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Constituents of commercial Labdanum oil
Author(s) -
Weyerstahl Peter,
Marschall Helga,
Weirauch Marlies,
Thefeld Katrin,
Surburg Horst
Publication year - 1998
Publication title -
flavour and fragrance journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 70
eISSN - 1099-1026
pISSN - 0882-5734
DOI - 10.1002/(sici)1099-1026(1998090)13:5<295::aid-ffj751>3.0.co;2-i
Subject(s) - chemistry , labdane , octane , stereochemistry , essential oil , terpenoid , organic chemistry , chromatography
Commercial Labdanum oil contains more than 300 constituents. 186 compounds (154 from the neutral part, 32 from the acidic part), representing about 95% of the oil, were identified mainly by their NMR spectra. Typical for the Labdanum oil in the C 15 to C 20 region are aromadendrane (23%), cadinane (9%) and labdane (7%) derivatives, mostly oxidized. The main constituents in this region are ledene ( 92 , 9.3%), allo ‐aromadendrene ( 86 , 1.5%), 1,5‐ cis ‐aromadendr‐9‐ene ( 91 , 1.4%), viridiflorol ( 112 , 4.3%), 1,2‐dehydroviridiflorol ( 104 , 1.4%), ledol ( 116 , 1.3%), palustrol ( 105 , 1.2%), the new cubeban‐11‐ol ( 113 , 4.1%), copaborneol ( 117 , 1.8%), and ambrox ® ( 137 , 1.4%). The following new natural compounds were isolated: 1. C 9 →C 14 compounds : 2,2,5‐trimethyloxepan‐4‐one ( 30 ), cis ‐p‐menth‐4(8)‐en‐2‐ol ( 40 ), (2 E ,4 E )‐6‐hydroxy‐2,6‐dimethylhepta‐2,4‐dienal ( 59 ), cis ‐5‐hydroxymentha‐1(6),8‐dien‐2‐one ( 71 ), 7‐acetyl‐2,2,6‐trimethylbicyclo[4.2.0]octane ( 72 ), 4,4,7a‐trimethyl‐1,4,5,6,7,7a‐hexahydro‐2 H ‐inden‐2‐one ( 83 ), 6‐acetyl‐5,8,8‐trimethylbicyclo[3.2.1]octan‐2,3‐dione ( 119 ), 1,1,5,6‐tetramethyl‐1,2‐dihydro‐ ( 89 ) and 1,1,5,6‐tetramethyl‐1,2,3,4‐tetrahydronaphthalene ( 95 ). 2. Sesquiterpenes : cubeb‐11‐ene ( 82 ), 1,2‐dehydroglobulol ( 106 ), 1‐ epi ‐3,4‐dehydroviridiflorol ( 110 ), 3,4‐dehydroglobulol ( 118 ), muurola‐4,10(14)‐dien‐1‐ol ( 120 ), 5‐ epi ‐ ( 130 ) and 1,10‐ seco ‐aromadendran‐1,10‐dione ( 132 ), 5,11‐epoxycadin‐1(10)‐en‐9‐ol ( 136 ), 10‐hydroxycalamenene‐8,9‐epoxide ( 140 ) as well as 9(10→1)‐ abeo ‐9‐hydroxy‐aromadendran‐10‐one ( 131 ) named by us as 9‐hydroxy‐ladanifer‐10‐one, possessing a new skeleton. 3. Labdane derivatives : 7‐ ( 145 ), 8‐ ( 143 ) and 8(17)‐15‐ nor ‐labdene ( 142 ). 4. From the acidic part : 3‐isobutenyl‐5‐methyl‐5‐vinylbutyrolactone ( M21 ), dimethyl ( Z )‐2‐ n ‐hexyl‐3‐methylbutendioate ( M24 ) and the two epimers of methyl 1,5,5‐trimethylbicyclo[4.1.0] heptan‐7‐carboxylate ( M16 , M,17 ). © 1998 John Wiley & Sons, Ltd.