trace analysis in complex mixtures can be obtained. This review summarizes the principles of the two main types of Fourier transform mass spectrometers, and it highlights applications, developments, and future perspectives in pharmaceutical analysis.

The bioactive alkaloids identified from Cortex Phellodendri ameliorate benign prostatic hyperplasia via LOX-5/COX-2 pathways

BACKGROUND

The bioactive alkaloids identified from Cortex Phellodendri (CP) were highly effective in treating rats with benign prostatic hyperplasia (BPH). Specifically, lipoxygenase-5 (LOX-5) and cyclooxygenase-2 (COX-2) were identified as two primary targets for alleviating inflammation in BPH rats. However, it remains unknown whether the alkaloid components in CP can interact with the two target proteins.

PURPOSE

To further identify bioactive alkaloids targeting LOX/COX pathways.

METHODS

An affinity-ultrafiltration mass spectrometry approach was employed to screen dual-target LOX-5/COX-2 ligands from alkaloid extract. The structures of bioactive alkaloids were characterized by high-resolution Fourier transform ion cyclotron resonance mass spectrometry. To understand the molecular mechanisms underlying the effects of bioactive alkaloids, the expression levels of LOX-5 and COX-2 in BPH model rats were investigated at both protein and mRNA levels. The LOX-5/COX-2 enzymes activity experiments and molecular docking analysis were performed to fully evaluate the interactions between bioactive alkaloids and LOX-5/COX-2.

RESULTS

After comprehensive analysis, the results showed that bioactive alkaloids could suppress the expression of LOX-5 and COX-2 simultaneously to exert an anti-inflammatory effect on the progression of BPH. In addition, the screened protoberberine, demethyleneberberine was found to exhibit prominent inhibitory activities against both LOX-5 and COX-2 enzymes, palmatine and berberine with moderate inhibitory activities. Molecular docking analysis confirmed that demethyleneberberine could interact well with LOX-5/COX-2.

CONCLUSION

This study is the first to explore the inhibitory effects of bioactive alkaloids from CP on LOX-5 and COX-2 activities in BPH rats. Our findings demonstrate that the bioactive alkaloids from CP can ameliorate BPH via dual LOX-5/COX-2 pathways, which serves as an efficient approach for the discovery of novel drug leads from natural products with reduced side effects.

Qualitative and quantitative evaluation of Flos Puerariae by using chemical fingerprint in combination with chemometrics method

In order to better control the quality of Flos Puerariae (FP), qualitative and quantitative analyses were initially performed by using chemical fingerprint and chemometrics methods in this study. First, the fingerprint of FP was developed by HPLC and the chemical markers were screened out by similarity analysis (SA), hierarchical clustering analysis (HCA), principal components analysis (PCA), and orthogonal partial least squares discriminant analysis (OPLS-DA). Next, the chemical constituents in FP were profiled and identified by HPLC coupled to Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FT-ICR MS). Then, the characteristic constituents in FP were quantitatively analyzed by HPLC. As a result, 31 common peaks were assigned in the fingerprint and 6 of them were considered as qualitative markers. A total of 35 chemical constituents were detected by HPLC-FT-ICR MS and 16 of them were unambiguously identified by comparing retention time, UV absorption wavelength, accurate mass, and MS/MS data with those of reference standards. Subsequently, the contents of glycitin, genistin, tectoridin, glycitein, genistein, and tectorigenin in 13 batches of FP were detected, ranging from 0.4438 to 11.06 mg/g, 0.955 to 1.726 mg/g, 9.81 to 57.22 mg/g, 3.349 to 41.60 mg/g, 0.3576 to 0.989 mg/g, and 2.126 to 9.99 mg/g, respectively. In conclusion, fingerprint analysis in combination with chemometrics methods could discover chemical markers for improving the quality control standard of FP. It is expected that the strategy applied in this study will be valuable for further quality control of other traditional Chinese medicines.

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The qualitative and quantitative analysis were carried out for Flos Puerariae.

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Fingerprints were combined with different chemometrics to discover the qualitative markers FP.

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Thirty five constituents of FP were characterized by HPLC-FT-ICR MS.

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Six chemical constituents were simultaneously determined by HPLC.

Rhodiola crenulata protects against Alzheimer's disease in rats: A brain lipidomics study by Fourier-transform ion cyclotron resonance mass spectrometry coupled with high-performance reversed-phase liquid chromatography and hydrophilic interaction liquid chromatography

RATIONALE

Alzheimer's disease (AD) is a chronic, severe, progressive neurodegenerative disorder associated with cognitive and memory impairment that ultimately causes death. Most approved drugs can only alleviate some of the symptoms of AD, but no interventions have been found that reverse the underlying disease mechanisms. Rhodiola crenulata extract (RCE) has been reported to alleviate AD symptoms in rats. However, its underlying mechanism of action is still unclear.

METHODS

A brain lipidomics study was conducted to investigate the protective effects of RCE against AD in rats to identify potential biomarkers of AD using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled with high-performance reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC). Differences in lipid metabolism profiles were evaluated using multivariate statistical analysis. Finally, the possible mechanism of action of RCE on AD was investigated by analysing metabolic pathways.

RESULTS

The RPLCHILIC/FT-ICR MS results showed 20 lipid components with significant differences between the control and model groups. After administration of RCE, the levels of 10 lipids in AD rats tended to shift toward reference levels. The pathway analysis revealed that the protective effect of RCE against AD might be related to regulation of glycerophospholipid metabolism.

CONCLUSIONS

This study provides a novel perspective on the potential intervention mechanism of RCE in the treatment of AD.

A simplified strategy for molecular formula determination of chemical constituents in traditional Chinese medicines based on accurate mass, A + 1 and A + 2 isotopic peaks using Fourier transform ion cyclotron resonance mass spectrometry

RATIONALE

Recently, isotopic fine structures derived from Fourier transform ion cyclotron resonance mass spectrometry have been used to determine the molecular formula for unknown compounds in many complex systems. However, a simplified strategy for molecular formula determination of chemical constituents in traditional Chinese medicines (TCMs) based on accurate mass, A + 1 and A + 2 isotopic peaks is necessary.

METHODS

Salviae miltiorrhizae was selected as a representative species. First, the chemical constituents were chromatographically separated and their accurate masses were obtained. The A + 1 and A + 2 isotopic peaks of all chemical constituents were then also acquired. Finally, the chemical formulae of the chemical constituents were determined.

RESULTS

In the sample of Salviae miltiorrhizae, the formulae of 38 CHO-containing chemical constituents were quickly determined, and all chemical constituents were identified using their tandem mass spectrometric data. Moreover, the method was validated by comparison of the A + 1 and A + 2 isotopic peaks, their fragmentation patterns and the retention times of six selected standard substances.

CONCLUSIONS

The results demonstrate that the described strategy performs well for molecular formula determination of chemical constituents in TCMs. This also indicates that this method will be meaningful for the structural identification of chemical constituents of TCMs.

Serum lipidomics study reveals protective effects of Rhodiola crenulata extract on Alzheimer's disease rats

Alzheimer's disease (AD) is a chronic and progressive neurodegenerative disorder. Rhodiola crenulata extract (RCE) has shown its protective effects on AD, however, the underlying mechanism is still unclear. In this work, serum lipidomics was conducted to reveal the action mechanism of RCE on AD by HPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). The animal model of AD was reproduced by intrahippocampal injection of Aβ_1-42 in rats. The novel object recognition test and passive avoidance test were performed to evaluate the protective effects of RCE on AD rats. The differences of lipid metabolism profiles in rats were evaluated by multivariate statistical analysis. Then, the potential lipid biomarkers were identified and the possible mechanism of RCE on AD was elucidated by metabolic pathways analysis. As a result, twenty-eight lipids with significant differences between the control group and the model group were screened out. With the treatment of RCE, 19 lipids in AD rats showed a trend of callback to the normal levels. The results of pathway analysis indicated that the protective effects of RCE on AD might be closely related to the regulation of linoleic acid metabolism, α-linoleic acid metabolism, sphingolipid metabolism and ether lipid metabolism. In conclusion, this study provides a new perspective on the potential intervention mechanism of RCE for AD treatment.

Rapid characterization of the chemical constituents of Duzhong Jiangya tablet by HPLC coupled with Fourier transform ion cyclotron resonance mass spectrometry

Duzhong Jiangya tablet is a hypotensive drug. In this study, high-performance liquid chromatography-Fourier transform-ion cyclotron resonance-mass spectrometry technology was used to quickly identify its chemical composition. SinoChrom ODS-BP column (250 mm × 4.6 mm, 5 μm) was used. The mobile phase was acetonitrile(A)-0.1% formic acid solution(B). The flow rate was 1 mL/min. Extracted ion chromatogram was used to analyze the samples in positive and negative ion modes. Based on the accurate mass spectrometry information (such as quasi-molecular ions and fragment ions) obtained from the instrument, combined with reference compounds and literature, the chemical composition of Duzhong Jiangya Tablets was identified. A total of 131 compounds were identified, including four types of penylpropanoids, six types of phenylethanoid glycosides, 10 types of organic acids, 14 types of iridoids, 12 types of lignans, 18 types of alkaloids, seven types of coumarins, and 60 kinds of flavonoids. This established method can quickly and efficiently identify chemical constituents in Duzhong Jiangya tablet, lay a foundation for the research on the efficacy and quality of this traditional Chinese medicine, and provide a reference for the characterization of the chemical constituents of other traditional Chinese medicine preparations.

Screening for natural inhibitors of 5-lipoxygenase from Zi-shen pill extract by affinity ultrafiltration coupled with ultra performance liquid chromatography-mass spectrometry

ETHNOPHARMACOLOGICAL RELEVANCE

Zi-shen pill (ZSP), a traditional Chinese medicine, is widely used for the treatment of benign prostatic hyperplasia (BPH) and has remarkable curative effect.

AIM OF THE STUDY

To screen the potential 5-Lipoxygenase(5-LOX) inhibitors from ZSP extract.

MATERIALS AND METHODS

A new approach based on affinity ultrafiltration-ultra performance liquid chromatography-mass spectrometry(UPLC-MS) was established and validated. Zileuton and glipizide were chosen as positive and negative control drug, respectively. For better screening result, the concentration of 5-LOX enzyme, incubation temperature and time, pH and ion strength were optimized. In addition, 5-LOX inhibitory assay in vitro and molecular docking technique were used for further verification.

RESULTS

20 compounds were characterized in the ultrafiltrate by high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and 16 ligands showed binding ability to 5-LOX. Among them, six ligands were deduced as high-potential 5-LOX inhibitors with their high specific binding values (>2.0). The inhibitory activities of anemarrhenasaponin I, timosaponin AI, nyasol and demethyleneberberine were confirmed by the 5-LOX inhibitory assay for validating the reliability of affinity ultrafiltration approach and the computer-simulated molecular docking technique further clarified the possible mechanism of action between the active compounds and the 5-LOX active sites.