TYR and melanoma: Roh et al. demonstrated that gallic acid and quercetin isolated from Stewartia pseudocamellia can inhibit melanin synthesis in melanoma cells and regulated the enzymatic activity of tyrosinase [135] Other plants rich in phenolic compounds with anti-tyrosinase activity are Cytinus hypocistis [134], Magnolia grandiflora [217] and Zingiber officinale Rosc.