- the green coloring matter of leaves and plants, essential to the production of carbohydrates by photosynthesis, and occurring in a bluish-black form, C55H72MgN4O5(chlorophyll a ), and a dark-green form, C55H70MgN4O6(chlorophyll b ).
- the green pigment of plants and photosynthetic algae and bacteria that traps the energy of sunlight for photosynthesis and exists in several forms, the most abundant being chlorophyll a (C 55 H 72 O 5 N 4 Mg): used as a colouring agent in medicines or food (E140)
