The chemical structure of atropine contains 4 main functional groups: an aromatic ring, an alcohol, an amine and an ester. Also, there are 4 hydrogen bond acceptors and 1 hydrogen bond donor.
The chemical structure of pilocarpine contains an imidazole ring, a methyl, a gamma-lactone ring and an ethyl. Also, there are 3 hydrogen bond acceptors and there is no hydrogen bond donor.
The chemical structure of physostigmine contains an aromatic ring, two nitrogen atoms and carbamate. Also, there are 4 hydrogen bond acceptors and 1 hydrogen bond donor.