0000000000371032
AUTHOR
M. Dräger
New potential DNA intercalators of the carbazole series from indole-2,3-quinodimethanes: Synthesis, crystal structure, and molecular modeling with a watson-crick mini-helix
1-Alkylpyrano[3,4-b]indol-3-ones3 react via a Diels-Alder step with an aryne or N-phenylmaleimide to furnish the new [b]annellated carbazoles4–10 in a one-pot process. In an analogous procedure, the in situ generated N-benzoylindole-2,3-quinodimethane (13) reacted with quinones to furnish the dioxocarbazoles14–16. Compounds4–8 and14–16 with a coplanar skeleton are members of a class of potential DNA intercalators, as has been shown for5 and8 by X-ray structural analysis. On the basis of the geometries determined by X-ray crystallography, the intercalative binding of these molecules with a Watson-Crick mini-helix was predicted by molecular modeling methods.
Environmentally relevant precursors of carbonyl sulfide in aquatic systems
Seawater solutions of environmentally relevant organosulfur compounds, commercial humic acid (HA), and natural dissolved organic matter (DOM) were incubated with and without UV light in order to determine the carbonyl sulfide (COS) producing capabilities of these compounds. COS dark- and photo-production rate constants were determined for dilute solutions of the organosulfur compounds (μmol l−1) and HA/DOM (mg l−1). Dissolved COS was determined using a purge and cryogenic trap method followed by GC/FPD detection. COS was produced in considerable amounts both non-photochemically and photochemically from the reduced form of free acid of glutathione (GSH) and photochemically from cysteine (CYS…