Role of Glutamine-Glutamate/GABA cycle and potential target GLUD2 in alleviation of rheumatoid arthritis by Tripterygium hypoglaucum (levl.) Hutch based on metabolomics and molecular pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Tripterygium hypoglaucum (levl.) Hutch (Celastraceae) (THH), as a traditional Chinese medicine, was clinically exploited to treat rheumatoid arthritis (RA), yet the underlying mechanism for this effect remains largely unclear. AIM OF THE STUDY: This study aimed to examine the beneficial effects of THH extract (THHE) against rheumatoid arthritis and its regulating role in differential metabolic pathways and potential targets. MATERIALS AND METHODS: In the present study, the Lewis rat model with rheumatoid arthritis induced by adjuvant was established and administrated THHE for 14 days. Untargeted/targeted metabolomics analysis were used for determining the changes of differential metabolites, and molecular docking method was further developed to verify predicted targets and investigate the therapeutic mechanism of THH extract on RA. RESULTS: The results showed that THH extract could obviously improve body weight, significantly decrease the joint index and swelling degree of the RA model rats to reduce damage in the joint. Meanwhile, THHE could significantly suppress the releases of IL-1α, IL-1ß and MMP3, but also the expression levels of IL-4 and IL-10 and percentage of Treg cells were significantly improved, a result consistent with inhibitory effects on multiplication of macrophages, inflammatory cell infiltration and fibro genesis in the synovial tissues. Furthermore, 516 differential metabolites were identified by serum metabolic profiles analysis, including vitamin, organic acids and derivatives, lipids and lipid-like molecule, hormone, amino acids and derivatives, and other compounds, which targeted 47 metabolic pathways highly correlated with immunosuppression, such as citrate cycle (TCA cycle), sphingolipid metabolism, urea cycle, arachidonic acid metabolism and amino acid metabolism (such as Glutamine-Glutamate metabolism). Targeted metabolomics was used to verify that L-Glutamate and Glutamine changed significantly after THHE administration for 14 days, and many active ingredients of THHE could be successfully docked with glutamate dehydrogenase 2 (GLUD2). CONCLUSION: This study indicated that the Glutamine-Glutamate/GABA cycle played essential regulation roles in protective effect of THHE on rat RA following adjuvant-induced damage, and GLUD2 as an attractive target also provides great potential for development of therapy agents for rheumatoid arthritis and autoimmune diseases with less unfavorable tolerability profile.

The Exploration of Novel Pharmacophore Characteristics and Multidirectional Elucidation of Structure-Activity Relationship and Mechanism of Sesquiterpene Pyridine Alkaloids from Tripterygium Based on Computational Approaches.

Sesquiterpene pyridine alkaloids are a large group of highly oxygenated sesquiterpenoids, which are characterized by a macrocyclic dilactone skeleton containing 2-(carboxyalkyl) nicotinic acid and dihydro-ß-agarofuran sesquiterpenoid, and are believed to be the active and less toxic components of Tripterygium. In this study, 55 sesquiterpene pyridine alkaloids from Tripterygium were subjected to identification of pharmacophore characteristics and potential targets analysis. Our results revealed that the greatest structural difference of these compounds was in the pyridine ring and the pharmacophore model-5 (Pm-05) was the best model that consisted of three features including hydrogen bond acceptor (HBA), hydrogen bond donor (HBD), and hydrophobic (HY), especially hydrophobic group located in the pyridine ring. It was proposed that 2-(carboxyalkyl) nicotinic acid part possessing a pyridine ring system was not only a pharmacologically active center but also a core of structural diversity of alkaloids from Tripterygium wilfordii. Furthermore, sesquiterpene pyridine alkaloids from Tripterygium were predicted to target multiple proteins and pathways and possibly played essential roles in the cure of Alzheimer's disease, breast cancer, Chagas disease, and nonalcoholic fatty liver disease (NAFLD). They also had other pharmacological effects, depending on the binding interactions between pyridine rings of these compounds and active cavities of the target genes platelet-activating factor receptor (PTAFR), cannabinoid receptor 1 (CNR1), cannabinoid receptor 1 (CNR2), squalene synthase (FDFT1), and heat shock protein HSP 90-alpha (HSP90AA1). Taken together, the results of this present study indicated that sesquiterpene pyridine alkaloids from Tripterygium are promising candidates that exhibit potential for development as medicine sources and need to be promoted.

A metabolomics study on the immunosuppressive effect of Tripterygium hypoglaucum (Levl.) Hutch in mice: The discovery of pathway differences in serum metabolites.

Tripterygium hypoglaucum (Levl.) Hutch (THH), a typical traditional Chinese medicine, is widely used in clinical practice for the treatment of rheumatoid arthritis, systemic lupus erythematous, and other connective tissue and autoimmune diseases. However, most related researches focused on the pharmacological effects of THH, while less attention has been paid to the immunosuppressive mechanism. The present study aims to determine the metabolic profiles, based on UPLC-Q-TOF-MS, identify differential metabolites, and find related metabolic pathways among the sensitization red blood cell (SRBC) model mice, THH treated mice, and cyclophosphamide treated group. Totally, 24 and 19 changed metabolites were found in the THH and cyclophosphamide treated groups respectively. Among them, we found that urocanate metabolic pathway change could be considered as the most relevant pathway associated with immunosuppression. This is the first study that comprehensively assessed the differences in metabolome between the model and THH treated groups. The results provide insights into the difference between the immunosuppressive mechanisms of THH and cyclophosphamide and also demonstrated that metabolomics is a valuable tool for investigating the efficacy of drugs in the treatment of diseases and the associated mechanism involved.

[Studies on difference of chemical compositions in plant species of Tripterygium genus].

We studied the content of chemical compositions and correlation among species of Tripterygium genus by principal component analysis(PCA) and variance analysis(ANOVA), and we also studied the difference among the 3 species.Using [BMIm]PF6 ionic liquid-based ultrasonic-assisted extraction, we determined the contents of 11 compounds including wilforgine, wilforzine, triptophenolide, wilforine, triptoquinone A, triptolide, tripterin, egallocatechin, epigallocatechin, catechin, and epicatechin in 28 batches of the Tripterygium species by HPLC and PCA. Partial least squares analysis (PLS) and ANOVA were also performed to verify the results.The analysis results of PCA and PLS showed that three species of Tripterygium genus were clustered into three regions respectively, and triptoquinone A was the important factor which affected the aggregation of these three species.There was a significant difference among the contents of 11 chemical components in the three species(P<0.000 1).These results indicated that there was a certain correlation between the chemical compositions and the classification of the species, and the difference of the chemical compositions among the three species was obvious. In this work, the content determination method is rapid and accurate, and the analysis method is simple and convenient, which provides a reference for the classification, the efficacy and the toxicity of the species.

[Evaluation of genetic diversity and population structure of genus Tripterygium based on SSR markers].

The genus Tripterygium is an immune suppressor in the Chinese traditional medicines. Due to the habitat destruction and anthropogenic over-exploitation, the wild genus Tripterygium plants have decreased dramatically in recent years or even been endangered. It is critical to evaluate and protect genus Tripterygium wild resource. In this research, simple sequence repeat (SSR) molecular markers were applied to the investigation of the genetic diversity and genetic structure of 28 populations for genus Tripterygium (396 samples from 9 provinces in China). We found a high level of genetic diversity (percentage of polymorphic loci PPL = 77.29%, Shannon's information index I = 0.639 4; Nei's expected heterozygosity H = 0.359 9) and high genetic differentiation among the populations (gene flow N_m = 0.228 7). Based on Nei's genetic distance, the phylogenic tree of populations was constructed and 28 populations were divided into 6 clusters according to STRUCTURE clustering analysis. T. hypoglaucumwas was mainly divided into 3 clusters, including Sichuan, Yunnan and Guizhou- Chongqing. T. regelii was separated to cluster 4, while T. wilfordii was divided into two clusters: the transition type LQ and NY were divided into cluster 5, and the others were in cluster 6. These results provide a theory basis for the conservation of wild resource, research of genetic polymorphism and molecular marker for assisted breeding of genus Tripterygium.

Identification of Species in Tripterygium (Celastraceae) Based on DNA Barcoding.

Species of genus Tripterygium (Celastraceae) have attracted much attention owing to their excellent effect on treating autoimmune and inflammatory diseases. However, due to high market demand causing overexploitation, natural populations of genus Tripterygium have rapidly declined. Tripterygium medicinal materials are mainly collected from the wild, making the quality of medicinal materials unstable. Additionally, identification of herbal materials from Tripterygium species and their adulterants is difficult based on morphological characters. Therefore, an accurate, convenient, and stability method is urgently needed. In this wok, we developed a DNA barcoding technique to distinguish T. wilfordii HOOK. f., T. hypoglaucum (LÉVL.) HUTCH, and T. regelii SPRAGUE et TAKEDA and their adulterants based on four uniform and standard DNA regions (internal transcribed spacer 2 (ITS2), matK, rbcL, and psbA-trnH). DNA was extracted from 26 locations of fresh leaves. Phylogenetic tree was constructed with Neighbor-Joining (NJ) method, while barcoding gap was analyzed to assess identification efficiency. Compared with the other DNA barcodes applied individually or in combination, ITS2+psbA-trnH was demonstrated as the optimal barcode. T. hypoglaucum and T. wilfordii can be considered as conspecific, while T. regelii was recognized as a separate species. Furthermore, identification of commercial Tripterygium samples was conducted using BLAST against GenBank and Species Identification System for Traditional Chinese Medicine. Our results indicated that DNA barcoding is a convenient, effective, and stability method to identify and distinguish Tripterygium and its adulterants, and could be applied as the quality control for Tripterygium medicinal preparations and monitoring of the medicinal herb trade in markets.

Halofuginone and artemisinin synergistically arrest cancer cells at the G1/G0 phase by upregulating p21Cip1 and p27Kip1.

Combinational drug therapy is one of the most promising strategies in modern anticancer research. Traditional Chinese medicine (TCM) formulas represent a wealth of complex combinations proven successful over centuries of clinical application. One such formula used to treat a variety of diseases, including cancer, contains two herbs, whose main active components are Halofuginone (HF) and Artemisinin (ATS). Here we studied the anticancer synergism of HF and ATS in various cancer cell lines and in a xenograft nude mice model. We found that the HF-ATS combination arrested more cells at the G1/G0 phase than either one alone, with the concomitant increased levels of CDK2 inhibitors, p21Cip1 and p27Kip1. By knocking down p21Cip1 and p27Kip1 separately or simultaneously in HCT116 cells and MCF-7 cells, we found that p21Cip1 was required for HF induced G1/G0 arrest, whereas p21Cip1 and p27Kip1 were both required for ATS or HF-ATS combination-mediated cell cycle arrest. Moreover, HF-ATS combination synergistically inhibited tumor growth in xenograft nude mice, and this was associated with the increased levels of p21Cip1 and p27Kip1. Collectively, these data indicate that the upregulation of p21Cip1 and p27Kip1 contributes to the synergistic anticancer effect of the HF-ATS combination.

[Species differences in caffeine metabolism in liver microsomes of rats and mice].

Caffeine and its metabolic products play an important role in clinical applications. An ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS/MS) method was applied to systemically study the caffeine metabolism in liver microsomes of rats and mice, and comprehensively evaluate caffeine metabolites in vitro and metabolism differences between species. The caffeine metabolites and metabolism differences between species in liver microsomes of rats and mice were analyzed by UPLC-Q-TOF-MS/MS high resolution mass spectrometry system and metabolitepolite software. The results showed that in addition to the demethylated and oxidized products in previous analysis, methylated, double oxidized, dehydrated and decarbonylated metabolites were also found in caffeine metabolism in liver microsomes of rats and mice, with significant difference in metabolism in vitro between rats and mice. The demethylated metabolite M2(C7H8N4O2) and decarbonylated metabolite M6(C7H10N4) in metabolism in vitro of mice were not found in rats, and the in vitro metabolite M7(C8H12N4O5) in rats were not found in mice. There was significant species difference in caffeine metabolism in vitro between rats and mice, providing important reference value for the further metabolism study and safety evaluation of caffeine.

[Progress on molecular biology of Isaria farinosa, pathogen of host of Ophiocordyceps sinensis during the artificial culture].

Isaria farinosa is the pathogen of the host of Ophiocordyceps sinensis. The present research has analyzed the progress on the molecular biology according to the bibliometrics, the sequences (including the gene sequences) of I. farinosa in the NCBI. The results indicated that different country had published different number of the papers, and had landed different kinds and different number of the sequences (including the gene sequences). China had published the most number of the papers, and had landed the most number of the sequences (including the gene sequences). America had landed the most numbers of the function genes. The main content about the pathogen study was focus on the biological controlling. The main content about the molecular study concentrated on the phylogenies classification. In recent years some protease genes and chitinase genes had been researched. With the increase of the effect on the healthy of O. sinensis, and the whole sequence and more and more pharmacological activities of I. farinosa being made known to the public, the study on the molecular biology of the I. farinosa would be deeper and wider.

[Chemical constituents from Mylabris phalerata and their cytotoxic activity in vitro].

Ten compounds were isolated from Mylabris phalerata by using preparative HPLC and column chromatography over MCI gel. On the basis of physical-chemical properties, NMR and MS data analysis, the compounds were identified as 5'-[(1 R,2 R,3 S,6R)-1-hydroxymethyl-2-methyl-3,6-epoxycyclohexane-1,2-dicarboximide]- ethyl-2'-methyl-2'-butenoate (1),cantharidin (2), cyclo-(L-Pro-L-Ala) (3), cyclo-(R-Pro-R-Leu) (4), cyclo-(S-Pro-R-Leu) (5), cyclo-(D-Pro-L-Tyr) (6), indole-3-aldehyde (7), 3-indoleacetic acid (8), valerolactam (9), and 4-hydroxyphthalid (10).Compound 1 was a new compound, and compounds 2-10 were obtained from this genus for the first time. Compounds 1-9 were subjected to cytotoxic activity on HCT-116, HepG2, BGC-823, NCI-H1650, A2780 cell lines, and only compound 2 showed inhibitory effect on all cancer cell lines.

Halofuginone inhibits colorectal cancer growth through suppression of Akt/mTORC1 signaling and glucose metabolism.

The Akt/mTORC1 pathway plays a central role in the activation of Warburg effect in cancer. Here, we present for the first time that halofuginone (HF) treatment inhibits colorectal cancer (CRC) growth both in vitro and in vivo through regulation of Akt/mTORC1 signaling pathway. Halofuginone treatment of human CRC cells inhibited cell proliferation, induced the generation of reactive oxygen species and apoptosis. As expected, reduced level of NADPH was also observed, at least in part due to inactivation of glucose-6-phosphate dehydrogenase in pentose phosphate pathway upon HF treatment. Given these findings, we further investigated metabolic regulation of HF through Akt/mTORC1-mediated aerobic glycolysis and found that HF downregulated Akt/mTORC1 signaling pathway. Moreover, metabolomics delineated the slower rates in both glycolytic flux and glucose-derived tricarboxylic acid cycle flux. Meanwhile, both glucose transporter GLUT1 and hexokinase-2 in glycolysis were suppressed in CRC cells upon HF treatment, to support our notion that HF regulates Akt/mTORC1 signaling pathway to dampen glucose uptake and glycolysis in CRC cells. Furthermore, HF retarded tumor growth in nude mice inoculated with HCT116 cells, showing the anticancer activity of HF through metabolic regulation of Akt/mTORC1 in CRC.

Wilfordonols A-D: four new norsesquiterpenes from the leaves of Tripterygium wilfordii.

Four new norsesquiterpenes wilfordonols A-D (1-4), along with three known compounds, sarmentol B (5), boscialin (6), and (+)-loliolide (7), were isolated from the leaves of Tripterygium wilfordii Hook.f.. The structures of the new compounds were elucidated on the basis of their spectroscopic analysis, and the absolute configuration of the compounds was confirmed by CD and modified Mosher's method. At a concentration of 10 µM, compounds 4, 6, and 7 inhibited signal transducer and activator of transcription 1 translocation by 34.27 ± 1.02%, 48.93 ± 1.76%, and 70.31 ± 2.20%, respectively.

Folding fan mode counter-current chromatography offers fast blind screening for drug discovery. Case study: finding anti-enterovirus 71 agents from Anemarrhena asphodeloides.

A new application of counter-current chromatography (CCC) in drug discovery, called folding fan mode (FFM), is designed to eliminate the extensive and time-consuming calculation of the partition coefficients of some preset compounds in conventional CCC separation. Careful reading of reports in the literature reveals that, when two-phase solvent systems are listed in a polarity-increasing sequence, the isolates also show a similar trend in polarity. The relationship between the two-phase solvent system and the isolates is like that between the folds and the picture of a folding fan. We can directly select a two-phase solvent system to separate fractions having similar polarity, just as opening a fan reveals a picture. The solvent ratio of two-phase solvent systems can be adjusted according to the polarity and weight ratio of active fractions rather than the partition coefficients. Without preset compounds, FFM-CCC not only requires no measurement of partition coefficients, but also achieves true blind screening. This paper reports the method's first success in drug discovery: six anti-EV71 saponins were found from the mixture (9.13 g) of ethanol extract and water extract of Anemarrhena asphodeloides after a total of four CCC separations, using hexan/ethyl acetate/methanol/butanol/water as the model solvent system. Among these saponins, timosaponin B-II displayed a comparable IC50 (4.3 ± 2.1 µM) and a 40-fold higher selective index (SI=92.9) than the positive control (IC50=361.7 ± 104.6 µM, SI=2.4), ribavirin. The structure-activity relationship (SAR) of these compounds was also studied.

Prenylated benzoylphloroglucinols and xanthones from the leaves of Garcinia oblongifolia with antienteroviral activity.

An acetone extract of the leaves of Garcinia oblongifolia showed antiviral activity against enterovirus 71 (EV71) using a cytopathic effect inhibition assay. Bioassay-guided fractionation yielded 12 new prenylated benzoylphloroglucinols, oblongifolins J-U (1-12), and five known compounds. The structures of 1-12 were elucidated by spectroscopic analysis including 1D- and 2D-NMR and mass spectrometry methods. The absolute configurations were determined by a combination of a Mosher ester procedure carried out in NMR tubes and ECD calculations. Compared to ribavirin (IC50 253.1 µM), compounds 1, 4, and 13 exhibited significant anti-EV71 activity in vitro, with IC50 values of 31.1, 16.1, and 12.2 µM, respectively. In addition, the selectivity indices of these compounds were 1.5, 2.4, and 3.0 in African green monkey kidney (Vero) cells, respectively.

Application of microscopy in authentication of valuable Chinese medicine I--Cordyceps sinensis, its counterfeits, and related products.

Light and polarized microscope was applied to authenticate 32 Cordyceps and 6 artificial counterfeits and 8 fermented Cordyceps as well as 7 Cordyceps capsules available in Hong Kong markets. Results showed that transverse sections of stroma and powder of larvae can be used to differentiate C. sinensis from its counterfeits. The fermented Cordyceps are in powder form. Among the eight fermented Cordyceps collected, half of them were pure; three were a mixture of fermented Cordyceps and soya beans; one was a mixture of unknown plant tissues and soya beans. For the seven Cordyceps capsules, the powders of five samples were a mixture of fermented Cordyceps and soya beans; the powders of other two were a mixture of C. sinensis stroma powder and fermented Cordyceps. The study indicated that the microscopy is an unambiguous method that requests fewer sample for the authentication of valuable Chinese medicine-C. sinensis and its related products.

Anti-oxidative and TNF-α suppressive activities of puerarin derivative (4AC) in RAW264.7 cells and collagen-induced arthritic rats.

Puerarin is a major active ingredient extracted from the root of P. lobata, a traditional Chinese herb, and possesses anti-oxidative and anti-inflammatory activities. However, the low oral bioavailability of puerarin limits its further application. Therefore, we synthesized tetraacetyl puerarin (4AC) through acetylation to improve its liposolubility and bioavailability. In the present investigations, we tested the anti-oxidative and TNF-α suppressive activity of 4AC in lipopolysaccharide (LPS)-induced RAW264.7 macrophages and bovine type II collagen-induced arthritic (CIA) rats. The results showed that 4AC retained the bioactivity of puerarin. And 4AC significantly increased the activity of SOD and reduced the level of MDA both in vitro and in vivo. It also improved the level of GSH-PX and the total antioxidant capacity in vivo. Furthermore, it dramatically decreased TNF-α level in the cultured supernatant of RAW264.7 cells treated with LPS and in the serum of CIA rats. These initial results indicated that 4AC had a potential therapeutic effect on CIA rats through an anti-oxidative and TNF-α suppressive activity. In addition, the molecular mechanism of anti-oxidation of 4AC was explored by testing the MAPKs/NF-κB signaling pathway. The results showed that 4AC significantly inhibited NF-κB expression and down-regulated the levels of p-ERK and p-JNK in LPS-activated RAW264.7 cells. These results indicated that 4AC had bioactive anti-oxidative effects and suggest the potential value of 4AC for the treatment of rheumatoid arthritis.

A new triterpene saponin from Androsace integra.

A new triterpene saponin, androsacin (1), along with two known compounds, ardisiacrispin A (2) and saxifragifolin A (3), were isolated from the whole plants of Androsace integra. The chemical structure of the new compound was elucidated as 3ß-O-{ß-D-glucopyranosyl-(1→4)-O-ß-D-xylopyranosyl-(1→2)-O-ß-D-glucopyranosyl-(1→4)-[O-ß-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl}-16α-hydroxy-13ß,28-epoxy-olean-30-al on the basis of spectral evidence. Ardisiacrispin A (2) was cytotoxic toward HepG2 cancer cell with the GI(50) value of 1.56µM.

[Proportion of Coptidis rhizoma and Evodiae fructus in the compound preparation: its effect in inducing apoptosis of SGC-7901 cells].

OBJECTIVE: To investigate the effect of water extracts of Coptidis Rhizoma and Evodiae Fructus (CREF) on the proliferation and apoptosis of human gastric carcinoma cells (SGC-7901) and determine the optimal proportion of Coptidis rhizoma to Evodiae fructus. METHODS: The growth inhibition of SGC-7901 cells treated with the water extracts of CREF of varying proportions was tested with MTT assay. The cell apoptotic rate and mitochondrial membrane potential were analyzed with flow cytometry. RESULTS: The water extract of CREF with Coptidis Rhizoma: Evodiae Fructus proportions at 1:6, 2:5, 3:4, 4:3, 5:2, and 6:1 all significantly inhibited the growth of SGC-7901 cells after a 24-h or 48-h treatment (P<0.05). The growth inhibition and cell death ratio both exhibited a dose-dependent pattern of Coptidis Rhizoma. Flow cytometry analysis showed that, after treatment of the cells with CREF at the proportions of 1:6, 2:5, 3:4, 4:3, 5:2, and 6:1, the apoptotic rate were (8.50 ∓ 1.59)%, (9.90 ∓ 1.01)%, (17.15∓1.68)%, (21.55 ∓ 1.97)%, (34.10 ∓ 1.06)% and (34.40 ∓ 1.02)%, respectively, all significantly higher than that in the control group [(1.69 ∓ 1.91)%, P<0.05]. JC-1 Kit staining showed that mitochondrial membrane potential of SGC-7901 cells was decreased and the ratio of green to red fluorescence increased significantly after incubation with CREF. CONCLUSION: CREF can inhibit the growth and induce apoptosis of SGC-7901 cells, and the strongest effect is achieved at the optimal proportion of Coptidis Rhizoma and Evodiae Fructus at 6:1.

Two new sesquiterpenes from Acorus calamus.

A novel cadinane sesquiterpene with a propan-2-ylidene, named (1R,4R,6S,10R)-1-hydroxy-7(11)-cadinen-5,8-dione (1), and a new sesquiterpene, named (2R,6R,7S,9S)-1(10),4-cadinadiene-2,9-diol (2), were isolated from the ethanol extract of the rhizome of Acorus calamus L. Their structures were elucidated on the basis of spectroscopic data including NMR spectroscopy and X-ray crystallography. The absolute configurations of compounds 1 and 2 were confirmed by comparison of their experimental optical rotations with those obtained from theoretical calculations at the B3LYP/6-311+G (d) level of theory.

Simultaneous determination of nine nucleosides and nucleobases in different Fritillaria species by HPLC-diode array detector.

A sensitive and reliable HPLC-diode-array detector method was developed for the first time to simultaneously determine nine nucleosides and nucleobases including uracil, cytidine, guanine, uridine, thymine, inosine, guanosine, thymidine and adenosine in 13 different Fritillaria species. The analysis was performed on a BaseLine C18 column with a gradient of acetonitrile in water at a flow rate of 0.8 mL/min. The diode-array detector wavelength was set at 260 nm for the UV detection of nucleosides and nucleobases. Satisfactory separation of these compounds was obtained in less than 40 min. The optimized method provided good linear relation (r(2)>0.9995 for all the investigated analytes), satisfactory precision (RSD <1.51%) and good recovery (from 97.64 to 101.16%). The established method was successfully applied to simultaneous determination of nine nucleosides and nucleobases in 61 batches of samples from 13 Fritillaria species collected from different habitats in China, which could be helpful to control the quality of Fritillaria bulbs.