D-Alanine, N-[(1,1-dimethylethoxy)carbonyl]-3-methyl-L-histidyl-N-(triphenylmethyl)- L-asparaginyl-2-methylalanyl-O-(1,1-dimethylethyl)-L-seryl-O-(1,1-dimeth ylethyl)-D-tyrosyl-3-(1-naphthalenyl)-,