RT Journal Article SR Electronic T1 Content of the neurotoxins cycasin (methylazoxymethanol β‐D‐glucoside) and BNLAA (β‐N‐methylamino‐L‐alanine) in cycad flour prepared by Guam Chamorros JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 1336 OP 1336 DO 10.1212/WNL.42.7.1336 VO 42 IS 7 A1 Glen E. Kisby A1 Mike Ellison A1 Peter S. Spencer YR 1992 UL http://n.neurology.org/content/42/7/1336.abstract AB Exposure to cycad seed kernel is an etiologic factor for the western Pacific amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex (PDC). Traditionally processed cycad flours (n = 17) obtained from Chamorro residents of Guam and the adjacent island of Rota at risk for neurodegenerative disease were extracted and analyzed by high-performance liquid chromatography for content of β-N-methylamino-L-alanine (BMAA) and methylazoxymethanol β-D-glucoside (cycasin). Cycasin (detection limit: picomole) was present in concentrations of 0.004 to 75.93 μg/g (mean, 12.45 ± 5.0 μg/g), and levels of BMAA (detection limit: subpicomole) ranged from 0.00 to 18.39 μg/g (mean, 5.44 ± 1.56 μg/g). On average, cycasin content was approximately 10 times higher than that of BMAA. The largest concentrations of cycasin were found in samples from villages with a high reported prevalence of ALS/PDC. Ingestion of cycad-derived food would result in estimated human exposure to milligram amounts of cycasin per day. The cytotoxic properties of cycasin merit consideration in relation to the etiology of western Pacific ALS/PDC.