Chlorophylls and Bacteriochlorophylls

Abstract

The chlorophylls are a structurally and functionally distinct group of macrocyclic tetrapyrrole pigments that may occur at the porphyrin, chlorin or bacteriochlorin oxidation levels. Biosynthetically, they are derived from protoporphyrin IX. Structurally, they are characterized by the presence of a fifth ring, isocyclic ring E, which confers the prefix ‘phyto’ to the porphyrin and chlorin type molecules. Chlorophylls generally have Mg as the central metal and a long-chain esterifying alcohol at C-17 3 .