The present invention relates to the N-substituted beta-carbolinium compounds of general formula A and formulae I and II wherein, R1 and R2 groups are selected from halogens or trifluoromethyl R3 group is selected from hydrogen or methyl Ar is selected from aryl and heteroaryl, X is selected from halogens and R1 and R2 groups may be attached to any position on ring E. The present invention particularly relates to synthesis and p-glycoprotein induction activity of the N-substituted beta-carbolinium compounds. In addition, the invention relates to methods of using compounds for treating or preventing Alzheimers disease.
