Source of "ketone" terminology

(Joey) #1

Came across an interesting organic chemistry tidbit … which may not be news to folks around this forum but it’s news to me:

The term “ketone” is derived from the German word for acetone - which was "aketon."

Perhaps this was posted before. Or may be of no interest.

And of course our German-speaking friends around here may roll their eyes at this naive Anglophone marveling at nothing much. Onward.


I never heard of Aceton pronounced like Aketon in German, we used a z rather than a k at school. In fact, Azeton is a spelling variant. Maybe is was different before, Aketon sounds like a latin pronunciation?

(KM) #3

I think that’s neat, I never put the two words together before even though I knew acetone and ketones were similar / measured similarly.

(Bacon enough and time) #4

The Latin word is acetum. I suspect that aketon is the Greek form. A lot of organic chemistry terms are derived from German words or compounds, since German was at one point the lingua franca of science. says the following;

ketone (n.)

chemical group, 1851, from German keton (1848), coined by German chemist Leopold Gmelin (1788-1853) from German Aketon, from French acétone (see acetone). “Appar. an arbitrary variation of acetone, to make a distinction” [Century Dictionary]. Its combining form is keto-. Related: Ketonic.

(Joey) #5

An ironic linguistic twist, mon ami*

(* - which I’ve read is not actually said in France?!)

(Bacon enough and time) #6

C’est vrai, mon vieux! :grin:

(Joey) #7

Quelle dommage :slightly_frowning_face:

(Susan) #8

Ketones is a category of molecules which have an oxygen double bonded to a carbon as part of the molecule, just as alcohols have an oxygen with a hydrogen single bonded to a carbon (think ‘sugar alcohols’). Acetone is 3 carbons with an oxygen double bonded to the middle carbon. It’s the logo for this web site on the upper left corner. You only need to read on if you’re interested in details. The following makes no real difference to the discussion of ketogenic diets and the benefits thereof. It’s only in an effort to be precise.

There are a few metabolically relevant molecules that we make when we metabolize fat, acetone is one but the other 2 get changed and no longer technically fit into the ‘ketone’ naming system. Since it doesn’t matter what they actually are, just that they are an indicator of fat metabolism, they get called ‘ketone bodies.’ When you get into the weeds and need to talk specifics, the other 2 ketone bodies are acetoacetate and beta hydroxybutarate. When taking about a ‘ketogenic diet’ we get lazy and say ketones instead of the more accurate ketone bodies. All of this matters not one whit when you’re thinking about what to eat. I taught biochemistry to nursing students and like the weeds, so I thought I’d chime in for the fun of it.

(Bacon enough and time) #9

Oh, and here I thought acetoacetate was also a ketone, and that β-hydroxybutyrate was the only one of the three that wasn’t. Live and learn!

(Joey) #10

Awesome - and thanks. I actually enjoy a good weed!

(BTW, with a couple of undergraduate degrees in forestry & environmental science I should add that a weed is defined as any plant you don’t want.)

(Susan) #11


(Susan) #12

Acetoacetate is both a ketone and a carboxylic acid, but the carboxylic acid trumps the ketone in our pigeon holes of naming organic molecules that doesn’t mean a whole lot in reality. The hydroxy part of beta-hydroxybutyrate means it’s also an alcohol, but again, the carboxyl group trumps that, making it also a carboxylic acid. (Most anything that ends in ‘ate’ or ‘ic acid’ is a carboxylic acid.) The beta part means that the hydroxyl group is on the second to last carbon, the ‘first’ carbon has the carboxyl group. As an acid, carboxylic acids lose a hydrogen and become ions with an O- (Oxygen with a negative charge) at the ‘beginning’ end of the molecule. As an ion, it’s named ‘ate’, as a neutral molecule (which never exists at the pH of blood) it’s named ‘ic acid’. You may have heard about beta-hydroxybutyric acid. It’s the same thing, but at a more acidic pH than blood.

We say ketone bodies to mean all 3 (acetone, acetoacetate and hydroxybutyrate) because they’re what you get when you metabolize fats instead of carbohyrates. We get lazy and shorten that to ‘ketones’ but it’s not accurate. Acetone, as the smallest molecule, comes out in our breath and it what is measured when we measure our ‘ketones’ from our breath. Acetoacetate comes out in the urine and is what is measured when we measure the ‘ketones’ in our urine. Beta-hydroxybutyrate is what we measure in the blood. Somehow, ketone bodyogenic diet doesn’t roll off the tongue as easily.

BTW, pet peeve, drinking alkaline (non-acidic) water does absolutely nothing for your health. It’s crucial that the pH (measurement of acidity) of our blood is VERY VERY stable. We have 4 large systems and multiple smaller ones that ensure that our pH remains just right. The two biggest are our kidneys and our breathing rate. For example, if you go up in altitude quickly and have to breathe harder to get enough oxygen, your pH goes off a little until your kidneys can catch up. You get a head ache because your brain (as well as other locations, but they’re not locked into a bony vault) swells and pushes on your skull! That’s why you spend weeks at the various base camps when you go up Everest. If you were to fly all the way up and stay for any length of time, you’d die. The large airplanes could be pressurized to something closer to sea level if they wanted to, but they’re pressurized to 10,000 feet so that walking around takes a little more energy and makes you feel just a little ill so you’ll stay in your seat. Anyone want any more ‘weeds’? :wink:

(Bacon enough and time) #13


BTW, I discovered that all ketone bodies can be measured in breath, urine, and blood; it’s just that the inexpensive home tests measure only one in each location. (Presumably, the one we measure is the easiest to measure in that location.) I learned this from a study (reference now lost, alas!) which relied on β-hydroxybutyrate measurements in the urine.

(Joey) #14

More great stuff. Thanks and keep it coming.

For those of us who live at elevations of just over a mile high year 'round, meandering around airplane aisles must be much easier. I never thought about it much.

On a related note: I do know that when we visit family who live at sea level, they get rather tipsy on the same amount of wine that has no meaningful effect on us, being their more “elevated” kin [… we arrived high(er)?] Apparently we’re pre-oxygenated. :man_shrugging: