I have synthesized a peptide amphiphile with 17 amino acids. the last of the amino group is protected with Fmoc group and I want to remove it in solution phase. It is a negatively charged peptide and soluble in basic pH in water. Solubility in the most of organic solvents is very low. Amino acids have no protecting groups on them since I remove the peptide from resin with TFA cleavage. Do you have any suggestions?