Table 11.

NMDA receptor activities of 3′-substituted-4-hydroxy-2-quinolones.^[65]

Compd	R	IC50[a] [nm]	ED50[b] [mgkg−1]
68		14	>250
69		4	>100
70	Ph	170	7.6
66		4.5	3.9
67		2.2	0.9

^[a]Inhibition of the binding of [³H]-4 to the strychnine-insensitive glycine site on rat brain membranes.

^[b]Protection from audiogenic seizure in DBA/2 mice (21–23 days old, weighing 5–9 g) after oral administration of test compounds.