Synthesis and theoretic calculations of benzoxazoles and docking studies of their interactions with triosephosphate isomerase

One-pot synthesis was carried out for Z or E stereoisomer derivates of 3-(benzoxazoyl)-2-propenoic acid following kinetic or thermodynamic control. All compounds were characterized by ¹H and ¹³C NMR, and the single crystal X-ray structure of (2Z)-3-(6-methyl-1,3-benzoxazol-2-yl)prop-2- enoic acid (3) was obtained. Furthermore, a theoretic study was done for all the synthesized compounds at the B3LYP/6-31G(d,p) level. The target compounds were docked on triosephosphate isomerase and trypanocidal activity was explored for the 4 and 6 compounds. The Z isomers showed an intramolecular hydrogen bond O-H···N according to the X-ray structure of 3. The docking studies indicate that the test compounds insert themselves between the monomers of triosephosphate isomerase, reaching the known binding site located at interdimeric shapes of triosephosphate isomerase by means of π-π interactions and electrostatic interactions, and in this way interrupt interactions between these monomers. Thus, could explain the biologic effects of the E isomer on triosephosphate isomerase. Finally, compounds 4 and 6 showed trypanocidal activity, which could be mediated by triosephosphate isomerase inhibition.