Abstract: | Four novel Schiff bases were synthesized by the condensation reaction of 2-hydroxyl-3-nitrobenzaldehyde with either benzothiazoles or benzimidazolamines. The compounds 1–4 were characterized by spectroscopic and analytical methods. The crystal structures of 6-methoxy-1,3-benzothiazol-2-amine and compound 2 are reported only. The 6-methoxy-1,3-benzothiazol-2-amine was found to crystallize in the orthorhombic crystal system in the space group Pbca, having eight molecules in the unit cell, while compound 2 was found to crystallize in the monoclinic crystal system in the space group P21/c.The biological activities of these compounds were investigated by evaluating their antibacterial, antifungal, antimalarial, anti-HIV and anti-trypanosomiasis activities. These compounds displayed very interesting antibacterial, antifungal, antimalarial, anti-trypanosomiasis, anti-HIV and low cytotoxicity activity against HeLa cells. |