Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.
J Am Chem Soc. 2012 Jan 18;134(2):788-91. doi: 10.1021/ja2093212. Epub 2011 Dec 28.
Notoamides produced by Aspergillus spp. bearing the bicyclo[2.2.2]diazaoctane core structure with unusual structural diversity represent a compelling system to understand the biosynthesis of fungal prenylated indole alkaloids. Herein, we report the in vitro characterization of NotB, which catalyzes the indole 2,3-oxidation of notoamide E (13), leading to notoamides C (11) and D (12) through an apparent pinacol-like rearrangement. This unique enzymatic reaction with high substrate specificity, together with the information derived from precursor incorporation experiments using (13)C-(15)N quadruply labeled notoamide S (10), demonstrates 10 as a pivotal branching point in notoamide biosynthesis.
