Table 5. Optimization of B-Ring Substituents.

^aFitted EC₅₀ values are shown for GluN1/GluN2C to two significant digits when potentiation at 30 μM of the test compound exceeded 120% of control; values in parentheses are the fitted maximum response as a percentage of the initial glutamate (100 μM) and glycine (30 μM) response. Hill slopes were between 1.3 and 1.9. Data for active compounds at GluN1/GluN2C are from between 6 and 27 oocytes from 2–3 frogs for each compound. When no effect was found (n = 4–11 oocytes), the lack of effect was confirmed by testing at 100 μM (data not shown, n ≥ 4 oocytes for all compounds).