Anti-tyrosinase, anti-elastase, and antioxidant activities of some symmetric bisthiocarbohydrazone compounds

Symmetric bisthiocarbohydrazone compounds (1, 2, 3) were obtained by the condensation of thiocarbohydrazide with carbonyl compounds such as isatin (a heterocyclic ketone) and two hydroxyl aldehydes (2-hydroxybenzaldehyde, 2-hydroxy-1-naphthaldehyde) respectively, according to the previously reported methods. These synthesized compounds were evaluated in terms of their anti-tyrosinase, anti-elastase and antioxidant potentials in vitro. All of the tested compounds exhibited anti-tyrosinase and anti-elastase activities. It was observed that the inhibition increased with the increase of bisthiocarbohydrazone concentrations. Compound 1 showed the highest anti-tyrosinase activity. The anti-tyrosinase activity is decreasing in the following order; 2<3<1. Compound 1 showed also the highest anti-elastase activity. The anti-elastase activity is decreasing as 3<2<1. As a result, the most effective compound in terms of anti-tyrosinase and anti-elastase activities is bisthiocarbohydrazone derived from isatin. Compounds 2 and 3 with the hydroxyl substitution showed antioxidant activity close to Trolox. These compounds were found to have significant reducing effects and to be effective scavengers of DPPH