Provided are quinolinyl derivative compounds of general formula I, where the variables are as defined in the specification. Examples of the compounds include (+/-)-3-(4-(1-(3-methylquinolin-2-ylamino)butyl)benzamido)propanoic acid and (+/-)-3-{ 4-[3-methyl-1-(quinoxalin-2-ylamino )-butyl]-benzoylamino} -propionic acid. The compounds act as glucagon antagonists or inverse agonists. The compounds may be useful in the treatment of diabetes.