Atropine

It is widely distributed from Central and Southern Europe to Asia, also naturalized in many other parts of the world. The plant can grow up to five feet, with oval leaves and greenish-purple flowers blooming from June to early September. The fruits are purple-black globular berries that are ripen in September.

All parts of the plant contain poisonous compounds. The highest content can be found in fruits and leaves. Among them, atropine (CAS 51-55-8, C17H23NO3, log P 1.53) is a tropane alkaloid mainly responsible for the anticholinergic toxicity of the plant. It acts by competitively binding to the active sites of acetylcholine in the central nervous system (CNS). Historically, crude extracts of atropine was used by Romans as a biological weapon to contaminate the enemies’ food; the plant was also listed in the witches’ pharmacopoeia as a poison. During World War II, atropine was used by the Germans as the only antidote to the deadly nerve gas they produced. To date, the poisonings of atropine and Atropa Belladona are still reported, mostly because of the mistaking of fruits as other edible berries. Despite its toxicity, when taking at a rigid dose, atropine is an important morden medicine. It is widely used by ophthalmologists as a mydriatic for eye-exams and surgery. In some cases, it is also used as a substitute of cardiac glycosides to reduce pain and distress.

SMILES:
CN1[C@H]2CC[C@@H]1C[C@@H](C2)OC(=O)C(CO)C1=CC=CC=C1

References:
Lee, M. R. "Solanaceae IV: Atropa belladonna, deadly nightshade." JOURNAL-ROYAL COLLEGE OF PHYSICIANS OF EDINBURGH 37.1 (2007): 77.

Scholtz, S., et al. "Poisons, Drugs and Medicine: On the Use of Atropine and Scopolamine in Medicine and Ophthalmology: An Historical Review of their Applications." J Eye Stud Treat 1 (2019): 51-58.

https://botanical.com/botanical/mgmh/n/nighde05.html

Figures
http://www.chemspider.com/Chemical-Structure.10194105.html
https://en.wiktionary.org/wiki/deadly_nightshade
http://poisonousnature.biodiversityexhibition.com/en/card/deadly-nightshade