[Determination of seven ingredients of different grades Alismatis Rhizoma by QAMS method].

The present study is to establish a quantitative analysis of multi-components by single marker(QAMS) for determining contents of seven compositions in Alismatis Rhizoma, alismoxide, alisol C 23-acetate, alisol A, alismol, alisol B, alisol B 23-acetate and 11-deoxy-alisol B. Six relative correction factors(RCFs) of alismoxide, alisol C 23-acetate, alisol A, alismol, alisol B and 11-deoxy-alisol B were established in the UPLC method with alisol B 23-acetate as the internal standard, which was to calculate the mass fraction of each. The mass fraction of seven effective constituents in Alismatis Rhizoma was calculated by the external standard method(ESM) at the same time. Compared with the content results determined by the ESM and QAMS, the feasibility and accuracy of QAMS method were verified. Within the linear range, the RCFs of alismoxide, alisol C 23-acetate, alisol A, alismol, alisol B, 11-deoxy-alisol B were 0.946, 4.183, 0.915, 1.039, 0.923 and 1.244, respectively, with good repeatability in different experimental conditions. There was no significant difference between the QAMS method and ESM method. Then, QAMS method was applied to determination of the different degree Alismatis Rhizoma from different areas. As a result, the concentrations of 7 components have differences in different areas, but no significant differences in different grades. The QAMS method is feasible and accurate for the determination of the seven chemical compositions, and which can be used for quality control of Alismatis Rhizoma.

Construction and Application of a Non-Enzyme Hydrogen Peroxide Electrochemical Sensor Based on Eucalyptus Porous Carbon.

Natural eucalyptus biomorphic porous carbon (EPC) materials with unidirectional ordered pores have been successfully prepared by carbonization in an inert atmosphere. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) were employed to characterize the phase identification, microstructure and morphology analysis. The carbon materials were used to fabricate electrochemical sensors to detect hydrogen peroxide (H2O2) without any assistance of enzymes because of their satisfying electrocatalytic properties. It was immobilized on a glassy carbon electrode (GCE) with chitosan (CHIT) to fabricate a new kind of electrochemical sensor, EPC/CHIT/GCE, which showed excellent electrocatalytic activity in the reduction of H2O2. Meanwhile, EPC could also promote electron transfer with the help of hydroquinone. The simple and low-cost electrochemical sensor exhibited high sensitivity, and good operational and long-term stability.

Diuretic Activity of Compatible Triterpene Components of Alismatis rhizoma.

Alismatis rhizoma (AR), the dried rhizoma of Alisma orientale Juzepzuk (Alismataceae), is a traditional Chinese medicine. AR is an important part of many prescriptions and is commonly used as a diuretic agent in Asia. This study aimed to evaluate the diuretic effects of total triterpene extract (TTE) and triterpene component compatibility (TCC, the mixture of alisol B 23-acetate, alisol B, alisol A 24-acetate, alisol A, and alisol C 23-acetate) of AR in saline-loaded rats. The optimal diuretic TCC of AR was optimized using a uniform design. Different doses (5, 20, and 40 mg/kg) of TTE and TCC groups (N1-N8) were orally administered to rats. Urinary excretion rate, pH, and electrolyte excretion were measured in the urine of saline-loaded rats. Results showed that TTE doses increased urine volume and electrolyte excretion compared with the control group. All uniformly designed groups of TCC also increased urine excretion. In addition, optimal diuretic TCC was calculated (alisol B 23-acetate: alisol B: alisol A 24-acetate: alisol A: alisol C 23-acetate 7.2:0.6:2.8:3.0:6.4) and further validated by saline-loaded rats. This study demonstrated that TTE presented a notable diuretic effect by increasing Na⁺, K⁺, and Cl − displacements. The most suitable TTC compatible proportion of alisol B 23-acetate: alisol B: alisol A 24-acetate: alisol A: alisol C 23-acetate for diuretic activity was validated, and triterpenes were the material basis for the diuretic activity of AR.

[Development of a cell-based peroxisome proliferator-activated receptors (PPARs) screening model and its application for evaluation of triterpenoids isolate from Alismatis Rhizoma].

Peroxisome proliferators activated receptors (PPARs) are closely related to human chronic disease, such as diabetes mellitus and the other metabolic diseases. In this study, a cell-based PPARs (PPAR α/ß/γ) model was developed for the screening of PPARs agonists from Alismatis Rhizoma (AR). Firstly, 293T cells were transfected with the reconstructed plasmid pBind-PPAR (α, ß, or γ)-LBD and reporter gene pGL4.35, and the known PPARs agonists were used as the positive control (fenofibrate for PPARα, L165041 for PPARß, and rosiglitazone for PPARγ). The ability of activation for PPARs was evaluated by analyzing the expression value of luciferase. Afterward, the 14 pure triterpenoids isolate from AR were analyzed on the developed PPARα, PPARß and PPARγ screening assay method. The results showed that the compounds 5, 6, 7, 8, 13 and 14 from AR have the ability of activation for PPARα. The compounds 5 and 7 from AR have the ability of activation for PPARß. The compounds 6, 7, 8 and 12 from RA have the ability of activation for PPARγ.In this study, the compound 12 from AR were found to display significant activation on PPARγ for the first time. AR triterpenoids extracts had the ability of activation for PPARα, PPARß and PPARγ. The results suggested that triterpenoids extracts from AR were PPARα, PPARß and PPARγ agonists. The results will help to provide reference for clinical application of AR, and establish a model for PPARs on 293T cell, which can be used to screen and evaluate PPARs natural agonists.

A calculation method of plant similarity giving consideration to different plant features.

A method to compute the similarity between different plants is proposed, using features of a plant׳s topological structure and peripheral contour, as well as its geometry. The topological structures are described using tree graphs, and their similarity can be calculated based on the edit distance of these graphs. The peripheral contour of a plant is abstracted by its three-dimensional convex hull, which is projected in several directions. The similarity of the different projections is calculated by an algorithm to compute the similarity of two-dimensional shapes. The similarity of the geometrical detail is computed by considering the geometrical properties of different level branches. Finally the overall similarity between different plants is calculated by combining these different similarity measures. The validity of proposed method is evaluated by detailed experiments.

A novel UPLC-MS/MS method for sensitive quantitation of boldine in plasma, a potential anti-inflammatory agent: application to a pharmacokinetic study in rats.

Boldine is a potential anti-inflammatory agent found in several different plants. Published bioanalytical methods using HPLC with ultraviolet and fluorescent detection lacked enough sensitivity and required tedious sample preparation procedures. Herein, we describe the development of a novel ultra-high performance LC with MS/MS for determination of boldine in plasma. Boldine in plasma was recovered by liquid-liquid extraction using 1 mL of methyl tert-butyl ether. Chromatographic separation was performed on a C18 column at 45°C, with a gradient elution consisting of acetonitrile and water containing 0.1% (v/v) formic acid at a flow rate of 0.3 mL/min. The detection was performed on an electrospray triple-quadrupole MS/MS by positive ion multiple reaction monitoring mode. Good linearity (r(2) > 0.9926) was achieved in a concentration range of 2.555-2555 ng/mL with a lower limit of quantification of 2.555 ng/mL for boldine. The intra- and inter-day precisions of the assay were 1.2-6.0 and 1.8-7.4% relative standard deviation with an accuracy of -6.0-8.0% relative error. This newly developed method was successfully applied to a single low-dose pharmacokinetic study in rats and was demonstrated to be simpler and more sensitive than the published methods, allowing boldine quantification in reduced plasma volume.

Qualitative and Quantitative Analysis of Major Triterpenoids in Alismatis Rhizoma by High Performance Liquid Chromatography/Diode-Array Detector/Quadrupole-Time-of-Flight Mass Spectrometry and Ultra-Performance Liquid Chromatography/Triple Quadrupole Mass Spectrometry.

Alismatis Rhizoma (AMR) is a well-known natural medicine with a long history in Chinese medicine and has been commonly used for treating a wide range of ailments related to dysuria, edema, nephropathy, hyperlipidaemia, diabetes, inflammation as well as tumors in clinical applications. Most beneficial effects of AMR are attributed to the presence of protostane terpenoids, the major active ingredients of Alismatis Rhizoma (AMR). In this study, a systematic high performance liquid chromatography/diode-array detector/quadrupole-time-of-flight mass spectrometry (HPLC-DAD-Q-TOF MS) and ultra-performance liquid chromatography/triple quadrupole mass spectrometry (UPLC-QqQ MS) method was developed for qualitative and quantitative analyses of the major AMR triterpenoids. First, a total of 25 triterpenoid components, including 24 known compounds and one new compound were identified by comparison with UV spectra, molecular ions and fragmentation behaviors of reference standards or the literature. Second, an efficient method was established for the rapid simultaneous determination of 14 representative triterpenoids by UPLC-QqQ MS. Forty-three batches of AMR were analyzed with linearity (r, 0.9980-0.9999), intra-day precision (RSD, 1.18%-3.79%), inter-day precision (RSD, 1.53%-3.96%), stability (RSD, 1.32%-3.97%), repeatability (RSD, 2.21%-4.25%), and recovery (98.11%-103.8%). These results indicated that new approaches combining HPLC-DAD-Q-TOF MS and UPLC-QqQ MS are applicable in the qualitative and quantitative analysis of AMR.

Ultrasound/microwave-assisted extraction and comparative analysis of bioactive/toxic indole alkaloids in different medicinal parts of Gelsemium elegans Benth by ultra-high performance liquid chromatography with MS/MS.

Indole alkaloids are the main bioactive/toxic components in Gelsemium elegans Benth. To determine the distribution and contents of indole alkaloids in its different medicinal parts, a novel and rapid method using ultra-high performance LC (UPLC) with MS/MS has been established and validated with an optimized ultrasound/microwave-assisted extraction method. Four constituents, namely, humantenidine, humantenmine, gelsemine, and koumine, were simultaneously determined in 6 min. Chromatographic separation was achieved on an ultra-high performance LC BEH C18 column with a gradient mobile phase consisting of methanol and water (containing 0.1% formic acid both in methanol and water) at a flow rate of 0.3 mL/min. The detection was performed on a triple quadrupole electrospray MS/MS by positive ion multiple-reaction monitoring mode. All the analytes showed good linearity (r ≥ 0.9934) within a concentration range from 0.1-25 µg/mL with a LOQ of 25-50 ng/mL. The overall intra- and intervariations of four components were <4.7% with an accuracy of 97.3-101.3%. The analysis results showed that there were remarkable differences in the distribution and contents of four chemical markers in the roots, stems, and leaves of G. elegans Benth. The findings can provide necessary and meaningful information for the rational utilization of its resources.

Development of a sensitive and rapid UPLC-MS/MS method for the determination of koumine in rat plasma: application to a pharmacokinetic study.

A rapid, selective and sensitive method using UPLC-MS/MS was first developed and validated for quantitative analysis of koumine in rat plasma. A one-step protein precipitation with methanol was employed as a sample preparation technique. Plasma samples were separated on an Acquity UPLC BEH C18 column (50 × 2.1 mm, i.d. 1.7 µm) with a gradient mobile phase consisting of methanol with 0.1% (v/v) formic acid and water containing 0.1% (v/v) formic acid at a flow rate of 0.3 mL/min. Detection and quantification were performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring mode via positive eletrospray ionization. Good linearity (r > 0.9997) was achieved using weighted (1/x(2) ) least squares linear regression over a concentration range of 0.025-15 µg/mL with a lower limit of quantification of 0.025 µg/mL for koumine. The intra- and inter- precisions (relative standard deviation) of the assay at all three quality control samples were 5.6-14.1% with an accuracy (relative error) of 5.0-14.0%, which meets the requirements of the US Food and Drug Administration guidance. This developed method was successfully applied to an in vivo pharmacokinetic study in rats after a single intravenous dose of 20 mg/kg koumine.

Antidiabetic effect of the total polyphenolic acids fraction from Salvia miltiorrhiza Bunge in diabetic rats.

An investigation was made to evaluate the therapeutic potential of the total polyphenolic acids fraction (PAF) from Salvia miltiorrhiza Bunge in the type 2 diabetes mellitus rats model with an oral dose of 187 mg/kg for 28 days. The results showed that PAF induced a significant decrease in fasting blood glucose (FBG), fasting blood insulin (FINS), total cholesterol (TC), triglyceride (TG) and blood urea nitrogen (BUN), and an obvious increase in insulin sensitivity index (ISI) in diabetic rats induced by a high fat diet and a low dose of streptozocin (STZ). These results suggested that PAF has antidiabetic potential in vivo.

A computer-aided diagnosis system using white-light endoscopy for the prediction of conventional adenoma with high grade dysplasia.

OBJECTIVES: We developed a computer-aided diagnosis system called ECRCCAD using standard white-light endoscopy (WLE) for predicting conventional adenomas with high-grade dysplasia (HGD) to optimise the patients' management decisions during colonoscopy. METHODS: Pretraining model was used to fine-tune the model parameters by transfer learning. 2,397 images of HGD and 2,487 low-grade dysplasia (LGD) images were randomly assigned (8:1:1) to the training, optimising, and internal validation dataset. The prospective validation dataset is the frames accessed from colonoscope videoes. One independent rural hospital provided an external validation dataset. Histopathological diagnosis was used as the standard criterion. The capability of the ECRCCAD to distinguish HGD was assessed and compared with two expert endoscopists. RESULTS: The accuracy, sensitivity and specificity for diagnosis of HGD in the internal validation set were 90.5%, 93.2%, 87.9%, respectively. While 88.2%, 85.4%, 89.8%, respectively, for the external validation set. For the prospective validation set, ECRCCAD achieved an AUC of 93.5% in diagnosing HGD. The performance of ECRCCAD in diagnosing HGD was better than that of the expert endoscopist in the external validation set (88.2% vs. 71.5%, P < 0.0001). CONCLUSION: ECRCCAD had good diagnostic capability for HGD and enabled a more convenient and accurate diagnosis using WLE.

[Study on dynamic of chemical components of rhizoma alismatis and Evodia rutaecarpa in their compatibility].

This article studied the changes of chemical components in decoctions that made from the single medicinal herb of Rhizoma Alismatis or Evodia rutaecarpa, the co-decoctions made from different compatibilities of the two medicinal herbs, and that mixed decotions of two single medicinal herb decotions, by HPLC. The changes of chemical components of the codicotions were focused on. The relationships between the changes of chemical components of the codicotions and defferent compatibility ratios of medicinal herb were summarized.

Impact of Gut Microbiota and Microbiota-Related Metabolites on Hyperlipidemia.

Hyperlipidemia, defined as the presence of excess fat or lipids in the blood, has been considered as a high-risk factor and key indicator of many metabolic diseases. The gut microbiota has been reported playing a vital role in regulating host lipid metabolism. The pathogenic role of gut microbiota in the development of hyperlipidemia has been revealed through fecal microbiota transplantation experiment to germ-free mice. The effector mechanism of microbiota-related metabolites such as bile acids, lipopolysaccharide, and short-chain fatty acids in the regulation of hyperlipidemia has been partially unveiled. Moreover, studies on gut-microbiota-targeted hyperlipidemia interventions, including the use of prebiotics, probiotics, fecal microbiota transplantation, and natural herbal medicines, also have shown their efficacy in the treatment of hyperlipidemia. In this review, we summarize the relationship between gut microbiota and hyperlipidemia, the impact of gut microbiota and microbiota-related metabolites on the development and progression of hyperlipidemia, and the potential therapeutic management of hyperlipidemia targeted at gut microbiota.

Sempervirine Mediates Autophagy and Apoptosis via the Akt/mTOR Signaling Pathways in Glioma Cells.

The potential antitumor effects of sempervirine (SPV), an alkaloid compound derived from the traditional Chinese medicine Gelsemium elegans Benth., on different malignant tumors were described in detail. The impact of SPV on glioma cells and the basic atomic components remain uncertain. This study aimed to investigate the activity of SPV in vitro and in vivo. The effect of SPV on the growth of human glioma cells was determined to explore three aspects, namely, cell cycle, cell apoptosis, and autophagy. In this study, glioma cells, U251 and U87 cells, and one animal model were used. Cells were treated with SPV (0, 1, 4, and 8 µM) for 48 h. The cell viability, cell cycle, apoptosis rate and autophagic flux were examined. Cell cycle, apoptotic, autophagy, and Akt/mTOR signal pathway-related proteins, such as CDK1, Cyclin B1, Beclin-1, p62, LC3, AKT, and mTOR were investigated by Western blot approach. As a result, cells induced by SPV led to G2/M phase arrest and apoptosis. SPV also promoted the effect of autophagic flux and accumulation of LC3B. SPV reduced the expression of p62 protein and induced the autophagic death of glioma cells. Furthermore, SPV downregulated the expressions of AKT and mTOR phosphorylated proteins in the mTOR signaling pathway, thereby affecting the onset of apoptosis and autophagy in U251 cells. In conclusion, SPV induced cellular G2/M phase arrest and blockade of the Akt/mTOR signaling pathway, thereby triggering apoptosis and cellular autophagy. The in vivo and in vitro studies confirmed that SPV inhibits the growth of glioma cancer.

Anti-osteoporotic effects of alisol C 23-acetate via osteoclastogenesis inhibition.

Alismatis rhizoma (AR) is the dried rhizome of Alisma orientale (Sam.) Juz. (Alismataceae). This traditional Chinese formula is diuretic, hypoglycemic, and hypolipidemic. Alisol C 23-acetate (AC23A) from AR is anti-inflammatory and ameliorates certain metabolic diseases. However, the mechanism by which AC23A mitigates osteoporosis is unknown. The present study investigated the anti-osteoporotic effects of AC23A in vivo and in vitro. In an ovariectomized (OVX) rat model, AC23A ameliorated OVX-induced organ coefficients and trabecular bone loss. In OVX rats, AC23A treatment lowered serum TRAP5b, CTK, ß-CTX, TNF-α, IL-6, and IL-1ß, raised serum E2, and did not significantly change serum OCN or BALP. AC23A inhibited osteoclast formation in a rat co-culture system without affecting osteoblast activity. RANK (receptor activator of nuclear factor kappaB) signaling channels are vital osteoclastogenesis transcription elements. AC23A inhibited RANK ligand (RANKL)-induced TRAP, c-Fos, MMP9, NFATc1, and CTK expression and JNK phosphorylation. Therefore, AC23A is anti-osteoclastogenic in vitro and in vivo by inhibiting RANKL-induced osteoclast differentiation and function. Moreover, AC23A could help prevent or limit osteoclast-mediated bone diseases by inhibiting osteoclastogenesis.

Alisol B 23-Acetate Ameliorates Azoxymethane/Dextran Sodium Sulfate-Induced Male Murine Colitis-Associated Colorectal Cancer via Modulating the Composition of Gut Microbiota and Improving Intestinal Barrier.

Hunting for natural compounds that can modulate the structure of the intestinal flora is a new hotspot for colitis-associated cancer (CAC) prevention or treatment. Alisol B 23-acetate (AB23A) is a natural tetracyclic triterpenoid found in Alismatis rhizoma which is well known for dietary herb. Alismatis rhizoma is often used clinically to treat gastrointestinal diseases in China. In this study, we investigated the potential prevention of AB23A in male mouse models of azoxymethane (AOM) and dextran sulfate sodium (DSS)-induced CAC. AB23A intervention alleviated the body weight loss, disease activity index, colon tumor load, tissue injury, and inflammatory cytokine changes in CAC mice. AB23A intervention leads to remarkable reductions in the activation of TLR, NF-κB and MAPK. AB23A significantly decreased the phosphorylation of p38, ERK, and JNK and up-regulated mucin-2 and the expression of tight junction proteins. The gut microbiota of AB23A-interfered mice was characterized with high microbial diversity, the reduced expansion of pathogenic bacteria, such as Klebsiella, Citrobacter, and Akkermansia, and the increased growth of bacteria including Bacteroides, Lactobacillus, and Alloprevotella. These data reveal that AB23A has the potential to be used to treat CAC in the future.

Alismatis Rhizoma Triterpenes Alleviate High-Fat Diet-Induced Insulin Resistance in Skeletal Muscle of Mice.

Alismatis rhizoma (AR), which is the dried rhizome of Alisma orientale (Sam.) Juz. (Alismataceae), is an important component of many famous Chinese formulas for hypoglycemic. This study aimed to evaluate the insulin resistance (IR) alleviating effects of AR triterpenes (ART) and ART component compatibility (ARTC, the mixture of 16-oxo-alisol A, 16-oxo-alisol A 23-acetate, 16-oxo-alisol A 24-acetate, alisol C, alisol C 23-acetate, alisol L, alisol A, alisol A 23-acetate, alisol A 24-acetate, alisol L 23-acetate, alisol B, alisol B 23-acetate, 11-deoxy-alisol B and 11-deoxy-alisol B 23-acetate) in high-fat diet-induced IR mice and plamitate-treated IR C2C12 cells, respectively. A dose of 200 mg/kg of ART was orally administered to IR mice, and different doses (25, 50, and 100 µg/ml) of ARTC groups were treated to IR C2C12 cells. IPGTT, IPITT, body weight, Hb1AC, FFA, TNF-α, MCP-1, and IR-associated gene expression (p-AMPK, p-IRS-1, PI3K, p-AKT, p-JNK, and GLUT4) were measured in IR mice. Glucose uptake, TNF-α, MCP-1, and IR-associated gene expression were also measured in IR C2C12 cells. Results showed that ART alleviated high-fat diet-induced IR in the skeletal muscle of mice, and this finding was further validated by ARTC. This study demonstrated that ART presented a notable IR alleviating effect by regulating IR-associated gene expression, and triterpenes were the material basis for the IR alleviating activity of AR.

Biomineralization and superhydrophobicity of BaCO3 complex nanostructures.

In this paper, we report on biomineralization of BaCO(3) hierarchical architectures with self-cleaning ability. The phase structures of the obtained samples were characterized by X-ray diffraction (XRD). All of these complex nanostructures, including dendrite-like nanostructures, dumbbell-like nanostructures, and spherical nanostructures of BaCO(3), were obtained by tuning the experimental parameters, such as the concentration of glucosan and Ba(2+) cations. The morphology and structures were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution TEM (HRTEM), and Fourier transform infrared (FT-IR) spectrum. The formation of dendrite-like, dumbbell-like, and spherical complex nanostructures can be explained by a rod-dumbbell-sphere (RDS) self-assembly growth mechanism. To our knowledge, this is the first demonstration of the biomimetic synthesis of BaCO(3) hierarchical architectures which uniquely display the characteristic of superhydrophobicity. A water contact angle of >150 degrees and sliding angle of 1 degree of the BaCO(3) hierarchical architectures can be adjusted, which opens up a wide range of new potential applications of bioinspired complex nanostructures in environmental chemistry.

Construction and Analysis of circRNA-miRNA-mRNA Molecular Regulatory Networks During Herba Gelsemium elegans Intoxication.

Gelsemium elegans (Gardner & Champ.) Benth. (GE) has therapeutic effects for pain and malignant tumors but also has high toxicity. Its mechanism of toxicity has not yet been fully clarified, thus limiting its application. Meanwhile, evidence has shown that circRNAs are closely related to the progression of disease. However, very little is known about their expression profiles during intoxication. In this paper, circRNA/mRNA microarrays were respectively performed to detect their expression profiles in mice with acute GE intoxication versus normal controls. CircRNAs were verified by qRT-PCR in subsequent experiments. A regulation pattern of circRNA→miRNA→mRNA was deduced based on intersection analysis of circRNA/mRNA microarrays. The results revealed circRNAs (143) and mRNAs (1,921) were significantly expressed during intoxication. Most of the circRNAs were exonic, and most distributions in chromosomes were transcribed from chr1, chr2, chr7, and chr11. Furthermore, dysregulated expression of mmu-circRNA-013703 and mmu-circRNA-010022 was verified. Then a circRNA-targeted miRNA-mRNA co-expression network was constructed. The network map contained 2 circRNAs, 52 miRNAs, and 752 mRNAs. GO & KEGG analysis further predicted that mmu-circRNA-013703 and mmu-circRNA-010022 may participate in cellular survival/demise-related, neuron/synapse-related, and channel-related pathways. Based on functional modules analysis, a new network was formed, in which mmu-circRNA-013703 VS mmu-miR-361-3p linked to most mRNAs. Most of these mRNAs were known to be involved in the aforementioned functional module. This indicated that mmu-circRNA-013703 functioned as a sponge of miRNAs to regulate the more comprehensive circRNA-miRNA-mRNA co-expression network. Our approach revealed a landscape of dysregulated circRNA-miRNA-mRNA and may be valuable for the identification of new biomarkers during intoxication.

Quantitative Analysis of Eight Triterpenoids and Two Sesquiterpenoids in Rhizoma Alismatis by Using UPLC-ESI/APCI-MS/MS and Its Application to Optimisation of Best Harvest Time and Crude Processing Temperature.

Rhizoma Alismatis (RA), widely known as "Ze-Xie" in China, is the tuber of Alisma orientale (Sam.) Juzep (Alismaceae), a Chinese herbal medicine that has been used to treat hyperlipidemia, diabetes, hypertension, dysuria, and inflammation. In this study, a sensitive and reliable method based on an ultra-performance liquid chromatography (UPLC) couple with two ionisation modes, including electrospray ionisation (ESI) and atmospheric pressure chemical ionisation (APCI) tandem mass spectrometry (MS), namely, UPLC-ESI/APCI-MS/MS was developed and validated to simultaneously determine 8 triterpenoids (ESI mode) and 2 sesquiterpenoids (APCI mode) in RA. Ten marker compounds were analysed with a Waters' CORTECS UPLC C18 column (200 mm × 2.1 m, 1.6 µm) and gradient elution with water (contained 0.1% formic) and acetonitrile within 7 min. The established method was validated for linearity, intra- and interday precisions, accuracy, recovery, and stability. The calibration curve for 10 marker compounds showed good linear regression (r > 0.9971). The limits of detection and quantification for analytes were 0.14-1.67 ng/mL and 0.44-5.65 ng/mL, respectively. The relative standard deviations (RSD, %) and accuracy (RE, %) of intra- and interday precisions were less than 3.83% and 1.21% and 3.22% and 1.46%, repeatability and stability for real samples were less than 2.78% and 3.19%, respectively. All recoveries of the 10 marker compounds ranged from 97.24% to 102.49% with RSDs less than 4.05%. The developed method efficiently determined the 10 marker compounds in RA and was subsequently applied to optimise harvest time and crude processing temperature. The result indicated the 90% wilted phase and 70°C (or lower) may be the best harvest time and the processing temperature of RA.