Hyoscine butylbromide vs Scopolamine: what is the difference?

How they differ

Hyoscine and scopolamine are two names for the same nightshade alkaloid, and hyoscine butylbromide is that molecule with a butyl group and a bromide added at its nitrogen. The change gives the nitrogen a permanent positive charge, C21H30BrNO4 at 440.4 against C17H21NO4 at 303.4, and a charged molecule barely crosses into the brain or through the gut wall. So scopolamine acts on the brain and is used against motion sickness, as the small patch worn behind the ear, while hyoscine butylbromide stays in the gut and relaxes its muscle, which is why it is sold as Buscopan for stomach cramps. Both block the same acetylcholine receptors.

Side by side

Structural similarity 0.60 of 1, computed as a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.

Common questions

What is the difference between Hyoscine butylbromide and Scopolamine?

Hyoscine and scopolamine are two names for the same nightshade alkaloid, and hyoscine butylbromide is that molecule with a butyl group and a bromide added at its nitrogen. The change gives the nitrogen a permanent positive charge, C21H30BrNO4 at 440.4 against C17H21NO4 at 303.4, and a charged molecule barely crosses into the brain or through the gut wall. So scopolamine acts on the brain and is used against motion sickness, as the small patch worn behind the ear, while hyoscine butylbromide stays in the gut and relaxes its muscle, which is why it is sold as Buscopan for stomach cramps.

Is Hyoscine butylbromide bigger than Scopolamine?

Hyoscine butylbromide is the heavier molecule, 440.4 g/mol against 303.35 g/mol for Scopolamine. Hyoscine butylbromide is C21H30BrNO4 and Scopolamine is C17H21NO4.