Synthesis of Fluorinated <i>N</i>- Benzylaniline Derivatives and Evaluations on Anti-Tyrosinase and Anti-Melanogenic Activities

Melasma, freckles, age spots, and acne scars are common aesthetic problems resulted from melanin overproduction. This study aimed to develop new skin depigmenting compounds and characterize on melanin inhibition activities. The fluorinated N-benzylaniline derivatives were synthesized and evaluated for their in vitro anti-tyrosinase activity. Derivatives with p-fluorine monosubstition, N-(4-fluorobenzyl)-3-fluoro-4-methoxyaniline (3d), was the most potent inhibitor against mushroom tyrosinase with 75.4 ± 0.34 % inhibition at 500 µM which was as potent as the positive control, kojic acid. Furthermore, compound 3d exhibited superior anti-melanogenic activity in α-MSH-induced B16F10 murine melanoma cells, compared to kojic acid. Therefore, N-(4-fluorobenzyl)-3-fluoro-4-methoxyaniline (3d) was proposed as a new agent effective against skin hyperpigmentation.