The hexane extract from the leaves of Dasymaschalon sootepense Craib ( Annonaceae) showed strong cytotoxic activity against the L1210 tumor cell line. Activity-directed fractionation of the extract by column chromatography on silica gel and high-pressure liquid chromatography led to the isolation of the acetogenins 1 ± 4 as the main active principles. The structures of the two novel structures named sootepensin A (1) and sootepensin B (2) were elucidated by spectroscopic analysis ( UV, EI-and ESI-MS, 1D-and 2D-1 H-and 13 C-NMR ). The absolute configurations were established by 2D-NMR experiments utilizing Mosher esters. Two recently described compounds, tonkinin C (3) and tonkinesin C (4), were also isolated and are new to the genus Dasymaschalon. All four acetogenins were found to be highly cytotoxic against the L1210 tumor cell line.

Alkaloids Alkaloids U 0600Synthesis and Nicotinic Binding Studies on Enantiopure Pinnamine Variants with an 8-Azabicyclo[3.2.1]octane Moiety. -The newly synthesized compounds (IV) and (V) which could be considered as conformationally restricted (-)-ferruginine analogues exhibit only nAChR affinities in the low micromolar range. -(SCHWARZ, S.; KAEMPCHEN, T.; TILOTTA, M. C.; GUENDISCH, D.; SEITZ*, G.; Pharmazie 58 (2003) 5, 295-299; Inst. Pharm. Chem., Philipps-Univ., D-35037 Marburg, Germany; Eng.) -K. Schneider 33-207

Nucleophile wie H2O, NH3‐Gas (IVa) bzw. Dimethylamin (IVb) reagieren mit dem Tetrazin (I) unter 1,4‐Addition zu dem Hydrazid (II) (Rotamerengemisch) bzw. zu den Azinen (IIIa) bzw. (IIIb); im Gegensatz dazu liefert Methylamin mit (I) das Aminotriazin (V).

Aus den Diacylcyclopentadienen (I) erhält man mit Tl‐ethanolat die Tl‐Cyclopentadienide (II), von denen (IIa) zu den Acyl‐ bzw. Silylenolethern (IV) umgesetzt werden.

Die Umsetzung des Tetrazins (I) mit N,N‐Dimethylanilin (II) führt zu den Addukten (III) und (IV).