Brucine (Bru)

Brucine is a bitter alkaloid closely related to strychnine. It occurs in several plant species, the most well known being the Strychnos nux-vomica tree, found in South-East Asia. A solution of brucine in concentrated sulfuric acid can be used to test for nitrates and nitric acid giving a red color. The alkaloid brucine is isostructural to strychnine, but with methoxy groups at positions 9 and 10 on the aromatic ring rather than hydrogen atoms. Both brucine and strychnine are commonly used as agents for chiral resolution, the separation of racemic mixtures. The ability of brucine, and to a lesser extent strychnine, to function as resolving agents for amino acids was reported by Fisher in 1899. Brucine and strychnine are basic and thus have a tendency to crystallize with acids. The acid-base reaction leaves the brucine protonated at the N(2) position. The formation of diastereomeric salts has been reported for thousands of organic compounds.