Synonyms: 33,34,49,50-Tetrathia-2,5,8,11,14,17,20,23,26,29,37,40,43,46-tetradecaazabicyclo[23.22.4]henpentacontane,cyclic peptide deriv.; Endothelin-38 (human); Human big endothelin (1-38);Human big endothelin 1 (1-38); Human big endothelin-1; Human proendothelin(1-38)