[veno]

Any idea why my peptide ends up with a purple color when cleavaged and precipitates into ether?

It is a peptide of 34 amino acids and I use as a cleavage cocktail 94% TFA/2.5% water/2.5 thioanisol/ 1% TIS for 2 hours.

[MOTOBALL]

Can you extract the purple colour into an organic solvent? (Prefer MeCn).

If so, scan the UV spectrum and determine lambda max as a first step.

Also, run an LCMS to determine [M+H]+ for Mol. At.

Then run MS/MS on the [M+H]+ ion to help elucidate structure.

Identification will help understand where it comes from.

Regards,
Motoball