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1.
Mar Drugs ; 22(3)2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38535459

ABSTRACT

Seven new phenol derivatives, subversins A-E (1-5), subversic acid A (6) and epi-wortmannine G (7); one new natural product, 4-hydroxy-7-methoxyphthalide (8); and five known compounds (9-13) were isolated from the fungus Aspergillus subversicolor CYH-17 collected from the Haima cold seep. The structures and absolute configurations of these compounds were determined via NMR, MS, optical rotation, electronic circular dichroism (ECD) calculation, X-ray diffraction analysis and comparison with the literature. Compounds 2 and 5 were two pairs of enantiomers. All compounds were tested for their α-glucosidase and acetylcholinesterase (AChE) inhibitory activity, antioxidant activity and antibacterial activity, but no obvious activity was observed among these studied compounds.


Subject(s)
Acetylcholinesterase , Aspergillus , Phenol , Phenols , Fungi
2.
Nat Prod Res ; : 1-6, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-38099373

ABSTRACT

One novel diketopiperazine derivative 8R-methoxy-9R-hydroxyl-fumitremorgin C (1), together with twelve known compounds, was separated from the fungus Aspergillus fumigatus CYH-5 collected from Haima cold seep. The structures of the compounds were identified by NMR, MS, optical rotation, hydrolysis reaction and comparing with literatures. Among them, compounds 10 and 11 exhibited inhibitory effect against bacteria. Compound 11 showed inhibitory activity on α-glucosidase and compound 8 displayed acetylcholinesterase (AchE) inhibitory activity.

3.
Tissue Cell ; 82: 102109, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37229935

ABSTRACT

Vanadium is a transition metal that naturally occurs in the environment and has a variety of biological and physiological impacts on humans. Sodium orthovanadate (SOV), a well-known chemical compound of vanadium, has shown notable anti-cancer activity in various types of human malignancies. However, the effect of SOV on stomach cancer is yet undetermined. Furthermore, only a few studies have investigated the association of SOV and radiosensitivity with stomach cancer. Our study has investigated the ability of SOV to increase the sensitivity of gastric cancer cells to radiation. To detect autophagy triggered by ionizing radiation and the influence of SOV on cell radiosensitivity, the Cell Counting Kit-8 (CCK8) test, EDU staining experiment, colony formation assay, and immunofluorescence were performed. The possible synergistic effects of SOV and irradiation were examined in vivo using a xenograft mouse model of stomach cancer cells. Both in vitro and in vivo studies showed that SOV markedly reduced the growth of stomach cancer cells and improved their radiosensitivity. Our results showed that SOV increased gastric cancer cells' radiosensitivity, thereby blocking the radiation-induced autophagy-related protein, ATG10. Thus, SOV can be considered a potential agent for radiosensitizing gastric cancer.


Subject(s)
Stomach Neoplasms , Humans , Mice , Animals , Stomach Neoplasms/radiotherapy , Vanadates/pharmacology , Vanadium/pharmacology , Apoptosis , Autophagy , Cell Line, Tumor
4.
Cancer Sci ; 113(9): 3085-3096, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35730319

ABSTRACT

Drug resistance is an important factor for treatment failure of gastric cancer. N6 -methyladenosine (m6 A) is the predominant mRNA internal modification in eukaryotes. The roles of m6 A modification in drug resistance of gastric cancer remains unclear. In the present study, the m6 A methylated RNA level was significantly decreased while the expression of m6 A demethylase fat mass and obesity-associated protein (FTO) was obviously elevated in cisplatin-resistant (SGC-7901/DDP) gastric cancer cells. Knockdown of FTO reversed cisplatin resistance of SGC-7901/DDP cells both in vitro and in vivo, which was attributed to the inhibition of Unc-51-like kinase 1 (ULK1)-mediated autophagy. Mechanistically, ULK1 expression was regulated in an FTO-m6 A-dependent and YTHDF2-mediated manner. Collectively, our findings indicate that the FTO/ULK1 axis exerts crucial roles in cisplatin resistance of gastric cancer.


Subject(s)
Cisplatin , Stomach Neoplasms , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism , Apoptosis , Autophagy/genetics , Autophagy-Related Protein-1 Homolog/genetics , Cisplatin/pharmacology , Cisplatin/therapeutic use , Humans , Intracellular Signaling Peptides and Proteins/genetics , Intracellular Signaling Peptides and Proteins/therapeutic use , Obesity/genetics , Stomach Neoplasms/drug therapy , Stomach Neoplasms/genetics
5.
Int J Biol Macromol ; 213: 718-727, 2022 Jul 31.
Article in English | MEDLINE | ID: mdl-35636527

ABSTRACT

We report a self-assembly method for the fabrication of multilayer-starch-based microgels used for anthocyanin encapsulation. Alcohol-heating treatment and ionization reactions were employed to reduce the crystallinity of starch and introduce ionic groups on the molecule to further cross-link it with sodium trimetaphosphate and produce a starch microgel. The molecular interactions between the starch and the anthocyanins facilitated the anthocyanin encapsulation and the starch-microgel/anthocyanin complexes with one, two, and three self-assembled layers were obtained. The Lay-1 microgel exhibited an encapsulation efficiency of 50.1% when the anthocyanin concentration, cross-linking starch concentration, contact time, and temperature were 0.25 mg/mL, 1.5 mg/mL, 3 h, and 40 °C, respectively. An increase in the number of layers resulted in a more compact microgel structure with the zeta potential presenting variations upon structural changes. Furthermore, the encapsulated anthocyanins presented a slow release from Lay-1, while the multilayered microgels (Lay-2 and Lay-3) displayed outstanding encapsulation stability. This study gives an insight on the encapsulation and release of anthocyanins by starch microgels, and provides a novel strategy for the design of starch-based encapsulation materials presenting great stability.


Subject(s)
Microgels , Starch , Anthocyanins/chemistry , Delayed-Action Preparations , Gels/chemistry , Starch/chemistry
6.
Food Chem ; 360: 129922, 2021 Oct 30.
Article in English | MEDLINE | ID: mdl-33965711

ABSTRACT

Starch based food packaging has been receiving increasing attention. However, the inherent poor properties of starch restrict its practical applications in the versatile material science field. In this study, a fast, simple, and environmentally friendly route to construct polyfunctional starch/tea polyphenols nanofibrous films (STNFs) by one-step temperature-assisted electrospinning was developed. The effects of introduction of tea polyphenols (TP) on the mechanical and antioxidant activity of STNFs were comprehensively investigated. Results of ABTS·+ free radical scavenging assay showed that the antioxidant activity of STNFs was endowed by addition of TP with optimum mechanical properties confirmed by tensile test. More interestingly, the hydrophobicity of STNFs was improved dramatically with increasing cross-linking time as indicated by water contact angle (WCA) measurement showing no effect on the antioxidant activity of the films. The results of this work offer a major step forward to promote functional starch-based materials for sustainable application in food packaging.


Subject(s)
Antioxidants/chemistry , Food Packaging/instrumentation , Polyphenols/chemistry , Starch/chemistry , Hydrophobic and Hydrophilic Interactions , Nanofibers , Permeability , Tea/chemistry , Water/chemistry
7.
J Agric Food Chem ; 69(17): 5067-5075, 2021 May 05.
Article in English | MEDLINE | ID: mdl-33844905

ABSTRACT

Starch-derived edible food films have great potential as biodegradable food packaging materials because they reduce the overuse of traditional petroleum-based plastic. Herein, we demonstrate a direct method of mass producing a pure starch food packaging film that consisted of starch nanofibers by using a temperature-assisted electrospinning technique without addition of any nonstarch components. To overcome the major issue of ultralow hydrophobicity of starch nanofibrous film (SNF), we used a facile and low-cost solution immersion approach to create a fiber coating of stearic acid (STA) inspired by biological organisms with superhydrophobic properties, such as lotus leaves. Hierarchical flower-like micronanostructures were obtained on SNF by controlled assembly of STA onto the surface of starch nanofibers. Benefiting from the effective formation of STA self-assembled lamella, the multiscale microstructure surface features, low surface energy, and enhancing thermal stability of SNF were obtained and confirmed to result in the variety of its hydrophobicity, which can be also tailored by simple controlling of the solution concentration of STA. Importantly, the STA-self-assembled coated SNF enabled water to roll freely in all directions, which is a crucial factor for self-cleaning. Our novel strategy based on self-assembly can guide development of bioinspired hydrophobic interfaces for starch-based films for edible hydrophobic materials.


Subject(s)
Food Packaging , Nanofibers , Hydrophobic and Hydrophilic Interactions , Permeability , Starch
8.
Curr Med Sci ; 41(2): 306-311, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33877546

ABSTRACT

This retrospective study aimed to investigate the clinical characteristics and neonatal outcomes of pregnant women with SARS-COV-2 in Wuhan Children's Hospital and further suggested a possible management strategy for infected pregnant women under epidemic situation. In this study, 8 pregnant women with SARS-COV-2 who were admitted into Wuhan Children's Hospital, China from February 1, 2020 to March 30, 2020 and the clinical features, laboratory data, maternal and neonatal outcomes were analyzed. The mean age of the women at the time of admission was 30.6 years. The mean gestational age of the women was 37 weeks+4 days, and one woman presented with dichorionic diamniotic (DCDA) twin pregnancy. Except for one woman who was febrile, others had no typical clinical symptoms. For all pregnant women, the count of white blood cells and lymphocytes appeared normal, but 6 had a lower percentage of lymphocytes. C-reactive protein (CRP) levels were normal for all the women. One neonate was tested positive for the coronavirus IgG and IgM antibodies. The clinical symptoms of the pregnant women with SARS-COV-2 were mild, and the laboratory data showed similar characteristics to those of non-infected pregnant women. Since one neonate was tested positive for coronavirus, there is a possibility of vertical transmission of SARS-CoV-2. Prompt and efficient screening, triage, and isolation of pregnant women are effective management strategies to reduce nosocomial infection during the SARS-COV-2 epidemic.


Subject(s)
COVID-19/epidemiology , Pregnancy Complications, Infectious/epidemiology , SARS-CoV-2/pathogenicity , Adult , COVID-19/complications , COVID-19/physiopathology , COVID-19/virology , China/epidemiology , Female , Humans , Immunoglobulin M/blood , Infant , Infectious Disease Transmission, Vertical/prevention & control , Pregnancy , Pregnancy Complications, Infectious/blood , Pregnancy Complications, Infectious/physiopathology , Pregnancy Complications, Infectious/virology , Pregnant Women , Retrospective Studies
9.
Phytochemistry ; 182: 112589, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33352309

ABSTRACT

Schipropins A-J, a series of undescribed lanostane and cycloartane-type triterpenoids, were isolated from the stems and leaves of Schisandra propinqua. Their structures, most of which were characterized by C-3/C-4 cleavage, were elucidated by extensive spectroscopic analyses. Noteworthily, the absolute configurations of schipropins A, D-G, and I were determined by single-crystal X-ray diffraction. Furthermore, schipropins E and G were found to possess moderate NO production inhibitory activity.


Subject(s)
Schisandra , Triterpenes , Crystallography, X-Ray , Molecular Structure , Plant Leaves
10.
ACS Omega ; 5(46): 29896-29902, 2020 Nov 24.
Article in English | MEDLINE | ID: mdl-33251425

ABSTRACT

Improving the electrochemical performance of biomass-derived carbon electrode-active materials for supercapacitor applications has recently attracted considerable attention. Herein, we develop hybrid electrode materials from rice-husk-derived porous carbon (RH-C) materials and ß-Ni(OH)2 via a facile solid-state reaction strategy comprising two steps. The prepared RH-C/Ni(OH)2 (C-Ni) was investigated using scanning electron microscopy (SEM) (energy-dispersive X-ray spectrometer (EDS)), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) to acquire the physical and chemical information, which was used to demonstrate the successful fabrication of C-Ni. Thermogravimetric analysis (TGA) measurement results confirmed that the thermal stability of C-Ni changed due to the presence of Ni(OH)2. As expected, C-Ni possesses a high capacitance of ∼952 F/g at a current density of 1.0 A/g. This result is higher than that of pure biomass-based carbon materials under the three-electrode system. This facile preparation method, which was used to synthesize the electrode-active materials, can extend to the value-added utility of other waste biomass materials as high-performing supercapacitor electrodes for energy storage applications.

11.
J Agric Food Chem ; 68(36): 9725-9732, 2020 Sep 09.
Article in English | MEDLINE | ID: mdl-32786859

ABSTRACT

Agricultural production-caused water contamination has become an urgent environmental issue that has drawn much attention in recent years. One such contamination case is the environmental disposal of colored effluents from the food processing industry (i.e., food dyes). Effective methods for removing dye contaminants from water have been increasingly sought, and different adsorbents have been developed for this purpose. Here, polysaccharide-based hydrogels derived from cellulose were constructed and used in the removal of methylene blue (MB) (as the representative dye) from an aqueous medium (as simulated dye liquor wastewater). To improve the purification efficiency, TiO2 nanoparticles were encapsulated into cellulose nanofibers, which were consequently changed to hydrogels with respective advantages. The morphology, chemical composition, and structure of the as-prepared polysaccharide-based hydrogels and the transformation process from nanofibers to hydrogels were revealed by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction, and the presence of a gel network structure and TiO2 nanoparticles was confirmed. As expected, the polysaccharide-based hydrogels exhibited good MB removal performance because of their synergistic effects of absorption and photocatalytic degradation. Furthermore, the cell cytotoxicity test showed that the polysaccharide-based hydrogels possessed good biocompatibility. The facile, noncytotoxic, and general strategy presented here could be extended to the preparation of other polysaccharide-based hydrogel materials and has good prospects for application in wastewater treatment.


Subject(s)
Cellulose/chemistry , Coloring Agents/chemistry , Hydrogels/chemistry , Nanofibers/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Adsorption , Wastewater/chemistry , Water Purification/instrumentation
12.
Int J Biol Macromol ; 149: 459-466, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-31978474

ABSTRACT

Nanoscale biomass materials derived from food materials (e.g., polysaccharide, protein, organic acid) have shown great promises with regard to the removal of heavy metal in wastewater treatment. Herein, we have developed the functionalized cellulose nanofibrous mats as an environment-friendly biosorbent via electrospinning of cellulose acetate solution, followed by deacetylation and citric acid modification. The morphology, chemical, and structural characterizations of the cellulose nanofibrous mats were examined by SEM, FTIR, XRD, DSC, and TGA to follow each stage of the preparation process of them. The effect of the incorporation of citric acid in the cellulose molecule on the adsorption performance of the naofibrous mats was then studied by batch adsorption experiments. Consequently, citric acid-modified cellulose nanofibrous mats with reasonably high absorption selectivity for Cr(VI) can be readily prepared. Results from this study may provide a promising food materials-based biosorbent that can be used as an emerging material in wastewater treatment application.


Subject(s)
Cellulose/chemistry , Chromium/isolation & purification , Nanofibers/chemistry , Water Purification , Chromium/toxicity , Citric Acid/chemistry , Humans , Metals, Heavy/isolation & purification , Metals, Heavy/toxicity , Polysaccharides/chemistry , Proteins/chemistry , Wastewater/chemistry , Water/chemistry
13.
Org Lett ; 21(17): 6805-6810, 2019 Sep 06.
Article in English | MEDLINE | ID: mdl-31407913

ABSTRACT

The activated alkynes have been used successfully for the first time as the dipolarophile in the palladium-catalyzed asymmetric (3 + 2) cycloaddition, affording highly functionalized cyclopentenes in good to high yields with high chemoselectivities and good to high enantioselectivities. The introduction of an additional carbonyl group at the α-position of the alkynyl esters is the key to activating the carbon-carbon triple bond. The reaction process was investigated, and an inverse process of Pd-catalyzed (3 + 2) cycloaddition was observed.

14.
Curr Med Sci ; 38(6): 949-961, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30536055

ABSTRACT

Microbial constituents naturally inhabiting the gastrointestinal tract may influence the homeostasis of the gut environment. The presence or overabundance of some bacterial taxa has been reported to be associated with complex diseases, and the metabolites of certain bacteria may contribute to diverse disorders by influencing signaling pathways. Therefore, the study of gut microbial population has emerged as a crucial field and a new potential area of clinical significance. Advances in the methods of microbiota analysis have shed light upon the details including species diversity, microfloral activities as well as the entire gut microbiota. Nevertheless, comprehensive reviews on this subject are still limited. For elucidating the appropriate selection strategy of the methods to address a particular research question, we comprehensively reviewed the continuously improving technologies, classical to newly developed, and dissected their relative advantages and drawbacks. In addition, aiming at the rapidly advancing next-generation sequencing, we enumerated the improvements in mainstream platforms and made the horizontal and vertical comparison among them. Additionally, we demonstrated the four main -omics methods, which may provide further mechanistic insights into the role of microbiota, to propel phylotyping analysis to functional analysis.


Subject(s)
Gastrointestinal Microbiome/genetics , Gastrointestinal Microbiome/physiology , Gastrointestinal Tract/microbiology , Microbiota/genetics , Microbiota/physiology , High-Throughput Nucleotide Sequencing/methods , Humans
15.
Nat Prod Bioprospect ; 8(2): 121-129, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29556983

ABSTRACT

A detailed chemical investigation of the secondary metabolites produced by the endophytic fungus Xylaria sp. isolated from the stems of Isodon sculponeatus afforded six new compounds, xylariahgins A-F (1-6), two new natural products (7 and 8), along with two known compounds (9 and 10) (Fig. 1). The structures of all compounds were unambiguously established by analyzing their spectroscopic data or referring to pertinent literature. Compounds 1-8 were tested for their cytotoxic activity against five human tumor cell lines.

16.
Fitoterapia ; 127: 193-200, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29454022

ABSTRACT

Five new schinortriterpenoids, propinqtrilactones A and B (1 and 2) with rare lancischiartane scaffold, and propindilactones V-X (3-5), were isolated from the stems and leaves of Schisandra propinqua var. propinqua. Their structures were elucidated on the basis of comprehensive spectroscopic and mass spectrometric analysis. The absolute configurations of 1-5 were determined by CD methods, X-ray diffraction analysis and theoretical calculations. 4 was tested for its cytotoxic activities against five human tumor cell lines.


Subject(s)
Schisandra/chemistry , Triterpenes/isolation & purification , Cell Line, Tumor , Circular Dichroism , Crystallography, X-Ray , Humans , Molecular Structure , Plant Leaves/chemistry , Plant Stems/chemistry
17.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(11): 1208-1212, 2017 Nov.
Article in Chinese | MEDLINE | ID: mdl-29132471

ABSTRACT

OBJECTIVE: To investigate the effect of oridonin on the human acute lymphocytic leukemia cell line Jurkat and its mechanism. METHODS: Jurkat cells were cultured in vitro and treated with various concentrations (0, 1.25, 2.5, 5, and 10 µmol/L) of oridonin for different lengths of time (24, 48, and 72 hours). The proliferation of Jurkat cells was analyzed by MTT assay. The changes in nuclear morphology were evaluated by fluorescence microscopy at 12 hours after treatment with various concentrations of oridonin. The expression levels of Brg1, P53, and C-myc were determined by semi-quantitative Western blot in Jurkat cells treated with various concentrations of oridonin for 24 hours or 5 µmol/L oridonin for various lengths of time (0, 2, 6, 12, and 24 hours). The expression levels of P53 and C-myc and proliferation of Jurkat cells were evaluated after Brg1 expression was knocked down by Brg1-specific siRNA. RESULTS: Compared with the control group, the proliferation of oridonin-treated Jurkat cells was significantly inhibited in a concentration- and time-dependent manner (P<0.05). According to the florescence microscopic analysis, oridonin treatment led to nuclear pyknosis in Jurkat cells. Compared with the control group, Jurkat cells treated with 5 µmol/L oridonin had reduced expression of Brg1 and C-myc but elevated expression of P53. Brg1 knock-down led to a significant reduction in proliferation of Jurkat cells (P<0.05), up-regulated expression of P53, and down-regulated expression of C-myc. CONCLUSIONS: Oridonin can inhibit the proliferation of Jurkat cells, probably via the Brg1 signaling pathway.


Subject(s)
Antineoplastic Agents, Phytogenic/pharmacology , DNA Helicases/physiology , Diterpenes, Kaurane/pharmacology , Nuclear Proteins/physiology , Transcription Factors/physiology , Cell Proliferation/drug effects , DNA Helicases/analysis , Dose-Response Relationship, Drug , Down-Regulation , Humans , Jurkat Cells , Nuclear Proteins/analysis , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Proto-Oncogene Proteins c-myc/analysis , Signal Transduction/physiology , Transcription Factors/analysis , Tumor Suppressor Protein p53/analysis
18.
Am J Reprod Immunol ; 61(5): 313-21, 2009 May.
Article in English | MEDLINE | ID: mdl-19341382

ABSTRACT

PROBLEM: The aim of our study was to investigate the functional changes of human peripheral B-lymphocytes in healthy and pre-eclamptic pregnancies. METHOD OF STUDY: Twenty patients with pre-eclampsia and 15 healthy third-trimester pregnant women were recruited in this study. Peripheral blood mononuclear cells (PBMCs) were isolated and directly stained with fluorescein isothiocyanate (FITC)-labeled anti-CD27 monoclonal antibody (mAb) and phycoerythrin (PE)-labeled anti-CD38 mAb. The percentages of the individual B-cell subsets were estimated out of total lymphocytes by flow cytometric analysis. Additionally, the enriched PBMCs were cultured with or without the stimulation of pokeweed mitogen (PWM) for 5 days. Then morphologic observation of plasma cells was analysed by Wright-Giemsa stain, and antibody-producing cells were detected by enzyme-linked immunospot assay. RESULTS: The percentage of CD27(-)CD38(-) naïve B-cells and CD27(-)CD38(+) plasma cells did not differ between study groups (P > 0.05). The percentage of CD27(+)CD38(-) memory B-cells and CD27(+)CD38(+) plasma cell precursors increased in pre-eclamptic women compared with the controls (P < 0.05). Irrespective of whether the PBMCs were stimulated with or w/o PWM in vitro, the mean percentages of generated plasma cells were significantly higher in pre-eclamptic group than in the controls (P < 0.05). There were more antibody-producing cells in pre-eclamptic women following the activation of PWM than those in the controls (P < 0.01). CONCLUSION: Our findings implicate that the functional changes of human circulating B-cells might contribute to the etiology of pre-eclampsia.


Subject(s)
B-Lymphocyte Subsets/immunology , Plasma Cells/immunology , Pre-Eclampsia/immunology , ADP-ribosyl Cyclase 1/immunology , ADP-ribosyl Cyclase 1/metabolism , Adult , B-Lymphocyte Subsets/drug effects , B-Lymphocyte Subsets/metabolism , Female , Humans , Plasma Cells/drug effects , Plasma Cells/metabolism , Pokeweed Mitogens/pharmacology , Pregnancy , Tumor Necrosis Factor Receptor Superfamily, Member 7/immunology , Tumor Necrosis Factor Receptor Superfamily, Member 7/metabolism
19.
J Agric Food Chem ; 56(18): 8261-7, 2008 Sep 24.
Article in English | MEDLINE | ID: mdl-18710242

ABSTRACT

Florfenicol (FF) is a broad-spectrum antibiotic used increasingly in aquaculture, livestock, and poultry to treat diseases. To avoid using labor-intensive instrumental methods to detect residues of FF in food and food products, a simple and convenient indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) method for florfenicol's major metabolite, florfenicol amine (FFA), was developed using a polyclonal antibody prepared in this study. FFA was covalently attached to carrier protein as immunogen by using the glutaraldehyde method. The antibodies obtained were characterized by an ELISA method and showed excellent specificity and sensitivity with the 50% inhibition values (IC 50) of 3.34 microg/L for FFA in PBS buffer. In the ELISA, sample extractions were performed by ethyl acetate/ammonium hydroxide (90 + 10, v/v) following combined acid hydrolysis of FF and its known metabolites. The limits of detection (LOD) calculated from the analysis of 20 known negative swine muscle, chicken muscle, and fish samples were 3.08, 3.3, and 3.86 microg/kg (mean + 3 SD), respectively. Recoveries of FFA fortified at the levels of 5, 50, 100, and 300 microg/kg ranged from 64.6 to 124.7%, with coefficients of variation of 11.3-25.8% over the range of FFA concentrations studied. Validation of the ELISA method with FFA-fortified swine muscle at the levels of 10, 50, 100, and 200 microg/kg was carried out using GC, resulting in a similar correlation in swine muscle ( r = 0.97). The results suggest that this ELISA is a specific, accurate, and sensitive method, which is suitable for use as a screening method to detect residues of FFA in animal edible tissues.


Subject(s)
Anti-Bacterial Agents/analysis , Enzyme-Linked Immunosorbent Assay/methods , Meat/analysis , Thiamphenicol/analogs & derivatives , Animals , Chickens , Fishes , Muscles/chemistry , Sensitivity and Specificity , Swine , Thiamphenicol/analysis
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