A method for inhibiting the autophagy of motor neurons in a subject is provided. The method comprises administrating to the subject an effective amount of an active ingredient selected from the group consisting of a compound of formula (I), a pharmaceutically acceptable salt of the compound, a pharmaceutically acceptable ester of the compound and combinations thereof:wherein A is a C1-C5 alkyl optionally having one or more unsaturated bonds and optionally being substituted by one or more substituents selected from a group consisting of —OH, ═O and C1-C3 alkyl； X is H, —OH,Y is O or S and can optionally combine with A to form a five-membered ring； and R1 is H or a substituted or unsubstituted C1-C20 alkyl, wherein one or more —CH2— of the C1-C20 alkyl are optionally being replaced by —NH— or —O—.
