title: Staurosporine derivatives from the ascidian eudistoma toealensis and its predatory flatworm pseudoceros sp
abstract: Two new indolocarbazole alkaloids, 3-hydroxy-3'-demethoxy-3'-hydroxystaurosporine (5) and 11-hydroxy-4'-N-demethylstaurosporine (6), were isolated from the marine ascidian Eudistoma toealensis and its predator, the marine flatworm Pseudoceros sp. In addition, five known derivatives were isolated in their protonated states, which caused the pyran-ring system to adopt a boat conformation. The structures were determined by 1D and 2D homonuclear and (1)H-detected heteronuclear NMR spectroscopy and from comparisons with published data. The heteronuclear correlations were necessary to establish reliable data for the structure elucidation.
authors.affiliation: Julius-von-Sachs-Institut fur Biowissenschaften, Lehrstuhl fur Pharmazeutische Biologie, Julius-von-Sachs-Platz 2, D-97082 Wurzburg, Gesellschaft fur Biotechnologische Forschung mbH, Mascheroder Weg 1, D-38124 Braunschweig, Max-P.
authors.initials: P
authors.lastname: Schupp
authors.initials: C
authors.lastname: Eder
authors.initials: P
authors.lastname: Proksch
authors.initials: V
authors.lastname: Wray
authors.initials: B
authors.lastname: Schneider
authors.initials: M
authors.lastname: Herderich
authors.initials: V
authors.lastname: Paul