Cevanine-type steroidal alkaloids from the bulbs of Fritillaria cirrhosa D. Don.

Eight previously undescribed cevanine-type steroidal alkaloids, cirrhosinones I-N and cirrhosinols A-B, along with five known analogs, were isolated from the bulbs of Fritillaria cirrhosa D. Don. Their structures were elucidated on the basis of comprehensive analysis of HRESIMS, 1D and 2D NMR spectroscopic data, and single-crystal X-ray diffraction analyses. All compounds revealed weak NO inhibitory activities in the LPS-stimulated NR8383 cells at the concentration of 20 µM, with inhibition ratios ranging from 5.1% to 14.3%.

Chemical profiling of Fritillariae thunbergii Miq prepared by different processing methods reveals two new quality markers: Zhebeininoside and imperialine-3-ß-D-glucoside.

ETHNOPHARMACOLOGICAL RELEVANCE: Fritillariae thunbergii Miq (FTM)exhibit versatile biological activities including the significant antitussive and expectorant activities. As a herbal medicine, the therapeutic effects of FTM may be expressed by multi-components which have complicated integration effects on multi-targets. With the time going, the different processing methods of FTM has been changed a lot. Thus，the study described the effect of processing methods to FTM and its quality. MATERIAL AND METHOD: Studies were undertaken by using UHPLC-LTQ Orbitrap MS and pharmacodynamic models. All reagents were involved of analytical grade. While a HPLC-ELSD's method has been developed and validated, a certified Quality System is conformed to ICH requirements. The experimental animals followed the animal welfare guidelines. AIM OF THE STUDY: We aimed to found the differences after the different processing methods of FTM, and to demonstrate the changes could be selected as quality control indicators, and established a method for simultaneous determination of these for quality control. RESULTS: we have previously found two new steroidal alkaloids: zhebeininoside and imperialine-3-ß-D-glucoside from the different processing methods of FTM, which is the difference between the different processing methods of FTM, mainly on the steroidal alkaloids. The activity analysis of zhebeininoside, imperialine-3-ß-D-glucoside, verticine and verticinone showed that the mouse model of cough expectorant has antitussive effect. The positive drug selected was dextromethorphan syrup. The positive group showed biological activity, but the blank group showed nothing. The model group showed illness which means that the model was effective. There are two ways of the mechanism of action of the expectorant action which can make sputum thin, reduce its viscosity, and be easy to cough up, or can accelerate the movement of mucous cilia in the respiratory tract and promote the discharge of sputum. In our study, the content of phenol red was significantly reduced in the administration group. CONCLUSIONS: To sum up, our results suggest that zhebeininoside and other three components cloud be selected as quality control indicators, and a method for simultaneous determination of zhebeininoside and other three components was established for quality control.

Identification of the Molecular Mechanisms of Peimine in the Treatment of Cough Using Computational Target Fishing.

Peimine (also known as verticine) is the major bioactive and characterized compound of Fritillariae Thunbergii Bulbus, a traditional Chinese medicine that is most frequently used to relieve a cough. Nevertheless, its molecular targets and mechanisms of action for cough are still not clear. In the present study, potential targets of peimine for cough were identified using computational target fishing combined with manual database mining. In addition, protein-protein interaction (PPI), gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using, GeneMANIA and Database for Annotation, Visualization and Integrated Discovery (DAVID) databases respectively. Finally, an interaction network of drug-targets-pathways was constructed using Cytoscape. The results identified 23 potential targets of peimine associated with cough, and suggested that MAPK1, AKT1 and PPKCB may be important targets of pemine for the treatment of cough. The functional annotations of protein targets were related to the regulation of immunological and neurological function through specific biological processes and related pathways. A visual representation of the multiple targets and pathways that form a network underlying the systematic actions of peimine was generated. In summary, peimine is predicted to exert its systemic pharmacological effects on cough by targeting a network composed of multiple proteins and pathways.

Isosteroid alkaloids with different chemical structures from Fritillariae cirrhosae bulbus alleviate LPS-induced inflammatory response in RAW 264.7 cells by MAPK signaling pathway.

Isosteroid alkaloids, natural products from Fritillariae Cirrhosae Bulbus, are well known for its antitussive, expectorant, anti-asthmatic and anti-inflammatory properties. However, the anti-inflammatory effect and its mechanism have not been fully explored. In this study, the anti-inflammatory activitives and the potential mechanisms of five isosteroid alkaloids from F. Cirrhosae Bulbus were investigated in lipopolysaccharide (LPS)-induced RAW264.7 macrophage cells. The pro-inflammatory mediators and cytokines were measured by Griess reagent, ELISA and qRT-PCR. The expression of MAPKs was investigated by western blotting. Treatment with the five isosteroid alkaloids in appropriate concentrations could reduce the production of nitric oxide (NO), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in supernatant, and suppressed the mRNA expressions of TNF-α and IL-6. Meanwhile, the five isosteroid alkaloids significantly inhibited the phosphorylated activation of mitogen activated protein kinase (MAPK) signaling pathways, including extracellular signal-regulated kinase (ERK1/2), p38 MAPK and c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK). These results demonstrated that isosteroid alkaloids from F. Cirrhosae Bulbus exert anti-inflammatory effects by down-regulating the level of inflammatory mediators via mediation of MAPK phosphorylation in LPS-induced RAW264.7 macrophages, thus could be candidates for the prevention and treatment of inflammatory diseases.

Mechanistic and therapeutic study of novel anti-tumor function of natural compound imperialine for treating non-small cell lung cancer.

ETHNOPHARMACOLOGICAL RELEVANCE: Bulbus Fritillaria cirrhosa D. Don (BFC) is a Chinese traditional herbal medicine that has long been used as an indispensable component in herbal prescriptions for bronchopulmonary diseases due to its well-established strong anti-inflammation and pulmonary harmonizing effects. Interestingly, there are few case reports in traditional Chinese medicine available where they found it to contribute in anti-tumor therapies. Imperialine is one of the most favored active substances extracted from BFC and has been widely recognized as an anti-inflammatory agent. AIM OF THE STUDY: The aim of the current work is to provide first-hand evidences both in vitro and in vivo showing that imperialine exerts anti-cancer effects against non-small cell lung cancer (NSCLC), and to explore the molecular mechanism of this anti-tumor activity. It is also necessary to examine its systemic toxicity, and to investigate how to develop strategies for feasible clinical translation of imperialine. MATERIALS AND METHODS: To investigate anti-NSCLC efficacy of imperialine using both in vitro and in vivo methods where A549 cell line were chosen as in vitro model NSCLC cells and A549 tumor-bearing mouse model was constructed for in vivo study. The detailed underlying anti-cancer mechanism has been systematically explored for the first time through a comprehensive set of molecular biology methods mainly including immunohistochemistry, western blot and enzyme-linked immunosorbent assays. The toxicity profile of imperialine treatments were evaluated using healthy nude mice by examining hemogram and histopathology. An imperialine-loaded liposomal drug delivery system was developed using thin film hydration method to evaluate target specific delivery. RESULTS: The results showed that imperialine could suppress both NSCLC tumor and associated inflammation through an inflammation-cancer feedback loop in which NF-κB activity was dramatically inhibited by imperialine. The NSCLC-targeting liposomal system was successfully developed for targeted drug delivery. The developed platform could favorably enhance imperialine cellular uptake and in vivo accumulation at tumor sites, thus improving overall anti-tumor effect. The toxicity assays revealed imperialine treatments did not significantly disturb blood cell counts in mice or exert any significant damage to the main organs. CONCLUSIONS: Imperialine exerts anti-cancer effects against NSCLC both in vitro and in vivo, and this previously unknown function is related to NF-κB centered inflammation-cancer feedback loop. Imperialine mediated anti-cancer activity is not through cytotoxicity and exhibit robust systemic safety. Furthermore, the liposome-based system we commenced would dramatically enhance therapeutic effects of imperialine while exhibiting extremely low side effects both on cellular and in NSCLC model. This work has identified imperialine as a promising novel anti-cancer compound and offered an efficient target-delivery solution that greatly facilitate practical use of imperialine.

Application of UPLC-MS/MS to simultaneously detect four bioactive compounds in the tumour-shrinking decoction (FM1523) for uterine fibroids treatment.

INTRODUCTION: The Chinese medicine formulation, tumour-shrinking decoction (TSD, FM1523), which consists of 15 natural medicines, is used for uterine fibroids (UFs) therapy and possesses excellent clinical therapeutic effect. OBJECTIVE: To develop a sensitive and validated analytical method for the simultaneous quantification of four crucial bioactive compounds including isorhamnetin-3-O-neohesperidoside, curcumin, peimine and tetrahydropalmatine in the principal formulation of this decoction. METHODS: An ultra-performance liquid chromatography coupled tandem mass spectrometry (UPLC-MS/MS) with an electrospray ionisation (ESI) source in multiple reaction monitoring (MRM) mode was conducted to investigate these bioactive compounds in the TSD. The chromatographic separation was performed on a C18 column when the flow rate was adjusted at 0.2 mL/min with gradient elution of acetonitrile-water with 0.1% formic acid. Accelerated solvent extraction (ASE) method with higher extraction efficiency was employed for TSD sample pre-treatment. RESULTS: The linearity, limit of detection (LOD) and limit of quantification (LOQ) were determined for this analytical method. The mean recoveries of the compounds were determined between 100.23% and 104.02% with satisfactory relative standard deviation (RSD) in the ranges of 2.65% to 3.81%. The precision was evaluated by intra-day and inter-day tests, which revealed RSD within the ranges of 1.21% to 2.14% and 1.24% to 2.32%, respectively. CONCLUSION: The bioactive compounds of TSD samples were successfully quantified via UPLC-MS/MS with MRM mode. This study could help to evaluate the pharmacokinetic study of TSD during clinical applications and present a facile strategy for quantifying bioactive compounds in traditional Chinese Medicine decoction.

Determination and Visualization of Peimine and Peiminine Content in Fritillaria thunbergii Bulbi Treated by Sulfur Fumigation Using Hyperspectral Imaging with Chemometrics.

Rapid, non-destructive, and accurate quantitative determination of the effective components in traditional Chinese medicine (TCM) is required by industries, planters, and regulators. In this study, near-infrared hyperspectral imaging was applied for determining the peimine and peiminine content in Fritillaria thunbergii bulbi under sulfur fumigation. Spectral data were extracted from the hyperspectral images. High-performance liquid chromatography (HPLC) was conducted to determine the reference peimine and peiminine content. The successive projection algorithm (SPA), weighted regression coefficient (Bw), competitive adaptive reweighted sampling (CARS), and random frog (RF) were used to select optimal wavelengths, while the partial least squares (PLS), least-square support vector machine (LS-SVM) and extreme learning machine (ELM) were used to build regression models. Regression models using the full spectra and optimal wavelengths obtained satisfactory results with the correlation coefficient of calibration (rc), cross-validation (rcv) and prediction (rp) of most models being over 0.8. Prediction maps of peimine and peiminine content in Fritillaria thunbergii bulbi were formed by applying regression models to the hyperspectral images. The overall results indicated that hyperspectral imaging combined with regression models and optimal wavelength selection methods were effective in determining peimine and peiminine content in Fritillaria thunbergii bulbi, which will help in the development of an online detection system for real-world quality control of Fritillaria thunbergii bulbi under sulfur fumigation.

Peiminine inhibits colorectal cancer cell proliferation by inducing apoptosis and autophagy and modulating key metabolic pathways.

Peiminine, a compound extracted from the bulbs of Fritillaria thunbergii and traditionally used as a medication in China and other Asian countries, was reported to inhibit colorectal cancer cell proliferation and tumor growth by inducing autophagic cell death. However, its mechanism of anticancer action is not well understood, especially at the metabolic level, which was thought to primarily account for peiminine's efficacy against cancer. Using an established metabolomic profiling platform combining ultra-performance liquid chromatography/tandem mass spectrometry with gas chromatography/mass spectrometry, we identified metabolic alterations in colorectal cancer cell line HCT-116 after peiminine treatment. Among the identified 236 metabolites, the levels of 57 of them were significantly (p < 0.05) different between peiminine-treated and -untreated cells in which 45 metabolites were increased and the other 12 metabolites were decreased. Several of the affected metabolites, including glucose, glutamine, oleate (18:1n9), and lignocerate (24:0), may be involved in regulation of the phosphoinositide 3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway and in the oxidative stress response upon peiminine exposure. Peiminine predominantly modulated the pathways responsible for metabolism of amino acids, carbohydrates, and lipids. Collectively, these results provide new insights into the mechanisms by which peiminine modulates metabolic pathways to inhibit colorectal cancer cell growth, supporting further exploration of peiminine as a potential new strategy for treating colorectal cancer.

Verticine, ebeiedine and suchengbeisine isolated from the bulbs of Fritillaria thunbergii Miq. inhibited the gene expression and production of MUC5AC mucin from human airway epithelial cells.

BACKGROUND: The bulb of Fritillaria thunbergii has been utilised as mucoregulators and expectorants for controlling the airway inflammatory diseases in folk medicine. HYPOTHESIS/PURPOSE: We investigated whether verticine, ebeiedine and suchengbeisine isolated from the bulbs of Fritillaria thunbergii inhibit the gene expression and production of MUC5AC mucin from human airway epithelial cells. STUDY DESIGN: Confluent NCI-H292 cells were pretreated with verticine, ebeiedine or suchengbeisine for 30 min and then stimulated with EGF, PMA or TNF-α for 24h. The MUC5AC mucin gene expression was measured by RT-PCR. Production of MUC5AC mucin protein was measured by ELISA. RESULTS: (1) Verticine, ebeiedine or suchengbeisine inhibited the expression of MUC5AC mucin gene induced by EGF, PMA or TNF-α; (2) The production of MUC5AC mucin protein induced by EGF, PMA or TNF-α were also inhibited by treatment of verticine, ebeiedine or suchengbeisine. CONCLUSION: These results suggest that verticine, ebeiedine and suchengbeisine isolated from the bulbs of Fritillaria thunbergii inhibit the gene expression and production of MUC5AC mucin, by directly acting on airway epithelial cells, and the results are consistent with the traditional use of Fritillaria thunbergii as remedy for diverse inflammatory pulmonary diseases.

Antiallergic effects of peiminine through the regulation of inflammatory mediators in HMC-1 cells.

Peiminine is the main biologically active component derived from Fritillaria ussuriensis. Peiminine was investigated in various pulmonary diseases, but its antiallergic effect and the related mechanism have not been reported yet. The present study aimed to evaluate the effect of peiminine on mast cell-mediated allergic inflammation in HMC-1 cells. The pro-inflammatory cytokine production was measured using ELISA, reverse transcription-polymerase chain reaction and nuclear factor-kappaB (NF-κB), mitogen-activated protein kinases (MAPKs) pathway activation, as determined by Western blot analysis. Peiminine inhibits the production of the pro-inflammatory cytokine, such as interleukin (IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α) and IL-1beta (IL-1ß). It was shown to have inhibitory effects on MAPKs phosphorylation and NF-B expression in human mast cells (HMC)-1 using Western blot. HMC-1 cells were observed for confirmation of histamine release. Passive cutaneous anaphylaxis (PCA) reactions were evaluated using an animal model and peiminine demonstrated inhibitory effects on IgE-dependent anaphylaxis. These results suggest that peiminine has regulatory potential for allergic inflammatory reactions mediated by HMC-1 cells.

The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death.

Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death.

Fusarium redolens 6WBY3, an endophytic fungus isolated from Fritillaria unibracteata var. wabuensis, produces peimisine and imperialine-3ß-D-glucoside.

The major biological active ingredients of Bulbus Fritillariae cirrhosae (BFC) are steroidal alkaloids, such as peimisine, imperialine-3ß-D-glucoside, and peimine. The bulbus of Fritillaria unibracteata var. wabuensis (FUW) was officially recorded in the National Pharmacopoeia of China (2010 edition) as one of the sources of BFC because of its positive therapeutic effects and few side effects. The endophytic fungus strain 6WBY3 was isolated from the fresh bulbus of FUW that had been cultivated for six years. Based on morphological methods and the phylogenetic analysis of internal transcribed spacer (ITS) sequences, this strain was identified as Fusarium redolens. Using color reaction analysis, high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD), and mass spectrometry (MS), it was demonstrated that F. redolens 6WBY3 could produce peimisine and imperialine-3ß-D-glucoside, similar to its host plant. The yields of peimisine and imperialine-3ß-D-glucoside were 16.0 µg·l(-1) and 18.8 µg·l(-1), respectively, in one week of culture. These results indicate that F. redolens 6WBY3 is a promising candidate for the large scale production of peimisine and imperialine-3ß-D-glucoside. In addition, the results from the strain 6WBY3 lay the foundation for further study into the mechanism of Fritillaria alkaloids biosynthesis in fungi.

Simultaneous determination of five constituents in Qinpijiegu capsule by high-performance liquid chromatography coupled with tandem mass spectrometry.

A rapid high-performance liquid chromatography coupled with tandem mass spectrometry method was developed for the simultaneous determination of five constituents in Qinpijiegu capsule (QJC), a classical Tibetan prescription. The separation of five compounds such as aesculin, aesculetin, fraxin, peimine and peiminine was performed on a Purospher STAR LP RP-C18 (250 × 4.6 mm, 5 µm) column with linear gradient elution of acetonitrile-0.3‰ formic acid water in 13 min. Detection was carried out by multiple reaction monitoring mode using electrospray ionization in the positive and negative ion switching mode. The sample was prepared with ultrasound extraction with methanol, which could obtain higher extraction efficiency and shorter extraction time comparing to reflux extraction with alkalized chloroform-methanol. The proposed method was applied to analyze three batches of samples with acceptable linearity (r(2) > 0.9977), precision [relative standard deviation (RSD) < 7.40%], repeatability (RSD < 2.49%), stability [relative error (RE) < 9.15%] and recovery (RSD < 10.76%). This is the first development of a multicomponent quantitation method for the quality control of QJC. Furthermore, the new established method was proven to be highly sensitive and effective in evaluating the quality of QJC.

Pharmacokinetics, tissue distribution and excretion of verticinone from F. hupehensis in rats.

Verticinone, the main active component in F. hupehensis, exhibits potent antitussive and expectorant effects. Here, a LC-MS method was developed and applied to study the pharmacokinetics, tissue distribution and excretion of verticinone in rats, and its plasma protein binding in vitro. A significant gender difference in the pharmacokinetics of verticinone in rats was observed, as its absolute oral bioavailability in male and female rats was 45.8% and 2.74%, respectively. The relative bioavailability of verticinone was significantly lower in female rats as compared to male, following intragastrical (i.g.) and intravenous (i.v.) administration. After successive i.g. administration of verticinone, accumulation was observed in female rats but not in the male ones. The tissue distribution study showed that verticinone had a good tissue penetrability and a high tissue affinity in most studied tissues, except brain. After a 2 mg/kg oral dose, less than 4% of the dose was excreted as unchanged parent compound in male rats, and less than 1% in female rats, which indicated that verticinone was metabolized more extensively in female rats than in male rats.

Peimisine and peiminine production by endophytic fungus Fusarium sp. isolated from Fritillaria unibracteata var. wabensis.

Steroidal alkaloids, as the major biologically active components in Bulbus Fritillariae, possess a variety of toxicological and pharmacological effects on humans. The objective of this work was to determine whether endophytic fungi isolated from fresh bulbs of Fritillaria unibracteata var. wabensis can produce one or more alkaloids like its host plant. Four classical reagents including Wagner's, iodine-potassium iodide, Mayer's and improved Dragendorff's were used for primary screening. Then thin-layer chromatography (TLC) and high performance liquid chromatography-evaporative light scattering detection (HPLC-ELSD) were employed to identify the fermentation products of the selected strains. The results showed that extract from one stain (WBS007) has positive reactions in process of primary screening. A further TLC scan and HPLC-ELSD showed that strain WBS007 had two components with the same TLC relative front (Rf) value and HPLC retention time (RT) as authentic peimisine and peiminine. In addition, strain WBS007 was identified as Fusarium sp. based on phylogenetic analysis of ITS sequences. Thus, strain WBS007 produced the bioactive ingredient peimisine and peiminine, as does its host plant, and could be used for the production of peimisine and peiminine by fermentation.

In vitro and in vivo antitumor activity of Bulbus Fritillariae Cirrhosae and preliminary investigation of its mechanism.

Bulbus Fritillariae Cirrhosae (BFC) is widely used in China both for food and folk medicine because of its powerful biological activities. Firstly, this study was designed to examine the antiproliferative activities of the different fractions from BFC in vitro by MTT assay. The results showed that chloroform extracts (CE) and the purified total alkaloids of BFC (TAF) exhibited stronger antiproliferative activity than the other fractions. We further determined the total alkaloids and 3 main alkaloids monomers content of CE and TAF by UV and HPLC-ELSD methods, respectively. Moreover, we assessed the antitumor activity of TAF in vivo and made preliminary investigation of its antitumor mechanism by histological and immunohistochemical staining technique. These results demonstrate that TAF showed significant antitumor activity and low toxicity in vivo. Meanwhile, TAF significantly inhibited tumor angiogenesis and induced apoptosis by improvement of expression level of caspase-3. These results suggest that alkaloids of BFC could hold a good potential for use as an antitumor drug.

Novel LC-MS/MS method for analyzing imperialine in rat plasma: development, validation, and application to pharmacokinetics.

A sensitive, selective, rapid liquid chromatography-electrospray ionization-tandem mass spectrometric method was developed and validated in rat plasma to quantify imperialine, a major active constituent extracted from Bulbus Fritillariae Cirrhosae. Before analysis, plasma samples were pre-treated using cost-effective protein precipitation in order to extract imperialine and the internal standard, carbamzepine. The two analytes were then separated on a Diamonsil ODS chromatography column using gradient elution with a mobile phase of 0.1% aqueous formic acid and acetonitrile. Mass spectrometry was carried out in multiple reaction monitoring mode using a positive electrospray ionization interface. The calibration curve was linear (r(2)=0.9998) over the concentration range 2-1000ng/mL, while the validated limit of determination (LOD) was 0.5ng/mL. Precision varied from 0.1% to 7.1%, and the accuracy varied within ±2%. The method proved robust to sample freezing and thawing, as well as short- and long-term sample storage. The developed method was successfully applied to the pharmacokinetic study of imperialine in rats. Different amounts of imperialine were administered in single doses orally or through the caudal vena cava, and pharmacokinetic parameters were evaluated. Oral bioavailability with a dose of 1mg/kg was 31.2%; 5mg/kg, 53.6%; and 10mg/kg, 47.4%.

A novel chenodeoxycholic acid-verticinone ester induces apoptosis and cell cycle arrest in HepG2 cells.

In this study, the in vitro antitumor activity of chenodeoxycholic acid-verticinone ester (CDCA-Ver), a novel compound and its underlying mechanisms were evaluated. Results showed that CDCA-Ver significantly inhibited HepG2 cell viability in a both dose- and time-dependent manner, moreover CDCA-Ver induced apoptotic cell death and G(0)/G(1) cell cycle arrest in HepG2 cells. ROS generation, loss of balance of Bax/Bcl-2 ratio, loss of mitochondrial transmembrane potential, activation of caspases and elevation of intracellular free Ca(2+) concentration were involved in the CDCA-Ver induced apoptosis pathway in HepG2 cells. We concluded that CDCA-Ver may be a potential candidate for the therapy of cancer.

Steroidal alkaloids from the bulbs of Fritillaria unibracteata.

Two new steroidal alkaloids peimisine-3-O-ß-D-glucopyranoside (1) and puqiedinone-3-O-ß-D-glucopyranoside (3), together with three known compounds peimisine (2), puqiedinone (4), and puqiedine (5), were isolated and characterized from the bulbs of Fritillaria unibracteata. Their structures were fully elucidated by spectroscopic and chemical methods. Compound 1 showed moderate protection effect on neurotoxicity of PC12 cell lines induced by rotenone.

Development and validation of a liquid chromatography-mass spectrometry method for the determination of verticinone in rat plasma and its application to pharmacokinetic study.

We have developed and validated a sensitive liquid chromatography-electrospray ionization-mass spectrometric (LC-ESI-MS) method for the quantification of verticinone, a major active constituent from Fritillaria hupehensis Hsiao et KC Hsia., in rat plasma. Verticinone and the internal standard (IS), hupehenine, were extracted from plasma samples by a simple liquid-liquid extraction with ethyl acetate after being alkalified by 1M ammonia hydroxide. Chromatographic separation was achieved on a C(18) column using a gradient elution program with methanol and water as the mobile phase. The detection was performed by selected ion monitoring (SIM) mode via positive electrospray ionization (ESI) interface. The lower limit of quantification (LLOQ) was 0.1 ng/mL. The calibration curves were linear (r(2)>0.998) over the concentration range of 0.1-200 ng/mL. Within- and between-run precision was less than 6.5% and accuracy was within +/-10.7%. The validated method was applied to the pharmacokinetic study of verticinone in rats after a single oral administration of 1 mg/kg.