Studies in the biochemistry of micro-organisms: Emodic acid (4:5:7-trihydroxyanthraquinone-2-carboxylic acid) and omega-hydroxyemodin (4:5:7-trihydroxy-2-(hydroxymethyl)-anthraquinone), metabolic products of a strain of Penicillium cyclopium Westling
Biochem J. 1940 Feb;34(2):159-68.
doi: 10.1042/bj0340159.