Biosynthesis and synthesis of natural colours

In nature, the detection of colours requires an organism having some type of eye with a retina and two or three types of photoreceptor connected to a nervous system, which can interpret the signals received. Evidence that certain simple organisms were coloured 1 billion years ago, and some more advanced creatures, which could have possessed eyes a few hundreds of million years ago, is exemplified. A vast array of chemicals essential to life are produced by living organisms and their biosynthesis depends upon individual genetic patterns, which determine the enzyme catalysts involved. Plants photosynthesise many pigments, which are essential for them to maximise the absorption of energy from the sun, while others offer protection from any harmful radiation. Such pigments, for example chlorophylls and the carotenoids, flavonoids and betalains, have traditionally been used as natural dyes, food colorants and medicines. This review compares the chemical processes involved in their biosynthesis and the laboratory methods adopted to confirm their chemical structure. Some engineered biosynthetic methods are now used for commercial production of natural colours and these methods may involve the controversial use of genetic engineering.