Despite numerous recent advances, Alzheimer’s disease continues to pose a challenge both for diagnostic and
treatment strategies. We have recently evaluated two compounds for potential use both as amyloid imaging
agents and as therapeutic agents.
Multiple lines of evidence suggest that the accumulation of neurotoxic oligomeric aggregates of amyloidbeta
(Aβ) may be a central event in the pathogenesis of Alzheimer's disease. It is possible that inhibitors of Aβ
aggregation and toxicity may be effective in blocking this pathogenic cascade. Here, we report the development of
a compound that could have both diagnostic and therapeutic roles by binding to oligomers. In an effort to combine
bioavailability and dual function we have tethered scyllo-inositol, known to bind and neutralize oligomers into
soluble complexes, to 2-ethyl-8-methyl-2,8-diazospiro-4,5-decan-1,3-dione, a muscarinic receptor agonist which
improves neurotransmitter function. These derivatives have recently been evaluated for Aβ peptide polymerization
inhibition.
In addition, F-18 labeled N-2-[fluoropropyl]-2-(4’-(methylamino)phenyl)-6-hydroxybenzothiazole (FMHT) was
prepared as a potential imaging agent for Alzheimer’s disease. Brain activity for F-18MHT was pronounced
within 2 minutes (4%ID/g) and washed out quickly; brain activity was 1.2%ID/g at 45 minutes and right and left
hemispheres were clearly visualized. Initial brain uptake of F-18MHT was higher than that of PIB. Interestingly, in
vitro Aβ studies showed cold FMHT had a 25-fold inhibition of Ab polymerization, suggesting that FMHT could be
a promising candidate for Alzheimer’s treatment.
