Biomedical subjects
Publications and source records attributed to D Wendisch.
The relative stereochemistries of bullatalicin [1] and bullatalicinone [2] were partially reassigned based on COSY and relayed COSY spectra. The structures of annonins VIII [3], IV [4], and XVI [5] were revised and concluded as bullatalicin [1], bullatanocin [6], and squamostatin A [7], respectively.
Five flavonoid glycosides were identified from flowers of Arnica montana, ten from A. CHAMISSONIS subsp. FOLIOSA var. INCANA. The structures were established on the basis of acid hydrolysis and spectral data (UV, NMR, MS) as the 7-beta-glucosides of pectolinarigenin, apigenin, and chrysoeriol; luteolin 3'- O-beta-glucoside; the 3-beta-glucuronides of kaempferol, isorhamnetin, and 6-methoxykaempferol; the 3,7-di-beta-glucosides of quercetin and patuletin; the 3-beta-glucosides of betuletol and quercetagetin 6,3',4'-trimethyl ether; and the 7-[6''- O-(2-methylbutyryl)]=glucosides of luteolin and eupafolin. The latter four are new natural compounds. Differences between these two ARNICA species are discussed.
The flowers of ARNICA MOLLIS afforded, in addition to baileyin ( 1A), baileyin acetate ( 1B), xanthalongin ( 3), and 2-deacetoxy-11alpha,13-dihydroxanthuminol ( 6), the new 1,5- CIS-guaianolides arnimollin acetate ( 2A) and arnimollin tiglinate ( 2A) and the new xanthanolides 11beta3,13-dihydroxanthalongin ( 4) and 11alpha,13-dihydroxanthalongin ( 5). No traces of helenanolides were discernible. The structures were elucidated mainly by high-field NMR spectroscopy. The stereochemistry of 1B has been revised on the basis of an X-ray crystallographic study to be a 4alpha,5beta-epoxygermacrolide instead of a 4alpha,5beta-epoxymelampolide. The implications for the biosynthesis of CIS- and TRANS-fused guaianolides are discussed. The co-occurrence of 1A with CIS-fused guaianolides and xanthanolides (no helenanolides) in A. MOLLIS and with TRANS-fused guaianolides and helenanolides (no xanthanolides) in A. ACAULIS supports the hypothesis that germacrolides represent the biogenetic precursors for CIS- and TRANS- fused guaianolides.
Annonin I ( 1) and anonin VI ( 9) were isolated from the seeds of ANNONA SQUAMOSA L. (Annonaceae). The constitution of 1 is identical with that of squamocin, isolated by Fujimoto et al. (8). The relative configuration of 1 was elucidated by X-ray diffraction analysis of a derivative. The constitution and relative configuration of 9 was established by (13)C- and (1)H-NMR spectroscopy using data of derivatives.
Annonacin ( 1), annonacin A ( 6), and annonastatin ( 7) were isolated from the seeds of ANNONA SQUAMOSA L. (Annonaceae). Compounds 6 and 7 are described for the first time. The relative configuration of the tetrahydrofuran core of 1 (with hitherto unknown configuration), as well as those of compounds 6, and 7 were established by (13)C- and (1)H-NMR spectroscopy using data of the derivatives 8- 11.
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