Science Buddies: "Ask an Expert"

Hello, past year one of my students workd with an herb oil and tested the antimocrobial effects against bacteria. This year she is trying to take it fruthur and see if she can seperate the compounds and test just one of them. Would you be so kind as advising how to go about it and if it is at all possible. Thank you.

Hi,

The components that you separate out will obviously depend on the herb oil that is being used, but that being said, distillation seems like a good method for separating the compounds (if you know what they are and their boiling points). If there is good enough separation between the boiling points of the compounds in the oil, the separation should be pretty clean. If not, there are always other methods, but I suspect that distillation should be fine.

Hope this helps!
Aaron Lin

Hi,

Aaron has made a good suggestion for separating the herbal oils into difference fractions according to volatility.

Does your student have access to a gas chromatograph. This would be one technique to separate volatile compounds from herbal oils:

http://pubs.acs.org/doi/pdf/10.1021/jf0489318

http://www.iop.org/EJ/article/1742-6596 ... 32fd658ca7

What type of compounds is your student trying to purify?



Donna Hardy

Thank you so much for the reply.
She is trying to seperate charvacrol from Oregano oil. Is it possible to sepaprate it and use it in a study apart from all other compounds. She will be testing it agains bacteria.
Thank you.

Hi,

This sounds like a great project. Here are some ideas:

Carvacrol can be purified by chromatography using a reversed phase chromatography with a C18 silica column. I am attaching a reference that includes a protocol that your student could use. You would need an HPLC system, a C18 column, methanol, DMSO, acetonitrile, and some SPE cartridges. Purifying the carvacrol would be an excellent learning experience, and this type of technique would yield very high purity product. I am attaching a reference that includes the details of this method:

http://pubs.acs.org/doi/pdf/10.1021/je000342k


Another possibility is to use dry ice to extract the carvacrol; here is a paper that describes this method:

http://pubs.acs.org/doi/pdf/10.1021/je000342k


Carvacrol is also available for purchase from Sigma:

http://www.sigmaaldrich.com/catalog/Pro ... =ON&F=SPEC

The US price is $48 for 100 grams, which is less than all of the chromatography reagents would be.

Here is a paper that describes a study using carvacrol in an antimicrobial study:

http://aem.asm.org/cgi/content/full/71/ ... type=HWFIG

Donna Hardy