This invention relates to substituted 6-membered N-Herterocyclic neurotrophic compounds of formula (I) or pharmaceutically acceptable salts or hydrates thereof, wherein R.sub.1, R.sub.2, X, Y, and Z are as defined in the description; their preparation methods, compositions comprising the same, and their use as inhibitors of FK560 binding proteases activity for treating and preventing neurodegenerative diseases and other nerve disorders associated with nerve injuries or other related diseases ##STR00001##