Opiate chemical groups
I said I’d do this a while ago (then again I’m a lazy sod at times), but eventually, a list of the main groups of opiates, with a few examples of each.
The main requirement for opiate activity is shown below (R’s represent alkyl, cycloalkyl, alkenyl etc – you get the drift)
Drugs derived from morphine’s structure
a) gives the modified structure to give dihydromorphine
b) gives the modified structure to give hydromorphone
c) gives the modified structure to give oxymorphone
d) is a modification that produces a drug about 20x the potency of morphine
For the corresponding codeine derivatives, the 3-hydroxy group is replaced by a 3-methoxy group. Heroin is the 3,6-diacetyl ester of morphine.
Removing the oxygen bridge (4,5 position) produces the morphinan series
Using thebaine as the starting material produces high potency oripavine series drugs
Replacing the saturated ring that carries the 6-OH group of morphine with two methyl groups, produces the benzomorphans
These tend to be partial mu agonists, some with partial kappa agonist activity as well (eg pentazocine)
Methadone derivatives, at first sight appear to have little in common with morphine, but do fit the requirements for opiate activity, and can spatially arrange themselves in the same way as morphine
Altering the methadone structure further, can give compounds with varying degrees of agonist activity