More SAR

All of the structures included will give a perfect structural overlay - right click @ 'save' image to open in Microsoft Paint. Select image cut & paste mode. Find the 'Selection' box with the arrow underneath (in the upper left corner) - scroll to the bottom of the menu and select "trasparent selection". This allows you to cut and drag one image over the other with a transparent background.

This image demonstrates the similarity between narcotics in their configuration to the Mu receptor. 

This image depicts the morphine backbone along with several opioids in a matching configuration, with the backbone in red. Note the similarities in each molecule. Also note the T-shape of their structures (th morphine-derivatives in particular). The structural characteristics of the more potent opioids emphasize the morphine rule, with enhancements or modifications in the areas most significant to receptor docking & recognition.

Please give due credit if re-publishing this image (Project Narco)