he·ma·to·por·phy·rin
| \ hi-ˌma-tə-ˈpȯr-fə-rən
, ˌhē-mə-tō-\
: any of several isomeric porphyrins C34H38O6N4 that are hydrated derivatives of protoporphyrins
especially
: the deep red crystalline pigment obtained by treating hematin or heme with acid