Xin-zhi Wang

Identification of liguzinediol metabolites in rats by ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry

Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/QTOF MS) was employed to investigate the in vivo metabolism of liguzinediol. Urine, bile, feces and plasma samples were collected after intravenous administration of 10mg/kg liguzinediol to healthy rats. Altogether seven metabolites were detected and tentatively identified based on the characteristics of their protonated ions. The metabolites were mainly transformed by four main metabolic pathways including oxidation, sulfation, glycine conjugation and glucuronidation.

Screening of immunomodulatory components in Yu-ping-feng-san using splenocyte binding and HPLC.

Yu-ping-feng-san (YPFS) is a widely used immunomodulatory herbal medication used in traditional Chinese medicine, but the active molecules remain obscure. To screen for bioactive components we combined splenocyte binding with high performance liquid chromatography (SB-HPLC). After enrichment by splenocyte binding, two YPFS components (C1 and C2) were analyzed by HPLC. Compound C2 was identified as linoleic acid (LA) based on UV absorption and mass spectrometry. Silica gel chromatography was used to purify compound C1 from Radix Saposhnikoviae, a major constituent of YPFS. This allowed identification of the molecule as panaxynol (PAN) based on EI-MS and NMR spectrometry. Bioassay in vitro demonstrated that PAN significantly inhibited splenocyte proliferation induced by concanavalin A (ConA) in a concentration-dependent manner, whereas LA had no significant effect on splenocyte proliferation. In vivo, PAN was found to attenuate allergic contact dermatitis in a mouse model of delayed-type hypersensitivity (DTH), a pharmacological activity not previously reported for this molecule. It is suggested that PAN contributes to the anti-DTH effects of YPFS. SB-HPLC provides a rapid and efficient method for the identification of potential immunomodulatory components in traditional Chinese medicines.

Metabolite identification of liguzinediol in dogs by ultra-flow liquid chromatography/tandem mass spectrometry

Ultra-flow liquid chromatography/quadrupole-time-of-flight mass spectrometry (UFLC/Q-TOF MS) method combined with metabolitepilot(MT) software was used for analysis of the metabolites of liguzinediol in dogs. Urine, bile, feces and plasma samples were collected after intravenous administration of 8 mg/kg liguzinediol to healthy dogs. Besides liguzinediol, seven metabolites were detected and identified by UFLC/Q-TOF MS method. The results showed that liguzinediol had some main metabolic pathways in dogs including oxidation, sulfation, cysteine conjugation, N-acetylcysteine conjugation and glucuronidation.

Influence of sulfur fumigation on the chemical profiles of Atractylodes macrocephala Koidz. evaluated by UFLC–QTOF–MS combined with multivariate statistical analysis

&NA; In the present study, the chemical compositions of Atractylodes macrocephala Koidz. (AMK) were analyzed systematically and influence of sulfur fumigation on the chemical profiles was evaluated by ultrafast flow liquid chromatography coupled with quadrupole‐time‐of‐flight mass spectrometry (UFLC–QTOF–MS) combined with multivariate statistical analysis. 52 components were detected from non‐fumigated AMK (NF‐AMK) and 28 components were newly produced after sulfur fumigation, out of which 59 major peaks were identified. The concentrations of 20 compounds significantly decreased and 37 compounds obviously increased. The potential structural transformation mechanism of terpenoids was explored to illustrate the correlation of the components contents before and after sulfur fumigation. Eight sulfur‐containing/dehydrated‐integrated atractylenolides that evolved from the NF‐AMK were screened out as potential characteristic chemical markers to examine the post‐harvest handling procedures of commercial AMK with excessive sulfur fumigation and maintain consistent quality. HighlightsThe chemical compositions of Atractylodes macrocephala Koidz. (AMK) were analyzed systematically and influence of sulfur fumigation on the chemical profiles was evaluated by UFLC–QTOF–MS combined with multivariate statistical analysis.52 components were examined from non‐fumigated AMK (NF‐AMK) and 28 compounds were newly produced after sulfur fumigation, out of which 59 major peaks were identified.Eight sulfur‐containing/dehydrated‐integrated atractylenolides that evolved from the NF‐AMK were screened out as potential characteristic chemical markers to examine the post‐harvest handling procedures of commercial AMK with excessive sulfur fumigation.

Peperomin E reactivates silenced tumor suppressor genes in lung cancer cells by inhibition of DNA methyltransferase.

Advanced lung cancer has poor prognosis owing to its low sensitivity to current chemotherapy agents. Therefore, discovery of new therapeutic agents is urgently needed. In this study, we investigated the antitumor effects of peperomin E, a secolignan isolated from Peperomia dindygulensis, a frequently used Chinese folk medicine for lung cancer treatment. The results indicate that peperomin E has antiproliferative effects, promoting apoptosis and cell cycle arrest in non‐small‐cell lung cancer (NSCLC) cell lines in a dose‐dependent manner, while showing lower toxicity against normal human lung epidermal cells. Peperomin E inhibited tumor growth in A549 xenograft BALB/c nude mice without significant secondary adverse effects, indicating that it may be safely used to treat NSCLC. Furthermore, the mechanisms underlying the anticancer effects of peperomin E have been investigated. Using an in silico target fishing method, we observed that peperomin E directly interacts with the active domain of DNA methyltransferase 1 (DNMT1), potentially affecting its genome methylation activity. Subsequent experiments verified that peperomin E decreased DNMT1 activity and expression, thereby decreasing global methylation and reactivating the epigenetically silenced tumor suppressor genes including RASSF1A, APC, RUNX3, and p16INK4, which in turn activates their mediated pro‐apoptotic and cell cycle regulatory signaling pathways in lung cancer cells. The observations herein report for the first time that peperomin E is a potential chemotherapeutic agent for NSCLC. The anticancer effects of peperomin E may be partly attributable to its ability to demethylate and reactivate methylation‐silenced tumor suppressor genes through direct inhibition of the activity and expression of DNMT1.

Hydrophilic Interaction Ultra-High Performance Liquid Chromatography Coupled with Triple-Quadrupole Mass Spectrometry for Determination of Nucleosides and Nucleobases in Animal Horns

Traditional Chinese Medicines (TCMs) derived from animal horns are one of the most important types of Chinese medicine. In the present study, a fast and sensitive analytical method was established for qualitative and quantitative determination of 14 nucleosides and nucleobases in animal horns using hydrophilic interaction ultra-high performance liquid chromatography coupled with triple-quadruple tandem mass spectrometry (HILIC-UPLC–QQQ-MS/MS) in selective reaction monitoring (SRM) mode. The method was optimized and validated, and showed good linearity, precision, repeatability, and accuracy. The method was successfully used to determine contents of the 14 nucleosides and nucleobases in 25 animal horn samples. Hierarchical clustering analysis (HCA) and principal component analysis (PCA) were performed and the 25 samples were thereby divided into two groups, which agreed with taxonomy. The method may enable quick and effective search of substitutes for precious horns.

Qualitative and quantitative analyses of bioactive secolignans from folk medicinal plant Peperomia dindygulensis using UHPLC-UV/Q-TOF-MS

Peperomia dindygulensis, with secolignans (SLs) as major bioactive constituents, is a commonly used traditional folk medicine in mainland China for treatment of stomach, liver, mammary, and esophageal cancers. However, to date, there is no method available for the qualitative and quantitative analyses of SLs in this medicinal plant. The purpose of this study was to establish a sensitive, selective, and reproducible method for rapidly profiling, identifying, and determining SLs in the whole plant of P. dindygulensis. Ultra high-performance liquid chromatography (UHPLC) coupled with ultraviolet detector (UV) and quadrupole tandem time-of-flight mass spectrometry (Q-TOF-MS) were used for this analyses. The fragmentation behaviors of different types of SLs were described. A total of thirteen SLs, including two new derivatives, were identified or tentatively characterized in P. dindygulensis samples. In addition, seven major SLs in herbal samples from different regions in China were successfully determined. The method developed in this study is suitable for the qualitative and quantitative analyses of SLs in P. dindygulensis, and may be applicable for determining or identifying SLs from other Pepermia genus plants.

Determination of a natural DNMT1 inhibitor, peperomin E, in rat plasma by UFLC-MS/MS and method application in a pharmacokinetic study

Peperomin E (PepE), a naturally occurring secolignan isolated from Peperomia dindygulensis, has drawn much attention recently owing to its anticancer and DNA methyltransferase 1 (DNMT1) inhibitory activity. Here, a simple and sensitive ultra-fast liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of PepE in rat plasma for the first time. Samples were prepared by simple protein precipitation. Separation was performed on an XBridge™ C18 column using a mobile phase of acetonitrile and 0.1% (v/v) aqueous formic acid. PepE and the internal standard arctigenin were detected in a positive-ion mode using multiple reaction monitoring of the transitions at m/z 413.2 → 261.0 and 373.2 → 137.2, respectively. The calibration curve for PepE was linear over the range of concentrations of 1.46-6000 ng/mL, with a lower limit of quantitation of 1.46 ng/mL. Both intra- and interday precisions were within 11.05%, and the accuracy ranged from -11.5 to 5.51%. The extraction recovery and matrix effect were within acceptable limits. Stability tests showed that PepE remained stable throughout the analytical procedure. The validated method was then used to analyze the pharmacokinetics of PepE administered to rats orally (12.5 and 25 mg/kg) or intravenously (6.25 and 12.5 mg/kg).

Rabbit conjunctivae edema and release of NO, TNF-α, and IL-1β from macrophages induced by fractions and esculentosides isolated from Phytolacca americana

Abstract Context: The roots of Phytolacca americana L. (Phytolaccaceae) may be toxic. Despite heated controversy over the toxic compounds of P. americana, especially esculentosides, relevant studies remain scarce. Objective: The objective of this study is to screen the toxic fractions and compounds of P. americana, to determine the controlling indices, and to provide evidence for unraveling the mechanism. Materials and methods: Petroleum ether (PE), CH2Cl2, n-BuOH, and water fractions were isolated from 70% ethanol extract of P. americana. The n-BuOH fraction was dissolved in 50% ethanol and precipitated by adding ethyl ether. The resultant supernatants and precipitates were referred to as SUPs and SEDs fractions, respectively. SUPs fraction was separated by column chromatography into four main stimulating esculentosides that were identified by HR-ESI/MS and NMR as EsA, EsB, EsC, and EsF. The irritating effects of esculentosides on rabbit conjunctivae (500 μg/eye) was observed by pathological examination and those on macrophages (5, 25, 50 and 100 μg/mL) were evaluated by detecting changes of NO, TNF-α, and IL-1β levels. Results and discussion: n-BuOH, SUP fractions, and EsC induced severe conjunctival edema. The four esculentosides induced dose-dependent releases of proinflammatory mediators NO, TNF-α, and IL-1β from macrophages, and releasing amounts peaked after 2 h of treatment. EsC and EsF induced macrophages to release mediators most significantly. EsC (50 μg/mL) functioned more effectively than EsF did, and similarly n-BuOH and SUPs fractions functioned more effectively than the esculentoside mixture. Thus, the four esculentosides exerted proinflammatory effects synergistically. Conclusion: All extracted esculentosides, especially EsC, induced inflammatory stimulation. Phytolacca americana-induced irritation of the gastrointestinal tract may be associated with esculentosides such as EsC.

Two new xanthone epimers from the processed gamboge

Abstract Two new xanthones, gambogollic acid (1), epigambogollic acid (2), together with three rare compounds, gambogellic acid (3), epigambogellic acid (4) and gambogic acid (5), were isolated from the processed gamboge. The new structures were determined by 1D and 2D NMR spectroscopic analysis. And the cytotoxicity of these five compounds was evaluated against human hepatoma carcinoma and human lung adenocarcinoma cell. Two new compounds showed excellent antitumor activity. All five compounds exhibited inhibitory effect against SMMC-7221cell and A549 cell.