Synthesis and biological activity of Schiff base series of valproyl, N-valproyl glycinyl, and N-valproyl-4-aminobenzoyl hydrazide derivatives.

Series of Schiff bases of valproic acid hydrazide, N-valproylglycine hydrazide and N-valproyl-4-aminobenzoyl hydrazide derivatives were synthesized and characterized by IR, NMR ((1)H- and (13)C-NMR) and elemental analysis. The prepared compounds were evaluated in transgenic zebrafish embryos (Tg: flil-1: enhanced green fluorescent protein (EGFP)) for antiangiogenic activity and in HepG2 liver carcinoma cell line for anti cancer activity. The Schiff bases of N-valproylglycine hydrazide derivatives were most potent in term of suppressing angiogenic blood vessels formation and anticancer activity at very low concentration, followed by the Schiff bases of valproic acid hydrazide derivatives which exhibited moderate activity, while the Schiff bases of N-valproyl-4-aminobenzoyl hydrazide derivatives, ethyl 4-(2-propylpentanamido)benzoate (VABE) and N-(4-(hydrazinecarbonyl)phenyl)-2-propylpentanamide (VABH) in contrast exhibited pro-angiogenic activity and weaker anticancer activity which mean that these derivatives targeted a common signaling pathway in term of affecting the blood vessels formation.