Simplification or drug dissection

We turn now to more drastic alterations of the morphine structure and ask whether the complete carbon skeleton is really necessary. After all, if we could simplify the molecule, it would be easier to make in the laboratory. This in turn would allow the chemist to make analogues much more easily, and any useful compounds could be made more efficiently and cheaply. 

C- ReceptorType2 Receptor Blocked No induced fit No message received 

Receptor Blocked Weak induced fit Weak message received 

There are five rings present in the structure of morphine (Fig. 12.18) and analogues were made to see which rings could be removed. 

Removing ring E leads to a complete loss of activity. This result emphasizes the importance of the basic nitrogen to analgesic activity. 

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