Hydrochloric Acid → 5-Bromo-L-tryptophan

Participants

Reaction Steps

To 200 nmols of DL-5-bromotryptophan or DL-6-bromotryptophan, 20 μl of ethanol:triethylamine:DW:phenyl isothiocyanate (sigma)=7:1:1:1 was added. The mixture was reacted at room temperature for 20 minutes. After drying, 50 μl of TFA was added thereto. The mixture was reacted at 50° C. for 10 minutes. After during, 50 μl of HCl: methanol=1:1 was added thereto, followed by reacting at 50° C. for 10 minutes. The reaction mixture was purified on reverse phase HPLC to give the PTH derivative of 5-bromotryptophan or 6-bromotryptophan. The final product was identified on a protein sequencer (FIGS. 17 and 18). These PTH derivatives were mixed with 20 amino acid PTH standard (ABI), and a protocol was prepared to separate the derivatives (TABLES 1 and 2). When the endogenous bovine GPR7 ligand was analyzed, the amino acid at the 1-position coincided with the peak of PTH-6-bromotryptophan (FIG. 19).

Provenance & Evidence