Abstract:
Hyperpigmentation is a condition when melanin is produced in excess, causing dark patches to
appear on the skin. Treatment of hyperpigmentation can be done through tyrosinase inhibition
which will inhibit the formation of melanin. One of the compounds that has activity as an
inhibitor of the tyrosinase enzyme is pyrazolin. The purpose of this study was to synthesize
the compound 4-(3-(4-fluorophenyl)-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-yl)
benzensulfonamide, then to characterize the synthesized compound and test it. molecular
docking. Pyrazoline compounds are synthesized by reacting 4-fluoroacetophenone and
4-methoxybenzaldehyde into chalcone through the clasen-schmidt reaction, then reacted with
4-hydrazinebenzensulfonamide which was also synthesized through diazotation and reduction
reactions and continued the final reaction by reacting chalcone and hydrazine through a
cyclization reaction to form pyrazoline. The structure of the synthesized compound was
confirmed by UV spectroscopic analysis, FTIR, 1H-NMR, and HRMS. The yield obtained from
the synthesis of pyrazoline was 78.11%. The synthesized pure compound was tested for activity
as a tyrosinase inhibitor with a molecular docking study. Molecular docking tests were carried
out on the crystal structure of tyrosinase (PDB:2Y9X) with natural ligands tropolone and kojic
acid as positive controls. The docking results showed that the pyrazoline compound had a free
bond energy (S score) = -10.5244 kcal/mol, while kojic acid had a free bond energy
2
(S score) = -8.7673 kcal/mol. The data that has been obtained indicate that the pyrazoline
compound is predicted to be a potential inhibitor of the tyrosinase enzyme.
