A compound represented by general formula (I) (in the formula, all symbols are as described in the description) or a salt thereof has a potent nerve-protecting and/or -repairing activity, and therefore can be used as a therapeutic agent for neuropathy (e.g., chronic inflammatory demyelinating polyneuropathy, Guillain-Barre syndrome, periarteritis nodosa, allergic vasculitis, diabetic peripheral neuropathy, entrapment neuropathy, peripheral neuropathy associated with the administration of a chemotherapeutic drug, or peripheral neuropathy associated with Charcot-Marie-Tooth disease).