| The so-called chrysophanic acid found in Xanthoria parietina is not an acid but a quinone and is better termed physcion. |
| Hypericin, a polycyclic quinone obtained from plants of the genus Hypericum, has been shown to be a promising photosensitizer. |
| The formation of the dimers is strongly favored by the contiguous presence of quinone and hydroquinone. |
| Lapachol, a quinone, is a recognized antitumor agent found in the wood and barely in the bark. |
| It may react with molecular oxygen and form quinone and superoxide radicals. |
| The inset shows the second differential curves calculated from peaks 7 and 8 of the quinone spectra. |
