2-Threonyl-6-threonyl-5-leucine enkephalin 85286-38-0 DTLET Deltakephalin Enkephalin leu, thr(2)-thr(6)- L-Threonine, N-(N-(N-(N-(N-L-tyrosyl-D-threonyl)glycyl)-L-phenylalanyl)-L-leucyl)- Leu-enkephalin, thr(2)-thr(6)- Leucine enkephalin, 2-threonyl-6-threonyl- N-(N-(N-(N-(N-L-Tyrosyl-D-threonyl)glycyl)-L-phenylalanyl)-L-leucyl)-L-threonine Thr(2)-leu(5)-enkephalyl-thr(6) Tyr-D-thr-gly-phe-leu-thr Tyrosyl-threonyl-glycyl-phenylalanyl-leucyl-threonine