The molecular formula C17H16O5 (molar mass: 300.30 g/mol, exact mass: 300.099773 u) may refer to: Coelogin, a phenanthrenoid found in the orchid Coelogyne cristata Confusarin, a phrenathrenoid found in orchids Flavokavain C, a kavalactone Gymnopusin, a phenanthrenoid found in several orchids Methyllinderone Plicatol A, a phenanthrenoid found in the orchid Flickingeria fimbriata 3,4,8-Trimethoxyphenanthrene-2,5-diol, a phenanthrenoid found in the orchid Dendrobium nobile