Development of an efficient liquid-phase peptide synthesis protocol using a novel fluorene-derived anchor support compound with Fmoc chemistry; AJIPHASE®

The development of a novel fluorene-type anchor support molecule and a liquid-phase peptide synthesis protocol (AJIPHASE®) is reported. With this support molecule, the synthesis of a protected peptide with a free carboxyl group could be carried out by repeated coupling/deprotection reactions and isolation by simple precipitation. Cleavage is performed under mild acidic conditions (2% TFA/CHCl3 or hexafluoroisopropanol) to release the products in good yield and purity. There were no signs of either diketopiperazine formation or the removal of protective groups in the side-chain.