A compound presented by the general formula (1), its racemic form, or their salt thereof:




wherein in general formula (1), X represents an oxygen atom, nitrogen atom, sulfur atom, or carbon atom, R1 represents R1a—Y—R1b, wherein R1a and R1b independently represent a saturated or unsaturated aliphatic hydrocarbon group, aromatic group, heterocyclic group, or a combination thereof, and Y represents an oxygen atom, nitrogen atom, sulfur atom, or carbon atom, R2 independently represents a saturated or unsaturated aliphatic hydrocarbon group, and R3 represents choline, ethanolamine, inositol, or serine.