Internal correction of spectral interferences and mass bias for selenium metabolism studies using enriched stable isotopes in combination with multiple linear regression

Exploring on the bioactive markers of Codonopsis Radix by correlation analysis between chemical constituents and pharmacological effects

ETHNOPHARMACOLOGICAL RELEVANCE

Codonopsis Radix is a commonly used traditional Chinese medicine, and has the effect of strengthening spleen and tonifying lung, nourishing blood and engendering liquid. In addition, it is also used as important food materials.

AIM OF THE STUDY

The aim of the study was to explain the underlying correlations between chemical constituents and pharmacological effects and explore the bioactive markers of Codonopsis Radix.

MATERIALS AND METHODS

Codonopsis Radix samples from Min county, Gansu province processed with different methods were taken as the materials, UPLC-ESI-Q-TOF-MS/MS analysis was conducted to identify the compounds and establish UPLC fingerprint. Meanwhile, hematopoietic and immunologic functions of Codonopsis Radix were investigated to obtain relevant pharmacological index. Then, the correlation analysis between chemical constituents in UPLC fingerprints and pharmacological effects was carried out. The plant name was confirmed to the database "The Plant List" (www.theplantlist.org).

RESULTS

According to the results of canonical correlation analysis, tryptophan, syringin, tangshenoside I, codonopyrrolidium A, lobetyolin and two unknown compounds might be the potential bioactive markers related to the hematopoietic and immunologic functions of Codonopsis Radix, which could be recommended as the index compounds.

CONCLUSION

This study illustrated the underlying correlations between chemical constituents and pharmacological effects, explored the pharmacological material basis, and could lay a foundation for the improvement of quality standard of Codonopsis Radix.

Screening anaphylactoid components of Shuang Huang Lian Injection by analyzing spectrum-effect relationships coupled with UPLC-TOF-MS

Shuang Huang Lian Injection (SHLI) has been used in China for over 30 years as an effective and widely used Chinese herbal prescription to treat acute respiratory infectious. SHLI has, however, caused many severe anaphylactoid reactions. It is important to identify the potential anaphylactoid components of SHLI. Spectrum-effect relationships were used to explore potentially anaphylactoid components. Based on the original herbal formula, honeysuckle, Fructus Forsythiae and Radix Scutellariae extracts were prepared and combined in appropriate proportions. The preparations were then injected into the caudal vein of rats to obtain in vivo serum samples for pharmacological evaluation and fingerprint analysis. The release rate of β-hexosaminidase from RBL-2H₃ cells and plasma histamine level was used as the pharmacological index. Chromatographic fingerprint analysis identified 22 common peaks. Regression analysis and correlation analysis were used to calculate the relationships between the peaks and the pharmacological effects and identified peaks 5, 6, 11, 12 and 17 as likely anaphylactoid agents. The correlated peaks were identified by comparing the fingerprints with in vitro samples and reference standard samples and the structure was identified by UPLC-TOF-MS. This study established a prospective method to clarify the anaphylactoid components in SHLI, which would provide guidances for screening anaphylactoid components in other traditional Chinese medicine injections.

Simultaneous Speciation of Selenoproteins and Selenometabolites in Plasma and Serum

Selenium is an essential element incorporated to different proteins with important biological functions in connection to antioxidant activity, cancer-protective properties, neurodegenerative pathologies, and prevention of effects of diabetes, among others. In addition, selenoamino acids play a basic role in the global equilibrium of key selenium-biomolecules synthesis, including selenoprotein P, selenoalbumin, and glutathione peroxidase. Homeostasis of these selenium-containing biomolecules involves different organs in living organisms including human, and bloodstream is the connection fluid in this process. Therefore, it is very important to have an analytical methodology suitable for selenium proteins and metabolites speciation in serum and plasma samples. For this purpose, a simultaneous speciation method for Se-containing biomolecules in serum/plasma is described on the basis of in series three-dimensional chromatography: size exclusion, affinity, and anion exchange high performance liquid chromatography (3D/SE-AF-AEC-HPLC), using different columns of each type and hyphenation to inductively coupled plasma-(quadrupole) mass spectrometry (ICP-MS). The method allows the quantitative simultaneous analysis of selenoprotein P (SeP), extracellular glutathione peroxidase (eGPx), selenoalbumin (SeAlb), selenite, and selenate in serum (from human and mouse) using species-unspecific isotope dilution (SUID). In addition, a simplified two-dimensional approach (2D/SE-AF-HPLC-SUID-ICP-MS) is described when selenium metabolites are globally analyzed. The method provides detection limits in the range 0.2-1.3 ng of Se g^-1 and avoids typical interferences in this matrix from chloride and bromide with a chromatographic runtime less than 35 min.

Studies on Isotope Ratio Measurement of Cl by Inductively Coupled Plasma Triple-quad Mass Spectrometry

Fundamental studies on isotope ratio measurement of Cl were carried out using inductively coupled plasma triple-quad mass spectrometry (ICP-MS/MS) and the analytical performance obtained was compared to that obtained by ICP sector field mass spectrometer (ICP-SFMS). Though the polyatomic ion interferences of ¹⁶O¹⁸O¹H and ³⁶Ar¹H with respect to ³⁵Cl and ³⁷Cl, respectively, made a negative effect on the accuracy and the precision for isotope ratio measurements of Cl, the ICP-SFMS could eliminate these interferences by medium mass resolution mode (m/Δm = 4000) and achieved the isotope ratio measurements with 0.2 - 0.5% of relative standard deviation (RSD) at the concentrations of Cl from 1 to 10 mg kg^-1. In the case of ICP-MS/MS, both the single-MS mode without collision reaction gas and the MS/MS mode with collision reaction gases such as oxygen (O₂) and hydrogen (H₂) were examined and compared their analytical sensitivities as well as the precisions of isotope ratio measurement of Cl. The precisions of Cl isotope ratio measurements were 3 - 14% of RSD at the concentrations of Cl from 5 to 100 mg kg^-1, when single-MS mode was carried out, even though the similar isotope ratios of ³⁵Cl/³⁷Cl could be obtained. In the case of O₂ gas for MS/MS mode with mass-shift method, precisions of 0.3 - 2% of RSD were obtained at the concentration range of 1 - 100 mg kg^-1. In the case of H₂ gas, similar sensitivities as those obtained by ICP-SFMS and the precisions of 0.2 - 0.5% of RSD at the concentration range of 1 - 10 mg kg^-1 were obtained. From these results, it was evaluated that the ICP-MS/MS in MS/MS mode with collision reaction gas could be used for Cl isotope ratio measurements for such studies as stable isotope tracers, isotope abundance measurements in nuclear chemistry and accurate determinations by isotope dilution mass spectrometry.