The aggregation of alpha-synuclein is clearly related to the pathogenesis of Parkinson's disease. Therefore, detailed understanding of the mechanism of fibril formation is highly valuable for the development of clinical treatment and also of the diagnostic tools. Here, we have investigated the interaction of alpha-synuclein with ionic liquids by using several biochemical techniques including Thioflavin T assays and transmission electron microscopy (TEM). Our data shows a rapid formation of a-synuclein amyloid fibrils was stimulated by 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BIMbF(3)Im], and these fibrils could be disaggregated by polyphenols such as epigallocatechin gallate (EGCG) and baicalein. Furthermore, the effect of [BIMbF(3)Im] on the alpha-synuclein tandem repeat (alpha-TR) in the aggregation process was studied. (C) 2010 Elsevier Inc. All rights reserved.