Synthesis and Protective Effect of New Ligustrazine-Benzoic Acid Derivatives against CoCl2-Induced Neurotoxicity in Differentiated PC12 Cells

A series of novel ligustrazine-benzoic acid derivatives were synthesized and evaluated for their protective effect against cobalt chloride-induced neurotoxicity in differentiated PC12 cells. Combining hematoxylin and eosin staining, we found compound that (3,5,6-trimethylpyrazin-2-yl)methyl 3-methoxy-4-[(3,5,6-trimethylpyrazin-2-yl)methoxy]benzoate (4a) displayed promising protective effect on the proliferation of the injured PC12 cells (EC50 = 4.249 µM). Structure-activity relationships are briefly discussed.