Atropine is a natural alkaloid extracted from deadly nightshade and other plants belonging to the Solanaceae family. The chemical formula of atropine is C17H23NO3. It has a tropane ring structure, which is a nitrogenous bicyclic ring system. Atropine can be classified into different groups based on its molecular structure. Here are some of the common functional groups present in atropine:

1. Tropane Ring: Atropine contains a tropane ring, which is a fused bicyclic structure consisting of a pyrrolidine ring (a five-membered ring with one nitrogen atom) and a tetrahydrofuran ring (a five-membered ring with one oxygen atom).

2. Ester Group: Atropine has an ester functional group formed by the reaction between the hydroxyl group of tropic acid and the carboxylic acid group of tropic acid. This ester linkage connects the tropane ring to the tropic acid moiety.

3. Hydroxyl Group: Atropine contains a hydroxyl group (-OH) attached to the carbon atom in the tropane ring. This hydroxyl group can undergo various chemical reactions, such as esterification and glycosylation.

4. Tertiary Amine: Atropine has a tertiary amine group, which is a nitrogen atom bonded to three alkyl or aryl groups. The tertiary amine in atropine is located within the tropane ring and plays a crucial role in binding to and blocking muscarinic cholinoreceptors.

These are some of the key functional groups present in atropine. The combination of these functional groups contributes to the overall structure and pharmacological properties of atropine, making it a potent anticholinergic drug with a range of therapeutic applications, including the treatment of certain eye conditions and as a premedication for various medical procedures.