Solution synthesis of a biologically active fragment (33-41) of thymosin β9

The C‐terminal fragment 33–41 of thymosin β9 is synthesized by solution synthesis, using the strategy of maximum side‐chain protection with acid‐labile tert‐butyl groups and temporary Nα‐benzyloxycarbonyl protection during the elongation steps. Part of this peptide is deprotected, coupled to KLH and the conjugate used for the production of antibodies. The biological activities of two fragments and of the nonapeptide are tested in our α‐amanitin‐inhibited E‐rosette assay.