cytoskyrin-a and rugulosin

Modified bisanthraquinones are complex dimeric natural products containing a cage-like structural motif. For their biosynthesis, monomeric dihydroanthraquinones have been proposed as key intermediates despite not being isolated from natural sources or synthesized as of yet. Here, isolation and characterization of dihydroemodin, as well as dihydrolunatin, synthesized by a biomimetic and chemoenzymatic approach using NADPH-dependent polyhydroxyanthracence reductase (PHAR) from Cochliobolus lunatus followed by Pb(OAc)

Topics: Anthraquinones; Ascomycota; Biological Products; Catalysis; Cycloaddition Reaction; Dimerization; Organometallic Compounds; Oxidation-Reduction; Oxidoreductases; Pyridines

The total syntheses of 2,2'-epi-cytoskyrin A, rugulosin, and the alleged structure of rugulin are described. These naturally occurring bisanthraquinones and their relatives are characterized by novel molecular architectures at the core, at which lies a more or less complete, cage-like structural motif termed "skyrane". The strategies developed for their total synthesis feature a cascade sequence called the "cytoskyrin cascade" and deliver these molecules in short order and in a stereoselective manner.

Topics: Anthraquinones; Crystallography, X-Ray; Dimerization; Free Radicals; Models, Molecular; Molecular Structure; Naphthoquinones; Nitriles; Oxidation-Reduction

Topics: Anthraquinones; Biomimetic Materials; Molecular Structure