tropano

Tropane, often written tropano in some languages, refers to a bicyclic nitrogen-containing heterocycle that forms the core scaffold of a family of natural products known as tropane alkaloids. The tropane ring system is a bridged bicyclo[3.2.1]octane framework bearing a tertiary amine; the core is rigid and chiral, allowing several stereoisomers and derivatives.

In nature, the tropane skeleton occurs mainly in plants of the Solanaceae family, such as Datura, Atropa, and Hyoscyamus species. These alkaloids function as defensive compounds against herbivores. Biosynthesis begins with amino acids like ornithine and lysine, proceeding through putrescine to generate an N-methylpyrrolinium cation. This unit condenses with an acetoacetate-derived fragment to form tropinone, the key bicyclic ketone. Tropinone is then reduced and further modified to yield tropine and related structures; subsequent esterification produces various tropane alkaloids such as atropine (hyoscyamine), scopolamine (hyoscine), and related esters. Cocaine is a prominent tropane alkaloid that features a substituted tropane core as part of its ecgonine-derived framework.

Notable tropane alkaloids include atropine and scopolamine, which are antimuscarinic agents used medically to dilate pupils, treat bradycardia, and manage motion sickness, among other uses. Cocaine, another tropane alkaloid, acts as a stimulant and local anesthetic. The tropane skeleton also serves as a versatile scaffold in medicinal chemistry, enabling the design of various pharmaceutical agents.

Overall, tropane denotes a distinct bicyclic scaffold central to a broad class of plant-derived alkaloids with diverse pharmacological properties and historical significance.