Science Buddies: "Ask an Expert"

I was reading up on capsaicin in a book and I found out that capsaicin has an antibacterial property. I was thinking about this and I wondered if other capsaicinoids were as effective as capsaicin.

I was wondering if it was possible too separate different capsaicinoids into their separate compounds. I want to do a science project where I separate different capsaicinoids and create a separate mixture with each one of them. I was going to get different cultures and spray them with a different capsaicinoid and see which produces the best result. I've read that High Pressure Liquid Chromatography (HPLC) is used to measure different concentrations of capsaicinoids in different peppers but I was wondering if it would actually separate them into a form I could use.

This could be a killer science project if I figure out all of the fine details of the project but I wanted to know if this was even possible to do.

Separating mixtures and obtaining enough of each component in a relatively pure state without any solvents can be very difficult. You can collect the peaks or fractions of the column effluent from an HPLC machine but it is difficult and you don't get very much product.
Also there are many things to consider about the second part of your suggested experiment that could take up lots of your time - for example, what type of bacteria will you test?, what concentrations of capsaicinoids are antibacterial?, how will you measure the bacterial growth?
You might want to consider optimising the antibacterial part of your experiment first. So select a method of bacterial growth (liqud cultures or plates) try testing with the mixture of capsaicinoids to see if you can get a good curve of growth inhibition with that. You will probably need to test different concentrations of capsaicinoids to find one that works. Also you will need controls - bacteria without any capsaicinoids added to see how fast they grow. And you will need a method to measure the growth, some are more quantitative than others - counting colonies or % coverage on the plate or using a turbidometer?
Then you could purchase some individual capsaicinoids from a chemical supplier such as Sigma aldrich and see if any of those can inihibit growth. Then if you still have time you could try the HPLC and see if any of the fractions of the mixture have activity.

Best of luck,
Caroline