Synthesis and antiamoebic activity of new oxime ether derivatives containing 2-acetylpyridine/2-acetylfuran

Various oxime ether derivatives of 2-acetylpyridine and 2-acetylfuran series have been synthesised. O-Alkylation of the oximes by various alkylaminoethyl halides gave the corresponding oxime ether derivatives. The structures of these compounds were elucidated by UV, IR, ¹H NMR, ¹³C NMR spectroscopic methods and elemental analyses. All the compounds were screened in vitro against the HM1:IMSS strain of Entamoeba histolytica. Based on the 50% inhibitory concentration (IC₅₀) data of the 12 compounds evaluated, two of the 2-acetylpyridine series and two in the 2-acetylfuran series showed better IC₅₀ values in vitro when compared with the standard amoebicidal drug, metronidazole. Moreover, one compound showed the most promising antiamoebic activity (IC₅₀ = 0.5 μM vs IC₅₀ = 1.9 μM of metronidazole).