Aspongopyrimidine A, a -Peralkylated Histidine Zwitterion from against Alzheimer's Disease Targeting MAPRE3.

Aspongopyrimidine A (), a hexa-1,3-diene-histidine-hexanoic acid adduct featuring a 4,5-dihydro-2-10λ-imidazo[5,1-]pyrrolo[2,1-]pyrimidine motif, was isolated from the insect . The structure was clarified by spectroscopic and computational methods and X-ray diffraction. Peralkylation of -atoms in histidine by two C6 units makes an inner salt with a 5/6/5 tricyclic system. Biological evaluation found that exerts activity against Alzheimer's disease targeting MAPRE3 through a chemical proteomics approach. This study revealed unusual modifications of amino acids as the fundamental units of protein.