Z-Phe-Ala-diazomethylketone binds directly to Aβ42 monomers and small oligomers. Z-Phe-Ala-diazomethylketone inhibits the formation of Aβ42 dodecamers and inhibits Aβ42 fibril formation in the solution. Z-Phe-Ala-diazomethylketone has the potential for neurodegenerative disorders research[1].