guanylate cyclase inhibitor Synonym(s): 3,7,12,17-Tetramethyl-8,13-divinyl-2,18-porphinedipropionic acid; 8,13-Divinyl-3,7,12,17-tetramethyl-21 H ,23 H -porphine-2,18-dipropionic acid zinc derivative; Protoporphyrin IX zinc(II) complex Empirical Formula:...