In the title compound, C22H18O6, the dimeth-oxy-substituted naphthalene ring system is twisted relative to the 4H-chromenon skeleton by 88.96 (3)°. The two meth-oxy substituents are tilted from the naphthalene ring system by 1.4 (4) and 113.0 (2)°, respectively. An intra-molecular O-H⋯O hydrogen bond closes an S(5) ring motif. In the crystal, pairs of O-H⋯O hydrogen bonds form inversion dimers with R (2) 2(10) loops and C-H⋯O inter-actions connect the dimers into [010] chains.
Keywords: crystal structure; flavonol; fluorescence; hydrogen bonding.