Abstract:
Pyrazoline and pyrazole are heterocyclic compounds containing two nitrogen atoms and possess
bioactivity such as tyrosinase inhibitor, antidiabetic and anticancer. Pyrazoline and pyrazole
derivatives of 3,4-dimethoxybenzaldehyde and 3-bromoacetophenone were synthesized through
one-pot synthesis and followed by an oxidative aromatization reaction. Pyrazoline compound
were purified by recrystallization and pyrazole compound were purified using column
chromatography. The purity of the target compounds was analyzed by TLC test, melting point
measurement and HPLC. The synthesized compounds were then structurally confirmed by UV,
FTIR, 1H-NMR and HRMS spectroscopy. The compounds was then tested for its activity as a
tyrosinase inhibitor through molecular docking of the tyrosinase crystal structure (PDB ID:
2Y9X). The activity of the target compounds was compared with kojic acid as a positive control.
The test results showed that the pyrazoline target compound had a free bond energy (S score) = -
10.2577 kcal/mol while the pyrazole target compound had a free bond energy (S score) = -
10.6895 kcal/mol. When viewed from the positive control, kojic acid has a bond free energy (S
score) = -8.4975 kcal/mol, the synthesized pyrazoline and pyrazole compounds have the
potential as tyrosinase inhibitor compounds.
