In the present paper, we report the synthesis and pharmacological evaluation of a new series of azo compounds with different groups (1-naphthol, 2-naphthol, and N,N-dimethylaniline) and trifluoromethoxy and fluoro substituents in the scaffold. All synthesized compounds (5a-5f) showed the most potent mushroom tyrosinase inhibition (IC₅₀ values in the range of 4.39 ± 0.76-1.71 ± 0.49 µM), compara...

The title compound, C(11)H(9)NO(2), was prepared by a condens-ation reaction of 2-hydr-oxy-1-naphthaldehyde with hydroxyl-ammonium chloride in refluxing ethanol. An intra-molecular O-H⋯N hydrogen bond is observed. In the crystal structure, inter-molecular O-H⋯O and C-H⋯O hydrogen-bond inter-actions result in a two-dimensional network.

The popular colorimetric assay for urinary 5-hydroxyindole-3-acetic acid based on the reaction with 1-nitroso-2-naphthol has been criticized for lack of specificity. Goldenberg (Clin. Chem. 19: 38-44, 1973) proposed a modification of this method, in which 2-mercaptoethanol is used to discharge unwanted chromophores. We compared results by both the unmodified and modified colorimetric methods wi...