Patent ID: 7081346

Claim:
A method of measuring affinity of a test compound for a receptor protein, the method comprising: (a) providing a receptor-test compound complex comprising a non-NMDA glutamate receptor and a test compound bound thereto; then (b) contacting the receptor-test compound complex of step (a) with a known concentration of quinoxaline derivative selected from the group consisting of a compound of Formula I: wherein R 1 and R 2 are independently selected from the group consisting of hydrogen; halo, substituted or unsubstituted alkyl, alkenyl, alkynyl; substituted or unsubstituted heteroalkyl; acyl; and substituted or unsubstituted aryl; and R 3 and R 4 are independently selected from the group consisting of hydrogen, hydroxy, halo; substituted or unsubstituted alkyl, alkenyl, alkynyl; substituted or unsubstituted heteroalkyl; acyl, carboxy, cyano, cyanoalkyl, nitro, amino, sulfonyl, alkylsulfonyl, amido, and sulfonamido; under conditions wherein the quinoxaline derivative binds to the receptor, thereby yielding a receptor-quinoxaline complex and an amount of free quinoxaline derivative; and then (c) measuring the amount of the free quinoxaline derivative generated as a result of step (b), using visible absorption spectrophotometry, and comparing the amount of the free quinoxline to the known concentration of quinoxaline used in step (b), whereby the affinity of the test compound for the receptor is determined.