amanitins and beta-amanitin

Amanitin poisoning still has no particular, effective antidote. Erdosteine has been shown to protect numerous tissues, particularly those in the liver. This study investigates the potential therapeutic effects of erdosteine on alpha-, beta- and gamma-amanitin-induced hepatotoxicity in in vitro models. Three hours after administering amatoxins at various concentrations (1-50 μg/mL) to the cells of the C3A human hepatocyte cell line, erdosteine was administered in different concentrations (i.e., 1, 10, 50, 100 and 250 μg/mL). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was selected to determine cell viability. When concentrations of 1, 10, 50, 100 and 250 μg/mL of erdosteine were applied to cell lines, the following cell viability rates were obtained: 106%,99%,93%,86% and 86%, respectively, at a 10 μg/mL alpha-amanitin-induced toxicity; 43%,41%,41%,37% and 35%, respectively, at a 25 μg/mL alpha-amanitin-induced toxicity; 44%,42%,41%,39% and 41%, respectively, at a 50 μg/mL alpha-amanitin-induced toxicity; 136%,142%,143%,137% and 120%, respectively, at a 10 μg/mL beta-amanitin-induced toxicity; 113%,107%,107%,106% and 86%, respectively, at a 25 μg/mL beta-amanitin-induced toxicity; 78%,77%,77%,74% and 70%, respectively, at a 10 μg/mL gamma-amanitin-induced toxicity; and 39%,40%,39%,35% and 31%, respectively, at a 25 μg/mL gamma-amanitin-induced toxicity. This study was the first to evaluate the in vitro efficacy of erdosteine in cytotoxicity induced by alpha-, beta- and gamma-amanitin. Non-high (low and medium) doses of erdosteine are capable of nearly entirely preventing toxicity at mild hepatotoxic concentrations caused by amatoxin and partially preventing toxicity at moderate and severe concentrations. The beneficial effects of erdosteine, especially on the toxicity of alpha- and beta-amanitin, are promising.

Topics: Alpha-Amanitin; Amanitins; Hepatocytes; Humans; Thioglycolates; Thiophenes

Amanitin (AMA) is responsible for human fatalities after ingestion of poisonous mushrooms, thus, a rapid and accurate detection method is urgently needed. Here, gold nanoparticle-based immunosensor with monoclonal antibody against AMA was constructed for rapid detection of alpha- and beta-amanitin (α- and β-AMA) in mushroom, serum and urine samples. Under optimized conditions, the visual limits of detection (vLOD) and calculated LOD for α-AMA and β-AMA in mushroom were 10 ng/g, 20 ng/g, and 0.1 ng/g, 0.2 ng/g, respectively. Analysis of wild mushroom samples was also performed using a strip scan reader in the 10 min range. Furthermore, in mushrooms containing amatoxins results were confirmed and compared with those determined by liquid chromatography tandem mass spectrometry. Thus, this immunosensor provided a useful monitoring tool for rapid detection and screening of mushroom samples and in serum and urine from subjects who accidentally consumed AMA-containing mushrooms.

Topics: Agaricales; Alpha-Amanitin; Amanitins; Antibodies, Monoclonal; Biosensing Techniques; Gold; Humans; Immunoassay; Metal Nanoparticles

α-Amanitin and related amatoxins have been studied for more than six decades mostly by isolation from death cap mushrooms. The total synthesis, however, remained challenging due to unique structural features. α-Amanitin is a potent inhibitor of RNA polymerase II. Interrupting the basic transcription processes of eukaryotes leads to apoptosis of the cell. This unique mechanism makes the toxin an ideal payload for antibody-drug conjugates (ADCs). Only microgram quantities of toxins, when delivered selectively to tumor sites through conjugation to antibodies, are sufficient to eliminate malignant tumor cells of almost every origin. By solving the stereoselective access to dihydroxyisoleucine, a photochemical synthesis of the tryptathion precursor, solid-phase peptide synthesis, and macrolactamization we obtained a scalable synthetic route towards synthetic α-amanitin. This makes α-amanitin and derivatives now accessible for the development of new ADCs.

Topics: Agaricales; Alpha-Amanitin; Amanitins; Chromatography, High Pressure Liquid; Circular Dichroism; Cyclization; Immunoconjugates; Proton Magnetic Resonance Spectroscopy

Amanita fuligineoides, a lethal mushroom discovered in China, contains abundant cyclic peptide toxins that can cause fatal poisoning. However, the MSDIN gene family encoding for these cyclic peptides in A. fuligineoides has not been systematically studied. In this research, the transcriptome sequencing of A. fuligineoides was performed and its MSDIN family members were analyzed. A total of 4.41 Gb data containing 30833 unigenes was obtained; sequence alignments throughout several databases were done to obtain their functional annotations. Based on these annotations, MSDIN genes were found and verified by RT-PCR. A total of 29 different core peptides were obtained: 3 toxin genes, encoding β-amanitin (β-AMA), phalloidin (PHD), and phallacidin (PCD), and 26 genes encoding unknown cyclic peptides, 20 of which are reported for the first time and may encode for novel cyclic peptides. Analysis of the predicted precursor peptides indicated that octocyclic peptides were the main MSDIN peptides synthesized by A. fuligineoides, accounting for the 45%. A phylogenetic analysis suggested that studied precursor peptides could be clustered into 7 clades, which might represent different functionalities. Results suggested that A. fuligineoides might have a strong capacity to synthesize cyclopeptides, laying the foundation for their excavation and utilization.

Topics: Alpha-Amanitin; Amanita; Amanitins; Amino Acid Sequence; China; Gene Expression Profiling; Peptides, Cyclic; Sequence Alignment; Toxins, Biological; Transcriptome

A non-target screening method of cyclopeptide toxins and their analogues in mushroom was developed, using ultra-high-performance liquid chromatography coupled with quadrupole Orbitrap mass spectrometry (UHPLC-Q-Orbitrap MS) followed by mass spectrometry databases retrieval and software tools analysis for the candidate analogues. Three cyclopeptide toxins in the toxic mushroom Amanita rimosa were firstly screened without standard, and two of them were unknown analogues which were tentatively identified by the accurate masses, isotopic patterns and characteristic fragments. A validated quantitative method was performed to rapidly quantify three major cyclopeptide toxins in the Amanita rimosa sample including α-manitin, β-amanitin and phalloidin, and their contents were detected to be 4.52 mg/kg, 2.37 mg/kg and 2.53 mg/kg, respectively. The developed method has good selectivity and sensitivity for rapid and comprehensive screening the cyclopeptide toxins and their analogues in mushrooms at trace levels. Successful non-target screening of trace cyclopeptide toxin analogues will guarantee the food safety in mushrooms consumption.

Topics: Alpha-Amanitin; Amanita; Amanitins; Chromatography, High Pressure Liquid; Mass Spectrometry; Phalloidine

Amatoxins, most of which are hepatotoxic, can cause fatal intoxication. While mushrooms in the amatoxin-containing Galerina genus are rare, they can poison humans and animals worldwide. Few studies have profiled the toxicity of Galerina marginata. In addition, many studies indicate that macrofungi can have different characteristics in different regions. In this study, the quantities of toxins present in G. marginata from different provinces in Turkey were analysed using reversed-phase high-performance liquid chromatography with ultraviolet detection (RP-HPLC-UV) and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). G. marginata samples were collected from three different regions of Turkey. The taxonomic categorization of mushrooms was based on their micro- and macroscopic characteristics. The presence of toxins α-amanitin (AA), β-amanitin (BA), γ-amanitin (GA), phalloidin (PHD) and phallacidin (PHC) quantities were measured using RP-HPLC-UV and then were confirmed using LC-ESI-MS/MS. BA levels were higher than AA levels in G. marginata mushrooms collected from all three regions. Moreover, the levels of GA were below the detection limit and no phallotoxins were detected. This is the first study to identify and test the toxicity of G. marginata collected from three different regions of Turkey using RP-HPLC-UV. This is also the first study to confirm the UV absorption of amatoxins in G. marginata using LC-ESI-MS/MS, which is a far more sensitive process. More studies evaluating the toxicity of G. marginata in other geographic regions of the world are needed.

Topics: Alpha-Amanitin; Amanitins; Mushroom Poisoning; Toxins, Biological; Turkey

Amatoxins are known to be one of the main causes of serious to fatal mushroom intoxication. Thorough treatment, analytical confirmation, or exclusion of amatoxin intake is crucial in the case of any suspected mushroom poisoning. Urine is often the preferred matrix due to its higher concentrations compared to other body fluids. If urine is not available, analysis of human blood plasma is a valuable alternative for assessing the severity of intoxications. The aim of this study was to develop and validate a liquid chromatography (LC)-high resolution tandem mass spectrometry (HRMS/MS) method for confirmation and quantitation of α- and β-amanitin in human plasma at subnanogram per milliliter levels. Plasma samples of humans after suspected intake of amatoxin-containing mushrooms should be analyzed and amounts of toxins compared with already published data as well as with matched urine samples. Sample preparation consisted of protein precipitation, aqueous liquid-liquid extraction, and solid-phase extraction. Full chromatographical separation of analytes was achieved using reversed-phase chromatography. Orbitrap-based MS allowed for sufficiently sensitive identification and quantification. Validation was successfully carried out, including analytical selectivity, carry-over, matrix effects, accuracy, precision, and dilution integrity. Limits of identification were 20 pg/mL and calibration ranged from 20 pg/mL to 2000 pg/mL. The method was applied to analyze nine human plasma samples that were submitted along with urine samples tested positive for amatoxins. α-Amanitin could be identified in each plasma sample at a range from 37-2890 pg/mL, and β-amanitin was found in seven plasma samples ranging from <20-7520 pg/mL. A LC-HRMS/MS method for the quantitation of amatoxins in human blood plasma at subnanogram per milliliter levels was developed, validated, and used for the analysis of plasma samples. The method provides a valuable alternative to urine analysis, allowing thorough patient treatment but also further study the toxicokinetics of amatoxins.

Topics: Amanitins; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Humans; Mushroom Poisoning; Tandem Mass Spectrometry

Rapid and accurate identification of multiple toxins for clinical diagnosis and treatment of mushroom poisoning cases is still a challenge, especially with the lack of authentic references. In this study, we developed an effective method for simultaneous identification of amanita peptide toxins by liquid chromatography coupled with photodiode array detection and ion trap time-of-flight mass spectrometry. The accuracy and selectivity of the methodology were validated through similar multiple fragmentation patterns and characteristic ions of standard α- and β-amanitin. The developed method could successfully separate and identify major toxic constituents in Amanita mushrooms. Two amatoxins and three phallotoxins were confirmed in a single run through their fragmentation patterns and characteristic ions, which can be used as diagnostic fragment ions to identify mushroom toxins in complex samples. Furthermore, the performance of the developed method was verified by using real biological samples, including plasma and urine samples collected from rats after intraperitoneal administration of toxins. Thus, the development methodology could be crucial for the accurate detection of mushroom toxins without standard references.

Topics: Amanita; Amanitins; Animals; Chromatography, High Pressure Liquid; Injections, Intraperitoneal; Mass Spectrometry; Mushroom Poisoning; Mycotoxins; Rats; Reference Standards; Reproducibility of Results

α-Amanitin and β-amanitin are the main toxins of mushroom poisoning. The application of traditional non-selective adsorbents is not satisfactory in clinical treatment of amanita mushroom poisoning due to lack of specificity adsorption capability of these adsorbents toward amanitin toxins. In the current work, we introduce a novel molecularly imprinted biomimetic adsorbent based on a ligand specificity determinant through surface imprinted strategy. Owing to the expensive price of the amanitin sources, we selected a typical common moiety of α, β-amanitin as specificity determinant to synthesize a template necessary for the preparation of molecularly imprinted polymers (MIPs). Computer simulation was used to initially select acidic methacrylic acid (MAA) and basic 4-vinyl pyridine (4-VP) together as functional monomers. The experiments further demonstrated that the synergistic interaction of MAA and 4-VP played a primary role in the recognition of α, β-amanitin by MIPs. By means of batch and packed-bed column experiment and the hemocompatibility evaluation, the resultant biomimetic adsorbent has been proved to be capable of selectively removing α, β-amanitin and possess good hemocompatibility. This novel adsorbent has great potential to find application in human plasma purification.

Topics: Adsorption; Alpha-Amanitin; Amanitins; Biomimetics; Chromatography, High Pressure Liquid; Humans; Microscopy, Electron, Scanning; Microspheres; Molecular Imprinting; Polymers; Silicon Dioxide

Most of the fatal cases of mushroom poisoning are caused by Amanita phalloides. The amount of toxin in mushroom varies according to climate and environmental conditions. The aim of this study is to measure α-, β-, and γ-amanitin with phalloidin and phallacidin toxin concentrations. Six pieces of A. phalloides mushrooms were gathered from a wooded area of Düzce, Turkey, on November 23, 2011. The mushrooms were broken into pieces as spores, mycelium, pileus, gills, stipe, and volva. α-, β-, and γ-Amanitin with phalloidin and phallacidin were analyzed using reversed-phase high-performance liquid chromatography. As a mobile phase, 50 mM ammonium acetate + acetonitrile (90 + 10, v/v) was used with a flow rate of 1 mL/min. C18 reverse phase column (150 × 4.6 mm; 5 µm particle) was used. The least amount of γ-amanitin toxins was found at the mycelium. The other toxins found to be in the least amount turned out to be the ones at the spores. The maximum amounts of amatoxins and phallotoxin were found at gills and pileus, respectively. In this study, the amount of toxin in the spores of A. phalloides was published for the first time, and this study is pioneering to deal with the amount of toxin in mushrooms grown in Turkey.

Topics: Alpha-Amanitin; Amanita; Amanitins; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Forests; Fruiting Bodies, Fungal; Humans; Mushroom Poisoning; Mycelium; Peptides, Cyclic; Phalloidine; Species Specificity; Spectrophotometry, Ultraviolet; Spores, Fungal; Turkey

Amatoxin poisoning from the genus Lepiota may have a deadly outcome, although this is not seen as often as it is from the genus Amanita. In this report, we present a patient who was poisoned by a sublethal dose of Lepiota brunneoincarnata mushrooms. The patient was hospitalized 12 hours after eating the mushrooms. The patient's transaminase levels increased dramatically starting on day 4. Aspartate transaminase peaked at 78 hours. Starting at 1265 IU/L, alanine transaminase peaked at 90 hours at 5124 IU/L. The patient was discharged on day 8 to outpatient care, and his transaminase levels returned to normal ranges in the subsequent days. A toxin analysis was carried out on the mushrooms that the patient claimed to have eaten. Using reversed-phase high-performance liquid chromatography analysis, an uptake of approximately 19.9 mg of amatoxin from nearly 30 g of mushrooms was calculated. This consisted of 10.59 mg of α-amanitin, 9.18 mg of β-amanitin, and 0.16 mg of γ-amanitin. In conclusion, we present a patient from Turkey who was poisoned by L. brunneoincarnata mushrooms.

Topics: Adult; Agaricales; Alanine Transaminase; Alpha-Amanitin; Amanitins; Aspartate Aminotransferases; Chromatography, High Pressure Liquid; Humans; Liver; Male; Mushroom Poisoning; Turkey

There are few data estimating the human lethal dose of amatoxins or of the toxin level present in ingested raw poisonous mushrooms. Here, we present a patient who intentionally ingested several wild collected mushrooms to assess whether they were poisonous. Nearly 1 day after ingestion, during which the patient had nausea and vomiting, he presented at the emergency department. His transaminase levels started to increase starting from hour 48 and peaking at hour 72 (alanine aminotransferase 2496 IU/L; aspartate aminotransferase 1777 IU/L). A toxin analysis was carried out on the mushrooms that the patient said he had ingested. With reversed-phase high-performance liquid chromatography analysis, an uptake of approximately 21.3 mg amatoxin from nearly 50 g mushroom was calculated; it consisted of 11.9 mg alpha amanitin, 8.4 mg beta amanitin, and 1 mg gamma amanitin. In the urine sample taken on day 4, 2.7 ng/mL alpha amanitin and 1.25 ng/mL beta amanitin were found, and there was no gamma amanitin. Our findings suggest that the patient ingested approximately 0.32 mg/kg amatoxin, and fortunately recovered after serious hepatotoxicity developed.

Topics: Amanita; Amanitins; Chromatography, High Pressure Liquid; Humans; Male; Middle Aged; Mushroom Poisoning

Poisonings with Amanita phalloides toxins require fast diagnosis in order to avoid expensive and unnecessary therapies. Initial clinical assessment in combination with urinary amanitin analysis is necessary for a definite diagnosis. Therefore, a simple, fast, and robust method was developed for reliable detection of α- and β-amanitin as well as for fully validated quantification of α-amanitin in human urine. After simple dilution and centrifugation of the urine sample, a fast on-line extraction using a Transcend TLX-II system based on turbulent flow chromatography (TurboFlow) was established. A new TurboFlow mode was introduced, the pseudo quick elute mode (PQEM), which had more options for method optimization than the generic quick elute mode (QEM). It allowed running several modes in one valve arrangement. The PQEM showed better practicability in routine and emergency analysis than the previously used methods. After extraction, the fast 15min LC-high resolution (HR)-MS/MS analysis allowed reliable identification of α- and β-amanitin based on fragments identified using so-called HR pseudo MS(3) experiments. According to international recommendations, the requirements for full validation including the parameters selectivity, calibration, accuracy, precision, recovery, matrix effects, and stability were fulfilled for α-amanitin. The method was successfully applied to the analysis of authentic urine samples containing amatoxins. In conclusion, this method allowed the determination of amatoxins using the novel PQEM in a faster, robust, and more reliable way than existing methods, making it suitable for daily routine and especially emergency toxicological analysis.

Topics: Amanita; Amanitins; Calibration; Chromatography, High Pressure Liquid; Humans; Reproducibility of Results; Tandem Mass Spectrometry

Amanita exitialis is a lethal mushroom that was first discovered in Guangdong Province, China. The high content of amanitin in its basidiocarps makes it lethal to humans. To comprehensively characterize the A. exitialis transcriptome and analyze the Amanita toxins as well as their related gene family, transcriptome sequencing of A. exitialis was performed using Illumina HiSeq 2000 technology. A total of 25,563,688 clean reads were collected and assembled into 62,137 cDNA contigs with an average length of 481 bp and N50 length of 788 bp. A total of 27,826 proteins and 39,661 unigenes were identified among the assembled contigs. All of the unigenes were classified into 166 functional categories for understanding the gene functions and regulation pathways. The genes contributing to toxic peptide biosynthesis were analyzed. From this set, eleven gene sequences encoding the toxins or related cyclic peptides were discovered in the transcriptome. Three of these sequences matched the peptide toxins α-amanitin, β-amanitin, and phallacidin, while others matched amanexitide and seven matched unknown peptides. All of the genes encoding peptide toxins were confirmed by polymerase chain reaction (PCR) in A. exitialis, and the phylogenetic relationships among these proprotein sequences were discussed. The gene polymorphism and degeneracy of the toxin encoding sequences were found and analyzed. This study provides the first primary transcriptome of A. exitialis, which provided comprehensive gene expression information on the lethal amanitas at the transcriptional level, and could lay a strong foundation for functional genomics studies in those fungi.

Topics: Alpha-Amanitin; Amanita; Amanitins; Amino Acid Sequence; Base Sequence; Fruiting Bodies, Fungal; Fungal Proteins; Molecular Sequence Annotation; Molecular Sequence Data; Peptides, Cyclic; Phylogeny; Polymorphism, Genetic; Sequence Analysis, DNA; Transcriptome

Amanitins, highly toxic cyclopeptides isolated from various Amanita species, are the most potent poisons accounting for the hazardous effects on intestinal epithelium cells and hepatocytes, and probably the sole cause of fatal human poisoning. The present study was focused on the development, optimization and application of an analytical methodology by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), following urine and liver sample preparation by protein precipitation with organic solvents, and solid phase extraction (SPE) procedure, for the determination of the amatoxins, α- and β-amanitin. Linearity, detection and quantification limits, selectivity, sensitivity, intra and inter-assay precision and recovery were studied, in order to guarantee reliability in the analytical results. The developed method proved to be specific and selective, with LOD (Limit of Detection) values for α- and β-amanitin of 0.22 and 0.20 ng mL(-1) in urine and 10.9 and 9.7 ng g(-1) in liver, respectively. LOQ (Limit of Quantification) values ranged from 0.46 to 0.57 ng mL(-1) in urine and 12.3-14.7 ng g(-1) in tissue, for both amanitins. Linearity, in the range of 10.0-200.0 ng mL(-1) or ng g(-1), shows that coefficients of correlation were greater than 0.997 for α-amanitin and 0.993 for β-amanitin. Precision was checked at three levels during three consecutive days with intra-day and inter-day coefficients of variation not greater than 15.2%. The extraction recovery presents good results for the concentrations analyzed, with values ranging from 90.2 to 112.9% for both matrices. Thus, the proposed analytical method is innovative, presents a high potential in the identification, detection and determination of α- and β-amanitins in urine and tissue samples, as well as in other biological samples, such as kidney and mushrooms.

Topics: Amanitins; Chemistry Techniques, Analytical; Chromatography, High Pressure Liquid; Humans; Liver; Molecular Structure; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization; Time Factors; Urinalysis

Although rarely seen, Amanita phalloides var. alba, a variety of A. phalloides type mushrooms, causes mushroom poisoning resulting in death. Since it is frequently confused with some edible mushrooms due to its white colored cap and macroscopic appearance, it becomes important in toxicological terms. Knowledge of the toxin amount contained in this mushroom type is invaluable in the treatment of cases involving poisoning. In this study, we examined the toxin levels of various parts of the A. phalloides var. alba mushroom growing Duzce region of Turkey. Toxin analyses were carried out for A. phalloides var. alba, which were collected from the forests Duzce region of Turkey in 2011, as a whole and also separately in its spore, pileus, gills, stipe and volva parts. The alpha amanitin, beta amanitin, gamma amanitin, phalloidin and phallacidine analyses of the mushrooms were carried out using the RP-HPLC method. A genetic analysis of the mushroom showed that it had similar genetic characteristics as A. phalloides and was a variety of it. The lowest toxins quantity was detected in spores, volva and stipe among all parts of the mushroom. The maximum amount of amatoxins was measured in the gills. The pileus also contained a high amount of amatoxins. Generally, amatoxins and phallotoxin concentrations were lower as compared to A. phalloides, but interestingly all toxins other than gamma toxin were higher in the spores of A. phalloides var. alba. The amount of toxin in all of its parts had sufficient concentrations to cause death. With this study, the amatoxin and phallotoxin concentrations in A. phalloides var. alba mushroom and in its parts have been revealed in detail for the first time.

Topics: Amanita; Amanitins; Chromatography, High Pressure Liquid; DNA, Fungal; Sequence Analysis, DNA; Toxins, Biological

Amanitins are toxins found in species of the mushroom genera Amanita, Lepiota and Galerina. Intoxication after ingestion of these mushrooms can be fatal with an estimated 20% of mortality rate. An early diagnosis is necessary in order to avoid invasive and expensive therapy and to improve patient's prognosis. In this paper, a Capillary Zone Electrophoresis method was developed and validated to determine alpha- and beta-amanitin in urine in less than 7 min using 5 mM, pH 10 borate buffer as background electrolyte. The separation conditions were: capillary: 75 microm I.D., 41 cm effective length, 48 cm total length, 25 degrees C, 20 KV and PDA detection at 214 nm. Sample treatment for analysis only required urine dilution in background electrolyte. The method was validated following established criteria and was found to be selective, linear in the range 5-100 ng/ml. Intra- and inter-day precision and accuracy were within required limits. Limit of detection (LOD) and limit of quantification (LOQ) were 1.5 and 5 ng/ml, respectively. Eight urine samples from suspected cases of intoxication with amanitins were analyzed after 2 years of storage at -20 degrees C, and beta-amanitin was determined in two samples with concentrations of 53 and 65 ng/ml, respectively. The method here described includes the use of non-aggressive reagents to the capillary or the system and is the first Capillary Electrophoresis method used to determine amanitins in clinical samples.

Topics: Alpha-Amanitin; Amanita; Amanitins; Borates; Buffers; Calibration; Chemistry, Clinical; Drug Stability; Electrophoresis, Capillary; Freezing; Humans; Hydrogen-Ion Concentration; Methanol; Molecular Structure; Mushroom Poisoning; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Time Factors

Spectral studies of the interaction between amanitine and ethidium bromide fluorophore showed the appearance of a new intensive fluorescence band after addition of amanitine to ethidium bromide solution, caused by the formation of a charge-transfer complex. The new fluorescence band is located in a shorter wave region of the spectrum compared to ethidium bromide fluorescence band. Based on the results, a rapid fluorescent method for detection of amanitines was developed.

Topics: Amanita; Amanitins; Ethidium; Spectrometry, Fluorescence

Polyclonal antisera to beta-amanitin were generated in sheep and used to construct a competitive ELISA for measurement of the toxin in human serum and urine. The assay had a detection limit of about 80 pg mL(-1), a dynamic range of 80-2,000 pg mL(-1), a cross reactivity of 22% with alpha-amanitin, and no cross reactivities with cyclic peptides from algal sources. Assay responses in buffer, serum, and urine were remarkably similar. Coupling of the toxin to carrier proteins was carried out by previously unreported methods. The key step that allowed the construction of the highly sensitive assay was the introduction of a novel heterologous hapten derivative made of beta-amanitin-cyanuric chloride derivative. The new derivative overcame the problems of bridge binding that was, in this case, particularly serious with the homologous hapten derivative. The study demonstrated that the developed antiserum and ELISA procedure can be used to detect beta-amanitin and related toxins from Amanita phalloides in human serum and urine samples from suspected poison cases and enable early treatment to be administered.

Topics: Amanitins; Animals; Binding, Competitive; Buffers; Calibration; Enzyme-Linked Immunosorbent Assay; Immune Sera; Molecular Structure; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Sheep; Titrimetry

High-performance liquid chromatographic (HPLC) assay has been developed for the simultaneous determination of alpha-amanitin, beta-amanitin and phalloidin in serum. Three toxins were extracted by reflux in a water bath at 80 degrees C for one hour and purified by Sep-Pak Plus tC18 cartridges. The HPLC assay was performed under gradient conditions using Develosil RP AQUEOUS column. The moble phase consisted with a mixture of acetonitorile containing 0.01 M ammonium acetate(pH 5.0). The column effluence was monitored at 295 nm, 302 nm and 230 nm for 35 min. Detection limit of three toxins in serum were 0.2 microgram/ml respectively. High recovery yields in the range of 81.5-88.1% for toxins were obtained by using this method.

Topics: Amanitins; Chromatography, High Pressure Liquid; Cryopreservation; Humans; Phalloidine; Specimen Handling; Time Factors

Specific detection of amanitins in body fluids is necessary for an early diagnosis of an intoxication with amanita mushrooms. In this paper, a liquid chromatographic-mass spectrometric assay after immunoaffinity extraction (IAE-LC-MS) is described for the determination of alpha- and beta-amanitin in urine. The method has been validated according to the criteria established by the Journal of Chromatography B. The assay was found to be selective. The calibration curves for alpha- and beta-amanitin were linear from 5 to 75 ng/ml. Intra- and inter-day accuracy and precision were inside the required limits. Amatoxins in frozen urine samples or immunoaffinity extracts were stable for more than 6 months, and the IAE columns could be used more than fifty times without remarkable loss in performance. LOD for alpha- and beta-amanitin was 2.5 ng/ml and LOQ for both was 5.0 ng/ml. The absolute recoveries of alpha- and beta-amanitin were 63% and 58% for the low quality control and 61% and 57% for the high quality control. The absolute recovery for the internal standard gamma-amanitin methyl ether at 25 ng/ml was 60%. The analysis of 5 authentic urine samples from patients intoxicated by amanita mushrooms showed a good correlation between the results measured by radioimmunoassay and the IAE-LC-MS assay. A partial validation showed that the assay was also suitable for plasma analysis.

Topics: Agaricales; Amanitins; Chromatography, Affinity; Chromatography, High Pressure Liquid; Mass Spectrometry; Reproducibility of Results

GC-MS is the method of choice for toxicological analysis of toxicants volatile in GC while non-volatile and/or thermally labile toxicants need LC-MS for their determination. Studies are presented on the toxicological detection of the amphetamine-like anorectic clobenzorex in urine by GC-MS after acid hydrolysis, extraction and acetylation and by fluorescence polarization immunoassay (FPIA, TDx (meth)amphetamine II). After ingestion of 60 mg of clobenzorex, the parent compound and/or its metabolites could be detected by GC-MS for up to 84 h or by FPIA for up to 60 h. Since clobenzorex shows no cross-reactivity with the used immunoassay, the N-dealkylated metabolite amphetamine is responsible for the positive TDx results. The intake of clobenzorex instead of amphetamine can be differentiated by GC-MS detection of hydroxyclobenzorex which is detectable for at least as long as amphetamine. In addition, the described GC-MS procedure allows the simultaneous detection of most of the toxicologically relevant drugs. Furthermore, studies are described on the atmospheric pressure ionization electrospray LC-MS detection of alpha- and beta-amanitin, toxic peptides of amanita mushrooms, in urine after solid-phase extraction on RP-18 columns. Using the single ion monitoring mode with the ions m/z 919 and 920 the amanitins could be detected down to 10 ng/ml of urine which allows us to diagnose intoxications with amanita mushrooms.

Topics: Amanitins; Amphetamines; Fluorescence Polarization Immunoassay; Gas Chromatography-Mass Spectrometry; Humans; Time Factors; Toxicology

Poly(A)-RNA fractions of dormant, dark-imbibed (non-germinating) and photoinduced (germinating) spores of Onoclea sensibilis were poor templates in the rabbit reticulocyte lysate protein synthesizing system, but the translational efficiency of poly(A)+RNA was considerably higher than that of unfractionated RNA. Poly(A)+RNA isolated from photoinduced spores had a consistently higher translational efficiency than poly(A)+RNA from dark-imbibed spores. Analysis of the translation products by one-dimensional polyacrylamide gel electrophoresis showed no qualitative differences in the mRNA populations of dormant, dark-imbibed, and photoinduced spores. However, poly(A)+RNA from dark-imbibed spores appeared to encode in vitro fewer detectable polypeptides at a reduced intensity than photoinduced spores. A DNA clone encoding the large subunit of maize ribulose bisphosphate carboxylase hybridized at strong to moderate intensity to RNA isolated from dark-imbibed spores, indicating the absence of mRNA degradation. Although alpha-amanitin did not inhibit the germination of spores, the drug prevented the elongation of the rhizoid and protonemal initial with a concomitant effect on the synthesis of poly(A)+RNA. These results are consistent with the view that some form of translational control involving stored mRNA operates during dark-imbibition and photoinduced germination of spores.

Topics: Amanitins; Cell-Free System; Genes, Plant; Germination; Plant Physiological Phenomena; Plants; Protein Biosynthesis; RNA, Messenger; Spores

The conjugates beta-amanitin-concanavalin A and phallacidin concanavalin A were tested for direct cytotoxicity on L1210 lymphocytic leukemia cells by a combined in vitro-in vivo bioassay. Both conjugates exerted strong direct cytotoxicity on the tumour cells.

Topics: Amanitins; Animals; Cell Survival; Concanavalin A; Cytotoxins; Immunotoxins; Leukemia L1210; Peptides, Cyclic; Tumor Cells, Cultured

Poly-L-ornithine with an average molecular weight of 32K was reacted with beta-amanitin hydroxysuccinimide ester to form an amide-linked toxin conjugate. Loading of the polymeric chain with amanitin was high, corresponding to up to 35% of the total weight. To this amatoxin vehicle we attached a targeting molecule, human recombinant leucine-21 epidermal growth factor (hrEGFL), via a disulfide-containing linker moiety. A typical average stoichiometry of the hrEGFL labeled toxin conjugate was (L-Orn)164(beta-amanitin)19(COC2H4SSC2H4CO-hrEGFL)2. The affinity for EGF receptors of hrEGFL bound in this conjugate was tested by using A 431 cells. The affinity was eight times lower than that of unsubstituted hrEGFL but regarded as high enough for studying specific toxicity effects with cells bearing EGF receptors. We found that beta-amanitin in the labeled conjugate was able to inhibit the growth of A 431 cells at a concentration of 28 nM, 80 times lower than for native beta-amanitin and 20 times lower than for poly-L-ornithine-bound beta-amanitin without the hrEGFL label. The approximately 20-fold enhancement of cytotoxicity suggests a specific internalization of the toxin conjugate mediated by the hormone label. This idea is supported by the fact that also in another transformed fibroblast cell line, with an increased though smaller number of EGF receptors than A 431 cells, the corresponding enhancement of cytotoxicity was demonstrable but less pronounced (7-fold). The hormone-mediated increase in cytotoxicity of EGF labeled poly-L-ornithine-beta-amanitin conjugates, combined with their moderate toxicity in the mouse, encourages further examination of such compounds in tumor model systems in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Amanitins; Animals; Cytotoxins; Epidermal Growth Factor; ErbB Receptors; Humans; Peptides; Tumor Cells, Cultured

A monoclonal antibody, with high affinity against the mushroom toxin alpha-amanitin, was prepared. Administration of the Fab fragment of the monoclonal antibody to mice caused a 50-fold increase in alpha-amanitin toxicity. Electron micrographs showed normal appearance of hepatocytes but typical, amanitin-induced lesions in cells of the proximal convoluted tubules of the kidney. The pronounced nephrotoxicity is mainly explained by glomerular filtration and tubular reabsorption of the Fab-amatoxin complex and, to a lesser extent, of the immunoglobulin-amatoxin complex, which is still c. Twice as toxic as free alpha-amanitin. To our knowledge this is the first reported case where immunoglobulins or their fragments enhance rather than decrease the activity of a toxin. Accordingly, immunotherapy of Amanita mushroom poisoning in humans does not appear promising.

Topics: Amanitins; Animals; Antibodies, Monoclonal; Female; Immunoglobulin Fab Fragments; Kidney Tubules; Mice; Mice, Inbred Strains; Microscopy, Electron; Mushroom Poisoning

Pure beta-amanitin was isolated by combined adsorption chromatography of a crude methanol extract from Amanita phalloides on Sephasorb HP Ultrafine and Sephadex LH-20. The beta-amanitin was coupled to concanavalin A by the carbodiimide method. The conjugate was purified by fractionation on a column of Sephadex G-75. The molar ratio beta-amanitin to concanavalin A in this conjugate was 4.14. The purified conjugate was tested by thin-layer chromatography and showed characteristic (for amatoxins) bright purple staining but different mobility. The ultraviolet spectrum of the conjugate was different from the spectra of the native beta-amanitin and the native concanavalin A. The toxicity of the conjugate was determined by in vivo toxicological studies and was four-fold lower than that of the native beta-amanitin. These results suggest that this conjugate may be used for immunization procedures and for the production of amatoxin-specific antibodies.

Topics: Amanitins; Animals; Chromatography, Thin Layer; Concanavalin A; Immunodiffusion; Spectrophotometry, Ultraviolet

A high-performance liquid chromatographic assay of alpha-amanitin and beta-amanitin in human serum, urine, or stomach washings is described. Sample preparation involves a chemical step with deproteinization and organic solvent treatment, and a selective cleanup and concentration step on reversed-phase prepacked cartridges. Separations are performed on a reversed-phase analytical column under isocratic conditions with uv detection at 280 nm. The method allows the quantitation of alpha- and beta-amanitin separately with a detection limit of 10 ng/ml for both toxins.

Topics: Amanitins; Chromatography, High Pressure Liquid; Freeze Drying; Gastrointestinal Contents; Humans; Microchemistry; Solvents