Endothelin 1-(pig reduced), 1-de-L-cysteine-2-de-L-serine-3-de-L-cysteine-4-de-L-serine-5-de-L-serine-6-de-L-leucine-7-de-L-methionine-8-de-L-aspartic acid-9-de-L-lysine-10-de-L-glutamic acid-, cyclic (11-15)-disulfide