Tautomers of anthrahydroquinones: enzymatic reduction and implications for chrysophanol, monodictyphenone, and related xanthone biosyntheses.
Reduction of emodin by sodium dithionite resulted in the formation of two tautomeric forms of emodin hydroquinone. Subsequent conversion by the short-chain dehydrogenase/reductase (SDR) MdpC into the corresponding 3-hydroxy-3,4-dihydroanthracen-1(2H)-one implies that deoxygenation is the first step in monodictyphenone biosynthesis. Implications for chrysophanol formation as well as reaction sequences in the related xanthone, ergochrome, and bianthraquinone biosyntheses are discussed.
Institut für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg, Albertstr. 25, 79104 Freiburg, Germany.
Michael A
MA
Schätzle
Syed Masood
SM
Husain
Sascha
S
Ferlaino
Michael
M
Müller
D000880:Anthraquinones / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D044004:Xanthones / Q000737:chemistry / Q000378:metabolism*
D000880:Anthraquinones; D044004:Xanthones; C009689:xanthone; D010088:Oxidoreductases