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The story of acetylthiocholine iodide links back to the fervor of neurochemistry research in the twentieth century. Scientists hunting for clarity on the intricacies of nerve transmission demanded synthetic molecules that could unlock the secrets of acetylcholine’s breakdown by cholinesterase enzymes. Acetylthiocholine iodide emerged as a chemical alternative—first as a research tool in the 1940s and 50s. Its utility became obvious when Ellman’s assay brought a simple way to measure cholinesterase activity, and acetylthiocholine iodide took center stage. Over decades, this reagent became a mainstay, central to efforts looking to understand cognition, neurodegeneration, and the mechanisms that underpin learning and memory.
Acetylthiocholine iodide, with its distinct white crystalline form, is not a compound you spot on the shelf of a regular chemical supplier for hobbyists. Dedicated chemical companies keep it in their inventory, serving laboratories digging into the mysteries of enzyme activity and neurological disorders. It sits on the bench of every neuroscience research group I’ve worked with, just as comfortable in physiology labs screening for nerve agent exposure. Laboratories value it for its stability, solubility in water, and predictable reactivity in enzyme assays, making it practical for repeated, long-term experiments.
Looking at its chemical makeup—C7H16INO2S—acetylthiocholine iodide presents a complex but approachable structure. It shows up as an off-white to slightly yellow powder, somewhat hygroscopic, and dissolves well in water while resisting dissolution in organic solvents like chloroform or ether. Melting point can dip around 210°C with decomposition. Its molecular weight stands at about 289.18 g/mol. Organic chemists appreciate its quaternary ammonium group and its accompanying iodide—both features mean careful storage, ideally in a cool, dry place. The thioester bond provides a substrate for cholinesterases, making enzymatic studies possible.
A reputable bottle of acetylthiocholine iodide comes with a technical datasheet listing purity often greater than 98%, with major manufacturers putting batch numbers, CAS RN 1866-15-5, and hazard warning codes. Any shelf in a research center or diagnostic lab will show warning labels indicating irritation or harmful exposure risks. Standard packaging comes in amber glass containers to guard against light-initiated decomposition. Accurate labeling—manufacturer, batch, purity, safety instructions, and expiry date—ensures safe use and repeatable results.
I recall long nights in the lab learning the two-step synthesis, watching the organic team combine thiocholine with acetic anhydride, forming acetylthiocholine base. The next step brought in hydroiodic acid, producing the iodide salt. This classical approach relies on rigorous control—keep everything dry, reaction times precise, and purification through ethanol recrystallization. Yield hinges on careful control of pH and low temperatures to limit byproduct formation. Any impurities can cause false readings in an enzyme assay, so repeated crystallization often features in the preparation process. Commercial suppliers stick to time-tested protocols, and their documentation provides the reassurance that researchers need when results hinge on chemical purity.
The chemical value of acetylthiocholine iodide lies in its thioester bond. Cholinesterase enzymes break this bond, releasing thiocholine and acetate. Ellman's reagent, DTNB (5,5'-dithiobis-2-nitrobenzoic acid), reacts with the released thiocholine to form a yellow anion, making colorimetric quantification possible—a technique at the cornerstone of cholinesterase research. Besides its primary application, chemists prepare modifications: alternate salts, or even labeled isotopes, help track enzyme kinetics and probe subtle differences in enzyme structure or activity. This adaptability has pushed new research into organophosphate pesticide detection, nerve agent screening, and the study of inherited cholinesterase deficiencies.
Chemical catalogs list acetylthiocholine iodide under several synonyms: Acetylthiocholine, AThCh, and O-Acetylthiocholine iodide. Some suppliers might call it thiocholine acetate iodide or N,N,N-Trimethyl-2-(acetylthio)ethanaminium iodide. While names shift slightly, the chemical fingerprint remains constant. Savvy chemists cross-check catalog numbers and CAS identifiers to avoid any mix-up—especially when time-pressed.
Lab routines with acetylthiocholine iodide mean wearing gloves, goggles, and working in a fume hood. The powder dusts easily and can irritate the respiratory system or skin. Ingestion or long exposure brings headaches and nausea, so clear protocols guide users at every step. Manufacturers supply MSDS sheets outlining risks—risk phrases, safe disposal, fire-fighting measures, spillage handling, and first aid. My own experience with chemical safety audits led to reinforced habits—double-check PPE, don’t pipette by mouth, and store the reagent tightly closed, away from incompatible oxidizers. In the event of a spill, protocols call for careful collection, using damp towels or vacuum, and chemical waste disposal compliant with local regulation. Training and drills build the muscle memory necessary for safe handling, not just of acetylthiocholine iodide, but of all laboratory-grade chemicals.
Research on acetylthiocholine iodide centers around cholinesterase activity measurement. Clinical toxicology departments count on this compound for screening organophosphate and carbamate pesticide poisoning, as enzyme inhibition can indicate exposure. Pharmaceutical development teams use it to screen drugs intended to target Alzheimer’s and other cognitive disorders, as cholinesterase inhibitors play a large part in slowing cognitive decline. Environmental monitoring, food and agriculture safety labs, and forensic science often lean on rapid assays made possible by acetylthiocholine iodide. Even veterinary toxicologists include it in their diagnostic panels. The wide reach across disciplines gives it status: not just a bench reagent, but a bridge connecting research, diagnostics, and product development.
Research groups keep pushing the envelope—changing assay formats, pairing acetylthiocholine iodide with microfluidics to miniaturize testing, or integrating it with biosensors for field-ready diagnostics. I remember collaborating with engineers on portable cholinesterase meters for rural clinics in developing countries. They needed a substrate that produced a clear signal, stored easily without refrigeration, and resisted breakdown. Acetylthiocholine iodide fit those specifications. Journals brim with papers tweaking formulations for greater robustness, longer shelf life, or compatibility with new detection technology. As society faces both old and emerging organophosphate threats, these innovations gain urgency.
Scrutiny on toxicity runs high—both for regular lab workers and for understanding environmental impact. Acute exposure brings moderate toxicity; ingestion can produce muscarinic effects such as salivation, bradycardia, and abdominal pain, echoing the compound’s close relationship to acetylcholine. Chronic or high-level exposure evidence remains thin, but most institutions err on the side of caution, treating all spills as hazardous. Animal studies demonstrate low toxicity at common lab concentrations, but higher doses affect nerve transmission, making chronic effects a concern in repeated accidental exposures. Occupational health guidelines continue to evolve as more is understood about similar quaternary ammonium compounds.
The path forward holds plenty of promise. Research continues to focus on smarter, faster detection of cholinesterase activity in field settings—military, agricultural, and environmental. Companies are working on stabilized formulations for high-temperature environments, direct-to-lab sensor integration, and safety profiles that ensure peace of mind during global shipment. The growing awareness of nerve agent threats has driven interest from defense agencies, driving these innovations to market with greater urgency. Translational research aims to leverage acetylthiocholine iodide as a bridge between basic science and real-world diagnostic devices, handling not only chemical exposures but also contributing to smarter neurological health management. The next generation of scientists, whether in basic chemistry, diagnostics, or environmental health, won’t be far from the quiet but enduring influence of acetylthiocholine iodide.
Scientists constantly search for ways to understand how the body’s communication networks work. Nerves pass signals to muscles with chemical messengers, and one of the main players is acetylcholine. Tracking how acetylcholine gets broken down tells us a lot about brain and muscle health. Acetylthiocholine iodide enters the picture as a lab-made compound, serving as a handy tool to measure how active an enzyme called acetylcholinesterase is. This enzyme cleans up acetylcholine signals after they have done their job, and keeping an eye on it can reveal early changes in memory problems, muscle diseases, and the effects of toxins or drugs.
In university labs, especially those studying neuroscience, acetylthiocholine iodide pops up in many tests. I recall working on projects that needed precise numbers for enzyme speeds. Using this compound, it became possible to track how chemicals influence the brain. Without it, our team would have had far less data on the subtle differences in nerve activity between healthy and sick cells. The chemical offers a kind of stand-in for acetylcholine and allows researchers to watch reactions that would otherwise happen too quickly or too quietly for most tests to catch. The method commonly uses Ellman’s reagent, which reacts with the breakdown products of acetylthiocholine, turning the whole mix a bright yellow. This shift makes it simple to measure enzyme action with a spectrophotometer.
Understanding how acetylcholinesterase works lies at the foundation of treatments for diseases like Alzheimer’s and myasthenia gravis. Medicines often work by slowing this enzyme, giving acetylcholine more time to act in the brain or at muscle junctions. Monitoring this enzyme also helps in toxicology labs. Certain nerve agents and pesticides harm by blocking acetylcholinesterase, so finding ways to measure its activity keeps people safe. Military and environmental health experts rely on this type of testing, making acetylthiocholine iodide a crucial part of their toolkit.
Trustworthy science depends on consistency and clear measurements. Acetylthiocholine iodide is known for giving solid results, which supports the repeatability that peer-reviewed journals require. Researchers often run these enzyme tests daily, checking the impact of new drug candidates or tracking the progress of experimental treatments. Improper or low-quality reagents can throw off a whole project, wasting time and resources. Because labs have confidence in acetylthiocholine iodide’s performance, they can focus on the questions at hand rather than troubleshooting basic chemistry steps.
The field sees a push for earlier, safer disease detection. New methods for spotting enzyme changes sooner could mean quicker intervention for nerve diseases and less damage in poisoned patients. Some groups work on digital tools and portable devices that use acetylthiocholine iodide-based tests outside the typical lab. These efforts matter for underserved communities, or for sites where getting lab results fast truly counts. Supporting wider access to these supplies and building better testing protocols tops the list for advancing public health.
Not all chemicals carry the same risks, but there’s a lesson every lab should take to heart: some compounds don’t forgive carelessness. Acetylthiocholine iodide lands firmly in that category. In research and chemical production, storage may not grab headlines, but it’s a step that separates safe workspaces from emergencies waiting to happen.
From experience in shared labs, there’s nothing quite like realizing a degraded reagent fouled up your results. Compounds like acetylthiocholine iodide bring that risk. This chemical, used widely to study cholinesterase activity, responds poorly to heat, moisture, and light. Exposing it to these conditions invites breakdown, bad data, and wasted money. Old bottles left unmarked or stored carelessly blur lines between sound planning and scientific guesswork.
It helps to ground storage advice in practical actions. Always cap containers tightly and reach for glass vials over plastic, since glass won’t react with the compound. Choose an amber-colored bottle, as light can break down acetylthiocholine iodide over time. For anyone tasked with inventory, nothing beats labeling the opening date. It’s easy to lose track between restocking cycles, but those notes remind everyone when to discard or reorder.
Temperature marks another crucial detail. My early research group kept all such reagents inside fridges set to around 2–8°C. Colder shelves slow down most forms of decay and hold back rogue moisture. Some suppliers suggest storing the chemical even closer to 0°C, so long as it stays dry. Frost-free freezers might seem tempting, but cycles of thawing and refreezing allow condensation to sneak in. Even a little moisture can kick off chemical changes in a salt this sensitive.
Most mistakes I’ve seen start with skipping the dry cabinet. Whenever possible, place acetylthiocholine iodide next to a desiccant sachet, such as silica gel or anhydrous calcium chloride. This acts like insurance against invisible humidity in busy spaces. Some labs tape a humidity strip right above chemical stocks—no high-tech gadgets, just another pair of eyes on the problem.
Labs built on good habits rarely face chemical spills, but training helps. Store the chemical away from acids and oxidizing agents, since even unintentional mixing can create hazards. I remember one instance where a misplaced bottle led to a scramble; a clear separation of chemicals, reviewed regularly, prevents costly accidents and surprises.
Expired or suspected-contaminated acetylthiocholine iodide shouldn’t linger on shelves. Labs should maintain well-documented disposal protocols and work with professional waste handlers. Research has shown that improper chemical disposal contributes to environmental pollution, so compliance protects both staff and surroundings.
There is real power in keeping a logbook for chemical stocks — not just for audits, but for the science itself. If problems show up in experiments, tracking back through the notes often explains what went wrong. I’ve often relied on generous coworkers who jotted down every detail; for a lab, those habits matter more than any single bottle on the shelf.
Acetylthiocholine iodide isn’t a name that shows up during casual conversation, yet it stands as an important tool in biochemistry labs. Its formula, C7H16INO2S, speaks volumes for those who work closely with cholinesterase enzymes. The molecule brings together a backbone of carbon, hydrogen, nitrogen, oxygen, iodine, and sulfur. Each element serves a purpose, creating a compound that plays a specific role in neurotransmitter studies.
Scientists have relied on acetylthiocholine iodide for decades. Its true value appears during enzyme assays, especially for studying acetylcholinesterase activity. This testing method expands our understanding of neural function and disease, since acetylcholinesterase breaks acetylcholine and maintains brain operation. Mistakes in that breaking-down process link to issues like Alzheimer’s disease, so any tool that helps map these pathways matters a great deal.
Researchers use acetylthiocholine iodide because it reacts predictably. It serves as a stand-in for natural acetylcholine, producing an easily measured byproduct. This predictability keeps experiments reliable and reproducible, both key for credible science. The sulfur group in thiocholine makes detection straightforward and measurable, allowing professionals to move from experiment to real-world impact in neurological health.
Most folks never stop to think about why formulas even matter. In practical terms, a molecular formula confirms the exact building blocks of any compound. For acetylthiocholine iodide, knowing it’s C7H16INO2S helps ensure that scientists mix the correct chemicals. Miss a nitrogen, drop an oxygen, or swap out iodine and the result changes. Lab professionals order reagents down to their exact formula since even small changes can change the pathway of an experiment or halt production altogether.
This attention to detail runs deep in scientific work because safety, cost, and time matter. Researchers cannot risk introducing a wrong compound. Supply chain issues have already challenged labs in recent years, and incorrect formulas only make matters worse. Historical data shows that small errors in chemical identity have triggered wasted time, resources, and sometimes even set back important projects.
Students see organic formulas on the board and often wonder if they’ll ever use them. Focusing on real-world compounds like acetylthiocholine iodide pulls those symbols out of the textbook and puts them in the hands of researchers fighting neurological disease. Teachers who introduce this compound in class discussions link chemistry with medical and psychological research, drawing a direct line between the classroom and lifesaving science.
Many instructors now build case studies or lab simulations around acetylthiocholine iodide, showing the compound’s structure and role in the human body. In some university labs, students safely practice enzyme assays using this compound as a substrate. Such experiences underline the formula’s relevance, moving it beyond sterile memorization and into the realm of innovation and care.
Even as new synthetic compounds emerge, the backbone principle stays put: knowing exactly what makes up each molecule drives accurate research and education. C7H16INO2S stands as more than a list of letters and numbers; it represents a bridge between chemistry, biology, and health. Labs, students, and suppliers continue to rely on close attention to molecular formulas, building a foundation for discoveries and real-world care that stretches far beyond the bench.
Acetylthiocholine iodide often pops up in biochemistry labs. Researchers use it for enzyme assays, especially for measuring the activity of cholinesterases—important for studies on nervous system function. The white powder looks harmless, but appearances can trick even the most experienced eyes in a lab.
Direct experience working with acetylthiocholine iodide explained why safety goggles and gloves line every lab bench. The chemical can irritate skin, eyes, and the respiratory tract if dust floats into the air. Touching it then rubbing an eye feels a bit like entering a sandstorm—your body protests to get it out fast. Inhaling the dust might feel like catching a whiff of pepper in your nose and throat, but medical journals outline more serious risks, especially for those handling this substance over months or years.
Toxicology reports point to data on cholinesterase inhibitors and related compounds: chronic exposure, even at low doses, stresses the nervous system. Animal studies note tremors, muscle weakness, or even breathing trouble. Short-term symptoms rarely endanger health in a properly ventilated room, but someone ignoring protective gear or eating lunch with contaminated hands takes a risk that shouldn't be underestimated.
Getting lazy with gloves or eye protection might seem harmless until someone develops a rash or cough, or lab work grinds to a halt as supervisors check for contamination. I saw a student skip hand washing one afternoon, and that person panicked after rubbing an eyelid. Nothing disastrous happened, but the experience stuck: even a small mistake turns into an unwanted story fast.
Labs adopting strict practices—sealed containers, handwashing sinks by the exit, reminders about not touching your face—lower the risk of anything going wrong. Most small chemical spills pose more hassle than hazard, especially if handled quickly by someone trained. Still, the real worry kicks in with chronic exposure. The nervous system does not forgive repeated insults, even if each one feels minor.
Manufacturers classify acetylthiocholine iodide as hazardous. The Globally Harmonized System for chemical safety labels it as harmful if swallowed or inhaled. Skin contact usually only brings short-term irritation, but ingesting it brings much greater risk, since it mimics molecules in the nervous system.
No chemical company would ship this substance without a Material Safety Data Sheet attached. These documents spell out what’s known: keep it away from the mouth, don’t let it touch skin for long, protect the eyes, and avoid inhalation at all costs. Emergency steps follow standard protocol: rinse affected skin, flush eyes, seek medical attention right away if someone swallows it or feels dizzy.
Most chemical dangers shrink when handled with respect. Wearing nitrile gloves, lab coats, and goggles does not just tick off a regulatory box—these habits buffer against mistakes. A fume hood or a bench-top extractor, backed by good ventilation, keeps dust out of the air and off skin. Supervisors should remind staff and students to change gloves after handling any container, not just during spills.
Safe disposal matters too. Flushing this kind of compound down the drain or tossing it in regular trash ignores hazards. Waste containers labeled for chemicals, regular pickups by hazardous waste handlers, and smart labeling keep danger out of reach once the experiment ends.
If you’re diving into neurobiology or pharmacology, acetylthiocholine iodide pops up all over lab benches. It shows up in enzyme studies looking for answers about the nervous system. So what makes it so useful? The molecule works as a handy proxy for acetylcholine. Since acetylcholine is busy as a neurotransmitter, acetylthiocholine iodide offers a more practical tool for experiments. The structure stays close enough for many enzymes to treat it like the real thing, but it’s easier to track and measure.
Out of all its jobs, measuring acetylcholinesterase activity tops the list. Labs use the compound as a sort of stand-in. Edward Ellman’s spectrophotometric method made things much smoother — researchers combine acetylthiocholine with Ellman’s reagent (DTNB), and acetylcholinesterase breaks down acetylthiocholine into thiocholine. The thiocholine reacts with DTNB, forming a bright yellow product you can measure with a spectrophotometer. Data heads can then score enzyme activity in real time.
This process helps in mapping neurological conditions. Alzheimer’s research often leans on the acetylthiocholine-DTNB duo. Scientists screen for inhibitors against acetylcholinesterase to see if they can slow down the breakdown of acetylcholine in the brain. Since acetylcholine levels dip in Alzheimer’s patients, blocking the enzyme could offer relief. Acetylthiocholine iodide becomes a gatekeeper for testing newer drugs.
Pharmaceutical research leans heavily on acetylthiocholine. Suppose you work in drug development. You need to see how candidate compounds affect cholinesterase activity. Acetylthiocholine iodide lets labs run safe, repeatable screens without pulling human or animal tissue for every run. This speeds things up and gives more consistent numbers across the board. You spot undesirable side effects earlier and can shape safer drugs.
Toxicology studies circle back to this compound, too. Some pesticides and nerve agents target cholinesterase enzymes. Researchers run acetylthiocholine iodide assays to check how these chemicals act or to trace markers of toxic exposure in blood samples. Quick, reliable data can mean the difference during medical emergencies.
The molecule isn’t limited to practical screens. It’s a reliable test tool for pinpointing enzyme kinetics. Basic neuroscience labs use it to learn how fast, slow, or reliably acetylcholinesterase works under different temperatures or in the presence of various ions. Patterns of activity in these tests reveal a ton about nerve function, stress, disease, and how our brains and muscles stay in tune.
Bringing a stable, readily available substrate into the lab means you get greater control and transparency over your experiments. The reliability of acetylthiocholine iodide, especially compared to more temperamental natural compounds, makes it a mainstay for published research. It’s easier to compare results from different labs or reproduce promising studies, which matters for scientific trust.
Scientists are always on the lookout for safer and even more selective substrates. Improved versions, or alternatives that mimic acetylcholine more closely without unwanted side reactions, could refine these tests. As research methods change, keeping an eye on the ethics of how and why we use chemical stand-ins like acetylthiocholine iodide becomes important, especially if they help reduce animal testing or support early, non-invasive screens in medical diagnostics.
Having worked in academic labs, it’s clear that acetylthiocholine iodide saves time, money, and stress. It keeps things consistent and keeps research on track, even as new treatments and diagnostics depend on the very enzymes it helps us study.
| Names | |
| Preferred IUPAC name | 2-(Acetylsulfanyl)-N,N,N-trimethylethanaminium iodide |
| Other names |
AThCh-I Acetylthiocholine iodide O-Acetylthiocholine iodide S-(Acetyloxy)ethyltrimethylammonium iodide |
| Pronunciation | /əˌsiːtɪlˌθaɪoʊˈkoʊliːn ˈaɪədaɪd/ |
| Identifiers | |
| CAS Number | 1866-15-5 |
| Beilstein Reference | 1722697 |
| ChEBI | CHEBI:29015 |
| ChEMBL | CHEMBL416702 |
| ChemSpider | 17013 |
| DrugBank | DB02557 |
| ECHA InfoCard | 100.044.786 |
| EC Number | 2186-42-9 |
| Gmelin Reference | Gmelin Reference: **8344** |
| KEGG | C02591 |
| MeSH | D000082066 |
| PubChem CID | 6917765 |
| RTECS number | AF8575000 |
| UNII | K94221397F |
| UN number | UN2811 |
| CompTox Dashboard (EPA) | DTXSID7055042 |
| Properties | |
| Chemical formula | C9H20INO2S |
| Molar mass | 367.19 g/mol |
| Appearance | White to off-white powder |
| Odor | Odorless |
| Density | D=1.558 g/cm3 |
| Solubility in water | Very soluble |
| log P | -2.6 |
| Acidity (pKa) | 4.0 |
| Basicity (pKb) | 8.15 |
| Magnetic susceptibility (χ) | -66.0×10⁻⁶ cm³/mol |
| Dipole moment | 6.54 D |
| Thermochemistry | |
| Std molar entropy (S⦵298) | 189.3 J·mol⁻¹·K⁻¹ |
| Pharmacology | |
| ATC code | N07AA06 |
| Hazards | |
| Main hazards | Harmful if swallowed. Causes serious eye irritation. Causes skin irritation. May cause respiratory irritation. |
| GHS labelling | GHS02, GHS07 |
| Pictograms | GHS07 |
| Signal word | Warning |
| Hazard statements | H302: Harmful if swallowed. |
| Precautionary statements | P261, P264, P270, P271, P272, P301+P310, P302+P352, P304+P340, P305+P351+P338, P308+P311, P330, P363, P405, P501 |
| Lethal dose or concentration | LD50 mouse (intraperitoneal): 25 mg/kg |
| LD50 (median dose) | LD50: 18 mg/kg (Intraperitoneal, Mouse) |
| NIOSH | Not established |
| PEL (Permissible) | Not established |
| REL (Recommended) | 0.05 mg/m³ |
| Related compounds | |
| Related compounds |
Acetylcholine Acetylcholine chloride Acetylthiocholine chloride Butyrylthiocholine iodide Butyrylthiocholine chloride |
