Sinapine is an alkaloidal amine found in some seeds, particularly oil seeds of plants in the family Brassicaceae.

[3] Sinapine typically occurs in the outer seed coat of oil crops and is plentiful in some types of press cake leftover after vegetable oil extraction.

[2] Typical oil seed cake residues high in sinapine include Brassica juncea (1.22% by mass),[4] and rapeseed (0.39-1.06% by mass).

[5] The typical protocol for extracting Sinapine from seed cakes entails defatting the cake with hexane via a Soxhlet apparatus followed by extraction with 70% methanol held at 75 °C.

Sinapoylglucose—choline O-sinapoyltransferase is an enzyme whose two substrates are 1-O-sinapoyl-β-D-glucose and choline, whereas its two products are D-glucose and sinapine.