However, there are instances when they can cause nuisances in the household, interfering with our daily activities. They might start to cause stress and pain. 

The only time that spiders show their aggressive nature is when they are provoked or agitated.  This usually happens when we attempt to get rid of them. They retaliate in return. When they do this, they resort to biting and secrete spider venom into the skin. 

If you enjoyed our last journey covering the differences between bee and wasp venom, join us for a new venomous journey, and the biochemistry behind it!

Are Spider Venoms Usually Very Dangerous?

The spider venom is a mix of a lot of chemicals. Usually, spider bites are not as deadly as people think.  The composition of their venom is often only enough to paralyze small animals.

So the short answer is no, besides some species that can be very dangerous or even deadly, in most cases, there is no reason to panic if bitten by a spider.

However, there are spider species like the black widow spider (Latrodectus) and the brown recluse spider (or brown fiddler) that causes more than just skin allergies. Their venom is composed of more fatal components. Those can lead to necrosis, severe skin infections, or worse. So let’s discuss what it comprises so we know how to deal with it. 

What Are the Components of a Spider Venom?

The venom is released through the spider’s fangs called “Chelicerae” as they bite. These are usually composed of the following substances. 

• Venomous Peptides: A variety of peptides (small-chain proteins) are the major components of the spider venom, some of these are venomous and in a dose high enough to harm humans, in some cases.  These peptidic toxins can serve many purposes. Among these, paralyzing small animals, or help the spider in the digestion process.
• Enzymatic and Non-Enzymatic Proteins: These, on the other hand, have a high molecular weight that usually act as agents to help spread the venom throughout the body of the bitten creature.
• Small Molecules: Different mixtures and concentrations of active small molecules can bee found in venom. The most notable ones act as neurotoxins or necrotic agents. Other active compounds like serotonin can also be found in spider venom. 
• Other Components: Spider venom has other more common substances like salts, biogenic amines, and carbohydrates.  All of these contribute to might contribute to producing pain, or have other functions.

Most people develop an allergic reaction to many of these chemicals because they are foreign agents. Plus, these can dissolve tissues and cause pain.  Depending on the components of the venom, it can either be categorized as a cytotoxin- or neurotoxin-based venom.  So what is the difference? 

Spider Venom: Is it Cytotoxins or Neurotoxins?

Two types of spider venom are found as harmful and dangerous to people. This includes venom composed mainly of cytotoxins and venom that consists of neurotoxins. The difference between these two types is obviously the nature of the main chemical components found within them and the physical damage that they cause to humans.

Cytotoxins

Cytotoxins are substances that have a toxic effect on cells.

Cytotoxins have enzymes and linear peptides that damage the cells and tissues of the prey. Insects that are charged with this venom are liquefied for the easy ingestion of the spider. In the case of humans, cytotoxins create blisters, inflammation, or lesions on the skin surrounding the bite (necrotic bite). Loxoscelism is the condition where necrosis of the skin and the spread of red blood cells occur. Other symptoms of this condition include fever, headache, and vomiting. Some of the spiders that secrete cytotoxins dangerous to humans include the recluse spider and the South African sand spider.

Neurotoxins

Neurotoxins have a toxic effect on cells, but only a specific type of cells: neurons. They are destructive to nerve tissue.

Neurotoxins present in spider venom usually are proteins, disulfide-containing peptides, or polyamines. These chemicals paralyze and then kill the prey. They attack and immobilize the nervous system. Animals can die because of neurotoxins but rarely does it happen to humans. Only in extreme situations neurotoxins from spider venom kill people. 

The condition known as Latrodectism is caused by neurotoxic venom that can cause muscle cramps, pain in the abdomen or chest, vomiting, and sweating. Out of the two kinds of venom, this is the most dangerous of all. The black widow spider or red back spider, the Brazilian wandering spider, and the Australian funnel web spider all have neurotoxins that can potentially harm humans. 

What to Do When Bitten by a Spider

Generally, spiders are harmless, but being bitten by a spider is a whole different story. The type of spider should be considered when treating a spider bite. And in extreme cases, the spider should be captured to identify the venom for the proper medical attention. This is many times not possible, so it always helps to have in mind the clearest description possible of how the spider looks like. As we said, almost always, spiders will only attack and bite when disturbed, so there should be not such thing as getting bitten while sleep without realizing.

The first aid treatment to a spider bite is to wash the affected area with soap and water. When the bite is painful and inflamed, a cold compress on the wound can be helpful. Antihistamines and analgesics can be used to reduce pain and swelling. 

Immediate medical attention is needed as soon as symptoms are detected, especially if the bite of the spider has neurotoxins or necrotic substances. The bite of the Australian funnel web, the red back spider, and the Brazilian wandering spider can be fatal to humans.

In any case, what you should not do is panicking. In most cases you are going to be perfectly fine even without serious treatment. But better be safe than sorry and if you spot any serious symptom, go get it checked out.

About the author

Jenelly Laroco is a writer for Go-Forth Pest Control. She writes about pests and how to get rid of them safely but effectively using environmentaly-friendly methods. 

The post Neurotoxin vs. Cytotoxin: The Difference between Spider Venoms appeared first on Chemistry Hall.

Let’s set the record straight here. Applying your knowledge of chemistry can help you cut through the marketing hype and fear mongering. The truth is often simpler than you might expect.

What Is Distilled Water?

Distilled water is simply water that has been purified through a process of distillation. That means it has been boiled, and the resulting steam has been collected and condensed, leaving you with what is, in theory, perfectly pure water (it is not a complicated set up, you could even do it at home).

What does “perfectly pure” mean, in this case? Consider tap water, spring water, or any other water you might encounter in daily life. All of this water has some amount of other “stuff” in it besides hydrogen and oxygen.

Some of it might be stuff you can see, like algae in lake water, for example. But most of it will be invisible to the naked eye: dissolved minerals like calcium, sodium, potassium and magnesium, chlorides and bicarbonates, and sometimes additives like chlorine and fluoride in tap water in some regions.

There may even be microscopic critters swimming around in the water. Most of them are harmless, but some pathogenic microorganisms cause very serious illness (this is why so many cities treat their water supplies with a small amount of chlorine).

So, the perfectly pure water that comes from distillation is missing all of the above—it contains no minerals, no bacteria, no nothing. Just plain ol’ H₂O.

Is it Safe to Drink?

The short answer is, yes, it’s safe to drink distilled water. But you might not want to make a habit of it.

Typically, distilled water of different qualities is employed to perform analytical chemistry techniques.

First of all, it’s not going to be any better for you than your regular tap water (assuming you are in an area where the water is safe to drink), and it can actually have certain negative long-term effects in some people.

Because it contains no minerals (i.e. electrolytes), it may be harder for your body to stay hydrated drinking distilled water, or you may get muscle cramps because of low calcium and magnesium. Still, these side effects are far from universal and certainly no reason to avoid distilled water if it is the only uncontaminated source available. You can always replenish electrolytes through food.

To illustrate just how safe it really is, consider that distilled water is often used to prepare formula for infants with particularly weak immune systems.

It has plenty of other uses, too. It’s essential for laboratory tests and chemical preparations like cosmetics, and it is very useful in cars and domestic appliances for reducing limescale and other mineral deposits.

But it’s not the best for drinking if you care at all about how your water tastes. If you look closely at any bottle of purified drinking water, you’ll see that, after purification, minerals have been added back into the water. This is because distilled water, without any minerals, tastes bland and flat.

Finally, it’s a lot more expensive than tap water. It’s worth paying extra to keep your car and clothes iron working smoothly, but for drinking? Why pay more for water that tastes bad and offers no benefits unless it’s really necessary?

What About Alkaline Water?

Speaking of water that is unnecessarily expensive and doesn’t offer any benefits…

I don’t know when this idea first came onto the scene, but I first heard someone peddling the idea of acidic and alkaline diets circa 2007. It didn’t seem terribly harmful at first—the proposed “alkaline diet” was rich in fresh vegetables and fruits, low in sugar and processed foods, and really an undeniably healthy way of eating—but this notion grabbed a foothold and is now being used to scam people out of their money with false health claims.

So now, over a decade later, alkaline water is being sold everywhere you look for exorbitant amounts of money compared to tap water. Depending on who you ask, this water will make sure your blood maintains its proper pH (very slightly basic), doing everything from reducing systemic inflammation to preventing cancer.

For anyone with a rudimentary understanding of chemistry and biochemistry, this is simply preposterous.

Yes, an alteration in your body’s pH is a big problem, but this does not happen as a result of consuming normal foods or drinks. We all eat and drink acidic and alkaline things every single day without any effect on the pH of our bodies. This is because the human body contains numerous regulatory mechanisms and buffering systems to prevent the things we ingest from affecting the pH of our blood or cells.

The body rids itself of excess acid by exhaling carbon dioxide, by excreting it through the kidneys, or by retaining bicarbonate.

So, what happens if you do drink alkaline water? Think about where that water is going: straight into the highly acidic environment of your stomach. Your body has its own built-in water alkalinization system! Before it is absorbed by the colon, the acidic water from your stomach is neutralized by bicarbonate secretions from the pancreas.

Drinking Distilled Water: Water Quality

With all of this in mind, we can say that, in general, it is safe to drink distilled water. Most tap water, however, is equally safe to drink, tastes better and is much cheaper. But if you know that the area you are in does not have safe drinking water, you should not hesitate to drink distilled water if it is the only clean water available.

I guess the same could be said about alkaline water—if there’s nothing else safe to drink, by all means—but that’s the only good reason to do it. Put your chemistry knowledge to use, don’t be fooled by marketing gimmicks, and save your money.

If you want to impress a chemist with a gift, please, don’t even think about these kinds of scammy trends, there are so much better options!

The post Is It Safe To Drink Distilled Water? appeared first on Chemistry Hall.

Chemicals are not bad (even not-organic ones). The thing is, everything we see or touch in our world, is made up of chemicals. From the purest distilled water that we use as solvent in the lab to a carrot that you just harvested from your backyard.

But there are many poisons out there in Nature, and other dangerous chemicals that may or may not be human-made.

On this informative article, we wanted to cover some of these scary compounds which you might want to steer away from.

If you are not a professional scientist, you probably will not encounter many of them in your every-day life, or for sure in any experiment that you might do at home but still is good, or interesting to be aware of them. or maybe you want to warn your chemist friend (together with a cool gift)

On the other hand, if you are a chemist, it is definitely possible that you might have to use some of these for your work. And it is always good to be prepared, so you can take the appropriate safety measurements. Or just nope the hell out of using them if ever asked to.

So, what is the most dangerous chemical known to man? What is the most toxic chemical?

What Kind of Dangerous Chemicals Are We Reviewing?

We have decided to divide the compounds in different categories.

This will depend on whether they are dangerous because they are poisonous (low LD50), corrosive, explosive, or extremely harmful chemicals for some reason.

We also have a category for typical dangerous laboratory chemicals (definitiely worth checking out if you’re a chemist or chemistry student).

Finally, we will also discuss some very dangerous compounds that can be found in every-day life situations.

In any case, all these nasty chemicals are interesting to know about.

Without further ado, let’s look into them!

The Most Dangerous Poisons

Botulinum toxin

Botulinum toxin, is basically the most lethal poison known to man. An average 70 kg human being only would have to take around 100 nanograms of this protein to die (it has an LD₅₀ of 1.5–2.0 ng/kg).

If you put it in perspective, one gram of this toxin can kill more than one million people!

What this toxin does chemically is basically preventing acetylcholine from being released between neuron connexions. This breaks down the connexions of neurons with with muscle cells. This leads to muscle paralysis, as contraction of the muscle cells cannot take place.

If you take enough, the neuron connexions which make the heart or respiratory systems work go down, which can kill you.

Funnily enough, this toxin is used in medicine. Botulinum toxin is commercialized under the name of Botox, among others.

As a tool that can paralyze muscles, it found uses in treating muscle spasticity (muscles that are contracted all the time) or other muscle-related diseases. The most potent toxin in the world has even been used in cosmetics, in order to “smooth” facial muscles!

Batrachotoxin

Following next, the next poison comes off the skin of some dart frogs. Specifically, phyllobates terribilis or Golden Poison Frog is known for being one of the most dangerous poisonous animals in the wild.

One of the key components of their poison is batrachotoxin.

Contrary to botulinum toxin, which is a protein, batrachotoxin is a small organic molecule.

You can see how their structures have absolutely nothing to do with each other. But they both work in a fairly similar manner: batrachotoxin, with an LD₅₀ of 2000 ng/kg (an order of magnitude less poisonous than botulinum toxin, but still scary), is also a neurotoxin. It blocks the Na+ ion channels permanently, preventing neurons from communicating with muscles, leading to paralysis and eventually heart failure.

Interestingly, dart frogs don’t make batrachotoxin by themselves.

They need to ingest certain alkaloids through their diet. If they are kept in captivity, dart frogs are rendered non-poisonous.

But in the wild, they make one of the most dangerous poison mixtures. Dart frogs can only be found in Colombia or Panama rain-forests, and they were used by indigenous tribes to make poisonous darts and arrows. That’s where they get their name from.

Ricin

We are back to the protein world with ricin. This is yet another order of magnitude less poisonous than botulinum toxin. Ricin’s LD₅₀ is 22.000 ng/kg. But this still means that 2 mg of ricin will kill an average adult.

One of the most dangerous chemicals in the world, ricin, can be find in castor beans.

The mechanism of action of ricin is very different to the one for botulinum toxin or batrachotoxin.

This protein disrupts the ability of the body to assemble proteins from amino acids in the ribosomes.

Since the mechanism of action is much subtler than for other toxins, the symptoms take time to show up. But they eventually do. The inability to make proteins (a very basic type of cell metabolism, essential for cells to survive), causes damage to the nervous system, kidneys and liver in hours to several days.

Ricin got more popular around the world after its appearance in AMC show Breaking Bad.

Maitotoxin

We are coming back down in the LD₅₀ score, since maitotoxin has a value of 50-130 ng/kg in mice. This is the highest for non-protein compounds. It is produced by a species of dinoflagellates, gambierdiscus toxicus, and can be found on the surface of some algae in Polynesia, or some animals such as the ciguateric fish.

But from a chemical point of view, the most interesting feature of maitotoxin is not its toxicity, but its chemical structure.

Maitotoxin is not a protein, but I wouldn’t call it a small molecule either. With a molecular weight of 3422 g/mol, maitotoxin is one of the toughest unbeaten synthetic challenges out there.

This impressive amphipathic structure made up of 32 fused rings and a handful of stereogenic centers has not been synthesized completely in organic chemistry labs. The research group of K. C. Nicolaou is involved on the total synthesis of this giant. So far, the synthesis of some of the ring domains has been published, but the entire molecule is still a challenge to overcome.

Tetrodotoxin

Tetrodotoxin is another small molecule, which similarly to batrachotoxin, is a potent neurotoxin. It is also a sodium channels blocker.

This poison is the one that makes dangerous several kinds of animals: fishes such as the porcupine fish or pufferfish. Also, blue-ringed octopuses or moon snails produce tetrodotoxin.

This is not a huge molecule as maitotoxin, but it is still an attractive synthetic target that has been the objective of many total synthesis project. The structure of the molecule was elucidated by Woodward in 1964, and the first total synthesis was reported in 1972.

Phosgene: COCl₂

All the poisons covered above are made by natural sources. However, phosgene, a truly small molecule, is human-produced in the range of several tons a year.

Phosgene, or carbonyl chloride, is classified as a chemical weapon, and it is responsible for many thousands of deaths during World Wars. A median concentration in air (LC₅₀) of 200-500 parts per milion is enough to kill a person.

Despite being one of the most dangerous chemicals in history, it is an extremely useful reactive building block on chemical synthesis, and it is massively produced and used all over the world.

It is normally made by reaction carbon monoxide with chlorine gas, and it is employed in the synthesis of carbonates, isocyanates (precursors of polyurethanes), among others.

The Most Dangerous Acids and Bases

Hydrogen fluoride: HF

Hydrogen fluoride is not a very acidic acid. In fact, it’s the least acidic of all the hydrogen halides.

But it is actually the most dangerous.

HF is extremely toxic and corrosive. As it happens with many fluorine-containing compounds, it has weird properties.

Fluoride really loves binding to silicon, so HF can easily eat through glass (made of SiO₂). This is the reason it needs to be handled and stored in plastic containers.

But HF can also bypass our skin barriers, and go through reaching the bones, dissolving them as CaF₂ is formed.

The guys at Periodic Videos have performed some experiments showing how scary this acid can be:

As you can see, there is a difference between an acid being “strong” and being “corrosive”.

Fluoroantimonic acid: HSbF₆

Fluoroantimonic acid is one of the most acidic compounds known to man. It is what is called a “superacid”. These are usually defined as chemicals which have an acidity (or ability to donate protons, H⁺) larger than pure sulfuric acid.

It is actually made by mixing HF with SbF₅. Surprisingly, this combination between a relatively weak Brønsted acid (HF) and a Lewis acid (SbF₅) gives rise to a compound which is 20.000.000.000.000.000.000 (2·10¹⁹) times stronger than H₂SO₄.

Piranha solution

Piranha solution is the name that chemists give to a mixture of hydrogen peroxide and sulfuric acid. H₂SO₄ and H₂O₂ react giving H₂SO₅ (Caro’s acid) and water.

This results on a strongly oxidizing acidic mixture. The “piranha” name is quite appropriate, since it easily eats through organic matter.

As a matter of fact, this mixture is used by chemists to remove organic residues from glassware (although the glassware has to be very valuable and all other common methods unsuccessful).

tert-Butyl lithium: t-BuLi

One of the most common dangerous laboratory chemicals is tert-butyl lithium. We have switched it to this category because it is an extremely strong base.

This makes it very useful in organic chemistry. If a proton cannot be abstracted by t-BuLi in an organic molecule, you will most likely not be able to remove it with anything else.

It can even react with THF (a common organic solvent, which usually are very chemically innert) at room temperature, removing one of their protons and leading to decomposition.

t-BuLi is very pyrophoric, it readily reacts with air catching fire, that’s why it has to be handled and stored with very special care, always under a protective inert atmosphere of pure nitrogen or argon.

The Most Dangerous Laboratory Chemicals

Dimethyl mercury: HgMe₂

Karen Wetterhahn was a chemistry professor working on toxic metal exposures. Ironically, she died in 1997, due to exposure to dimethyl mercury.

One of the most famous dangerous lab chemicals is Me₂Hg. Prof. Wetterhahn was using full protective equipment, but unfortunately, a couple of drops of dimethyl mercury fell in the top of her gloves. The amount of compound that could be absorbed through the gloves and her skin was enough to kill her by metal poisoning, slowly, after less than a year. Even using very strong chelation therapy, it was not possible to save her life.

Dimethyl mercury was used in very specialized NMR experiments using ¹⁹⁹Hg nucleus, but I don’t think I would ever work with it. Me₂Hg can actually go through most types of safety gloves. The use of this substance in any scenario is strongly discouraged.

The price of a potential accident is just too high.

Dimethyl cadmium: CdMe₂

If you thought dimethyl mercury is nasty, meet its bigger brother, dimethyl cadmium. It is not only highly toxic as Me₂Hg, but it is also highly reactive.

Dimethyl mercury reacts with air, or organic matter, not only exploding but also giving rise to more and more toxic Cd-compounds.

Dimethyl cadmium is also very volatile, and inhaling only a few micrograms of it can lead to cadmium metal poisoning, and eventually, to death.

Diazomethane: CH₂N₂

Diazomethane is the simplest diazo compound there is.

Diazo compounds are organic molecules which have a -N₂ functional group attached to it. As you can imagine, thermodynamically, that nitrogen really wants to jump out of the organic molecule and leave as nitrogen gas.

So these compounds are extremely reactive, and some of them have a high tendency to explode. Besides, they are usually extremely toxic. Specifically, several deaths have been reported by diazomethane poisoning.

It is a useful reagent in organic chemistry, since nitrogen gas release is an extremely powerful driving force for achieving difficult chemical transformations, such as cyclopropanation or homologation reactions. Finding alternatives to diazomethane and its derivatives is an important challenge in modern organic chemistry.

Chloride trifluoride: ClF₃

Chloride trifluoride is a compound which will look very unusual to you if you don’t have a very advanced chemistry knowledge. This is a hypervalent chlorine compound, with three fluorides attached to it.

ClF₃ is a very poisonous and reactive gas, which has found applications in fields such as rocket fuel research (although it is not used yet as rocket propellant), or as fuel in nuclear reactors.

It is manufactured by mixing F₂ and Cl₂ gases and then separating it by distillation.

It is a highly oxidizing agent. It can also act as a potent fluorinating compound.

Dioxygen difluoride: FOOF

As far as oxidants go, dioxygen difluoride is the top pick.

It can be prepared by mixing oxygen and fluorine gas, and the resulting compound is so oxidizing and unstable, that it starts decomposing even at temperatures as low as -160 ºC. It hass a funny structure, common to the one for classical peroxydes

O₂F₂ reacts in a vigorous manner with virtually any chemical that it comes in contact with. It is usually referred to by the name “FOOF” due to its high tendency to make anything explode.

Osmium tetroxide: OsO₄

Osmium tetroxide is not as scary as the last previous oxidants, but it is also a much more common laboratory chemical.

This reagent is great for oxidizing alkenes to diols, or for epoxydation reactions. As a matter of fact, most of the chemistry awarded one half of the 2001 Nobel prize in chemistry (to Barry Sharpless) is based on the use of osmium oxides for the asymmetric oxidation of alkenes.

However, one should handle this chemical with care. OsO₄ is very poisonous and inhalation of small concentrations can cause pulmonary edema, and cases of death have been reported.

Handling osmium tetroxide with care, and disposing it appropriately is of great importance.

Fluorine: F₂

Playing with fluorine gas is something most chemists are scared of.

However, due to its very particular properties, introducing fluorine atoms into molecules is of great interest in organic synthesis and all its applications.

That’s why there are many research groups specialized in doing fluorine chemistry.

But a great deal of care must be taken. The following video illustrates how fluorine can behave.

Fluorine reacts with moisture to give hydrogen fluoride, which is scary enough by itself. But contrary to HF that can be handled in solution, F₂ has to be handled as a gas, and always using containers and tubing made of resistant plastic materials.

The Most Dangerous Chemicals in “Real Life”

Carbon monoxide: CO

Carbon monoxide can be a silent killer.

It can bind to the iron atom in hemoglobin, displacing oxygen, basically shutting down cell respiration.

Carbon monoxide, along with CO₂, is one of the products of burning organic matter. If the concentration of oxygen is low during combustion, the amount of CO that is produced increases. This can happen in a closed fireplace inside a house, and you could get poisoned without noticing.

In fact, dozens of deaths are reported every year due to CO poisoning.

Amatoxin

We are back to natural poisons, this time discussing amatoxin.

This is a general name for several toxins with a similar structure (several amino acids arranged in a macrocyclic fashion) that are responsible for the toxicity of different mushrooms, such as the death cap (amanita phalloides).

There is nothing as picking up your own shrooms out in the goods and making a great meal out of it… But it can also be dangerous!

Always make sure you known perfectly well what you are getting your hands into, and if you are in doubt, ask an expert before eating any mushrooms.

The Most Dangerous Chemicals… For Other Reasons

Azidoazide azide

This compound with a very illustrative name (and structure), is one of the most explosive chemicals that has ever been prepared.

Azidoazide azide is among the “high-nitrogen energetic materials”, and its molecular formula of C₂N₁₄ speaks for itself.

The thermodynamic feasibility of this substance to react releasing nitrogen is just HUGE.

Anything can set if off. Hit it with something, it explodes. Heat it up, it explodes.

I don’t recommend any of you ever getting close to this stuff. Instead, just check out what other people have already tested:

Thioacetone

Smell may seem like a “minor” danger sign for a chemical. But it can get beyond unpleasant, to the realm of actually being literally unbearable.

One of the most extremely unpleasant odors in chemistry comes from thioacetone.

Imagine an acetone molecule in which you swap the oxygen for a sulfur atom. The result is a substance with one of the worst smells known to man.

A famous incident involving this molecule involved a couple of milliliters dropped in a German laboratory in 1889.

The result was people unconscious and vomiting in a radius of almost one kilometer (half a mile).

For its extremely foul odor, thioacetone is considered one of the most dangerous chemicals in the world.

We are now wrapping up this list of really dangerous chemicals. These guys are the actual chemicals that should scare you, but do know that everything out there is made of chemicals, which simply can be very good or very bad!

Make sure to share if you found this useful or interesting, and up next, check out our explanations for 100 chemistry facts!

The post The 21 Most Dangerous Chemicals in the World (Steer Away!) appeared first on Chemistry Hall.

I hear the same discussion pop up form time to time among both chemists and non-chemists: why does some people’s urine smell funny after eating asparagus?

A lot of people claim to never have experienced this phenomenon. Then, they incorrectly assume that it is because they do not metabolize the chemical components of asparagus the same way. This is not completely true.

But for starters, what are the chemical components of asparagus?

The Chemical Composition of Asparagus

Chemophobia is present all over the place these days. People don’t realize that everything is made up of chemicals. A lot of badly-informed people would be shocked if they took a quick look at the actual chemical composition of completely natural foods, such as asparagus.

Check out the ingredients list of asparagus! This picture was taken out of the book called “Molecules: The Elements and the Architecture of Everything“. This is a great chemistry reading, by Theodore Gray and Nick Mann.

But out of that huge list, we actually just need to look at one ingredient: asparagusic acid.

What is Asparagusic Acid, and Does it Make our Urine Smell?

Asparagusic acid is a carboxylic acid which has a disulfide group as a part of a five membered heterocyclic ring.

Even though asparagusic acid is a organosulfur compound, it doesn’t really smell bad. As a matter of fact, asparagusic acid is just the precursor of different sulfur-containing volatile metabolites.

Usually, compounds such as carboxylic acids have low volatilities. For us to detect a smell, we need the responsible compound to be airborne.

The boiling point of asparagusic acid is 324 ºC, so even if it really smelled bad, it would have a hard time reaching our olfactory receptors. Actually, this compound was both isolated and prepared synthetically in a chemistry lab, and it does not show the typical asparagus pee smell.

Total Synthesis of Asparagusic Acid

A convenient laboratory total synthesis of asparagusic acid was reported by Yanagawa and co-workers in 1973. They started by treating a readily available diethyl malonate diol derivative with hydrogen iodide. This allows carrying out, at the same time, iodination of both alcohols, and a single decarboxylation.

After hydrolysis of the resulting monoester, the first intermediate with two iodines is obtained. Reaction of this intermediate with sodium trithiocarbonate (Na₂CS₃) gives the corresponding dithiol after treatment with sulfuric acid.

Finally, oxidation using DMSO at high temperature gives asparagusic acid. This organic synthesis, leads you to the desired compound in just three steps.

We have confirmed that asparagusic acid is not smelly. So, what does actually cause the asparagus pee smell?

When we eat stuff, we metabolize its chemical components, and the (bio)chemical transformations that take place in our body, generate new chemical compounds. The compounds generated after eating and processing asparagusic acid, together with the asparagus pee smell gene, are the two players that cause this unpleasant sensation for many people.

What is the Asparagus Pee Smell Gene?

So, our bodies break down asparagusic acid into smaller sulfur-containing molecules, which are smelly? That’s it?

Reality is, there is a gene that controls if each human being is able to smell or detect the metabolites that make asparagus urine smell. This is what we call the asparagus pee smell gene.

We have already covered this briefly in our list of explanations to 100 fun chemistry facts, but we felt that an entire post for this one may be useful and interesting.

This gene makes the whole story complete. Not all of us can smell the asparagusic acid metabolites. So even though it seems like not all of us produce them, we actually all do! It is just that some of us cannot smell them.

You can read further in this study published in Chemical Senses. The summary is that, actually, there are individual differences in both the production AND detection of the cabbage-like smell of asparagus-pee. The biology associated with metabolite production is mostly unknown. However, the inability to smell these metabolites is identified in association with an individual nucleotide polymorphism. This is what we refer to as the “asparagus pee smell gene”.

If you look really closely, it seems that there are many variations of these two traits: some people actually produce very small amount of these compounds, which can be enough to be detected by some, but not by others. So it is not a matter of black or white, there are intermediate situations.

A recent online survey with almost 3000 participants, showed that around 70% of the population can detect the smell in their own urine after eating asparagus.

Which Are the Chemicals that Actually Smell Bad in Our Urine?

A lot of small organic molecules containing sulfur atoms have a particular unpleasant smell.

For example, tert-butylthiol is used in very small concentrations to give natural gas (which is odorless by itself) a detectable smell. But in higher concentrations, I can tell you that it is extremely unpleasant. I’ve seen labs evacuated for the day after a few microliters of the stuff were dropped out of a fumehood.

Not tert-butylthiol, but different volatile compounds are produced while metabolizing asparagusic acid. Many structures have been proposed over the years. As far as 1891, it was proposed that methanethiol was the responsible of this smell. More recently, gas chromatography analysis allowed detection of different volatile organo-sulfur compounds arising from the metabolism of asparagusic acid:

Some compounds showing the functional groups in the table above, smell extremely bad in high concentrations. However, our ability to detect them in the amounts in which are metabolically produced by our bodies, depends on this asparagus urine smell gene.

I Got the Asparagus Pee Smell Gene: Can I Neutralize Asparagus Smell?

Maybe you enjoy eating asparagus. But also maybe, thanks to the asparagus pee smell gene, you are unlucky enough to be able to detect very low concentration of the sulfur metabolites.

To be fair, most people report the fetid odor going away quite quickly: you will naturally pee once or twice with the smell before it disappears.

Disappointingly, there is no clear way of making the smell go away quicker. The rate at which you get rid of metabolites through your urine depends on your glomerular activity (kidney filtration rate). This is not really accelerated by drinking more water or by other home-remedies.

However, drinking a lot of water will definitely dilute your urine and turn the smelly sensation milder.

But there is no big short-cut other than not eating asparagus!

Are There Other Foods that Make Your Urine Smell?

Asparagusic acid is a compound that is found almost only in asparagus. But other foods, such as Brussels sprouts, also have sulfur-contaning precursors that give rise to smelly metabolites.

Other foods can act as dyes for pee, making your urine colored. For example, don’t be surprised if your pee turns pink/red after eating beets or blackberries!

If you are interesting in other food-related stories such as these, you really need to get a copy of “Why Does Asparagus Make Your Wee Smell? And 57 Other Curious Food and Drink Questions” by Andy Brunning.

This is a great read for any science student or enthusiast. It can be enjoyed by all audiences: from kids at school to professional chemists. We were really inspired by that book for writing this post.

Asparagusic Acid and the Asparagus Pee Smell Gene: Conclusion

In conclusion, there is a combination of two factors that allow you to smell this annoying “asparagus urine smell” or not:

Asparagusic acid gets metabolized to different extent by different individuals, giving smelly volatile organo-sulfur compounds. On the other hand, there is a gene that determines our detection threshold for these compounds. Some people detect very low concentrations, and others are just lucky and simply can’t detect them!

The post The Asparagus Pee Smell Gene (Chemistry Behind the Scenes) appeared first on Chemistry Hall.

]]> https://chemistryhall.com/asparagus-pee-smell-gene/feed/ 1 https://chemistryhall.com/bee-wasp-sting-venom/ https://chemistryhall.com/bee-wasp-sting-venom/#comments Tue, 02 Jul 2019 08:59:06 +0000 https://chemistryhall.com/?p=17702 I have read from many different sources the same statement about bee vs wasp sting venom: Bee sting venom is acidic, and wasp venom is basic (alkaline), therefore, the “treatment” or remedy selected to treat each case should be based on this consideration. This would be based on a simple acid-base neutralization. There is some... [Read More]

The post Bee vs Wasp Sting Venom: Truth and Chemical Myths appeared first on Chemistry Hall.

]]> I have read from many different sources the same statement about bee vs wasp sting venom:

Bee sting venom is acidic, and wasp venom is basic (alkaline), therefore, the “treatment” or remedy selected to treat each case should be based on this consideration. This would be based on a simple acid-base neutralization.

There is some truth, but also plenty of myth (or popular folklore) behind this reasoning. I’ve read and heard that theory plenty of times, and even I spread it around in the past.

Why?

It is a simple enough explanation. And it makes sense chemically. It makes most chemistry enthusiasts happy. But the real answer is not that simple. That “acid-base neutralization” argument is not correct.

Keep reading and you’ll know why…

What’s on bee and wasps sting venom?

As we have explained before, relative acidity and basicity are measured through the pH scale. By convention we say that any solution or mixture with a pH below 7 is considered acidic, and above 7, basic.

“Venoms” are just solutions or mixtures of different components, some of them are actually poisonous and other components are innocuous. Insect venoms present components of different types:

• Water
• Peptides and proteins (such as enzymes, main responsible of causing pain)
• Small molecules (such as norepinephrine)

The mixture of all those components results in the actual insect venom. This mixture can have a determined pH, so it can be overall acidic, basic or neutral. But this does not imply that the active poisonous molecules can be simply neutralized by treatment with an acid or a base.

Bee vs wasp sting venom: are they actually acidic and basic?

In fact, even though bee venom is indeed acidic, with a pH between 5.0 and 5.5 (which is not alarmingly acidic anyway! Even bananas and tomatoes are more acidic than that), the pH of the sting venom of a wasp is actually very close to neutral (6.8–6.9), as it was disclosed by researchers at Keele University. Furthermore, wasps and bees have both types of glands (some acidic and some basic) from which they secrete their poisonous cocktail.

What are the components of bee venom?

The composition of the venom of different insects can vary significantly. The main responsible from pain after you are stung by a bee are peptides and proteins, although small molecules are also present, which enhance the main effects. These are some of the most important ones from bee sting venom:

• Melittin: It is a peptide, and one of the major toxic ingredients of bee venom. It basically kills and breaks up cells. This toxin stimulates enzymes involved in inflammation.
• Apamin: This globular peptide is a neurotoxin that can pass the blood-brain barrier. Acts on the nervous central system, blocking ion channels.
• Phospholipase A: Enzyme that destroys cells (by breaking its membranes). It is also a strong allergen, responsible of “bee allergy”.
• Hyaluronidase: Enzyme in charge of breaking down carbohydrates from proteins (degradation of hyaluronic acid). This process allows the venom to go through tissue.
• Alarm pheromones: Bees also release pheromones in their poison. These substances attract nearby bees, which will potentially take part on defensive actions (that’s why you should leave the place where you were stung by a bee or wasp).
• MCD Peptide: A peptide responsible for inflammation.
• Small molecules: Not only peptides and enzymes are components of the poison. Small molecules are also present and contribute to the undesired effects that we experience after a bee stung. They basically enhance the effect caused by the former. Some of them are histamine (contributes to pain and itching, and can also be an allergen), serotonin (contributes to the pain, it is an irritant), noradrenaline (responsible of the constriction of the blood vessels, which results on a blood pressure increase).

What are the components of wasp venom?

Surprisingly or not, some of the “ingredients” of both the venoms of wasps and bees are exactly the same. But the main components are different. We will list them below, detailing the components which are exclusive to wasps:

• Wasps and bees share the following components on their poisonous “cocktail”: Phospholipase A, alarm pheromones and hyaluronidase. They also share all small molecular components such as histamine, serotonin, dopamine and noradrenaline.
• Phospholipase B: This variant of phospholipase has a similar effect than the A, but it also plays a role in immobilizing prey.
• Wasp Kinin: This is the main component of wasp venom. The exact structure of this peptide is still not clear. It triggers the immune system, mediating inflammatory responses.
• Acetylcholine: The presence of this small molecule stimulates pain nerves. This might be the main responsible for the high degree of pain that you experience after a wasp sting. Acetylcholine and serotonin are components of wasp venom that “get the nerves on fire”.

These small molecule components will be familiar with anyone with basic knowledge on organic chemistry and molecular biology.

There are more differences, other than chemical, between bee and wasp stings which are usually common knowledge. For example, a bee can only sting once. Then it loses the stinger. In this process, the bee injects a relatively large amount of poison (around 50 micrograms of venom). On the other hand, a wasp injects lower doses (2–15 micrograms). But for wasps it’s not all or nothing: wasps can sting many different times.

What is actually causing pain from the bee and wasp sting venom?

Both wasp and bee sting venoms have a clearly defensive purpose, the venom causes enough pain on the “attacker” to convince them to back off and leave them alone. Furthermore, wasps can also use it as an offensive weapon to paralyze insects (food) and then move them easily to their nests.

But, what is causing the pain?

First off, how do we define pain? Pain is a localized physical suffering sensation, an uncomfortable feeling which has the objective of telling us that something is wrong with our bodies. In simpler terms, is the way our body has of telling your brain that it might be damaged.

The pain caused by wasp or bee venom sting is exaggerated, in the sense that the actual physical damage that we suffered is not that much (in the end, the sole purpose of this defensive mechanism is to scare us off).

But what is going on during this process?

• First, the stinger gets the poisonous mixture into your blood.
• The main destructive components of the venom are the peptides and enzymes in charge of breaking cells down (see previous section). These components rip through many kinds of cells. One of these types of cells happen to be neurons. When neurons are damaged, they send a signal of pain to the brain. This is what actually makes us experience pain.
• The other components of the venomous mixture help to intensify this main process. For example, the blood vessel constriction produced by noradrenaline reduces the venom diffusion away from the sting site, so prolongs and intensifies the local action of the venom. This is also used by your dentist – many use local anaesthetics include phenylephrine (a noradrenaline analogue) to keep the anaesthetic local (thanks, Malcom from comments section!).
• In case of smaller animals as victims, such as small insects, these effects can end up in paralysis. This is a hunting mechanism that wasps use to capture prey.

Myths vs facts: What does or does not help?

Here at Chemistry Hall we are always trying to put myths and facts into perspective.

So, we got a clear picture of what is causing pain after a bee or wasp stings us. In a nutshell, it is basically enzymes and peptides breaking our cells off. Neurons are among those killed cells. This transmits the pain sensation to our brain. Other small molecules, contribute to make this effect stronger and last longer.

So how do you minimize those effects?

Well, I have read on countless occasions that “bee sting is acid, treat with alkali, wasp sting is alkaline, so treat with acid”.  It would be cool if it were that simple.

But it is not. Unfortunately, chemistry is never that simple, if you look at it with enough depth.

We already stated that wasp sting venom is not actually basic but neutral. And also, based on the mechanism of action, alkali or base would need to have the potential of destroying the peptides and enzymes that cause pain for being effective as an antidote.

How should you actually deal with wasp or bee sting venom?

If this basic rule is not real, what does in fact work, and why?

Unfortunately, there are not many science-supported remedies, but basically anything that cools or numbs the injury will help. Also, helping the injured getting his mind elsewhere, and off the pain, will help significantly.

We are chemists, we base our conclusions in observations and experiments:

Many people report and claim that vinegar actually helps with both bee and wasp stings! So this piece of empirical data must be the key for understanding what is really happening.

This seems completely contradictory with the hypothesis that you need to neutralize the pH of the venom for it to wear off. After all, both venoms range in pH from 5.0 to 7.0, so lowering it down wouldn’t help, right?

As a matter of fact, vinegar does seem to help, and apparently it is the best home remedy for both stings. Scientifically, we cannot conclude that we are neutralizing any “alkaline compound” of the venomous mixtures. However, it is well known that changes in pH can cause proteins to denaturalize and lose its effect. This might be what is actually happening.

The bottom line is that, a modification on the pH might be actually helping to relief the pain, but it is definitely not through a simple acid-base neutralization process, as many people claim.

I just got stung and it hurts like hell, what should I do!?

Some important and actually helpful steps that you can follow are clear:

• Wash with plenty of soap and water. This is the easiest one to do and also the most helpful.
• Cool down the wound. You can use ice. This will reduce swelling. (Remember to place a napkin, paper towel or actual towel between the ice and your skin, you don’t want to get ice-burnt).
• Although there is no real proof, many people claim that vinegar helps. It definitely won’t hurt trying. Also, other typical home remedy is washing it with alkaline baking soda water solution. Again, there is no proof for this remedy working, and most likely you are getting exactly the same effect that you get by just washing with soap and abundant water.
• You can use an antihistamine spray or tablets if the pain gets too annoying. In case of severe allergic reaction, get medical assistance immediately!
• If you have any history on being allergic or especially susceptible to insect bites, go get medical attention as soon as possible.
• When a bee stings you, it usually leaves the stinger inside your skin. It is not recommended to attempt to remove It by hand (you could make it worse, pushing them further inside your skin). However, you can do it using tweezers.

Is an alkaline treatment good for any sting venom?

There are plenty of venoms in nature, and some of them can actually be neutralized by a simple acid-base reaction. For example, fire ants are known to produce a venom based on different compounds. One of these components is formic acid (although it is not the only one), particularly for ants that “spray” their poisonous cocktails rather than biting or stinging you. Formic acid can be easily neutralized with typical bases such as sodium bicarbonate and baking soda, and relief the pain.

As opposed to bee and wasp sting venoms, the pain caused by formic acid from ants, can be relieved by neutralizing it with a base. For this case, the nice and simple chemical explanation does work.

Bee vs wasp sting: Wrapping up and summary

To wrap up:

Both bee and wasp venoms have similar effects in humans, but their compositions are relatively different. There is no scientific evidence that you can simply neutralize through an acid-base process either poison. Many people claim that vinegar (acetic acid) helps relieving the pain of both, most likely through a protein denaturalization process.

The best and easiest remedy is just washing with soap and abundant water. If you get an allergic reaction, antihistamines help, but if it gets bad, go and reach for medical assistance!

If you enjoyed the reading, now time to to take a look at more scary stuff with spider venom.

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