| Title: | Isolation of the major chiral compounds from Bubonium graveolens essential oil by HPLC and absolute configuration determination by VCD |
| Author(s): | Said ME; Bombarda I; Naubron JV; Vanloot P; Jean M; Cheriti A; Dupuy N; Roussel C; |
| Address: | "Aix-Marseille Universite, EA4672 LISA Equipe METICA, Marseille, France. Aix-Marseille Universite, CNRS FR1739 Spectropole, Marseille, France. Aix-Marseille Universite, CNRS, Centrale Marseille, iSm2, Marseille, France. Phytochemistry and Organic Synthesis Laboratory, University of Bechar, Bechar, Algeria" |
| ISSN/ISBN: | 1520-636X (Electronic) 0899-0042 (Linking) |
| Abstract: | "The chirality issues in the essential oils (EOs) of leaves and flowers from Bubonium graveolens were addressed by chiral high-performance liquid chromatography (HPLC) with polarimetric detection and vibrational circular dichroism (VCD). The chemical compositions of the crude oils of three samples were established by gas chromatography / mass spectrometry (GC/MS). The well-known cis-chrysanthenyl acetate (1), oxocyclonerolidol (2), and the recently disclosed cis-acetyloxychrysanthenyl acetate (3), the three major chiral compounds, were isolated by preparative HPLC. The naturally occurring oxocycloneroledol (2), mostly found in the leaf oil (49.4-55.6%), presents a (+) sign in the mobile phase during HPLC on a chiral stationary phase (CSP) with a Jasco polarimetric detection. The naturally occurring cis-chrysanthenyl acetate (1) and cis-acetyloxychrysanthenyl acetate (3), mostly found in the flower EO (35.9-74.9% and 10.0-34.3%, respectively), both present a (-) sign. HPLC on a CSP with polarimetric detection is an unprecedented approach to readily differentiate the flower and leaf EOs according to their chiral signature. The comparison of the experimental and calculated VCD spectra of pure isolated 1, 2, and 3 provided their absolute configuration as being (1S,5R,6S)-(-)-2,7,7-trimethylbicyclo[3.1.1]hept-2-en-6-yl acetate 1, (2R,6R)-(+)-6-ethenyl-2,6-dimethyl-2-(4-methylpent-3-en-1-yl)dihydro-2H-pyran-3(4H)-one) 2 and (1S,5R,6R,7S)-(-)-7-(acetyloxy)-2,6-dimethylbicyclo[3.1.1]hept-2-en-6-yl]methyl acetate 3. Compounds 1, 2, and 3 were already known in B. graveolens but this is the first report of the absolute configuration of (+)-2 and (-)-3. The VCD chiral signatures of the crude oils were also recorded" |
| Keywords: | "Bridged Bicyclo Compounds/chemistry/*isolation & purification Chromatography, High Pressure Liquid Circular Dichroism Gas Chromatography-Mass Spectrometry Monoterpenes/chemistry/*isolation & purification Oils, Volatile/*chemistry Stereoisomerism Bubonium;" |
| Notes: | "MedlineSaid, Mohammed El-Amin Bombarda, Isabelle Naubron, Jean-Valere Vanloot, Pierre Jean, Marion Cheriti, Abdelkrim Dupuy, Nathalie Roussel, Christian eng 2016/12/27 Chirality. 2017 Feb; 29(2):70-79. doi: 10.1002/chir.22672. Epub 2016 Dec 26" |
