Anatoxin a

165.23

165.23

80023A73NK

Oil

2933990090

29.10000

1.74500

1.037 g/cm3

291ºC at 760 mmHg

124.7ºC

1.503

In water, 7.2X10+4 mg/L at 25 °C (est)

Desiccate at +4°C

5.8X10-3 mm Hg at 25 °C (est)

Abdominal cavity-mouse LDL0: 0.25 mg/kg

Flammable; burning produces toxic nitrogen oxide fumes

D25 +39.8°

Henry's Law constant = 6.6X10-9 atm-cu m/mol at 25 °C (est)

pKa = 9.4

Unstable under basic conditions|C10H15NO.HCl; WM: 201.7 /Anatoxin A hydrochloride/|Hydroxyl radical reaction rate constant = 1.2X10-10 cu cm/molec-sec at 25 °C (est)

Anatoxin-a

Warehouse ventilated, low temperature and dry

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

EPA; Cyanobacteria and Cyanotoxins: Information for Drinking Water Systems EPA-810F11001 (September, 2014)[Available from, as of October 4, 2018: https://www.epa.gov/sites/production/files/2014-08/documents/cyanobacteria_factsheet.pdf]|WHO; Guidelines for Safe Recreational Water Environments, Vol 1: Coastal and Fresh Waters. ISBN 92 4 154580 1 (2003).[Available from, as of July 14, 2009: http://whqlibdoc.who.int/publications/2003/9241545801_contents.pdf]|WHO; Cyanobacterial toxins: Microcystin-LR in Drinking-water. Background document for development of WHO Guidelines for Drinking-water Quality. WHO/SDE/WSH/03.04/57 (2003).[Available from, as of September 24, 2018: http://www.who.int/water_sanitation_health/dwq/chemicals/cyanobactoxins.pdf]|Toxic Cyanobacteria. Current Status of Research and Mangement. Proceedings of an International Workshop. Adelaide, Australia, March 22-26, 1994. Steffensen DA, Nicholson BC, eds. Amer Water Works Assoc Res Found; Australian Centre for Water Quality Res; Centre for Water Research, Belgium. (1994)

|Warning|H302+H312+H332 (97.44%): Harmful if swallowed, in contact with skin or if inhaled [Warning Acute toxicity, oral; acute toxicity, dermal; acute toxicity, inhalation]|P201, P202, P261, P264, P270, P271, P280, P281, P301+P312, P302+P352, P304+P312, P304+P340, P308+P313, P312, P322, P330, P363, P405, and P501|Aggregated GHS information provided by 39 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a POTW is acceptable only after review by the governing authority. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal. If it is not practicable to manage the chemical in this fashion, it must meet Hazardous Material Criteria for disposal.|... Nanofiltration membranes are an effective barrier against anatoxin-a and microcystins in drinking water. Anatoxin-a and especially microcystins were almost completely removed, regardless of the variations in feed water quality (natural organic matter and competitive toxin), the water recovery rate and the pH values. Anatoxin-a removal was governed by electrostatic interactions and steric hindrance, whereas for microcystins the latter was the main mechanism. In turn, fluxes were significantly impacted by background organics and, especially, inorganics (pH, calcium).

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.|Because adequate surveillance is difficult and few immediate management options are available (other than precluding or discouraging use or cancelling water sports activities such as competitions), provision of adequate public information is a key short-term measure. Medium- to long-term measures are identification of the sources of nutrient (in many ecosystems phosphorus, sometimes nitrogen) pollution and significant reduction of nutrient input in order to effectively reduce proliferation not only of cyanobacteria, but of potentially harmful algae as well. /Cyanotoxins/|Within areas subject to the occurrence of marine toxic algae or cyanobacteria, it is important to carry out adequate monitoring activities and surveillance programs. In affected areas, it is appropriate to provide health information to general practitioners and the general public, in particular recreational water users. Precautionary measures include avoiding areas with visible algal concentrations and/or algal scums in the sea as well as on the shore, avoiding sitting downwind of any algal material drying on the shore and showering to remove any algal material. /Cyanobacteria and toxic algae/

Symptoms reported include ... skin and eye irritations. /Cyanotoxins/

most toxic

IDENTIFICATION AND USE: Anatoxin A is an oil. Anatoxin A is a neurotoxin produced by several freshwater cyanobacteria and implicated in lethal poisonings of domesticated animals and wildlife. HUMAN STUDIES: Teenager who had been wrestling and diving in a pond with a heavy scum of toxic Anabaena flos-aquae died through exposure to blue-green algal toxin. The cyanobacterial cells were found in fecal samples, and toxin was measured in scum samples. The teenager and his friend both suffered severe vomiting, diarrhea, and abdominal pain. In the more severely affected individual, this ended in shock and seizure 48 hr after exposure. The toxin implicated, anatoxin A, is a fast-acting neurotoxin, but there are no data on human exposure. A neurotoxin would not be expected to cause the gastroenteritis, though it could cause death through respiratory inhibition and convulsions. ANIMAL STUDIES: Anatoxin A is a potent neurotoxin produced by several genera of cyanobacteria. Deaths of wild and domestic animals due to anatoxin-a exposure have been reported following a toxic response that is driven by the inhibition of the acetylcholine receptors at neuromuscular junctions. The consequent neuron depolarization results in an overstimulation of the muscle cells. Doses of 200 or 125 ug/kg bw anatoxin A were given i.p. to hamsters one or three times per day, respectively, at days 12 to 14 of pregnancy (after organogenesis), and the dams were sacrificed at day 15. The treatment given three times per day caused fetal malformation (hydrocephaly) in all fetuses in one of 10 litters, and stunted growth in almost all litters. Treatment given once per day resulted in stunted growth. No maternal toxicity was observed. Anatoxin A caused dose-dependent histopathological changes in the testes of mice such as degenerations in seminiferous tubules, intercellular disassociation of spermatogenetic cell lines, sloughing of germ cells into tubular lumen, vacuolization in Sertoli cells and loss of germ cells. Genotoxicity test was conducted on Salmonella typhimurium TA 1535/pSK1002 strain, with and without metabolic transformation. The toxin concentrations were 0.25, 0.5, 1 and 2 ug/mL. The highest inefficient concentration of anatoxin A without metabolic transformation was 0.25 ug/m. No effects were detected with metabolic activation. Dog deaths occurred in 1990 and 1991 after the animals drank water containing blooms of benthic cyanobacteria along the shoreline of Loch Insh, Scotland. Signs of poisoning in the affected animals and the high neurotoxicity of bloom extracts in laboratory bioassays indicated acute poisoning due to cyanobacterial neurotoxin(s). The neurotoxic blooms consisted largely of benthic Oscillatoria species which were also observed in the stomach contents of the poisoned dogs. Stomach contents were also neurotoxic in bioassays with the same signs of poisoning as the Oscillatoria blooms. The cyanobacterial alkaloid neurotoxin anatoxin A was identified in bloom extracts and poisoned dog stomach contents. ECOTOXICITY STUDIES: A die-off of bats was observed in a lake about 150 km north of Edmonton, Alberta, Canada, in 1985. Over 1000 Myotis spp. and hoary bats (Lasiurus cinereus) died of 'algal poisoning' caused by an alkaloid when they drank water from the lake. Cyanobacterial blooms were implicated in bird kills at lakes in Denmark in July 1993 and June-July 1994. Anatoxin A is an inducer of apoptosis in fish immune cells. Stages 17 and 25 toad embryos (Bufo arenarum) were exposed to 0.03-30.0 mg/L of anatoxin-a for 10 days. Adverse effects included a dose-dependent transient CNS depression, edema and loss of equilibrium. Most notable was the occurrence of 100% mortality at the high dose in both groups 6-13 days post-exposure.

Some 2000 species of cyanobacteria (blue-green algae) occur globally in aquatic habitats. They are able to survive under a wide range of environmental conditions and some produce potent toxins. Toxin production is correlated with periods of rapid growth (blooms) and 25%-70% of blooms may be toxic. Anatoxin-a is an alkaloid neurotoxin that acts as a potent neuro-muscular blocking agent at the nicotinic receptor. Acute toxicity, following consumption of contaminated water, is characterized by rapid onset of paralysis, tremors, convulsions and death. Human exposures may occur from recreational water activities and dietary supplements, but are primarily through drinking water. The current studies were conducted to examine the effect of in utero exposure on postnatal viability, growth and neurodevelopment, to evaluate the potential of in vitro embryotoxicity, and to explore the synergistic relationship between anatoxin-a and the algal toxin microcystin-LR by the oral route. The results of preliminary studies on amphibian toxicity are also reported. Time-pregnant mice received 125 or 200 ug/kg anatoxin-a by intraperitoneal injection on gestation days (GD) 8-12 or 13-17. Pup viability and weight were monitored over a 6-day period. Maternal toxicity (decreased motor activity) was observed at 200 ug/kg in both treatment periods. There were no significant treatment-related effects on pup viability or weight on postnatal day (PND) 1 or 6. The GD 13-17 pups were evaluated on PND 6, 12 and 20 for standard markers of neurodevelopmental maturation (righting reflex, negative geotaxis and hanging grip time). No significant postnatal neurotoxicity was observed. In vitro developmental toxicity was evaluated in GD 8 mouse embryos exposed to 0.1-25 um anatoxin-a for 26-28 hr. Perturbations in mouse yolk sac vasculature were noted from the 1.0 um concentration in the absence of significant embryonic dysmorphology. Potential algal toxin synergism was tested in mice receiving either 0, 500 or 1,000 ug/kg microcystin-LR by gavage and approximately 50 min later receiving either 0, 500, 1,000 or 2,500 ug/kg anatoxin-a by the same route. No deaths occurred at any dose and no definitive signs of intoxication were observed. Stages 17 and 25 toad embryos (Bufo arenarum) were exposed to 0.03-30.0 mg/L of anatoxin-a for 10 days. Adverse effects included a dose-dependent transient narcosis, edema and loss of equilibrium. Most notable was the occurrence of 100% mortality at the high dose in both groups 6-13 days post-exposure. The observed delay between initial exposure and death is highly unusual for anatoxin-a.

LD50 Mouse oral >5000 ug/kg|LD50 Mouse iv <100 ug/kg|LD50 Mouse ip 200 ug/kg|LD50 Mouse iv 386 ug/kg /(+)anatoxin-a hydrochloride/|LD50 Mouse iv 913 ug/kg (846-985 ug/kg) /Racemic anatoxin-a hydrochloride/

/BIRDS and MAMMALS/ A die-off of bats was observed in a lake about 150 km north of Edmonton, Alberta, Canada, in 1985. Over 1000 Myotis spp. and hoary bats (Lasiurus cinereus) died of 'algal poisoning' caused by an alkaloid known as Anabaena Very Fast Death Factor when they drank water from the lake.|/BIRDS and MAMMALS/ Cyanobacterial mats at hot springs on the shore of the alkaline Lake Bogoria, Kenya, were investigated regarding species community and cyanobacterial toxin content. The hepatotoxins microcystin-LR, -RR, -LF and -YR, and the neurotoxin anatoxin-a were present. The mats were dominated by Phormidium terebriformis, Oscillatoria willei, Spirulina subsalsa and Synechococcus bigranulatus. The concentration of microcystins in mat samples, ranged from 221 to 845 ug microcystin-LR equivalents g(-1) DW of mat. Anatoxin-a concentrations ranged from 10 to 18 ug/g DW of mat. A contribution of the cyanobacterial toxins from the hot spring mats to the mass mortalities of Lesser Flamingos is suggested by: (a), the presence of hot spring cyanobacterial cells and cell fragments, and high concentrations of the cyanobacterial hepato- and neurotoxins in flamingo stomach contents and faecal pellets; (b), observations of neurological signs of bird poisoning at the lake. Cyanobacterial toxins in stomach contents, intestine and fecal pellets were 0.196 ug/g fresh weight (FW) for the microcystins and 4.34 ug/g FW for anatoxin-a. Intoxication with cyanobacterial toxins could occur by uptake of detached cyanobacterial cells from the mats, as the flamingos need to drink fresh or brackish water, and to wash their feathers daily, which they do in the vicinity of the hot springs, where salinity is lower than in the main body of water of the lake.|/BIRDS and MAMMALS/ Cyanobacterial blooms were implicated in bird kills at lakes in Denmark in July 1993 and June-July 1994. These blooms were dominated by Anabaena lemmermannii and were shown to contain a neurotoxin with anticholinesterase activity. In this study, the toxin was isolated by mouse lethality guided column chromatographies from the field sample collected at Lake Knud so in 1993. Various spectroscopic data indicated that the toxin was anatoxin-a(s), an irreversible anticholinesterase, first reported in Anabaena flos-aquae. Chemical detection of the same toxin in cultured A. lemmermannii also confirmed this species as the cause of the deaths of the wild birds.|/AQUATIC SPECIES/ Cyanobacteria (Cyanophyta, Cyanoprocaryota, Cyanobacteria) (blue-green algae) are procaryotic phototrophic microorganisms playing an important ecological role in the freshwater and marine environment as primary producers. However, as a consequence of water eutrophication observed in many reservoirs in different parts of the world, these microorganisms form massive scums, known as water blooms, releasing cyanotoxins hazardous to fish and other aquatic organisms. Cyanotoxins are cyanobacterial secondary metabolites of various chemical structures harmful to humans, terrestial and aquatic animals such as fish. The most abundant cyanotoxins are microcystins and hepatotoxins inducing toxic changes in fish liver, kidney, gills, digestive tract and immune system. Very little is known on the effects of alkaloid neurotoxic anatoxin-a on fish and their immunity. The aim of this study was to assess the in vitro influence of anatoxin-a on immune cells isolated from the common carp (Cyprinus carpio L.). The leukocyte intracellular level of ATP was reduced only at the highest concentration of anatoxin-a. Apoptotic and necrotic leukocytes were observed at the lower and the highest concentrations of anatoxin-a, respectively. Elevated activity of caspases 3/7 after 2 hours and a concentration-dependent decrease in the proliferative ability of T and B lymphocytes was also observed. The results suggest that anatoxin-acould be a possible immunotoxic agent in the aquatic environment and may increase the susceptibility of fish to infectious and neoplastic diseases. Therefore, constant monitoring of anatoxin-a and its producers in lakes and fish ponds should be performed.|For more Ecotoxicity Excerpts (Complete) data for Anatoxin A (18 total), please visit the HSDB record page.

Anatoxin A is a potent, neurotoxic, nicotinic, post-synaptic, depolarizing, neuromuscular blocking bicyclic amine isolated from bluegreen alga Anabaena flos-aquae and Oscillatoria (Planktothrix)(1-3). The first neurotoxins to be identified in the planktonic freshwater cyanobacteria, Anabaena circinalis, was anatoxin A. Isolates of Anabaena circinalis have been found throughout Europe, North America, Asia, South Africa, Japan, New Zealand, and Australia. Anabaena flos-aquae NRC 44-1 and Anabaena flos-aquae NRC 525-17 are also neurotoxic strains that produce anatoxin A(4).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 110(SRC), determined from a regression derived equation(2), indicates that anatoxin A is expected to have high mobility in soil(SRC). Volatilization of anatoxin A from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6.6X10-9 atm-cu m/mole(SRC), using a fragment constant estimation method(2). Anatoxin A is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 5.8X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation half-lives of 5 days were observed for anatoxin A in reservoir water containing bed sediments(3), suggesting that biodegradation may be an important environmental fate process in soil(SRC).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 110(SRC), determined from a structure estimation method(2), indicates that anatoxin A is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 6.6X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). According to a classification scheme(4), an estimated BCF of 2.6(SRC), from an estimated log Kow of 1.12(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Anatoxin A was found to be stable in reservoir water at pH 4 for 21 days but at pH 8-10 less than 5 percent anatoxin A was remaining after 14 days. In the presence of bed sediment the half-life of anatoxin A in reservoir water was 5 days(5), suggesting biodegradation may be an important environmental fate process in water(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), anatoxin A, which has an estimated vapor pressure of 5.8X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase anatoxin A is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 1.1 hours(SRC), calculated from its rate constant of 1.2X10-10 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(2). Anatoxin A does not contain chromophores that absorb at wavelengths >290 nm(3) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

The rate constant for the vapor-phase reaction of anatoxin-A with photochemically-produced hydroxyl radicals has been estimated as 1.2X10-10 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 1.1 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Anatoxin-A is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(2). Anatoxin-A does not contain chromophores that absorb at wavelengths >290 nm(2) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).|Anatoxin-a is relatively stable in the dark, but in pure solution in the absence of pigments it undergoes rapid photochemical degradation in sunlight. Breakdown is further accelerated by alkaline conditions. The half-life for photochemical breakdown is 1-2 hours. Under normal day and night light conditions at pH 8 or pH 10, and at low initial concentrations (10 ug/L), the half life for anatoxin-a breakdown was found to be approximately 14 days.

An estimated BCF of 2.6 was calculated in fish for anatoxin-A(SRC), using an estimated log Kow of 1.12(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of anatoxin A can be estimated to be 110(SRC). According to a classification scheme(2), this estimated Koc value suggests that anatoxin A is expected to have high mobility in soil(SRC).

The Henry's Law constant for anatoxin A is estimated as 6.6X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that anatoxin A is expected to be essentially nonvolatile from water surfaces(2). Anatoxin A's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected(SRC). Anatoxin A is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 5.8X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(1).

SURFACE WATER: Lake water samples collected from a lake near the University of Kentucky that had recently experienced an algae bloom contained anatoxin A at a level of 3.2 ppb(1). A screening program from 1995-1997 covering nearly 80 lakes in Germany found the presence of anatoxin A in 22 percent of the samples collected. Anatoxin was only found during the months of May to November. The highest concentration measured was 13.1 ug/L in several species of cyanobacteria. The dry weight equivalent of anatoxin A was determined to range from 100-1500 ug/g dry weight although. Other studies noted detected anatoxin at levels of up to 4400 ug/g in Finland, 10-100 ug/g in Ireland, and 0.3-16 ug/g in Japan. A study noted a cyanobacteria bloom in Black Lake, Idaho in 1981; 2.5 ug/mg resulted in the deaths of 2 dogs and 11 cows(2). In 2014 monitoring study in Jordan Lake, North Carolina, anatoxin-A was detected in 57% of grab samples over the course of a year with concentrations ranging from below the detection limit (not specified) to 0.68 ug/L, at an average of 0.11 ug/L(3).|SURFACE WATER: Anatoxin-A was identified in benthic cyanobacteria (blue-green algae) and in associated dog poisonings at Loch Insh, Scotland in 1990-91(1). Several Finnish and Canadian samples detected anatoxin A from a variety of species of cyanobacteria with results ranging from 1107-13,013 ug/g of lyophilized cells. Japanese samples also detected 0.2-52.4 ug/g of anatoxin A. In addition to these results quantities of related degradation products were also detected(2). Anatoxin A was measured from isolates of natural cynobacterial blooms from Japanese fresh waters. The concentrations of anatoxin A ranged from 0.2-357.8 ug/g, with the highest value detected at Lake Barato, Japan(3). Another study revealed concentrations of 12.13 ug/g from the cyanobacterial species Planktothrix rubescens isolated from a fishing pond in Northern Italy(4).|SEAWATER: Three alkaline-saline lakes, Bogoria, Elermetria, and Nauku, in the Eastern Rift Valley of Kenya commonly harbor large cyanobacteria populations. Anatoxin A was detected in Lake Nauku (up to 9 ug/g DW) and Lake Bogoria (up to 223 ug/g DW) by HPLC and mass confirmed by MALDI-TOF(1).

In 2017 a survey of 18 algae dietary supplements, anatoxin-A was detected in 2 supplements and its transformation products were detected in 6 (including the 2 with anatoxin-A). No anatoxin-A concentrations were found at more than 5% of the WHO's tolerable daily intake guideline of 6 ug(1).

Occupational exposure to anatoxin A is unlikely but may occur via dermal contact or ingestion at workplaces of regular exposure to freshwaters containing high cyanobacteria populations. Monitoring data indicate that the general population may be exposed to anatoxin A via dermal contact or ingestion of this compound in freshwater swimming areas or drinking water contaminated with cyanobacterial blooms. (SRC)

Anatoxin-a and homoanatoxin-a are potent neurotoxins produced by cyanobacteria such as Oscillatoria PCC 6506. Sequencing of the genome of this strain is underway, and ... a 29 kb DNA fragment containing a sequence called ks2 t... previously shown to be specific to Oscillatoria cyanobacteria producing anatoxin-a and homoanatoxin-a /was identified/. Bioinformatic analysis of this 29 kb fragment revealed a cluster of genes, which were annotated. The function assigned to the products of eight contiguous genes, from anaA to anaH, provides a clue to the biosynthesis of anatoxin-a and homoanatoxin-a. Proline is first loaded on an acyl carrier protein and its five-membered cycle oxidized to the pyrroline oxidation state. This activated ring is then successively loaded on three polyketide synthase modules for elongation, reduction, cyclization, and methylation. The final step is the hydrolysis of the thioester with subsequent decarboxylation. GC-MS and NMR analyses of homoanatoxin-a produced by PCC 6506 using labeled precursors confirm that proline is very likely the starter of these polyketide synthases. ... Specific PCR amplifications ... showed that the anaC, anaE, anaF, and anaG genes are always present in the genome of cyanobacteria producing anatoxin-a and homoanatoxin-a and absent in nonproducing strains. Histidine-tagged AnaC was purified to homogeneity and showed to catalyze the loading of proline on purified histidine-tagged AnaD that had been previously transformed into its holo form using the Bacillus subtilis Sfp phosphopantetheinyl transferase. All of these data provide strong evidence that ... the gene cluster responsible for the production of anatoxin-a and homoanatoxin-a in Oscillatoria PCC 6506 /has been identified/.

Anatoxin-a is a nicotinic (cholinergic) agonist that binds to neuronal nicotinic acetylcholine receptors. It has been suggested that the activation of presynaptic nicotinic acetylcholine receptors by anatoxin-a results in an influx of Na+, producing sufficient local depolarization to open voltage sensitive Ca++ and Na+ channels. The latter may then amplify the response, activating further Ca++ channels. As a result of this depolarization there is a block of further electrical transmission, and at sufficiently high doses this can lead to paralysis, asphyxiation and death. Anatoxin-a is more potent than nicotine or acetylcholine in evoking type 1A or type 2 current responses in rat hippocampal neurones, and it is more potent than nicotine in its ability to evoke the secretion of endogenous catecholamines from bovine adrenal chromaffin cells through their neuronal-type nicotinic receptors. Similar to nicotine, anatoxin-a was more potent than noradrenaline in releasing dopamine from striatal nerve terminals from rat superfused hippocampal synaptosomes. In vivo studies in the rat showed that the toxin stimulates the sympathetic system through the release of catecholamines from nerve endings.|Anatoxin-a is a nicotinic (cholinergic) agonist that binds to neuronal nicotinic acetylcholine receptors. It has been suggested that the activation of presynaptic nicotinic acetylcholine receptors by anatoxin-a results in an influx of Na+, producing sufficient local depolarisation to open voltage sensitive Ca++ and Na+ channels. The latter may then amplify the response, activating further Ca++ channels. As a result of this depolarization there is a block of further electrical transmission, and at sufficiently high doses this can lead to paralysis, asphyxiation and death.|Anatoxin-a (AnTx) is a natural neurotoxin, which acts as a potent and stereoselective agonist at the nicotinic acetylcholine receptors. ... The aim of this study was to determine the neurochemical bases for AnTx-induced striatal DA release, using the brain microdialysis technique, in freely moving rats. Local application of AnTx (3.5 mM) through the microdialysis probe produced an increase in striatal DA levels (701 +/- 51% with respect to basal values). The effect of infusion of AnTx in Ca(2+)-free Ringer medium, in Na(+)-free Ringer medium and with TTX in the medium, was inhibited. Also, reserpine pre-treatment blocked the action of AnTx on striatal DA levels. To investigate the involvement of the DA transporter, the effects of AnTx were observed in the presence of nomifensine. The coadministration of AnTx and nomifensine evoked an additive effect on striatal DA levels. The latter results show that the DA release is not mediated by a decreased DA uptake. Taken as a whole, these results suggest that the effects of AnTx are predominantly mediated by an exocytotic mechanism, Ca(2+)-, Na(+)- and TTX-dependent, and not by a mechanism mediated by the DA transporter.|(+)-Anatoxin-a (ANTX) stimulated guinea pig ileum contraction with a potency similar to that of acetylcholine (ACh); the stimulation was blocked by tubocurarine, hexamethonium, or atropine. Although the contraction stimulated by ANTX was blocked by atropine, no specific inhibition of the binding of [3H]N-methylscopolamine to ileum membranes was observed in the presence of ANTX. Furthermore, ANTX failed to stimulate the secretion of alpha-amylase from pancreatic acinar cells, a process that is activated by cholinergic agonists at the muscarinic receptors. When the ileum itself was stimulated by ACh, the contraction was not blocked by either hexamethonium or tubocurarine. Preincubation of the ileum with hemicholinium caused a 50% reduction in the ability of ANTX to stimulate contraction. Based upon these data, it was inferred that ANTX binds to postganglionic synaptic nicotinic receptors in the ileum, thus releasing endogenous ACh, which in turn causes ileum contraction by interacting with the postsynaptic muscarinic receptors. It was also observed that thymopentin (TP-5), a pentapeptide corresponding to positions 32-36 of thymopoietin, blocked the stimulation of ileum contraction by ANTX.

VET: There is no specific antidote for anatoxin-a. Because of the rapid onset of clinical signs, emesis is not likely to be useful. Although there are no studies that evaluate the efficacy of specific decontamination procedures, administration of activated charcoal has been recommended. In addition, artificial respiration may be of benefit along with general supportive care. Specific measures to control seizures include benzodiazepines, phenobarbital or pentobarbital. If given, they may cause central nervous system (CNS) and respiratory depression and careful monitoring of the animal is necessary. In any seizuring animal, control of body temperature is an important part of the symptomatic care.|/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

/CASE REPORTS/ A coroner in Wisconsin ... concluded that a teenager who had been wrestling and diving in a gold course pond with a heavy scum of toxic Anabaena flos-aquae died through exposure to blue-green algal toxin. The cyanobacterial cells were found in fecal samples, and toxin was measured in scum samples. The teenager and his friend both suffered severe vomiting, diarrhea, and abdominal pain. In the more severely affected individual, this ended in shock and seizure 48 hr after exposure. The toxin implicated, anatoxin-a, is a fast-acting neurotoxin, but there are no data on human exposure. A neurotoxin would not be expected to cause the gastroenteritis, though it could cause death through respiratory inhibition and convulsions.|/SIGNS AND SYMPTOMS/ Most documented cases of human injury through cyanotoxins involved exposure through drinking-water, and they demonstrate that humans have become ill - in some cases seriously - through ingestion or aspiration of toxic cyanobacteria. Symptoms reported include abdominal pain, nausea, vomiting, diarrhea, sore throat, dry cough, headache, blistering of the mouth, atypical pneumonia, and elevated liver enzymes in the serum, as well as hay fever symptoms, dizziness, fatigue, and skin and eye irritations. /Cyanotoxins/|/SIGNS AND SYMPTOMS/ Neurotoxins are not considered as widespread in water supplies, and they do not appear to pose the same degree of risk from chronic exposure as microcystins. The neurotoxins, such as anatoxin-a and -a(s), are highly toxic nerve poisons but have short biological half-lives. On acute exposure, the neurotoxins cause death within minutes to a few hours, depending on the species, the amount of toxin ingested, and the amount of food in the stomach. ...

anatoxin I

Anatoxin A is a bicyclic amine isolated from bluegreen alga Anabaena flos-aquae. /SRP: Potent neurotoxin./|The hepatotoxins are produced by various species within the genera Microcystis, Anabaena, Oscillatoria, Nodularia, Nostoc, Cylindrospermopsis, and Umezakia, although not all strains do so. Most hepatotoxins (all cyclic heptapeptides) are microcystins. At least 50 congeners of microcystins are known, and several of these may be produced during a bloom. The chemical structure of microcystins includes two variable amino acids and an unusual aromatic amino acid, ADDA (3-amino-9- methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid), containing a substituted phenyldecadienoic acid. Different microcystins have different lipophilicities and polarities, which could affect their toxicity ... Microcystis and Anabaena blooms occur widely in the temperate regions of the world. In general, 50-75% of bloom isolates can produce toxins, often with more than one toxin being present. Toxic and non-toxic blooms of the same species can be found together.|Anatoxin-a (ANTX) is a neurotoxin produced by several freshwater cyanobacteria and implicated in lethal poisonings of domesticated animals and wildlife. The factors leading to its production in nature and in culture are not well understood. Resource availability may influence its cellular production as suggested by the carbon-nutrient hypothesis, which links the amount of secondary metabolites produced by plants or microbes to the relative abundance of nutrients. We tested the effects of nitrogen supply (as 1, 5, and 100% N of standard cyanobacterial medium corresponding to 15, 75, and 1500 mg/L of NaNO(3) respectively) on ANTX production and release in a toxic strain of the planktonic cyanobacterium Aphanizomenon issatschenkoi (Nostocales). We hypothesized that nitrogen deficiency might constrain the production of ANTX. However, the total concentration and more significantly the cellular content of anatoxin-a peaked (max. 146 ug/L and 1683 ug/g dry weight) at intermediate levels of nitrogen supply when N-deficiency was evident based on phycocyanin to chlorophyll a and carbon to nitrogen ratios. The results suggest that the cellular production of anatoxin-a may be stimulated by moderate nitrogen stress. Maximal cellular contents of other cyanotoxins have recently been reported under severe stress conditions in another Nostocales species.|A study was made of the biosynthesis by Anabaena flos-aquae of the tropane-related alkaloid anatoxin-a. Evidence is presented that the toxin arises from ornithine via putrescine (1,4-diaminobutane) and that ornithine decarboxylase (EC 4.1.1.17) is involved. An ornithine decarboxylase preparation, with optimal activity at pH 8, was obtained from Anabaena flos-aquae and partially purified by gel-filtration chromatography on DEAE-cellulose. One major and one minor peak of enzymic activity were obtained with Km values of 1.25 and 2.5 mM, respectively. Plasmid DNA (10 Kb; Mr 6.5 x 10(6] was detected in the toxic strain of Anabaena flos-aquae but not in a non-toxic strain. DNA from the toxin-producing strain of Anabaena flos-aquae transforms the non-toxic into a toxic strain.

High affinity DNA aptamers against anatoxin-a (ATX), the smallest potent neurotoxin (Mol. Wt, 165.23 Da) were selected and identified in vitro using the systematic evolution of ligands by exponential enrichment (SELEX) approach. Aptamers with dissociation constants (Kd) of nanomolar range were isolated. The aptamer sequence of highest affinity was used to design a label-free impedance based aptasensor to assay ATX, for which there are no reported biosensors so far. The aptamer self assembled monolayer is formed on a gold electrode using the disulfide modified aptamer. The assembly process of the aptasensor was characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Upon ATX binding to the immobilized aptamer, a significant decrease in the electron-transfer resistance was observed as a result of the aptamer conformation change, which is used as the sensor signal. The aptasensor showed a limit of detection of 0.5 nM and a wide linear range for ATX concentrations between 1 nM and 100 nM. The Kd of anti-ATX aptamer was calculated by electrochemical methods as well as the fluorescence. Interestingly, the Kd that was calculated from the aptasensor signal showed a lower value implying that the anchoring of the aptamer on the Au surface enhanced its affinity to ATX. The ATX aptasensor showed high stability as well as high specificity against common cynaobacterial toxins. Further development of biosensors that use anatoxin-a binding aptamers as a new recognition receptors could provide potential alternatives to the traditional assays for fast and simple monitoring of anatoxin-a.|In order to identify the cyanobacterial species responsible of anatoxin-a (ATX) production in Lake Garda (Northern Italy), an intensive isolation and culturing of filamentous cyanobacteria were established since 2014 from environmental samples. In this work, we report a detailed account of the strategy adopted, which led to the discovery of a new unexpected producer of ATX, Tychonema bourrellyi. So far, this species is the first documented example of cultured Oscillatoriales able to produce ATX isolated from pelagic freshwater ecosystems. The isolated filaments were identified adopting a polyphasic approach, which included microscopic species identification, genetic characterization and phylogenetic analyses based on 16S rRNA genes. The taxonomic identification was further confirmed by the high (>99%) rbcLX sequence similarities of the T. bourrellyi strains of Lake Garda with those deposited in DNA sequence databases. More than half of the isolates were shown to produce a significant amount of ATX, with cell quota ranging between 0.1 and 2.6 ug/cu mm, and 0.01 and 0.35 pg/cell. The toxic isolates were tested positive for anaC of the anatoxin-a synthetase (ana) gene cluster. These findings were confirmed with the discovery of one ATX producing T. bourrellyi strain isolated in Norway. This strain and a further non-ATX producing Norwegian Tychonema bornetii strain tested positive for the presence of the anaF gene of the ana gene cluster. Conversely, none of the Italian and Norwegian Tychonema strains were positive for microcystins (MCs), which was also confirmed by the absence of mcyE PCR products in all the samples analyzed. This work suggests that the only reliable strategy to identify cyanotoxins producers should be based on the isolation of strains and their identification with a polyphasic approach associated to a concurrent metabolomic profiling.|Microcystins, anatoxins and okadaic acid are toxins produced by freshwater cyanobacteria and marine dinoflagellates. These toxins have been the responsible for the illness and death of biota and humans. To determine their presence in water during blooms, sensitive analytical methods are needed. In this study, we have developed a new liquid chromatography tandem mass spectrometry (LC-MS/MS) method for fast multiresidue determination of five toxins in suspended material and sediment samples. For each target compound, two selected reaction monitoring (SRM) transitions were optimized. Chromatographic conditions were optimized considering that the compounds analyzed had different chemical structure and chromatographic behavior. Using a Luna C18 column and specific SRM transitions, five phytotoxins were resolved. Method detection limits (MDL) for anatoxin-a, microcystins RR, LR and YR and okadaic acid were 7.1, 3.3, 81.7, 102.8 and 28.8 ng/g dry weight in sediment, respectively. The developed analytical method was successfully applied to analyze the presence of toxins in suspended solids and sediment from Ebro River (NE Spain) and Ebro delta-associated lagoons. Anatoxin-a was detected downstream of the Riba-Roja reservoir with levels ranging from 20 to 1120 ng/g dry weight of suspended solids. Okadaic acid was only detected in three samples collected in the Alfacs Bay (Ebro delta, Spain) affected by Dinophysis blooms in 2012.|An analytical method based on on-line SPE-LC-HESI-MS/MS has been developed for the detection and quantification of eight selected cyanotoxins in algal bloom waters that include mycrocystins, anatoxin-a and cylindrospermopsin. The injection volume was 2 mL according to the expected concentration of cyanotoxins in matrix. The method provides an analysis time of 7 min per sample, acceptable recovery values (91-101%), good precision (RSD < 13%) and method limits of detection at the sub-microgram per liter levels (0.01-0.02 ug/L). A detailed discussion on optimization parameters that have an impact on the overall performance of the method are presented. In particular, method optimization permitted the chromatographic separation of anatoxin-a and phenylalanine, an isobaric interference with a similar chromatographic characteristics. All optimization and validation experiments for the on-line SPE method and chromatographic separation were performed in environmentally relevant algal bloom water matrices. The applicability of the method was tested on several algal bloom water samples from monitored lakes across the province of Quebec (Quebec, Canada) known to produce cyanotoxins. All of the targeted cyanotoxins were detected with the exception of cylindrospermopsin. In addition, it was found that total microcystin concentrations in several surface water samples exceeded the proposed guidelines established by the province of Quebec in Canada of 1.5 ug/L as well as the World Health Organization of 1 ug/L for both free and cell-bound microcystin-LR equivalent.|For more Analytic Laboratory Methods (Complete) data for Anatoxin A (16 total), please visit the HSDB record page.

Forensic investigations of suspected anatoxin-a (AN) poisonings are frequently hampered by difficulties in detecting this toxin in biological matrices due to its rapid decay. ... Approaches to prevent the misidentification of AN ... included: (a) fluorimetric LC following derivatisation using 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F); (b) methylation using diazomethane prior to LC-MS determination; (c) multiple tandem MS using a quadrupole ion-trap (LC-MS3); and (d) hybrid quadrupole time-of-flight (QqTOF). Interference from Phe was not observed in any of procedures, (a)-(c), and the high mass accuracy obtained in method (d), readily distinguished between AN (165.11536) and Phe (165.07898). LC-MSn was also employed to study the fragmentation pathway of Phe and multi-stage MS spectra provided characteristic fragmentation information that clearly distinguished between AN and Phe. The difficulties associated with the over reliance on low resolution MS without MS/MS data in forensic toxicology are discussed.