Definition of protoporphyrin in English:

protoporphyrin

noun

Chemistry
  • Any of a group of fifteen isomeric porphyrins having the formula C₃₄H₃₄N₄O₄, in which the porphin nucleus has four methyl, two vinyl, and two propionic acid substituents; especially (more fully "protoporphyrin IX") the isomer which occurs widely in living organisms, mainly as haem (in which it is bonded to an iron atom).

Origin

1920s; earliest use found in Chemical Abstracts. From proto- + porphyrin, after German Protoporphyrin.

Pronunciation

protoporphyrin

/ˌprəʊtə(ʊ)ˈpɔːf(ɪ)rɪn/