SIALIC ACID DERIVATIVES

摘要

Sialic acid derivatives represented by general formula (1AA) and further derivatives thereof: wherein R<1> represents a residue of cholestane or other steroidal compound; R<2> represents hydrogen or methyl; R<3> represents C1-C6 alkyl, etc.; R<4> represents hydrogen or acyl; R<5> represents R<15>O- (R<15> being C2-C7acyl) etc.; and X represents oxygen or sulfur. These derivatives have the effect of enhancing a choline acetyltransferase activity in cholinergic neurons and are useful for preventing and treating dementia, memory disorder, peripheral nerve disorder, and so forth.