The present invention provides a compound of Formula (I)(I)or a pharmaceutically salt thereof wherein R1, R2, Ra, L, Z, Z1and Z2are as defined herein, that act as Ghrelin antagonists or inverse agonists; pharmaceutical compositions thereof; and methods of treating diseases, disorders, or conditions mediated by the antagonism of the Ghrelin receptor.本發明提供一種式(I)之化合物(I)或其醫藥上可接受的鹽,其中R1、R2、Ra、L、Z、Z1和Z2係如本文中所定義,其作為腦腸肽(Ghrelin)拮抗劑或逆促效劑;彼之醫藥組成物;且治療由腦腸肽受體之拮抗作用所媒介之疾病、病症或症狀的方法。