2-Arg-5-leu-enkephalin 76939-27-0 D-Arg(2)-leu(5)-enkephalin Enkephalin, arg(2)-leu(5)- L-Leucine, N-(N-(N-(N2-L-tyrosyl-D-arginyl)glycyl)-L-phenylalanyl)- Leucine-enkephalin, arg(2)-