The development of second-generation valienamine-type chemical chaperones for G_M1-gangliosidosis is described. Several N-substituted (+)-conduramine F-4 derivatives were designed as novel chemical chaperones based on a lead chaperone compound, N-octyl-4-epi-β-valienamine, to decrease the inhibitory activity while increasing the enzyme enhancement activity. Among the derivatives synthesized during this study, a conduramine derivative with an N-cyclohexylmethyl group has demonstrated significant enhancement of R201C mutated β-galactosidase activity.