New bis-heterocyclic structures: Synthesis, characterization and biological activity

New bis-heterocyclic compounds were synthesized by reacting two moles of isoniazid, cyanoguanidine and 2-aminophenol with one mole of a bis-chalcone. The bis-chalcone was prepared from the reaction between acetophenone and terephthalaldehyde using sodium hydroxide. All the prepared compounds were purified and their structures confirmed by spectroscopic methods, such as Fourier transform infrared, 1 H NMR and 13 C NMR. Their effect against three types of bacteria (negative and positive) for gram stain Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus was studied and discussed. The results obtained were compared with those of gentamicin, chloramphenicol and amikacin. Our new compounds showed clear inhibition of the different bacteria types with some of them exceeding the effects of the drugs possibly due to the bis-heterocyclic structures of our compounds. The effects of our compounds on the growth of certain types of fungi, Trichophyton and Aspergillus, were studied, showing inhibition of the growth of these fungi at high concentrations.