The preparation of α-D-benzylpenicilloyl-n-propylamine and octa-ε-(α-D-benzylpenicilloyl)-octa-α-L-lysine are described. Their structures were established by chemical and spectroscopic evidence. Proton and carbon-13 nuclear magnetic resonance spectra of these two penicillin derivatives and some related compounds are provided. These compounds are useful in skin testing for penicillin allergy.