Tyrosinase refers to an oxidase, a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation. Compounds which disrupt the activation of tyrosinase would affect the normal growth and development of pests. To find new lead compound with high anti-tyrosinase activity, a series of novel 2-(1H-pyrazole-5-carbonyl)hydrazine carbothioamide derivatives were designed using the method of linking active sub-structures which were pyrazole and thiosemicarbazide. The target compounds were synthesized from substituted acetophenone in four steps and their structures were confirmed by 1H NMR spectra, IR spectrum and elemental analysis. The results of anti-tyrosinase activity assay demonstrated that compounds exhibited potent activities with IC50 values ranged from 12.8 to 56.8 �M while kojic acid was 113.8 �M. The most active molecule had an IC50 value of 12.8 �M and functioned as a non-competitive inhibitor of tyrosinase. Additionally, all the compounds exhibit some fungicidal activity against F. graminearum, A. solani and C. lagenarium, and one compound exhibited equivalent fungicidal activities to Polyoxin B at a concentration 100 �g/mL. The preliminary structure-activity relationships were also employed for further optimization.

Synthesis and biological activity of novel 2-(1H-pyrazole-5-carbonyl)hydrazine carbothioamide derivatives

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.