The present invention relates to novel pyridine-2-carboxyamide derivatives of formula (I) useful as metabotropic glutamate receptor antagonists: wherein Y, Z, R1, R2 and R3 are as defined in the specification herein.本發明係關於可用作代謝型麩胺酸受體拮抗劑的通式(I)之新穎吡啶-2-甲醯胺衍生物:其中Y、Z、R1、R2及R3係如本說明書中所定義。