Biosynthetic Studies on Acetosellin and Structure Elucidation of a New Acetosellin Derivative[*]
received 07 October 2016
revised 13 December 2016
accepted 16 December 2016
12 January 2017 (eFirst)
Natural products from fungi, especially Ascomycota, play a major role in therapy and drug discovery. Fungal strains originating from marine habitats offer a new avenue for finding unusual molecular skeletons. Here, the marine-derived fungus Epicoccum nigrum (strain 749) was found to produce the azaphilonoid compounds acetosellin and 5′,6′-dihydroxyacetosellin. The latter is a new natural product. The biosynthesis of these polyketide-type compounds is intriguing, since two polyketide chains are assembled to the final product. Here we performed 13C labeling studies on solid cultures to prove this hypothesis for acetosellin biosynthesis.
Key wordsAcetosellin - Epicoccum nigrum - Didymellaceae - azaphilones - polyketides - isotope labeling
* Dedicated to Prof. Max Wichtl in recognition of his outstanding contribution to pharmacognosy research.