title: Alkaloid biosynthesis. XVI. Colchicine: origin of the tropolone ring and studies with the C 6 -C 3 -C 6 -C 1  system.
mesh_terms: D000438:Alcohols / Q000096:biosynthesis; D002247:Carbon Isotopes; D002855:Chromatography, Thin Layer; D003078:Colchicine / Q000096:biosynthesis*; D003508:Cycloheptanes / Q000096:biosynthesis*; D007659:Ketones / Q000096:biosynthesis; D009682:Magnetic Resonance Spectroscopy; D010944:Plants / Q000378:metabolism; D013055:Spectrophotometry, Infrared
chemical_list: D000438:Alcohols; D002247:Carbon Isotopes; D003508:Cycloheptanes; D007659:Ketones; D003078:Colchicine