Targeted chemical profiling for p-HAP glycosides by using molecular networking and comparative analysis of their contents between Artemisia japonica and Artemisia capillaris.

A total of 65 phenolic acid compounds were annotated or identified by UHPLC-MS/MS method, among them, 17 p-HAP (p-hydroxyacetophenone) glycosides were firstly targeted profiled based on molecular networking. Their characteristic product ions of MS/MS spectra were found and examined on the guideline of targeted isolation. As a result, a new p-HAP glycoside was thus obtained and determined as 2'-O-caffeoyl-p-HAP-4-O-ß-D-glucopyranoside (33) based on 1D and 2D NMR data. Besides, multicomponents quantitative analysis indicated the distinct regional variability in chemicals distribution of A. japonica, and meanwhile, the contents of p-HAP glycosides from A. japonica were higher than those in A. capillaris as a whole, which further suggested the potential medicinal value of A. japonica.

Anti-inflammatory activity effect of 2-substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole on TPA-induced skin inflammation in mice.

2-Substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole, a key structural moiety exiting in many bioactive molecules, has been shown to have excellent selective activity on COX-2. In the present study, the anti-inflammatory activity and the underlying molecular mechanism of 2-substituted-1,4,5,6-tetrahydrocyclopenta[b]pyrrole on skin inflammation were assessed by 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mice. Most of the compounds showed anti-inflammatory activity on TPA-induced skin inflammation. The anti-inflammatory activity of compound 4 showed higher anti-inflammatory activity than celecoxib (3.2-fold). Compound 4 pretreatment resulted in markedly suppression of TPA-induced IL-1ß, IL-6, TNF-α, and COX-2, respectively. Furthermore, the mechanical study indicated that the anti-inflammatory activity of compound 4 was associated with its ability to inhibit activation of factor kappa-κB (NF-κB) by blocking IκB kinase (IKK) activities. Accordingly, compound 4 could be used as a potential anti-inflammatory agent for skin inflammation.

Synthesis and evaluation of curcumin-related compounds containing benzyl piperidone for their effects on human cancer cells.

Eleven curcumin-related compounds containing a benzyl piperidone moiety were synthesized and evaluated for their effects on cultured prostate cancer PC-3 cells, pancreas cancer BxPC-3 cells, colon cancer HT-29 cells and lung cancer H1299 cells. Inhibitory effects of these compounds on the growth of PC-3, BxPC-3, HT-29 and H1299 cells were determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue exclusion assay. Compounds benzyl piperidone 2 (P2), P4, P7, 4-bromo-2-fluoro-benzyl piperidone 2 (PFBr2), PFBr3 and PFBr4 (see syntheses and structures in Figs. 1, 2) exhibited potent inhibitory effects on the growth of cultured PC-3, BxPC-3, HT-29 and H1299 cells. The IC50 for these compounds was lower than 2 µM in all four cell lines. PFBr4 was 41-, 36-, 40- and 46-fold more active than curcumin for inhibiting the growth of PC-3, BxPC-3, HT-29 and H1299 cells, respectively. The benzyl piperidone-containing compounds studied also stimulated apoptosis in PC-3 cells. Mechanistic studies indicate that the effects of both curcumin and PFBr4 on PC-3 cells were associated with a decrease in phospho-Akt and phospho-extracellular signal-regulated kinase (Erk)1/2. The present study indicates that P2, P4, P7, PFBr2, PFBr3 and PFBr4 may have useful effects on human cancer cells.

[Enzymatic extraction and antibacterial activity of aucubin from Eucommia ulmoides leaves].

OBJECTIVE: To investigate the technology of Aucubin in Eucommia ulmoides leaves extracted by enzymatic method and its antibacterial activity. METHODS: Aucubin in Eucommia ulmoides leaves was extracted by cellulase method. The extraction technology was optimized using the content of Aucubin as index. The antibacterial activity of Aucubin was determined. RESULTS: The results showed that the optimum technology was as follows; The solid-liquid ratio was 1:12, extracted for 50 min by 0.4% enzyme at 50 degrees C in pH 6.0. The extraction rate of Aucubin was as high as 17.892 mg/g. The Aucubin extracted could obviously inhibit the growth of Escherichia coli and Staphylococcus aureus, the MIC of Aucubin against Staphylococcus aureus and Escherichia coli were 4.832 mg/mL and 9.664 mg/mL respectively. However, Aucubin presented weak inhibitory effect on Streptococcus pneumonia and MG-hemolytic streptococcus, the MIC of Aucubin against them were all 28.946 mg/mL. CONCLUSION: The extraction technology obtained in this experiment is reasonable and feasible with high extraction rate, and the Aucubin has some antibacterial activity.

Intestinal Models for Personalized Medicine: from Conventional Models to Microfluidic Primary Intestine-on-a-chip.

Intestinal dysfunction is frequently driven by abnormalities of specific genes, microbiota, or microenvironmental factors, which usually differ across individuals, as do intestinal physiology and pathology. Therefore, it's necessary to develop personalized therapeutic strategies, which are currently limited by the lack of a simulated intestine model. The mature human intestinal mucosa is covered by a single layer of columnar epithelial cells that are derived from intestinal stem cells (ISCs). The complexity of the organ dramatically increases the difficulty of faithfully mimicking in vivo microenvironments. However, a simulated intestine model will serve as an indispensable foundation for personalized drug screening. In this article, we review the advantages and disadvantages of conventional 2-dimensional models, intestinal organoid models, and current microfluidic intestine-on-a-chip (IOAC) models. The main technological strategies are summarized, and an advanced microfluidic primary IOAC model is proposed for personalized intestinal medicine. In this model, primary ISCs and the microbiome are isolated from individuals and co-cultured in a multi-channel microfluidic chip to establish a microengineered intestine device. The device can faithfully simulate in vivo fluidic flow, peristalsis-like motions, host-microbe crosstalk, and multi-cell type interactions. Moreover, the ISCs can be genetically edited before seeding, and monitoring sensors and post-analysis abilities can also be incorporated into the device to achieve high-throughput and rapid pharmaceutical studies. We also discuss the potential future applications and challenges of the microfluidic platform. The development of cell biology, biomaterials, and tissue engineering will drive the advancement of the simulated intestine, making a significant contribution to personalized medicine in the future. Graphical abstract The intestine is a primary organ for digestion, absorption, and metabolism, as well as a major site for the host-commensal microbiota interaction and mucosal immunity. The complexity of the organ dramatically increases the difficulty of faithfully mimicking in vivo microenvironments, though physiological 3-dimensional of the native small intestinal epithelial tissue has been well documented. An intestinal stem cells-based microfluidic intestine-on-a-chip model that faithfully simulate in vivo fluidic flow, peristalsis-like motions, host-microbe crosstalk, and multi-cell type interactions will make a significant contribution.

[Preparation and characterization of quantum dots with polyacrylic acid modified method in water-soluble core-shell structure].

Cd-Zn quantum dots (QDs) modified with thiourea was firstly prepared asthe cores, then the cores were coated with polyacrylic acid with PVP K-30 as the stabilizer in water-soluble reaction system. The water-soluble fluorescence QDs were the same size and stable. The water-soluble QDs were characterized by fluorescence emission spectra, infrared spectra (IR), and transmission electron microscopy (TEM). The effects of the nuclear QDs with different concentration under polyacrylic acid solution on the optical properties of QDs were also studied. The results showed that the nanoparticles of QDs modified with polyacrylic acid have more uniform particle distribution, and the main peak was blueshifted from 548 to 448 nm. C==O and C--O stretching vibration absorption peaks were 2092.8 and 1384.3 cm(-1) in infrared spectra, amide bond of C==O stretching vibration absorption peaks were 1644.5 cm(-1). The best concentration of nuclear QDs under polyacrylic acid solution was 2.67 mg x mL(-1). QDs prepared by this simple method have good stability and strong fluorescence intensity. The approach introduced in this paper will lay a solid foundation for biological markers and applications of QDs in the future.

[Study on the extraction technology of total flavonoids from Selaginella uncinata].

OBJECTIVE: To optimize the extraction technology of total flavonoids and improve the extraction ratio of total flavonoids from Selaginella uncinata. METHODS: Using the content of flavonoids as the index determined by UV spectrophotometry, chose single factor experiment to investigate the total flavonoids content influenced by four factor ethanol concentration, extracting time, extraction times and solvent content on the influence of extraction efficiency. And on the basis, L9 (3(4)) orthogonal experiment was carried out. RESULTS: The ethanol reflux extraction conditions were as tollows: extracted in 60% ethanol (solid-liquid rate at 1: 35) for 3 times and heated for 1.5 hours per time. CONCLUSION: The optimum extraction by the orthogonal design method is rational and feasible, provides experimental basis for improving the content of the total flavonoids and further scientific theoretical basis for industrial production of the total flavonoids from Selaginella uncinata.

Preparation of Anti-Aristolochic Acid I Monoclonal Antibody and Development of Chemiluminescent Immunoassay and Carbon Dot-Based Fluoroimmunoassay for Sensitive Detection of Aristolochic Acid I.

Aristolochic acid (AA) toxicity has been shown in humans regarding carcinogenesis, nephrotoxicity, and mutagenicity. Monitoring the AA content in drug homologous and healthy foods is necessary for the health of humans. In this study, a monoclonal antibody (mAb) with high sensitivity for aristolochic acid I (AA-I) was prepared. Based on the obtained mAb, a chemiluminescent immunoassay (CLEIA) against AA-I was developed, which showed the 50% decrease in the RLUmax (IC50) value of 1.8 ng/mL and the limit of detection (LOD) of 0.4 ng/mL. Carbon dots with red emission at 620 nm, namely rCDs, were synthesized and employed in conventional indirect competitive enzyme-linked immunosorbent assay (icELISA) to improve the assay sensitivity of a fluoroimmunoassay (FIA). Oxidized 3,3'',5,5''-tetramethylbenzidine dihydrochloride (oxTMB) can quench the emission of the rCDs through the inner-filter effect; therefore, the fluorescence intensity of rCDs can be regulated by the concentration of mAb. As a result, the assay sensitivity of FIA was improved by five-fold compared to CLEIA. A good relationship between the results of the proposed assays and the standard ultra-high performance liquid chromatography-triple quadrupole mass spectrometer (UPLC-QQQ-MS/MS) of real samples indicated good accuracy and practicability of CLEIA and FIA.

[Studies on the lowering blood sugar substances from agrimony (II)].

OBJECTIVE: To isolate and identify the chemical constituents from the active section with lowering blood sugar of agrimony. METHODS: The compounds were separated by repeated silica gel, polyamide and HPLC chromatographies. The structures of compounds isolated were identified by analysis of their spectral data and chemical peoperties. RESULTS: Nine compounds were isolated from the active section with lowering blood sugar of agrimony and their structures were identified as oleanoic acid (1), ursolic acid (2), 19alpha-hydroxy ursolic acid (3), tormentic acid (4), apigenin (5) , luteolin (6), kaempferol (7), 3,3'-di-O-methyl ellagic acid (8), kaempferol-7-O-alpha-L-rhamnoside (9). CONCLUSION: Compounds 1-3, 8, 9 are isolated from Agrimony for the first time.

Preparation of artificial antigen and egg yolk-derived immunoglobulin (IgY) of citrinin for enzyme-linked immunosorbent assay.

OBJECTIVE: To prepare artificial antigens and anti-citrinin egg yolk-derived immunoglobulin (IgY) to build an enzyme-linked immunosorbent assay (ELISA) for citrinin (CTN). METHODS: CTN was conjugated with bovine serum albumin (BSA), ovalbumin (OVA) with formaldehyde condensation method to prepare artificial antigens and identified by ultraviolet (UV) spectrometry and Infrared (IR) spectrometry. Artificial antigens for CTN and anti-CTN IgY were purified with polyethylene glycol two-step precipitation method and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). ELISA with IgY was established. Cross-reactivity of IgY with various structural similarities to CTN and possible co-occurrence with CTN in agricultural commodities were studied. RESULTS: UV and IR absorption spectra suggested that CTN was correlated with the carrier protein of BSA or OVA. SDS-PAGE patterns showed that the anti-CTN IgY was almost pure with a molecular weight of approximate 100 KD. The indirect competitive ELISA showed that the detection limit of CTN was 10 ng x mL(-1), with a good linearity ranging 20-640 ng x mL(-1). CONCLUSION: Artificial antigens of CTN can be successfully synthesized. The established ELISA can be used to determine CTN- contaminated samples.

2-Amino-6-nitro-1H-benzoimidazol-3-ium chloride.

In the cation of the title compound, C(7)H(7)N(4)O(2) (+)·Cl(-), the benzimidazole ring system is planar with a maximum deviation of -0.019 (3) Å. In the crystal structure, C-H⋯Cl, N-H⋯Cl, and N-H⋯Cl inter-actions link the mol-ecules into a two-dimensional network. π-π contacts between benzimidazole rings [centroid-centroid distances = 3.928 (1) and 3.587 (1) Å] may further stabilize the structure.

[The determination of three effective constituents in wild and cultivated Gastrodia elata from Bomi].

OBJECTIVE: To determine the contents of gastrodin, amino acids and total flavonoids in wild and cultivated Gastrodia elata, in order to choose the best method for its cultivation. The Gastrodia elata was picked at Guxiang town Bomi county Linzhi Region in Tibet. METHODS: HPLC was used to determine the content of gastrodin. The autoanalyzer was used to determine the content of amino acid. The ultraviolet spectrophotometer was adopted to measure the content of total flavonoids. RESULTS: The Gastrodin in wild Gastrodia elata was the highest. The contents of amino acids and total flavonoids in organic cultivated Gastrodia elata were higher than those in common cultivated and wild Gastrodia elata. CONCLUSION: The organic cultivated Gastrodia elata has better quality.

Synthesis and biological evaluation of novel oleanolic acid analogues as potential α-glucosidase inhibitors.

Considerable interest has been attracted in oleanolic acid and its analogues because of their hypoglycemic activity. In this study, a series of novel oleanolic acid analogues against α-glucosidase were synthesized and their biological activities were evaluated in vitro and in vivo. In vitro α-glucosidase inhibition activity results indicated that most of the designed analogues exhibited prominent inhibition activities, especially compounds 10, 15, 16 and 26 which with the IC50 values of 0.33 ±â€¯0.01, 0.98 ±â€¯0.06, 0.69 ±â€¯0.01 and 0.72 ±â€¯0.21 µM, respectively. Enzyme kinetic studies on the most potent compounds reveled that derivatives 10, 15, 16 and 26 were noncompetitive inhibitors. Moreover, the docking studies were carried out to prove that the four compounds could interact with the hydrophobic region of the active pocket and form hydrogen bonds to enhance the binding affinity of them with the α-glucosidase. Cytotoxicity evaluation assay demonstrated a high level of safety profile of the active compounds (10, 15, 16 and 26) against normal 3T3 cell line. Furthermore, the in vivo actual pharmacological potential studies on derivatives 10, 15, 16 and 26 showed that the hypoglycemic effects of them were comparable to that of positive control, acarbose.

[Study on spectral and immune identification of artificial antigen of bisphenol A].

Bisphenol A(BPA) is able to mimic the effects of endogenous hormones and it influences the central nervous system in human being. In recent years, BPA has largely arisen because it is released into our environment from many kinds of the polycarbonate plastics and epoxy resins of food cans. Because trace residual amount of BPA might be harmful to human being, many instrument analysis methods have been developed for the determination of BPA. But these instrument analysis methods require complicated pre-treatment steps and do not suit rapid processing of multiple samples. Gold-labeled immunochromatography assay method can provide in situ monitoring of trace BPA in ground-water and drinking water. In order to build the simple and fast gold-labeled immunochromatography assay method, it is necessary to synthesize and identify artificial antigen of BPA firstly. The modified BPA was conjugated with the carrier of bovine serum albumin (BSA) by EDC * HCl, after dialyzed, the synthesized artificial antigen of BPA was lyophilized, and then stored at -20 degrees C. Three methods such as UV and IR spectra scanning and immunoassay were used to determine whether artificial antigen of BPA had been synthesized. The results showed that UV spectrum of artificial antigen of BPA has one absorbance band at 278 nanometers (nm) which is the characteristic absorbance band of the carrier of bovine serum albumin, and another absorbance band at 226 nm which is the characteristic absorbance band of BPA. The IR spectrum absorbance bands of bovine serum albumin and BPA appeared on the IR spectrum graph of artificial antigen of BPA, moreover, shrinked vibration bands at 1 000-1 300 cm(-1) showed that a C-N bond was produced and suggested that the modified BPA and BSA had been linked. The antibody of anti-BPA was raised in sera of immunized Balb/c mice by indirect competitive ELISA. So the above results showed that the artificial antigen of BPA was synthesized successfully. The artificial antigen of BPA can be used to develop monoclonal antibody of anti-BPA and also to prepare gold-labeled immunochromatography assay method for in situ monitoring of BPA in the future.

[Inhibition of extracts from Synotis erythropappa on tyrosinase].

OBJECTIVE: To study the inhibition of extracts from Synotis erythropappa on tyrosinase. METHODS: The 70% ethanol extracts were extracted by petroleum benzine, ethyl acetate and n-butanol, and the inhibitory activities against tyrosinase of every fraction were determined in vitro and the inhibitory kinetics of ethyl acetate and n-butanol fractions were investigated. RESULTS: The four fractions extracted all had inhibitory activities on tyrosinase, inhibitory activities of ethyl acetate and n-butanol fraction were higher. Their IC50 were 57.8, 140 microg/ml for monophenol oxidase activity and 41.2, 59.6 microg/ml for diphenol oxidase activity, respectively. The inhibition kinetics analyzed by Hnewaver-Burk plots showed that ethyl acetate fraction was a competitive type inhibitor, and its Ki was determined to be 19.7 microg/ml. n-butanol fraction was an uncompetitive type inhibitor, and its Ki was determined to be 60.7 microg/ml. CONCLUSION: Ethyl acetate and n-butanol fractions of extracts from Synotis erythropappa show potential inhibitory activity on tyrosinase.

The biological evaluation of fusidic acid and its hydrogenation derivative as antimicrobial and anti-inflammatory agents.

BACKGROUND: Fusidic acid (FA) (WU-FA-00) is the only commercially available antimicrobial from the fusidane family that has a narrow spectrum of activity against Gram-positive bacteria. METHODS: Herein, the hydrogenation derivative (WU-FA-01) of FA was prepared and both compounds were examined against a panel of six bacterial strains. In addition, their anti-inflammatory properties were evaluated using a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema model. RESULTS: The results of the antimicrobial assay revealed that both WU-FA-00 and WU-FA-01 displayed a high level of antimicrobial activity against Gram-positive strains. Moreover, killing kinetic studies were performed and the results were in accordance with the minimum inhibitory concentration and minimum bactericidal concentration results. We also demonstrated that the topical application of WU-FA-00 and WU-FA-01 effectively decreased TPA-induced ear edema in a dose-dependent manner. This inhibitory effect was associated with the inhibition of TPA-induced upregulation of proinflammatory cytokines IL-1ß, TNF-α, and COX-2. WU-FA-01 significantly suppressed the expression levels of p65, IκB-α, and p-IκB-α in the TPA-induced mouse ear model. CONCLUSION: Overall, our results showed that WU-FA-00 and WU-FA-01 not only had effective antimicrobial activities in vitro, especially to the Gram-positive bacteria, but also possessed strong anti-inflammatory effects in vivo. These results provide a scientific basis for developing FA derivatives as antimicrobial and anti-inflammatory agents.

Synthesis and biological evaluation of novel ursolic acid analogues as potential α-glucosidase inhibitors.

Ursolic acid (UA) is a major pentacyclic triterpenoid in plants, vegetables and fruits, which has been reported to have a potential anti-diabetic activity. Despite various semi-synthetic ursolic acid derivatives already described, new derivatives still need to be designed and synthesized to further improve the anti-diabetic activity. In the present study, two series of novel UA derivatives, were synthesized and their structures were confirmed. The enzyme inhibition activities of semi-synthesized analogues against α-glucosidase were screened in vitro. The results indicated that most of UA derivatives showed a significant inhibitory activity, especially analogues UA-O-i with the IC50 values of 0.71 ± 0.27 µM, which was more potential than other analogues and the positive control. Furthermore, molecular docking studies were also investigated to verify the in vitro study. Structure modification at the C-3 and C-2 positions of UA was an effective approach to obtain the desired ligand from UA, whose structure was in accordance with the active pocket. Besides, suitable hydrophobic group at the position of C-2 might play an important role for the docking selectivity and binding affinity between the ligand and the homology modelling protein. These results could be helpful for designing more potential α-glucosidase inhibitors from UA in the future.

Pyridine analogues of curcumin exhibit high activity for inhibiting CWR-22Rv1 human prostate cancer cell growth and androgen receptor activation.

The concentrations required for curcumin to exert its anticancer activity (IC50, 20 µM) are difficult to achieve in the blood plasma of patients, due to the low bioavailability of the compound. Therefore, much effort has been devoted to the development of curcumin analogues that exhibit stronger anticancer activity and a lower IC50 than curcumin. The present study investigated twelve pyridine analogues of curcumin, labeled as groups AN, BN, EN and FN, to determine their effects in CWR-22Rv1 human prostate cancer cells. The inhibitory effects of these compounds on testosterone (TT)-induced androgen receptor (AR) activity was determined by performing an AR-linked luciferase assay and by TT-induced expression of prostate-specific antigen. The results of the current study suggested that the FN group of analogues had the strongest inhibitory effect of growth on CWR-22Rv1 cultured cells, and were the most potent inhibitor of AR activity compared with curcumin, and the AN, BN and EN analogues. Thus, the results of the present study indicate the inhibition of the AR pathways as a potential mechanism for the anticancer effect of curcumin analogues in human prostate cancer cells. Furthermore, curcumin analogues with pyridine as a distal ring and tetrahydrothiopyran-4-one as a linker may be good candidates for the development of novel drugs for the treatment of prostate cancer, by targeting the AR signaling pathway.

Comparative proteomic analysis of B. henselae Houston and B. henselae Marseille by two-dimensional gel electrophoresis.

OBJECTIVE: To compare the protein difference between B. henselae Houston and B. henselae Marseille by two-dimensional gel electrophoresis. METHOD: Protein samples were prepared by vorterx, ultrasonic treatment, and centrifugation. Protein concentrations were determined by Bradford method. Protein difference was compared by the first IEF and the second SDS-polyacrylamide gel electrophoresis. RESULTS: Protein concentrations in samples of Bartonella henselae Houston and Bartonella henselae Marseille were 2.117 microg/microL and 2.200 microg/microL respectively. Sample protein of 40 microg for IPG strips loading was perfect. The results of 2-DE in pH 4 to 7 IPG strips showed that the total protein spots of Bartonella henselae Houston and Bartonella henselae Marseille were 375 and 379 respectively, 95% of the spots were the same between the two strains of Bartonella henselae. CONCLUSION: The procedure of 2-DE may prove successful for the proteomic analysis of Bartonella henselae. Bartonella henselae Houston and Bartonella henselae Marseille are different genotypes.

Studies on purification of methamidophos monoclonal antibodies and comparative immunoactivity of purified antibodies.

OBJECTIVE: To purify Methamidophos (Met) monoclonal antibodies with two methods and compare immune activity of purified antibodies. METHOD: Caprylic acid ammonium sulphate precipition (CAASP) method and Sepharose protein-A (SPA) affinity chromatography method were used to purify Met monoclonal antibodies, UV spectrum scanning was used to determine protein content and recovery of purified antibodies, sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) was used to analyze the purity of purified antibodies, and enzyme-linked immunosorbent assay (ELISA) was used to determine immune activity of purified antibodies. RESULTS: Antibody protein content and recovery rate with CAASP method were 7.62 mg/mL and 8.05% respectively, antibody protein content and recovery rate with SPA method were 6.45 mg/mL and 5.52% respectively. Purity of antibodies purified by SPA method was higher than that by CAASP method. The half-maximal inhibition concentration (IC50) of antibodies purified by SPA to Met was 181.26 microg/mL, and the linear working range and the limit of quantification (LOD) were 2.43-3896.01 microg/mL and 1.03 microg/mL, respectively. The IC50 of antibodies purified by CAASP to Met was 352.82 microg/mL, and the linear working range and LOD were 10.91-11412.29 microg/mL and 3.42 microg/mL, respectively. CONCLUSION: Antibodies purified by SPA method are better than those by CAASP method, and Met monoclonal antibodies purified by SPA method can be used to prepare gold-labelled testing paper for analyzing Met residue in vegetable and drink water.