Syntheses of two deacetyl-thymosin α(1) analogues and their effects on low E-rosette-forming lymphocytes of uraemic patients

Two deacetyl-thymosin α(1) analogues containing Phe (4Br) or D-Phe (4Br) residue—[D-Phe(4Br)(21)]deacetyl-thymosin α(1) and [Phe(4Br)(21)]deacetyl-thymosin α(1), respectively—were synthesized by the manual solid-phase method and their immunological effects on the low E-rosette-forming lymphocytes of uraemic patients were examined. One of the synthetic analogues, [Phe(4Br)(21)deacetyl-thymosin α(1), demonstrated a restorative effect on the low E-rosette-forming lymphocytes of uraemic patients, which was stronger than that of deacetyl-thymosin α(1), but the other analogue, [D-Phe(4Br)(21)]deacetyl-thymosin α(1), showed no restorative effect under the same conditions.