Investigation of the efficacy on tyrosinase enzyme of 5-substituted-1H-tetrazole derivatives synthesized with Pd-containing nanoparticle

Synthesis of 5-substituted-1H-tetrazole derivatives from aryl aldehydes under the influence of Palladium nanoparticles entrapped in aluminum hydroxide matrix (Pd/AlO(OH) NPs) was carried out in ethanol for 3-6 h. The use of the catalyst in this synthesis is the first. Sodium azide and malononitrile used in the reaction are chemical compounds required in the synthesis of tetrazoles. The reactions were concluded with good yields under thermal conditions. In the reactions, twelve derivatives were synthesized. The synthesized compounds were characterized by IR, ¹H, and ¹³C NMR. The olefinic proton's signal, which is around 8.5 ppm, reveals the formation of the tetrazole ring. The tyrosinase enzyme activity for each synthesized derivative was examined, and the results were recorded. According to the results obtained, all tetrazole derivatives were found to be effective compounds for tyrosinase enzyme inhibition. 3-(3,4-dichlorophenyl)-2-(1H-tetrazol-5-yl)acrylonitrile (2k) with two chloride groups at the meta and para position of the phenyl ring seems to be the most potent tyrosinase inhibitor with an IC₅₀ value of 45 µM.

Graphical abstract

SYNOPSIS: 5-substituted-1H-tetrazole derivatives were synthesized under the influence of PdAlO(OH) NPs and under mild conditions. Tyrosinase enzyme activity was investigated for each of the twelve synthesized derivatives. As a result, synthesized tetrazole derivatives were identified as potential tyrosinase inhibitors.