Naturally occurring quinones. Part XIII. Anthraquinones and related naphthalenic compounds in Galium spp. and in Asperula odorata
The roots of Galium(seven spp.) and Asperula odorata contain anthraquinone pigments (<13) and one or more of the following naphthalenic compounds: 4-methoxy-1-naphthol, 1-naphthyl isopentyl ether, 1-naphthyl isopentenyl ether, and 2,2-dimethylnaphtho[1,2-b]pyran and its 3,4-dihydro-derivative. The relevance of these products to the biogenesis of the anthraquinones is discussed.