Sciencemadness Discussion Board

Chamazulene, natural blue dye extraction and purification

Ormarion - 19-3-2023 at 09:07

Hi everyone, today i wanted to share a little experiment i realised today on the purification of chamazulene from chamomille essential oil.
As you migh know, azulene are a group of hydrocarbon made of a 7 and 5 member ring. They most of the time are a beautiful shade of blue and in my opinion really worth working with.

I am myself passionned about perfumery and ordered some time ago some blue egyptian chamomile oil ( from the website perfumery supply house). It contain naturally up to 5% of chamazulene from the sources i have found and i wanted to extract it.

I built a little protocole following some test i have done and ended up purifying it on column (it was my first column at home)

First i measured 1,2g of chamomile oil and added it in a test tube, i then added 5ml of methanol, and over it 10ml of heptane.
The mix is shaked in order to extract the chamazulene into the heptane layer.
After a few minutes the heptane layer become dark blue while the methanol one stay dark green
The top layer is removed and this operation is repeated until no more blue color is observed.
I dried the heptane phase on dry CaCl2 and evaporated it with my rotavap.

I then did a few TLC and found out the best solvent seem to be pure heptane.

A 60cm column is filled with silica and heptane mix and half of the dark green liquid obtained is put into it.
The column is then pressurized with air and heptane is added
You can see on the pic that a blue fraction rapidly form wich is collected
This fraction is then evaporated with my rotavap , transfering it to a smaller vial onces it's possible

In the end i obtained 110mg of a very dark blue oil wich correspond to a little less of 10% yeild, i believe i still have impurities into it as it smell slightly like chamomile

Ill soon do tlc on it to see how pure i got it

For fun i decided to do a 10mg bromation test in DCM with Br2 and obtained this beautiful dark green liquid

Hope you enjoyed it , it was a really cool synth.

See ya :p

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DraconicAcid - 19-3-2023 at 13:32

That is a fantastic colour for organic chemistry- I never realized that there were any naturally-occurring azulenes.

clearly_not_atara - 20-3-2023 at 12:22

Kind of funny to realize that Europeans were running back and forth searching for blue dyes for thousands of years when chamomile was growing right under their noses.

Nice work, always good to see new people exploring chromatography, since it's in that small intersection of "interesting" and "safe".

Texium: you sure about consigning this to "Beginnings"?

Texium - 20-3-2023 at 19:25

Apologies. I totally meant to move this thread to Organic Chemistry, but accidentally moved it to Beginnings, probably because that is where I usually have to move threads.

Very nice work, and stunningly beautiful product! I love to see people successfully making use of column chromatography in a home lab. Certainly makes things easier though when your target compound is bright blue and elutes in pure heptanes ;)

Ormarion - 20-3-2023 at 23:17

Thanks a lot, yea it wasn't the hardest one indeed.

j_sum1 - 21-3-2023 at 22:44

Quote: Originally posted by clearly_not_atara  
Kind of funny to realize that Europeans were running back and forth searching for blue dyes for thousands of years when chamomile was growing right under their noses

It is blue. And beautiful at that. But will it actually work as a dye? There are a few necessary properties other than hue.

Ormarion - 22-3-2023 at 02:39

I believe it would probably not be the best, iirc azulene can sublime by itself. Also i remember that on my tlc that i left in air overnight the spot slowly became greenish blue like the chamazulene oxidized or something

Amos - 1-12-2023 at 19:18

There’s also a naturally-occurring azulene in the Lactarius indigo species complex (indigo milk caps). Blue mushrooms that bleed bluer latex! They’re also edible and have an odor mainly consisting of limonene.

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clearly_not_atara - 2-12-2023 at 10:02

Edible, yet my mind is screaming "do not eat that, it will kill you" :D

Ormarion - 8-12-2023 at 13:39

Amos i know they are yea ! i have some mycellium of them but they are rather hard to grow sadly, always wanted to extract the azulene stearic acid derivative in them