(Ser(2)(O-t-butyl)-leu(5))enkephalyl-thr(6) 110786-67-9 111035-56-4 Dstbulet L-Threonine, N-(N-(N-(N-(O-(1,1-dimethylethyl)-N-L-tyrosyl-D-seryl)glycyl)-L-phenylalanyl)-L-leucyl)- Leu(5) enkephalin, ser(2)(O-tert-butyl)-thr(6) Tyr-ser(O-tert-Bu)-gly-phe-leu-thr Tyrosyl-seryl(O-tert-butyl)-glycyl-phenylalanyl-leucyl-threonine