Abstract
Labelling studies have shown that the biosynthesis of emodin (6) and related anthraquinone pigments in fungi and higher plants occurs via the acetate/malonate pathway (ref. 1). Details of the early steps in this biosynthesis, however, remain unknown. It can be assumed that after assembling of the octaketide chain condensation to a carboxylic acid 1 takes place, which can either be decarboxylated to atrochrysone (4) or dehydrated to endocrocin anthrone (2) (Scheme 1). Atrochrysone then may undergo water elimination to emodin anthrone (5) followed by oxidation to emodin (6), which is the precursor of many neutral anthraquinones. The possibility that 5 is formed from 1 by a concerted loss of water and CO2 has also to be considered. On the other hand, 2 can be converted into endocrocin (3) which serves as precursor to other anthraquinone carboxylic acids.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
