RESUMO
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.
RESUMO
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.
Assuntos
Antineoplásicos Fitogênicos/química , Furanos/química , Plantas Medicinais/química , Adenocarcinoma/tratamento farmacológico , Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Carcinoma/tratamento farmacológico , Neoplasias do Colo/tratamento farmacológico , Furanos/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Células Tumorais CultivadasRESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
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.
RESUMO
The flowers of ARNICA CHAMISSONIS ssp. GENUINA afforded in addition to 8 helenanolides ivalin, the first eudesmanolide found in the genus ARNICA.
RESUMO
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.
RESUMO
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).