Biological roles, chromonics

Of the classes of compounds discussed in this chapter the chromones (1 R Ph), including flavones and isoflavones (1 R = 2-Ph and R = 3-Ph), and coumarins (2) are the most numerous. Many of these compounds are found in plants and there is a wide variety of structures amongst them. There appears not to be a single well-defined biological role for... 

---