Haems and chlorophylls: comparison of function and formation.

In 1844 Verdeill reported that acid treatment of chlorophyll or haem yielded apparently similar red compounds; he even postulated that chlorophylls would contain iron. Hoppe-Seyler2 confirmed the apparent similarity of acid derivatives of haems and chlorophylls from their light absorption characteristics, a point rather overshadowing the discovery at the same time by McMunn3 of cytochromes, another group of haem proteins. It was the demonstration by Nencki and coworkers 45 that the degradation of both chlorophylls and haems yielded monopyrroles that led them, in true neo-Darwinian fashion, to postulate a common origin for animals and plants.