Sesquiterpene lactones and inositol esters from Arnica angustifolia.

From flowerheads of Arnica angustifolia ssp. attenuata nine helenanolides, two 1,5- trans-guaianolides, and a mixture of inositol-tetraesters were isolated. Five of the helenanolides are described for the first time. One of them, 4- O-tigloylarnicalpin, is the first 7(12),6-trans-lactonized pseudoguaianolide isolated from a natural source. The occurrence of inositol esters within the genus Arnica has not been reported before.

Structural revisions of some non-adjacent bis-tetrahydrofuran annonaceous acetogenins.

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.

New Flavonoid Glycosides from Arnicae Flos DAB 91.

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 Relative Configuration of Acetogenins Isolated from Annona squamosa: Annonin I (Squamocin) and Annonin VI]. / Die relative Konfiguration der aus Annona squamosa isolierten Acetogenine Annonin I (Squamocin) und Annonin VI1.

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.

[Annonacins and Annonastatin from Annona squamosa]. / Annonacine und Annonastatin aus Annona squamosa.

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.

[Germacranolides, Guaianolides, and Xanthanolides from the Flowers of Arnica mollis and an X-Ray Structure Analysis of Baileyin Acetate]. / Germacranolide, Guaianolide und Xanthanolide aus Blüten von Arnica mollis und Röntgenstrukturanalyse von Baileyinacetat.

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.

Flavonoid Glucuronides from the Flowers of Arnica montana1.

Five flavonoid glucuronides were identified from flowers of ARNICA MONTANA L. The structures were established on the basis of total acid hydrolysis and spectral data (UV, (1)H-NMR, (13)C-NMR, mass) as 3- O-beta- D-glucuronides of quercetin, kaempferol, isorhamnetin, patuletin, and 6-methoxykaempferol. The last one is a new natural compound. This is the first report on glucuronides in the genus ARNICA. Additionally, tricin and 3,5,7-trihydroxy-6,3',4'-trimethoxyflavone were identified. Up to now these two flavonoid aglycones have been rarely found in the family of the Asteraceae.

Flavonoid Glycosides from Arnica montana and Arnica chamissonis.

Five flavonoid glycosides were identified from flowers of ARNICA MONTANA, four from A. CHAMISSONIS subsp. FOLIOSA var. INCANA. The structures were established on the basis of total acid hydrolysis and spectral data (UV, (1)H-NMR, (13)C-NMR, MS) as hispidulin 7- O-beta-glucoside, isorhamnetin 3- O-beta-glucoside, 3- O-beta- D-glucopyranosides of spinacetin, 6-methoxykaempferol and patuletin and querectin 3- O-(6''- O-acetyl)-beta- D-glucopyranoside. The latter compound can serve as distinctive marker between these two ARNICA species. The (1)H-NMR spectra in CD (3)OD are discussed.

[Demethoxyencecalin and Thymol derivatives from Arnica sachalinensis1.]. / Desmethoxy-encecalin und Thymolderivate aus Arnica sachalinensis1.

From the flowers of ARNICA SACHALINENSIS the chromene desmethoxyencecalin, 10-acetoxy-8,9-epoxy-3- O-isobutyrylthymol, and 10-acetoxy-8-hydroxy-9-isobutyryloxythymol were isolated and their structures established by mass spectrometry (13)C-, and (1)H-NMR spectroscopy.

Sesquiterpenlactone aus Arnica chamissonis IV.1,2 Ivalin und andere Sesquiterpenlactone aus den Blütenkörbchen der Subspecies genuina.

The flowers of ARNICA CHAMISSONIS ssp. GENUINA afforded in addition to 8 helenanolides ivalin, the first eudesmanolide found in the genus ARNICA.

6-O-Isobutyryl-tetrahydrohelenalin from the flowers of Arnica montana.

From the flowers of ARNICA MONTANA L., the helenanolides 6- O-isobutyryl-tetrahydrohelenalin and 2beta-ethoxy-6- O-isobutyryl-2,3-dihydrohelenalin were isolated and their structures established by spectroscopic methods.

[Sesquiterpenlactone aus Arnica chamissonis].

From the flowers of Arnica chamissonis Less, sub-sp. foliosa (Nutt.) Maguire and its variety incana (Gray) Hulten two new naturally occuring pseudoguaianolides were isolated and their structures established by spectroscopic methods. They are shown to be 4-O-acetyl-6-desoxychamissonolide ( 3) and the propionylic ester of 11,13-dihydrohelenalin which was named arnicolide G ( 6).