The stereocontrolled three-step synthesis of either enantiomer of α-thujone from commercially available 3-methyl-1-butyne is described. The enantioselectivity originates from a Brown crotylation which is then conferred to the all-carbon quaternary center via chirality transfer in a gold-catalyzed cycloisomerization. The route is highly atom economical and requires no protecting groups or redox manipulations.
The discovery of the (+)-α-thujone and (-)-β-thujone stereoisomers in the essential oil of sage (Salvia officinalis L.) and dietary supplements is documented for the first time. The detection was accomplished using a chiral resolution protocol of racemic α-/β-thujone on headspace solid-phase microextraction-gas chromatography-mass spectrometry. Because the previously unreported stereoisomers, (+)-α-thujone and (-)-β-thujone, are not commercially available, a three-step synthesis of racemic thujone from commercially available starting materials was developed. Thermolysis studies demonstrated that no racemization at the cyclopropane stereocenters occurs, corroborating that the detection is not an artifact from the hydrodistillation process. The developed chiral resolution of thujone was also used to provide evidence for the absence of the (+)-α-thujone and (-)-β-thujone enantiomers in other common thujone-containing essential oils.
BACKGROUND:The essential oil (EO) of Artemisia vulgaris L. has been traditionally used worldwide for treating a large number of diseases. Although major components in A. vulgaris EO have been shown to inhibit growth of different cancer cells, as pure compounds or part of other plants extracted oil, no information is known about its anti-proliferative activities. Therefore, the current investigation has evaluated the toxicity of the plant extracted oil from buds (AVO-b) and leaves (AVO-l) and characterized their growth inhibitory effects on cancer cells.METHODS:AVO-b and AVO-l from A. vulgaris L. were extracted by hydrodistillation, and their effect on the viability of human HL-60 promyelocytic leukemia and various other cancer cell lines was tested using MTT assay. Flow cytometric analysis of apoptosis, DNA fragmentation assay, caspases enzymatic activities and Western blotting were used to determine the apoptotic pathway triggered by their action on HL-60 cells.RESULTS:Low concentrations of AVO-b and AVO-l inhibited the growth of HL-60 cells in a dose- and time-dependent manner. Employing flow cytometric, DNA fragmentation and caspase activation analyses, demonstrated that the cytotoxic effect of the oils is mediated by a caspase-dependent apoptosis. Kinetic studies in the presence and absence specific caspase inhibitors showed that activation of caspase-8 was dependent and subsequent to the activation of caspases-9 and -3. In addition, the essential oil caused a disruption of the mitochondrial transmembrane potential (ΔΨm), increased the release of cytochrome c to the cytosol, and altered the expression of certain members of Bcl-2 family (Bcl-2, Bax and Bid), Apaf-1 and XIAP. Interestingly, low doses of AVO-b and AVO-1 also induced apoptosis in various cancer cell lines, but not in noncancerous cells.CONCLUSIONS:The results demonstrate that the EO-induced apoptosis in HL-60 cells is mediated by caspase-dependent pathways, involving caspases-3, -9, and -8, which are initiated by Bcl-2/Bax/Bid-dependent loss of ΔΨm leading to release of cytochrome c to the cytoplasm to activate the caspase cascade. The finding that AVO-b and AVO-l are more efficient to induce apoptosis in different cancer cell lines than noncancerous cells, suggests that A. vulgaris might be a promising source for new anticancer agents.
Artemisia vulgaris L. was collected from various regions in the USA and Montreal Canada. Gas Chromatography-Mass Spectrometry was used to identify the analytes present in the volatiles extracted by headspace solid-phase microextraction of the crushed leaves and flowers. Four distinct chemotypes are were found: One featuring the coexistence of ar-curcumene and α-zingiberene; two marked by the presence or absence of thujone and santolinatriene; and a fourth characterized by the presence of crysanthenyl acetate (40%). DNA was used to confirm the identity of Artemisia vulgaris L.
Essential Oil from wild growing Artemisia vulgaris L. originating in Erie, Pennsylvania was obtained by hydrodistillation of the aerial parts of the plant. Gas chromatographic-mass spectral analysis was used to identify the major volatiles present. Up to 22 components were detected in the essential oils. Germacrene D (25%), Caryophyllene (20%), α-Zingiberene (15%) and Borneol (11%) represent the major components of leaf oil, while the buds were rich in 1,8-Cineole (32%), Camphor (16%), Borneol (9%), and Caryophyllene (5%). trans-2-Hexenal was also detected in the aerial parts of the plant. α-Zingiberene and trans-2-Hexenal have not been previously reported for Artemisia vulgaris L. The major analytes are compared to those from Artemisia vulgaris L, originating outside of the United States.
Essential Oil from wild growing Artemisia vulgaris L. originating in Erie, Pennsylvania was obtained by hydrodistillation of the aerial parts of the plant. Gas chromatographic-mass spectral analysis was used to identify the major volatiles present. Up to 22 components were detected in the essential oils. Germacrene D (25%), Caryophyllene (20%), α-Zingiberene (15%) and Borneol (11%) represent the major components of leaf oil, while the buds were rich in 1,8-Cineole (32%), Camphor (16%), Borneol (9%), and Caryophyllene (5%). trans -2-Hexenal was also detected in the aerial parts of the plant. α-Zingiberene and trans -2-Hexenal have not been previously reported for Artemisia vulgaris L. The major analytes are compared to those from Artemisia vulgaris L, originating outside of the United States.
Identification of the analytes present in the volatile portion of a number of confectionaries was made using solid phase microextraction in combination with gas chromatography mass spectroscopy. This represents a first step in formulating a database of confectionary volatiles, which considering the recent problems with food adulteration should prove useful.
In the study of thioanhydrides, a fast, simple, and cost effective means of producing thioanhydrides is necessary being that commercially available thioanhydrides are limited. A simple method of converting an anhydride into a thioanhydride involves the use of sodium sulfide. In general, this method of thioanhydride synthesis is effective in producing a substantial yield of thioanhydride from the conjugate anhydride. However, in the case of itaconic anhydride, this method seems to fail. By monitoring the reaction of itaconic anhydride with sodium sulfide using 1 H NMR spectrometry, Raman spectrometry, and IR spectrometry, it is clear that the resulting product is not the expected itaconic thioanhydride, but is instead citraconic anhydride, an isomer of itaconic anhydride. While this isomerization reaction has been recorded using nitrogen-based compounds, this is the first instance in which sodium sulfide has been recorded as a catalyst in the isomerization of itaconic anhydride to citraconic anhydride.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSyntheses of cyclic bisthioacylals. 1,3-dithiane-4,6-diones and 1,3-dithiolane-4,5-dioneJ. Herman Schauble, William A. Van Saun Jr., and Jack D. WilliamsCite this: J. Org. Chem. 1974, 39, 20, 2946–2950Publication Date (Print):October 1, 1974Publication History Published online1 May 2002Published inissue 1 October 1974https://pubs.acs.org/doi/10.1021/jo00934a002https://doi.org/10.1021/jo00934a002research-articleACS PublicationsRequest reuse permissionsArticle Views221Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of 1,2-dithiolane-3,5-diones and thietane-2,4-dionesJ. Herman Schauble and Jack D. WilliamsCite this: J. Org. Chem. 1972, 37, 15, 2514–2516Publication Date (Print):July 1, 1972Publication History Published online1 May 2002Published inissue 1 July 1972https://pubs.acs.org/doi/10.1021/jo00980a036https://doi.org/10.1021/jo00980a036research-articleACS PublicationsRequest reuse permissionsArticle Views132Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts