Tritiuh‐labelling in two phenylalanine residues of norleucine11‐substance P

Abstract
Norleucine11‐substance P and 4‐chlorophenylalanine 7.8‐Norleucine11‐ substance P were synthesized by fragment condensation. Phe/3H/7.8‐norleu‐cine11 ‐substance P was obtained by catalytic tritiation of the precursor peptide with a specific radioactivity of 27 Ci/mmole and full biological activity.