Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 158
Filter
1.
AAPS PharmSciTech ; 22(3): 78, 2021 Feb 18.
Article in English | MEDLINE | ID: mdl-33604777

ABSTRACT

Six Australian and five overseas complementary medicines (CM) and meal replacement shake products were analysed for potential adulteration with two common active pharmaceutical ingredients, caffeine and sibutramine, using thin-layer chromatography and mass spectrometry. The declared amount of caffeine in each product was also reviewed. Finally, the products were examined for heavy metal contamination using inductively coupled plasma-mass spectrometry. The results showed that there was no detected adulteration of either caffeine (for those products that did not list caffeine as an ingredient) or sibutramine in the 11 products; however, based on the product labels, one Australian and one overseas (two in total) CM product contained more than the maximum daily safety limit (400 mg) of caffeine. Potentially excessive lead and/or chromium was detected in six products, including four Australian products and two products purchased online. One Australian CM product appeared to contain these heavy metals at concentrations at, or exceeding, the safety limits specified in the United States Pharmacopeia or set by the World Health Organization. The overconsumption of caffeine and heavy metals has the potential of causing significant health effects in consumers.


Subject(s)
Complementary Therapies/standards , Drug Contamination , Nonprescription Drugs/analysis , Caffeine/analysis , Cyclobutanes/analysis , Humans , Mass Spectrometry/methods , Metals, Heavy/analysis
2.
Anal Chem ; 92(12): 8497-8505, 2020 06 16.
Article in English | MEDLINE | ID: mdl-32438796

ABSTRACT

As an important cellular signal transduction messenger, Ca2+ has the capability to regulate cell function and control many biochemical processes, including metabolism, gene expression, and cell survival and death. Here, we introduce an accessible method for the photoactivation of Ca2+ channels mediated by squaraine (SQ) to rapidly induce cellular Ca2+ release and activate signal transduction. With a short preparation time, the maximum Ca2+ concentration increase could reach approximately 450% in 30 s, resulting from marked Ca2+ release channel opening in the endoplasmic reticulum (ER). This release was enhanced by another target location of SQ, that is, the outer mitochondrial-associated membrane where Ca2+ channels accumulate, and by the consequent large amounts of reactive oxygen species resulting from the respiratory chain activity stimulated by Ca2+ load. We used this method to investigate cellular signal transduction in different cancer cells and revealed rapid intracellular Ca2+ flow, unidirectional intercellular signaling processes, and neuronal signaling activity, which demonstrated the potential and convenience of the method for routine Ca2+ research.


Subject(s)
Calcium Channels/metabolism , Cyclobutanes/metabolism , Phenols/metabolism , Animals , Calcium Channels/chemistry , Calcium Signaling , Cyclobutanes/analysis , Endoplasmic Reticulum/metabolism , Humans , Hydrogen-Ion Concentration , Mice , Phenols/analysis , Photochemical Processes , Reactive Oxygen Species/analysis , Reactive Oxygen Species/metabolism , Tumor Cells, Cultured
3.
Bioconjug Chem ; 31(2): 214-223, 2020 02 19.
Article in English | MEDLINE | ID: mdl-31756298

ABSTRACT

New methods are described for the construction of targeted fluorescence probes for imaging cancer and the assessment of tumor targeting performance in a living mouse model. A novel noncovalent assembly process was used to fabricate a set of structurally related targeted fluorescent probes with modular differences in three critical assembly components: the emission wavelength of the squaraine fluorochrome, the number of cRGDfK peptide units that target the cancer cells, and the length of the polyethylene glycol chains as pharmacokinetic controllers. Selective targeting of cancer cells was proven by a series of cell microscopy experiments followed by in vivo imaging of subcutaneous tumors in living mice. The mouse imaging studies included a mock surgery that completely removed a fluorescently labeled tumor. Enhanced tumor accumulation due to probe targeting was first evaluated by conducting Single Agent Imaging (SAI) experiments that compared tumor imaging performance of a targeted probe and untargeted probe in separate mouse cohorts. Although there was imaging evidence for enhanced tumor accumulation of the targeted probe, there was moderate scatter in the data due to tumor-to-tumor variability of the vasculature structure and interstitial pressure. A subsequent Paired Agent Imaging (PAI) study coinjected a binary mixture of targeted probe (with emission at 690 nm) and untargeted probe (with emission at 830 nm) into the same tumor-burdened animal. The conclusion of the PAI experiment also indicated enhanced tumor accumulation of the targeted probe, but the statistical significance was much higher, even though the experiment required a much smaller cohort of mice. The imaging data from the PAI experiment was analyzed to determine the targeted probe's Binding Potential (BP) for available integrin receptors within the tumor tissue. In addition, pixelated maps of BP within each tumor indicated a heterogeneous spatial distribution of BP values. The results of this study show that the combination of fluorescent probe preassembly and PAI is a promising new way to rapidly develop targeted fluorescent probes for tumors with high BP and eventual use in clinical applications such as targeted therapy, image guided surgery, and personalized medicine.


Subject(s)
Cyclobutanes/analysis , Fluorescent Dyes/analysis , Neoplasms/diagnostic imaging , Optical Imaging/methods , Phenols/analysis , A549 Cells , Animals , Female , Fluorescence , Humans , Mice , Mice, Nude , Molecular Probes/analysis
4.
Anal Bioanal Chem ; 412(29): 8135-8144, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32914397

ABSTRACT

Immunochromatographic assay (ICA) has been used widely for the onsite monitoring of illegal additives due to its simplicity, speed, and low cost. However, a scanner is commonly required for ICA to achieve quantitative results. In this work, we developed a visual semi-quantitative ICA for sibutramine, a banned additive in diet foods, without the need for a scanner for measurement. Monoclonal antibodies specific for sibutramine were raised and conjugated with upconversion nanoparticles (UCNPs) as the luminescent tracer. ICA was developed by employing multiple test lines to achieve the semi-quantitative detection of sibutramine. Based on the optimal conditions, the cutoff levels (limit of quantitation, LOQ) of T1 line, T2 line, T3 line, and T4 line were 0.02 µg/mL, 0.15 µg/mL, 1.0 µg/mL, and 7.5 µg/mL, respectively, in buffer system. The ICA demonstrated a LOQ at 0.2 mg/kg for sibutramine in diet food samples. The assay (including pretreatment) can be finished within 30 min without the aid of other instruments, except a laser pen. No false positive or false negative results were observed. The results indicated that the proposed method was reliable, simple, and rapid for the screening of sibutramine abuse in diet food samples.


Subject(s)
Appetite Depressants/analysis , Chromatography, Affinity/methods , Cyclobutanes/analysis , Nanoparticles/chemistry , Animals , Antibodies, Monoclonal/chemistry , Enzyme-Linked Immunosorbent Assay , Food Contamination/analysis , Limit of Detection , Mice , Spectrometry, Fluorescence
5.
Vopr Pitan ; 89(6): 123-129, 2020.
Article in Russian | MEDLINE | ID: mdl-33476505

ABSTRACT

Sibutramine is a highly effective drug for the treatment of obesity. In this regard, unscrupulous manufacturers can add sibutramine as a biologically active synthetic substance prohibited for use in the composition of dietary supplements. Thus, the problem associated with the illegal circulation of such dietary supplements is especially actual, given the scale of the sale of these products. The development and validation of methods for the determination of sibutramine in dietary supplements for slimming (anorexigenic action) for the purpose of quality control in order to ensure the quality of dietary supplements when introduced into civil circulation at customs and on the market. The aim of the study - to develop a method for the quantitative determination of sibutramin in dietary supplements for weight loss by high performance liquid chromatography (HPLC) and to validate it. Material and methods. For the quantitative determination of sibutramine in dietary supplements, we used an Agilent 1100 high performance liquid chromatograph with a UV-detector. The stationary phase was a chromatographic column C18 NUCLEOSIL 4.6×150 mm, particle size 5 µm. The mobile phase contained 0.05 M formate buffer pH 4.0 and acetonitrile in a ratio of 40:60 (by volume). Results and discussion. A methodology has been developed for the determination of sibutramine in dietary supplements for weight loss, which makes it possible to control the quality of dietary supplements. Based on the obtained chromatograms, the specificity was determined; the plant components did not influence the determination of sibutramine in model mixtures. The suitability of the chromatographic system was determined: the retention factor of the compound - 2.222 (more than 2.0), N - 5776 theoretical plates (more than 5000), T peak of sibutramine - 0.939 (not more than 1.5). Within the analytical area of the linearity method: R2=0.9993 (over 0.9950). ε=0.46% (does not exceed 1.5%), the confidence interval includes the value of 100%, the calculated value of the Student's criterion tcalc (2.47) was less than the tabular ttable (2.80), which proved the correctness of the methodology. The precision of the results was determined by the obtained RSD value, which was 0.91% (less than 1%). Limit of detection (LOD) and limit of quantification (LOQ) took values of 0.1 and 1.0%, respectively. The range of measured concentrations was 0.01-20.0 mg/g. Conclusion. As a result of the studies, the method for sibutramine determination in dietary supplements with anorexigenic action was tested and can be used in quality control of dietary supplements.


Subject(s)
Cyclobutanes/analysis , Dietary Supplements/analysis , Chromatography, High Pressure Liquid , Humans
6.
J Sci Food Agric ; 99(1): 47-54, 2019 Jan 15.
Article in English | MEDLINE | ID: mdl-29797405

ABSTRACT

BACKGROUND: A survey on Fusarium species and moniliformin (MON) occurrence in sorghum grains collected from one of the main sorghum-producing areas of Argentina was conducted. Also, growth of F. thapsinum, one of the main sorghum pathogens, and MON production under different water activity (aw ) conditions on a sorghum-based medium were determined. RESULTS: Infection of sorghum grains by Fusarium species ranged from 82.5 to 99%; closely related species F. verticillioides, F. thapsinum and F. andiyazi were the most frequently recovered, followed by F. proliferatum and F. subglutinans. By sequencing a portion of the translation elongation factor-1α (TEF-1α) gene and by maximum parsimony analysis, F. verticillioides and closely related species were identified as F. thapsinum, F. andiyazi and F. verticillioides. Species within the F. graminearum species complex (FGSC) were isolated in high frequency. Maximum growth rates of 12 F. thapsinum strains were obtained at 0.995 aw . All evaluated strains were able to produce MON at all aw values tested, but MON production was higher at 0.995-0.982 aw . MON was detected in 41% of the samples at levels ranging from 363.2 to 914.2 µg kg-1 . CONCLUSION: This study provides new data on the occurrence of Fusarium species in sorghum grains destined for animal consumption in Argentina. The production of MON at different aw values showed that the toxin can be produced under field conditions. The risk to livestock exposed to daily low levels of MON associated with the toxin occurrence in the sorghum grains analyzed is unknown. © 2018 Society of Chemical Industry.


Subject(s)
Animal Feed/analysis , Cyclobutanes/analysis , Fusarium/isolation & purification , Mycotoxins/analysis , Sorghum/microbiology , Argentina , Cyclobutanes/metabolism , Food Contamination/analysis , Fusarium/classification , Fusarium/genetics , Fusarium/growth & development , Mycotoxins/metabolism , Phylogeny , Plant Diseases/microbiology , Seeds/chemistry , Seeds/microbiology , Sorghum/chemistry
7.
Photochem Photobiol Sci ; 17(4): 404-413, 2018 Apr 18.
Article in English | MEDLINE | ID: mdl-29464256

ABSTRACT

The amount of photolesions produced in DNA after exposure to physiological doses of ultraviolet radiation (UVR) can be estimated with high sensitivity and at low cost through an immunological assay, ELISA, which, however, provides only a relative estimate that cannot be used for comparisons between different photolesions such as cyclobutane pyrimidine dimer (CPD) and pyrimidine(6-4)pyrimidone photoproduct (64PP) or for analysis of the genotoxicity of photolesions on a molecular basis. To solve this drawback of ELISA, we introduced a set of UVR-exposed, calibration DNA whose photolesion amounts were predetermined and estimated the absolute molecular amounts of CPDs and 64PPs produced in mouse skin exposed to UVC and UVB. We confirmed previously reported observations that UVC induced more photolesions in the skin than UVB at the same dose, and that both types of UVR produced more CPDs than 64PPs. The UVR protection abilities of the cornified and epidermal layers for the lower tissues were also evaluated quantitatively. We noticed that the values of absorbance obtained in ELISA were not always proportional to the molecular amounts of the lesion, especially for CPD, cautioning against the direct use of ELISA absorbance data for estimation of the photolesion amounts. We further estimated the mutagenicity of a CPD produced by UVC and UVB in the epidermis and dermis using the mutation data from our previous studies with mouse skin and found that CPDs produced in the epidermis by UVB were more than two-fold mutagenic than those by UVC, which suggests that the properties of CPDs produced by UVC and UVB might be different. The difference may originate from the wavelength-dependent methyl CpG preference of CPD formation. In addition, the mutagenicity of CPDs in the dermis was lower than that in the epidermis irrespective of the UVR source, suggesting a higher efficiency in the dermis to reduce the genotoxicity of CPDs produced within it. We also estimated the minimum amount of photolesions required to induce the mutation induction suppression (MIS) response in the epidermis to be around 15 64PPs or 100 CPDs per million bases in DNA as the mean estimate from UVC and UVB-induced MIS.


Subject(s)
Cyclobutanes/radiation effects , Cyclobutanes/toxicity , Mutagens/radiation effects , Mutagens/toxicity , Pyrimidine Dimers/radiation effects , Pyrimidine Dimers/toxicity , Skin/metabolism , Skin/radiation effects , Ultraviolet Rays , Animals , Cattle , Cyclobutanes/analysis , DNA/drug effects , DNA/genetics , DNA Damage , Enzyme-Linked Immunosorbent Assay , Mice , Mice, Transgenic , Mutagens/analysis , Mutation/drug effects , Pyrimidine Dimers/analysis , Pyrimidine Dimers/biosynthesis
8.
Int J Mol Sci ; 18(5)2017 Apr 29.
Article in English | MEDLINE | ID: mdl-28468238

ABSTRACT

18F-fluciclovine (trans-1-amino-3-18F-fluorocyclobutanecarboxylic acid) is an amino acid positron emission tomography (PET) tracer used for cancer staging (e.g., prostate and breast). Patients scheduled to undergo amino acid-PET are usually required to fast before PET tracer administration. However, there have been no reports addressing whether fasting improves fluciclovine-PET imaging. In this study, the authors investigated the influence of fasting on fluciclovine-PET using triple-tracer autoradiography with 14C-fluciclovine, [5,6-³H]-2-fluoro-2-deoxy-d-glucose (³H-FDG), and 99mTc-hydroxymethylene diphosphonate (99mTc-HMDP) in a rat breast cancer model of mixed osteolytic/osteoblastic bone metastases in which the animals fasted overnight. Lesion accumulation of each tracer was evaluated using the target-to-background (muscle) ratio. The mean ratios of 14C-fluciclovine in osteolytic lesions were 4.6 ± 0.8 and 2.8 ± 0.6, respectively, with and without fasting, while those for ³H-FDG were 6.9 ± 2.5 and 5.1 ± 2.0, respectively. In the peri-tumor bone formation regions (osteoblastic), where 99mTc-HMDP accumulated, the ratios of 14C-fluciclovine were 4.3 ± 1.4 and 2.4 ± 0.7, respectively, and those of ³H-FDG were 6.2 ± 3.8 and 3.3 ± 2.2, respectively, with and without fasting. These results suggest that fasting before 18F-fluciclovine-PET improves the contrast between osteolytic and osteoblastic bone metastatic lesions and background, as well as 18F-FDG-PET.


Subject(s)
Bone Neoplasms/diagnostic imaging , Bone Neoplasms/secondary , Bone and Bones/diagnostic imaging , Carboxylic Acids/analysis , Contrast Media/analysis , Cyclobutanes/analysis , Positron-Emission Tomography/methods , Animals , Breast Neoplasms/diagnostic imaging , Cell Line, Tumor , Fasting , Female , Fluorodeoxyglucose F18/analysis , Male , Rats , Rats, Sprague-Dawley , Technetium Tc 99m Medronate/analogs & derivatives , Technetium Tc 99m Medronate/analysis
9.
BMC Complement Altern Med ; 15(1): 430, 2015 Dec 04.
Article in English | MEDLINE | ID: mdl-26637485

ABSTRACT

BACKGROUND: Weight-loss medicines, including crude drugs and herbal supplements disguised as diet-aid products, are readily obtainable and distributed widely, especially in Southeast Asia. Even if such products are unapproved or prescription-only medicines, consumers can purchase them through an agency or directly on the Internet. We evaluated the quality and safety of herbal products purchased on the Internet to reveal their influence on public health. METHODS: Diet-aid products containing Bukuryo (Poria sclerotium), Bakumondo (Ophiopogonis tuber), or Daio (rhubarb rhizome) were purchased through websites that did not provide physical addresses or which advertised misleading medicines (e.g., unapproved Cialis 100 mg tablets, Viagra 100 mg tablets) on websites. We carefully noted details in the descriptions on package inserts or accompanying product characteristics and analyzed the ingredients using qualitative and quantitative methods, namely high-performance liquid chromatography equipped with a photodiode array detector. We requested the respective manufacturers to authenticate their products through a structured questionnaire. RESULTS: We purchased 15 items from 15 Internet sites and imported all 15 items to Japan. One item stated to contain rhubarb rhizome was identified as a prescription medicine; the others were dietary supplements and not medicines. Even though we did not analyze the constituents of all crude drugs, we found some active ingredients in the items. Sibutramine was detected in items confirmed to be supplements, including those containing Poria sclerotium and Ophiopogonis tuber. Each capsule contained ≈ 12 mg of sibutramine, which is the daily dose for anti-obesity medicines. Sibutramine is not approved for use in Japan and its sale has been suspended in Europe and the USA owing to serious adverse effects on the circulatory system. CONCLUSIONS: Our findings indicate that dietary supplements containing injurious ingredients are distributed to Japanese consumers and potentially to a broader international audience, and that purchasing them through unreliable websites bears potential health risks. To avoid potential adverse events, there should be adequate alerts about the risks of taking products without appropriate indications.


Subject(s)
Anti-Obesity Agents/analysis , Anti-Obesity Agents/standards , Cyclobutanes/analysis , Internet , Plant Preparations/chemistry , Plant Preparations/standards , Complex Mixtures/chemistry , Complex Mixtures/standards , Cross-Sectional Studies , Dietary Supplements/analysis , Dietary Supplements/standards , Europe , Japan , Ophiopogon , Phytotherapy , Poria , Rheum
10.
Folia Med (Plovdiv) ; 66(2): 255-263, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38690822

ABSTRACT

INTRODUCTION: In the period between 1997 and 2010, sibutramine-containing drugs were widely prescribed for obesity and over-weight management. Due to safety concerns, in 2010 all medicines containing sibutramine were urgently withdrawn from the USA and European pharmaceutical market. Although sibutramine is no longer available in pharmaceutical products, there have been numerous reports of mislabeled weight-loss dietary supplements containing sibutramine.


Subject(s)
Appetite Depressants , Cyclobutanes , Dietary Supplements , Cyclobutanes/analysis , Dietary Supplements/analysis , Chromatography, Thin Layer/methods , Appetite Depressants/analysis , Humans
11.
Pharmazie ; 68(1): 15-8, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23444775

ABSTRACT

Adulteration of botanical food supplements with undeclared synthetic drugs is a common problem. One of the most affected product groups are the slimming agents. There are no analytical protocols for the detection of synthetic adulterants from these products. The present study aimed at the development of a multistep analytical method for the quick and reliable determination of sibutramine, one of the most common adulterants among botanical food supplements. The extract of a sibutramine-containing slimming formula was analysed by colour tests, TLC, HPLC-DAD, MS and NMR. The multistep method proposed by the authors allows the quick identification of sibutramine in counterfeit samples in laboratories with different instrumentation.


Subject(s)
Appetite Depressants/analysis , Cyclobutanes/analysis , Dietary Supplements/analysis , Chromatography, High Pressure Liquid , Chromatography, Thin Layer , Color , Drug Contamination , Magnetic Resonance Spectroscopy , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Ultraviolet
12.
Analyst ; 137(17): 3982-8, 2012 Sep 07.
Article in English | MEDLINE | ID: mdl-22814401

ABSTRACT

A room temperature ionic liquids (RTILs) matrix-assisted desorption corona beam ionization (DCBI) technique was proposed. The quantification of the DCBI method for low-polar small molecules was improved greatly in terms of accuracy and precision. The thermal desorption processes of analytes in different liquid matrices under DCBI interrogation was investigated with thermal imaging and mass spectrometry simultaneously. When in a volatile liquid matrix, the analyte was not only desorbed thermally from the solid residue phase, but also desorbed along with evaporation of the matrix. The varying matrix evaporation speed and unstable sample introduction path clearly influence the quantitative result. With non-volatile RTILs utilized as the matrix in the sample introduction, a micro slow release system (MSRS) is formed to relieve the fluctuation of analyte evaporation. With the RTILs matrix-assisted DCBI-MS technique, dramatic improvement of the quantification precision (RSD from about 20% to less than 3%) for model analytes was achieved. Seventeen small pharmaceutical and four pesticide molecules were detected successfully. With a shared mechanism, other thermal desorption and/or APCI-related ambient ionization techniques may also benefit from the RTILs matrix.


Subject(s)
Ionic Liquids/chemistry , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Cyclobutanes/analysis , Small Molecule Libraries/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/instrumentation , Temperature , Water/chemistry
13.
Phytopathology ; 101(11): 1338-45, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21635142

ABSTRACT

Crop rotations with putative non-host crops such as sugar beet are often recommended to reduce Fusarium head blight (FHB) in cereals. However, recent observations have shown pathogenic, endophytic, and saprotrophic colonization of sugar beet with various Fusarium spp. Therefore, strains of seven species frequently isolated from sugar beet were tested for pathogenicity on wheat. Species-specific symptoms on heads and kernels were evaluated and the grains were analyzed for 20 mycotoxins with liquid chromatography-tandem mass spectrometry. Fusarium graminearum, F. culmorum, and F. cerealis from sugar beet caused typical FHB symptoms and mycotoxin contamination with deoxynivalenol and nivalenol, while a high incidence of black point was observed in heads inoculated with F. tricinctum or F. equiseti. Black point kernels revealed 3.4 to 14.5 times higher mycotoxin concentrations than symptomless grains, containing enniatin B1 at 38,000 µg/kg, moniliformin at 4,900 µg/kg, and 2-amino-14,16-dimethyloctadecan-3-ol at 5,500 µg/kg, as well as monoacetoxyscirpenol at 2,600 µg/kg and nivalenol at 3,800 µg/kg. Monitoring of these latter two species in the field is hampered by the lack of typical head symptoms after infection. In further experiments, the impact of sugar beet residues on FHB severity and the correlation between mycotoxin contamination of cereal lots and the amount of black point have to be evaluated.


Subject(s)
Beta vulgaris/microbiology , Fusarium/pathogenicity , Mycotoxins/biosynthesis , Plant Diseases/microbiology , Triticum/microbiology , Cyclobutanes/analysis , Depsipeptides/analysis , Depsipeptides/biosynthesis , Edible Grain/microbiology , Fusarium/chemistry , Fusarium/metabolism , Mycotoxins/analysis , Plant Leaves/microbiology , Plant Roots/microbiology , Species Specificity , Sphingolipids/analysis , Sphingolipids/biosynthesis , Trichothecenes/analysis , Trichothecenes/biosynthesis
14.
Phytopathology ; 101(11): 1330-7, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21770776

ABSTRACT

Based on a 2-year field trial at two locations in Lower Saxony (Germany), 395 Fusarium isolates belonging to 13 species were collected from more than 3,000 sugar beet roots that were apparently healthy at harvest. In a comparative screen, subsamples were analyzed for Fusarium infection directly after harvest and after different storage conditions. Depending on the storage duration, a different species composition was observed. F. redolens was predominant in freshly harvested beets, while F. culmorum, F. cerealis, and F. graminearum comprised 50.0% (2006) and 84.8% (2007) of the Fusarium mycoflora of sugar beets subjected to long-term pile storage. Randomly selected isolates of all species detected were tested for pathogenicity to sugar beet, but only isolates of F. graminearum and F. sambucinum caused severe root symptoms. Overall, 34 isolates of all species detected were characterized for their mycotoxin profile in rice culture to determine potentially produced toxins for future analysis of sugar beet. A total of 26 Fusarium mycotoxins were detected by liquid chromatography-tandem mass spectrometry, including trichothecenes, zearalenone, and especially high amounts of beauvericin, enniatins, and moniliformin. Further work is required to analyze the natural occurrence of these mycotoxins in sugar beet.


Subject(s)
Beta vulgaris/microbiology , Fusarium/classification , Fusarium/pathogenicity , Mycotoxins/biosynthesis , Cyclobutanes/analysis , Depsipeptides/analysis , Depsipeptides/biosynthesis , Edible Grain/microbiology , Fusarium/isolation & purification , Fusarium/metabolism , Germany , Mycotoxins/analysis , Oryza/microbiology , Plant Leaves/microbiology , Plant Roots/microbiology , Trichothecenes/analysis , Trichothecenes/biosynthesis , Zearalenone/analysis , Zearalenone/biosynthesis
15.
Folia Med (Plovdiv) ; 53(3): 65-7, 2011.
Article in English | MEDLINE | ID: mdl-22359985

ABSTRACT

Due the presence of sibutramine and citalopram in a number of drugs, neurotransmitter reuptake inhibitors. Sibutramine reduces the reuptake of serotonin, norepinephrine, and dopamine; citalopram is an antidepressant drug of the selective serotonin reuptake inhibitor. The thin-layer chromatography-densitometric behavior of some centrally acting serotonin reuptake inhibitors has been studied. The proposed analytical method is suitable for qualitative and quantitative analysis of sibutramine and citalopram.


Subject(s)
Antidepressive Agents/analysis , Chromatography, Thin Layer/methods , Citalopram/analysis , Cyclobutanes/analysis , Densitometry/methods
16.
Article in English | MEDLINE | ID: mdl-33412503

ABSTRACT

With an increase in the obese population, the indiscriminate demand for anti-obesity drugs for rapid weight loss or maintenance has grown. As a result, illegal substances that could induce unexpected negative health effects or fatal side effects are being produced and mixed into consumer products. In the present study, the metabolites of five major illegal anti-obesity drugs are analyzed for the first time. Our data can be utilized to identify related compounds and predict their toxicological effects. Didesmethylsibutramine, desmethylsibutramine, homosibutramine, chlorosibutramine, and benzylsibutramine were metabolized in in vitro and in vivo models, and the metabolites were identified using liquid chromatography quadrupole-time of flight mass spectrometry (LC-Q-TOF-MS) and tandem mass spectrometry (LC-Q-TOF-MS/MS). The in vivo metabolite analysis was carried out using urine and feces samples from rats, and the in vitro metabolite analysis was performed by incubating the analogues with human liver microsomes. We found that each sibutramine analogue was metabolized into several constituents: 2 (M1-2), 5 (M1-5), 11 (M1-11), 7 (N1-7), and 5 (O1-5). In conclusion, our metabolic study could be used for toxicological detection of illegal obesity treatments and metabolite identification in forensic cases.


Subject(s)
Anti-Obesity Agents , Chromatography, Liquid/methods , Cyclobutanes , Illicit Drugs , Tandem Mass Spectrometry/methods , Animals , Anti-Obesity Agents/analysis , Anti-Obesity Agents/metabolism , Cyclobutanes/analysis , Cyclobutanes/metabolism , Humans , Illicit Drugs/analysis , Illicit Drugs/metabolism , Male , Microsomes, Liver/metabolism , Rats , Rats, Sprague-Dawley
17.
Toxins (Basel) ; 13(9)2021 09 15.
Article in English | MEDLINE | ID: mdl-34564657

ABSTRACT

Fusarium proliferatum and Fusarium subglutinans are common pathogens of maize which are known to produce mycotoxins, including moniliformin (MON) and fumonisins (FBs). Fungal secondary metabolism and response to oxidative stress are interlaced, where hydrogen peroxide (H2O2) plays a pivotal role in the modulation of mycotoxin production. The objective of this study is to examine the effect of H2O2-induced oxidative stress on fungal growth, as well as MON and FBs production, in different isolates of these fungi. When these isolates were cultured in the presence of 1, 2, 5, and 10 mM H2O2, the fungal biomass of F. subglutinans isolates showed a strong sensitivity to increasing oxidative conditions (27-58% reduction), whereas F. proliferatum isolates were not affected or even slightly improved (45% increase). H2O2 treatment at the lower concentration of 1 mM caused an almost total disappearance of MON and a strong reduction of FBs content in the two fungal species and isolates tested. The catalase activity, surveyed due to its crucial role as an H2O2 scavenger, showed no significant changes at 1 mM H2O2 treatment, thus indicating a lack of correlation with MON and FB changes. H2O2 treatment was also able to reduce MON and FB content in certified maize material, and the same behavior was observed in the presence and absence of these fungi, highlighting a direct effect of H2O2 on the stability of these mycotoxins. Taken together, these data provide insights into the role of H2O2 which, when increased under stress conditions, could affect the vegetative response and mycotoxin production (and degradation) of these fungi.


Subject(s)
Cyclobutanes/metabolism , Fumonisins/metabolism , Fusarium/chemistry , Fusarium/growth & development , Fusarium/metabolism , Hydrogen Peroxide/metabolism , Oxidative Stress/drug effects , Cells, Cultured/drug effects , Crops, Agricultural/microbiology , Cyclobutanes/analysis , Fumonisins/analysis , Italy , Zea mays/microbiology
18.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 41(5): 873-6, 895, 2010 Sep.
Article in Zh | MEDLINE | ID: mdl-21302462

ABSTRACT

OBJECTIVE: To develop a method for simultaneous determination of hydrochlorothiazide, furosemide, clopamide, bumetanide and sibutramine hydrochloride in weight control foods with solid phase extraction-high performance liquid chromatography. METHODS: The analytes in the samples were extracted with 2% phosphoric acid-methanol (1:1, V/V) solution ultrasonically and centrifuged. The extracts were clean-up with Osis MCX SPE columns, concentrated under weak N2 stream, and reconstituted with 2% phosphoric acid-methanol (1:1, V/V) solution, vortex mixing and centrifugation at 12,000 r/min. The high performance liquid chromatography was performed with Phenomenex C18 (250 x 4.60 mm, 5 microm) as separation column, 0.02 mol/L acetonitrile potassium dihydrogen phosphate buffer as mobile phase, gradient elution of 1.0 mL/min for the flow rate, and 40 degrees C for the column temperature. The standard curve method was used for the quantitative analysis. RESULTS: A good linear range appeared for the five analytes from 0.25 to 100 microg/mL (r > or = 0.999). The detection limits were 5.2-108 microg/kg. The average recoveries were 86.5%-113.1%, with the relative standard deviations of 1.6%-8.9%. CONCLUSION: The proposed method is a reliable method with high selectivity and high sensitivity for the detection of the five illegal chemicals in the weight control foods.


Subject(s)
Chromatography, High Pressure Liquid , Clopamide/analysis , Food Contamination/analysis , Food, Formulated/analysis , Furosemide/analysis , Hydrochlorothiazide/analysis , Bumetanide/analysis , Chromatography, High Pressure Liquid/methods , Cyclobutanes/analysis , Sensitivity and Specificity , Solid Phase Extraction/methods
19.
Food Chem ; 317: 126409, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32087516

ABSTRACT

The main objective of this study was to screen, for the first time, the natural occurrence of non-regulated fungal metabolites in 204 maize samples harvested in Serbia in maize growing seasons with extreme drought (2012), extreme precipitation and flood (2014) and moderate drought conditions (2013 and 2015). In total, 109 non-regulated fungal metabolites were detected in examined samples, whereby each sample was contaminated between 13 and 55 non-regulated fungal metabolites. Moniliformin and beauvericin occurred in all samples collected from each year. In samples from year 2012, oxaline, questiomycin A, cyclo (l-Pro-l-Val), cyclo (l-Pro-l-Tyr), bikaverin, kojic acid and 3-nitropropionic acid were the most predominant (98.0-100%). All samples from 2014 were contaminated with 7-hydroxypestalotin, 15-hydroxyculmorin, culmorin, butenolid and aurofusarin. Bikaverin and oxaline were quantified in 100% samples from 2013 and 2015, while 3-nitropropionic acid additionally occurred in 100% samples from 2015.


Subject(s)
Food Contamination/analysis , Mycotoxins/analysis , Zea mays/microbiology , Cyclobutanes/analysis , Depsipeptides/analysis , Droughts , Food Contamination/legislation & jurisprudence , Food Microbiology , Fungi/metabolism , Mycotoxins/metabolism , Serbia , Zea mays/chemistry
20.
J Food Sci ; 85(8): 2608-2614, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32634283

ABSTRACT

The food irradiation marker, 2-dodecylcyclobutanone (2-DCB), assayed by SPME provides a fast and simple method to estimate the irradiation history of fat-containing food products. The SPME conditions were optimized to maximize the extraction of 2-DCB from chicken jerky treats (CJT) irradiated at low (5 kGy) and high (50 kGy) doses. The extracted 2-DCB was measured using GC-MS in selected ion mode (m/z 98, and 112). Water dilution (1:5) was needed to mobilize 2-DCB and allow partition to the headspace form the CJT matrix. Increasing the incubation temperature to 80 °C resulted in higher response. Spiking control jerky samples with 2-DCB from 10 to 150 ng/g CJT compared with spiking water revealed a significant food matrix effect. This method provides a fast, simple, and environmental friendly alternative for the existing solvent extraction methods.


Subject(s)
Cyclobutanes/isolation & purification , Meat Products/analysis , Meat Products/radiation effects , Solid Phase Microextraction/methods , Animals , Biomarkers/analysis , Chickens , Cyclobutanes/analysis , Food Irradiation , Gas Chromatography-Mass Spectrometry , Glycerol/analysis
SELECTION OF CITATIONS
SEARCH DETAIL