The neuroprotective activity of the purified compounds against
glutamate-induced neurotoxicity in cultures of PC12 cells was
evaluated by the MTT assay. As shown in Table 4, treatment with
glutamate (20 μM) resulted in significant inhibition of MTT
reduction. However, exposure of compounds 4 and 17 at the
concentration of 10-5 M for 24 h remarkably attenuated glutamateinduced glutamateinduced
cytotoxicity, whereas, 11-13 increased the cell damage.
The other compounds were all inactive.