1) Heroin is 3, 6-diacetylmorphine. Heroin is 2-3 times more potent than morphine.

In vitro and in vivo, to which product does heroin hydrolyze first, (3- or 6-acetylmorphine), and why?

Hint: What are the acidic pKa values of the respective hydroxyl products? Look up the structures on the internet or use the UF library online e-journals.

2) Acetylsulfisoxazole, is readily hydrolyzed in vivo to sulfisoxazole. On the other hand, the acyl group in amikacin, is stable to hydrolysis in vivo. Both N-acetylsulfisoxazole and N-acetylamikacin are acyl derivatives where the acyl group is attached to nitrogen.

Why is one stable and the other not?

Hint: What are the acidic pKa values of the respective N-H groups formed on hydrolysis. Look up the structures on the internet or use the UF library online e-journals.