Application of mass spectrometry in structural problems in triterpenes
TL;DR: In this paper, mass spectral data on 105 pentacyclic triterpenoids have been collated and analysed from which it has been possible to identify base peaks which are characteristic of specific stereoskeletons.
About: This article is published in Phytochemistry.The article was published on 1981-01-01. It has received 102 citations till now. The article focuses on the topics: Mass spectrometry.
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TL;DR: The cloning of the first bacterial steroid biosynthesis gene, cas, encoding the cycloartenol synthase (Cas) of S. aurantiaca is described, indicating a close evolutionary relationship between myxobacterial and eukaryotic steroids biosynthesis.
Abstract: Summary
Steroids, such as cholesterol, are synthesized in almost all eukaryotic cells, which use these triterpenoid lipids to control the fluidity and flexibility of their cell membranes. Bacteria rarely synthesize such tetracyclic compounds but frequently replace them with a different class of triterpenoids, the pentacyclic hopanoids. The intriguing mechanisms involved in triterpene biosynthesis have attracted much attention, resulting in extensive studies of squalene-hopene cyclase in bacteria and (S)-2,3-oxidosqualene cyclases in eukarya. Nevertheless, almost nothing is known about steroid biosynthesis in bacteria. Only three steroid-synthesizing bacterial species have been identified before this study. Here, we report on a variety of sterol-producing myxobacteria. Stigmatella aurantiaca is shown to produce cycloartenol, the well-known first cyclization product of steroid biosynthesis in plants and algae. Additionally, we describe the cloning of the first bacterial steroid biosynthesis gene, cas, encoding the cycloartenol synthase (Cas) of S. aurantiaca. Mutants of cas generated via site-directed mutagenesis do not produce the compound. They show neither growth retardation in comparison with wild type nor any increase in ethanol sensitivity. The protein encoded by cas is most similar to the Cas proteins from several plant species, indicating a close evolutionary relationship between myxobacterial and eukaryotic steroid biosynthesis.
167 citations
Cites methods from "Application of mass spectrometry in..."
..., 1963; Claude, 1966), by their retention time in GC (Hewlett-Packard HP 5890 A series II) and GC-MS analysis (GC: Carlos Erba; MS: Kratos MS 50 or Finnigan MAT GCQ) of the extracts after silylation with MSTFA (Donike, 1969) or acetylation with acetic acid anhydride or trifluoroacetic acid anhydride against various standards as described previously (Ogunkoya, 1981)....
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...…HP 5890 A series II) and GC-MS analysis (GC: Carlos Erba; MS: Kratos MS 50 or Finnigan MAT GCQ) of the extracts after silylation with MSTFA (Donike, 1969) or acetylation with acetic acid anhydride or trifluoroacetic acid anhydride against various standards as described previously (Ogunkoya, 1981)....
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TL;DR: In this article, the largest source of river sediment to the Arctic Ocean, the Mackenzie River, has been analyzed for alkanes, triterpenes and polycyclic aromatic hydrocarbons (PAHs).
166 citations
TL;DR: The distribution of free 4-desmethyl sterols in sediments from the Peru coastal zone at 15°S have been determined in this paper, indicating that free sterols are rapidly degraded in this sedimentary environment.
162 citations
TL;DR: In this article, the tri-and tetraaromatic hydrocarbon fractions of a brown coal sample from the Latrobe Valley, Victoria, Australia indicate the predominance of pentacyclic hydroaromatic components.
124 citations
TL;DR: In this paper, fresh triterpenoid (dammar and mastic) resins were analysed by on-line HPLC-MS using atmospheric pressure chemical ionisation (APCI).
118 citations
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822 citations
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TL;DR: In this article, five triterpenoids, arundoin (Ia), cylindrin (IIa), fernenol (Ib), isoarborinol (IIb) and simiarenol (IVa), have been isolated and the structures of Ia, IIa and Ib determined.
75 citations
TL;DR: From the exudate of the bark of Ficus macrophylla Desf, cycloartenol, butyrospermol, and lupeol were isolated as their acetates.
Abstract: From the exudate of the bark of Ficus macrophylla Desf., cycloartenol, butyrospermol, and lupeol were isolated as their acetates. The leaves contained nonacosane, triacontane, hentriacontane, dotriacontane, tritriacontane, "ceryl alcohol", and a new triterpene, moretenol. By degradative and mass spectrometric studies, the latter was shown to b3 3β-hydroxy-2lαH-hop-28-ene.
50 citations