Benzopyran and tetrapyrrole derivatives

The basic common stracture of the anthocyanidins, flavins and tannins is the ring stracture shown in Fig. 7.3a. The anthocyanidins consist basically of this stracture with some hydroxyl groups through which are conjugated sugar molecules. The anthocyanidins refers to the molecule without the glycoside residue. The stmctoe of flavonoids differs from anthocyanidins in that they 

The common structural element in these molecules is a central metal atom surrounded by four linked pyrrole rings (hence tetrapyrrole) known as a 

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