[crackstreetboys]

Hello,

I had added some Sodium Hypochlorite (5%) solution to 5-hydroxytryptophan and observed a change in colour from colourless to a purple-black (if the 5htp was dissolved in water) and orange (if the 5htp was solid).
I was just wondering what the changes to the structure of 5htp has the sodium hypochlorite done. I have some ideas as to what has occurred but not 100% confident.

Thanks

[rolnor]

What are your ideas?

[crackstreetboys]

What are your ideas?

Oxidation of the phenol group into a quinone? I expected this to occur however wouldn't expect such a prominent colour change to occur.

[rolnor]

I think the nitrogens can react with hypochlorite. One problem is its difficult to monitore your reaction with TLC, you need LC-MS och NMR.

[spirochete]

There are lots of things that could do during oxidation. It depends both on conditions for oxidation like pH, and also on the substrate. This link talks about some possibilities: http://reag.paperplane.io/00002530.htm

Unfortunately I don't think you can use color to determine the major pathway. Very small amounts of colored impurities can cause large amounts of visible color change. Like others said, you need spectroscopy to determine what really happened. Changes in color indicate difference in amount or type of conjugation, but this could be in major or minor product. You can't always "eye ball" it.