Mass spectral study of ring <i>E</i> of taraxasterol and compounds with similar ring substitution

Lee, Hsiu-Pu Daniel; Eichmeier, Larry S.; Piatak, David M.

doi:10.1002/oms.1210200315

Cited by 6 publications

(4 citation statements)

References 6 publications

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“…In addition to the triterpenediols and -triols, the monols taraxasterol (17) and y-taraxasterol (18), b-amyrin (19) and a-amyrin (20) were identified as constituents of the DCM extract by GC-MS analysis and comparison of the EI-MS information with literature data [10], [11].…”

Section: Table1 13 C-nmr Data Of Ursane and Oleanane Type Triterpene mentioning

confidence: 99%

“…Eight fractions were collected (C1 ± C8). Fraction C2 (379 mg; CH 2 Cl 2 /EtOAc, 9 : 1; elution volume: 4090 ± 4825 mL) contained 17, 18, 19 and 20 which were identified by GC-MS analysis in direct co-chromatography with authentic samples (19 and 20) and by comparison (17 ± 20) of their mass spectral data with those given in the literature [10], [11].…”

Section: Extraction and Isolationmentioning

confidence: 99%

“…Moreover, arnitriol A (6), lupane-3b,16b,20-triol (14) and 24-epi-fouquierol (16) are new naturally occurring triterpene alcohols. In addition, the structure elucidation of the isolated esters, carried out by extensive 1 H-and 13 C-NMR spectroscopic measurements including 1 H/ 1 H-COSY, 1 H/ 13 C-HMQC and -HMBC as well as DEPT-135 experiments, allowed the assignment of the hitherto unknown 13 C-NMR data for arnidiol (3), faradiol epoxide (5), heliantriol F (8), heliantriol A1 (11), and fouquierol (15) (see Tables 1 and 2) as well as a more complete assignment of the 1 H-NMR data (see Tables 3 ± 5) in the case of compounds whose data had already been partially reported.…”

Section: Table1 13 C-nmr Data Of Ursane and Oleanane Type Triterpene mentioning

confidence: 99%

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New Triterpene Esters from Flowerheads ofArnica lonchophylla

Schmidt

Raison²,

Willuhn³

2004

Planta med

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From the flowerheads of Arnica lonchophylla Greene ssp. lonchophylla Maguire (Asteraceae), a variety of mono-, di- and trihydroxytriterpenes of the oleanane, ursane, lupane and dammarane types were isolated and their structures elucidated by EI and CI mass spectrometry and extensive NMR spectroscopic analysis. Most of the compounds are esterified at position 3 with lauric, myristic, palmitic and stearic acids. Several ester derivatives of known triterpenes represent new natural products. The triterpenetriols 20(30)-taraxasten-3beta,16beta,21alpha-triol (arnitriol A) and lupane-3beta,16beta,20-triol, both isolated in the form of their C3-fatty acid ester derivatives, possess hydroxylation patterns which have not been described previously. Besides small amounts of triterpenetriol esters, the lauric, myristic, palmitic and stearic acid esters of arnidiol, faradiol, maniladiol and calenduladiol were also identified in the flowerheads of A. montana (Arnicae flos Ph. Eur.), A. chamissonis ssp. foliosa and A. angustifolia ssp. attenuata. A search for sesquiterpene lactones in the flowers of A. lonchophylla resulted in the identification of small amounts of helenalin and 11alpha,13-dihydrohelenalin.

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Section: Table1 13 C-nmr Data Of Ursane and Oleanane Type Triterpene mentioning

confidence: 99%

Section: Extraction and Isolationmentioning

confidence: 99%

Section: Table1 13 C-nmr Data Of Ursane and Oleanane Type Triterpene mentioning

confidence: 99%

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New Triterpene Esters from Flowerheads ofArnica lonchophylla

Schmidt

Raison²,

Willuhn³

2004

Planta med

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“…Synthetic or semisynthetic approaches can give access to compounds with well-defined isotopic substitutions, but are very laborious and might require different synthetic strategies for each target position of the natural product. Deuterium has often been used successfully to study EI-MS fragmentation mechanisms of terpenes, [16][17][18][19][20] but sometimes gave unclear results as a consequence of unspecific scrambling. [21] In previous studies on EI-MS fragmentation mechanisms we have enzymatically prepared 13 C-labelled terpenes from the corresponding synthetic 13 C-labelled terpene precursors, which allowed to label each individual carbon.…”

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confidence: 99%

Revision of the Cyclisation Mechanism for the Diterpene Spiroviolene and Investigations of Its Mass Spectrometric Fragmentation

Dickschat

2020

ChemBioChem

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The diterpene spiroviolene, its diterpene synthase from Streptomyces violens and the experimentally determined terpene cyclisation mechanism were reported in 2017. Recently, the structure of spiroviolene was revised based on a total synthesis, with consequences for the cyclisation mechanism. Herein, a reinvestigation of the terpene cyclisation to spiroviolene and the mass spectrometric fragmentation mechanism investigated by 13C‐labelling experiments are presented.

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Triterpenoids

Connolly¹,

Hill²

1991

Dictionary of Terpenoids

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Mass spectral study of ring E of taraxasterol and compounds with similar ring substitution

Cited by 6 publications

References 6 publications

New Triterpene Esters from Flowerheads ofArnica lonchophylla

New Triterpene Esters from Flowerheads ofArnica lonchophylla

Revision of the Cyclisation Mechanism for the Diterpene Spiroviolene and Investigations of Its Mass Spectrometric Fragmentation

Triterpenoids

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