An Analysis of Polysaccharides from Eight Plants by a Novel Heart-Cutting Two-Dimensional Liquid Chromatography Method.

Natural polysaccharides are important active biomolecules. However, the analysis and structural characterization of polysaccharides are challenging tasks that often require multiple techniques and maps to reflect their structural features. This study aimed to propose a new heart-cutting two-dimensional liquid chromatography (2D-LC) method for separating and analyzing polysaccharides to explore the multidimensional information of polysaccharide structure in a single map. That is, the first-dimension liquid chromatography (1D-LC) presents molecular-weight information, and the second-dimension liquid chromatography (2D-LC) shows the fingerprints of polysaccharides. In this 2D-LC system, the size-exclusion chromatography-hydrophilic interaction chromatography (SEC-HILIC) model was established. Coupling with a charged aerosol detector (CAD) eliminated the need for the derivatization of the polysaccharide sample, allowing the whole process to be completed within 80 min. The methods were all validated in terms of precision, linearity, stability, and repeatability. The capability of the new 2D-LC method was demonstrated in determining various species of natural polysaccharides. Our experimental data demonstrated the feasibility of the whole systematic approach, opening the door for further applications in the field of natural polysaccharide analysis.

[Determination of gypenoside XLVI and LVI in Gynostemma pentaphyllum from Fujian by ultra-high performance liquid chromatography-charged aerosol detector].

Gynostemma pentaphyllum (Thunb.) Makino contains dammarane-type triterpenoid saponins, similar to ginseng, with a host of pharmacological activities. However, its planting resources and chemical composition are quite complex. The chemical constituents of Gynostemma pentaphyllum vary drastically among different origins and varieties. Thus, the corresponding quality control methods also need to be different. Currently, limited information is available about the quality control of Gynostemma pentaphyllum from Fujian. A new method based on ultra-high performance liquid chromatography-charged aerosol detection (UHPLC-CAD) was established for the determination of gypenoside XLVI and LVI in Gynostemma pentaphyllum. The major components of Gynostemma pentaphyllum were characterized using UHPLC-quadrupole time-of-flight-mass spectrometry (UHPLC-Q-TOF/MS) combined with UHPLC-CAD. The results revealed gypenoside XLVI, LVI, and their corresponding malonyl-containing acidic saponins as the main components. However, malonylgypenoside XLVI and LVI can easily remove their malonyl group and convert to gypenoside XLVI and LVI during the application of Gynostemma pentaphyllum. In this study, the samples were pretreated using alkali hydrolysis to transform the acid saponins completely, and the final contents of gypenoside XLVI and LVI were determined via UHPLC-CAD. The optimal alkaline hydrolysis, extraction, and liquid chromatography conditions were established. First, the alkaline hydrolysis conditions were optimized. The effects of the volume of ammonia and reaction time on the contents of gypenoside XLVI, LVI, malonylgypenoside XLVI, and LVI were examined. Malonylgypenoside XLVI and LVI could be transformed completely to gypenoside XLVI and LVI by standing for 24 h in an ethanol-water-ammonia (50∶46∶4, v/v/v) mixture. Furthermore, the extraction conditions were optimized. Next, effects of the different solvents, extraction time, and solid-liquid ratio on the extraction rates of gypenoside XLVI and LVI were investigated. The extraction method for Gynostemma pentaphyllum powder using the ethanol-water-ammonia (50∶46∶4, v/v/v) and a solid-liquid ratio of 1∶150 (g∶mL) for 30 min was established. Finally, a prepared test solution was separated on a Waters ACQUITY UPLC BEH C18 chromatographic column (100 mm×2.1 mm, 1.7 µm). Acetonitrile and 0.1% (v/v) formic acid aqueous solution were used as the mobile phases for gradient elution. The flow rate was set to 0.5 mL/min and column temperature was maintained at 40 ℃. The separation was detected using a charged aerosol detector. Results indicated that the logarithm of the mass concentrations of gypenoside XLVI and LVI had a linear relationship with the logarithm of the peak area in the range of 9.94-318.00 µg/mL and 12.78-409.00 µg/mL, respectively. The correlation coefficients (r) were 0.9993 and 0.9995, respectively. The limit of detection (LOD) and the limit of quantification (LOQ) of gypenoside XLVI were 1.58 µg/mL and 6.36 µg/mL, respectively. The LOD and LOQ of gypenoside LVI were 2.05 µg/mL and 8.18 µg/mL, respectively. The relative standard deviations (RSDs) of precision, repeatability, and 24 h stability were less than 2.0% (n=6). The spiked recoveries of gypenoside XLVI were 100.2%-107.2% and the RSD value was 2.4%. The spiked recoveries of gypenoside LVI were 97.9%-104.2% and the RSD value was 2.6%. The results of 16 batches of Gynostemma pentaphyllum samples indicated that the gypenoside XLVI content was 0.57%-2.57%, and gypenoside LVI content was 0.66%-2.99%. Hence, this method has high sensitivity and good reproducibility. Therefore, it can be used for quality research and quality control of Gynostemma pentaphyllum from Fujian.

Quality analysis of hawthorn leaves (the leaves of Crataegus pinnatifida Bge. var major N.E.Br) in different harvest time.

INTRODUCTION: Harvest time plays an important role on the quality of medicinal plants. The leaves of Crataegus pinnatifida Bge. var major N.E.Br (hawthorn leaves) could be harvested in summer and autumn according to the Pharmacopoeia of the People's Republic of China (Pharmacopoeia). However, little is known about the difference of the chemical constituents in hawthorn leaves with the harvest seasonal variations. OBJECTIVE: The chemical constituents of hawthorn leaves in different months were comprehensively analysed to determine the best harvest time. METHODS: Initially, the chemical information of the hawthorn leaves were obtained by ultra-high-performance liquid chromatography and quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS). Subsequently, principal component analysis (PCA) was applied to compare the chemical compositions of hawthorn leaves harvested in different months. Then, an absolute quantitation method was established using high-performance liquid chromatography-charged aerosol detector (HPLC-CAD) to determine the contents of five compounds and clarify the changes of these components with the harvest seasonal variations. Meanwhile, a semi-quantitative method by integrating HPLC-CAD with inverse gradient compensation was also established and verified. RESULTS: Fifty-eight compounds were identified through UHPLC-Q-TOF-MS. PCA revealed that the harvest season of hawthorn leaves had a significant effect on the chemical compositions. The contents of five components were relatively high in autumn. Other four main components without reference standards were further analysed through the semi-quantitative method, which also showed a high content in autumn. CONCLUSIONS: This work emphasised the effect of harvest time on the chemical constituents of hawthorn leaves and autumn is recommended to ensure the quality.

Effects of detoxification process on toxicity and foreign protein of tetanus toxoid and diphtheria toxoid.

Formaldehyde detoxification is a process for converting tetanus toxin (TT) and diphtheria toxin (DT) into tetanus toxoid (TTd) and diphtheria toxoid (DTd), respectively. The mechanism of this detoxification process has been investigated by several previous studies based on lab-scale toxoids. To obtain greater insights of the effects induced by formaldehyde, industrial TTd and DTd batches obtained from different detoxification processes were studied in this work. Using liquid chromatography-mass spectrometry (LC-MS), 15 and 20 repeatable formaldehyde-induced modification sites of TTd and DTd were identified, respectively. Toxoid which had a higher formaldehyde-induced modification rate observed by LC-MS, also had larger bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Aggregates which were observed on size exclusion chromatogram (SEC) were confirmed by SDS-PAGE and LC-MS. Formaldehyde detoxification also led to a decrease of isoelectric point (pI) values and an increase of retention on weak anion exchange (WAX) column. Specific toxicity tests were conducted to evaluate toxicity of the TTd and DTd samples obtained with different detoxification conditions. Results from the specific toxicity tests showed that all toxoids used in this study were qualified, including toxoids obtained from mild and drastic detoxification conditions. However, obtained from mild detoxification conditions had less aggregates and may lead to a higher degree of glycosylation in conjugate vaccines than the ones obtained from drastic detoxification conditions. Thus, we suggest that mild detoxification conditions should be used to obtain TTd and DTd. Furthermore, as well as studying the formaldehyde-induced modifications and toxicity in TTd and DTd, the effects of the detoxification process on foreign proteins were also investigated. An increase in foreign proteins were observed in the aggregate than in the monomer of the toxoids. Additionally, some foreign proteins in the monomer of the toxins transferred to the aggregate of toxoids due to the formation of cross-linking. To eliminate the risk of cross-linking foreign proteins to toxoids in vaccination programs, a purification process is necessary before the detoxification process and/or the use of toxoids in vaccines.

Mechanism of Shengmai Injection on Anti-Sepsis and Protective Activities of Intestinal Mucosal Barrier in Mice.

OBJECTIVE: To study the mechanism of Shengmai Injection (SMI, ) on anti-sepsis and protective activities of intestinal mucosal barrier. METHODS: The contents of 11 active components of SMI including ginsenoside Rb1, Rb2, Rb3, Rd, Re, Rf, Rg1, Rg2, ophioposide D, schisandrol A and schisantherin A were determined using ultra-performance liquid chromatography. Fifty mice were randomly divided into the blank, the model, the low-, medium- and high-dose SMI groups (0.375, 0.75, 1.5 mL/kg, respectively) by random number table, 10 mice in each group. In SMI group, SMI was administrated to mice daily via tail vein injection for 3 consecutive days, while the mice in the blank and model groups were given 0.1 mL of normal saline. One hour after the last SMI administration, except the blank group, the mice in other groups were intraperitoneally injected with lipopolysaccharide (LPS) saline solution (2 mL/kg) at a dosage of 5 mL/kg for development of endotoxemia mice model. The mice in the blank group were given the same volume of normal saline. Inflammatory factors including interferon-γ (INF-γ), tumor necrosis factor-α (TNF-α), interleukin (IL)-2 and IL-10 were measured by flow cytometry. Myosin light-chain kinase (MLCK), nuclear factor κB (NF-κB) levels, and change of Occludin proteins in jejunum samples were analyzed by Western blot. RESULTS: The decreasing trends of INF-γ, TNF-α and IL-2 were found in serum of SMI treatment groups. In SMI-treated mice, the content of Occludin increased and MLCK protein decreased compared with the model group (P<0.05 or P<0.01). The content of cellular and nuclear NF-κB did not change significantly (P>0.05). CONCLUSION: SMI may exert its anti-sepsis activity mainly through NF-κB-pro-inflammatory factor-MLCK-TJ cascade.

Investigation of the Mechanism of Shengmai Injection on Sepsis by Network Pharmacology Approaches.

Shengmai injection (SMI) contains Ginsen Radix et Rhizoma Rubra, Ophiopogon japonicus, and Schisandrae Chinensis Fructus. It is used as a supportive herbal medicine in the management of sepsis, systemic inflammatory response syndrome, and septic or hemorrhagic shock. An UPLC method was established to identify and evaluate SMI fingerprints. Fingerprint similarities of 9 batches of SMI were compared. The network platform, "TCM-components-core targets-key pathways," was established, and the mechanism of SMI in the treatment of sepsis was investigated. The similarity of 9 batches of SMI fingerprints was greater than 0.91. 44 peaks were selected as the common peaks, of which 11 peaks were identified. KEGG functional pathway analysis showed SMI was mainly involved in the pathways of cancer, cell cycle, and p53 signaling, suggesting SMI protects multiple organs via regulating immunity, inflammation, apoptosis, and energy metabolism. GO enrichment analysis showed active SMI components regulated various biological processes and altered the pathophysiology of sepsis. The interplays between SMI and multiple energy metabolism signaling cascades confer protection from life-threatening multiple organ failure in sepsis.