Science Buddies: "Ask an Expert"

Hi!

I am doing a project on natural dyes. Having difficulty determining what the dye molecule is that gives the dye bath its color. I am using mint, red cabbage, turmeric, and yellow onion skins. This is what I think they are:

mint - chlorophyll a and b and carotenoids
red cabbage - anthocyanin
yellow onion skins - cepaic acid
turmeric - curcumin

I want to explain how the functional groups on the dye molecule interact with the metal salt mordant and the protein fiber. I am also googling the internet to find the chemical structure of these dye molecules.

I am also having trouble identifying the class of my dyes listed above. I'm not sure if they are acid dyes, direct dyes, since I don't know if I have the right dye constituent. If I know the correct structure for my dye material I can identify the chromophore and the auxochrome.

Any help would be appreciated. My research paper is due on Wednesday, Sept. 23. THANK YOU!!!

Hello!

I have already posted as "Organic/Inorganic Chemistry Help" but haven't received a reply. Please see my previous message on Sept. 19 below. My research paper is due on Wed., Sept. 23. Any help would be great!

Thanks!
*****************************************************************************************************
Hi!

I am doing a project on natural dyes. Having difficulty determining what the dye molecule is that gives the dye bath its color. I am using mint, red cabbage, turmeric, and yellow onion skins. This is what I think they are:

mint - chlorophyll a and b and carotenoids
red cabbage - anthocyanin
yellow onion skins - cepaic acid
turmeric - curcumin

I want to explain how the functional groups on the dye molecule interact with the metal salt mordant and the protein fiber. I am also googling the internet to find the chemical structure of these dye molecules.

I am also having trouble identifying the class of my dyes listed above. I'm not sure if they are acid dyes, direct dyes, since I don't know if I have the right dye constituent. If I know the correct structure for my dye material I can identify the chromophore and the auxochrome.

Any help would be appreciated. My research paper is due on Wednesday, Sept. 23. THANK YOU!!!

Hello. I am sorry you haven't received a reply yet. The experts are all volunteers and ones with this expertise may not have viewed your question, yet. I applaud you doing research on your own, and hopefully an expert will respond soon. Thank you for using Science Buddies.

Hi,

I never did receive a reply and had to turn in my research paper with the information that I had. I still have time to make corrections before science fair, so if anyone can verify that my guess is correct that would be helpful.

Thank you.

Hello,
I did some internet research and came up with the same molecules that you listed. Good job doing your research to come up with those molecules, I had to dig into some scientific journal articles to find some of them. Don't forget to list all your sources for your project, I'm sure it took a lot of work to track all that information down. Good luck with the science fair and let us know if you have any other questions.

Thank you for your help! I feel better now that I know I'm on the right track.