Helga Marschall

Constituents of commercial Labdanum oil

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 C15 to C20 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. C9→C14compounds: 2,2,5-trimethyloxepan-4-one (30), cis-p-menth-4(8)-en-2-ol (40), (2E,4E)-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-2H-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).

Constituents of Haitian vetiver oil

155 constituents in the neutral part of commercial Haitian vetiver oil were identified. Their structures were assigned mainly by 1H- and 13C-NMR spectra, as reported previously. Furthermore, the following new compounds are described: acora-2,4-diene (7) and its 10-epimer (8), 3-isopropyl-2-(3-methylcyclopent-2-enyl)-tetrahydrofuran (4), 3-isopropyl-6-methyl-2-(3-methylcyclopent-2-enyl)-3,4-dihydro-2H-pyran (15) and its precursor 6-hydroxy-3-isopropyl-6-methyl-2-(3-methycyclopent-2-enyl)-3,4,5,6-tetrahydr-2H-opyran (D), 12,13-di-nor-6(7←8)-abeo-eremophil-1(10)-en-7-one (16), 8α-methyl-11,12,13-tri-nor-eremophil-1(10)-en-7-one (20), eudesma-5,7-dien-4-ol (cascarilladienol, 50), 13-nor-7,8-epoxy-eremophil-1(10)-en-11-one (98), eremophil-7(11)-en-10β-ol (111), 7,11-epoxy-eremophila-1,9-dien-8α-ol (124), two epimers of 6,12;7,11-diepoxy-eudesm-4-ene (125, 128) and of 7,11;8,12-diepoxy-eremophil-9-ene (129, 137). NMR data of β-vetispirene (18), γ-amorphene (22), β-vetivenene (48), elema-1,3-dien-6α-ol (6-epi-shyobunol, 32), eudesm-4(15)-en-5β-ol (69), trans-eudesma-4(15),7-dien-12-yl formate (vetiselinenyl formate, 127), ziza-6(13)-en-12-yl acetate (142), preziza-7(15)-en-12-yl acetate (143), methyl (E)-eremophila-1(10),7(11)-dien-12-oate (139) and (E)-eremophila-1(10),7(11)-dien-12-yl (isovalencenyl acetate, 144) are described. The contribution of some constituents to the very complex odour of vetiver oil is discussed. Copyright

Constituents of commercial Brazilian lantana oil

The constituents of the commercial Brazilian lantana oil are mainly bisabolene derivatives, altogether about 65%. The following new natural compounds were characterized by their 1H-NMR and partly 13C-NMR data: 1,12-epoxycadina-3,11-dienes (37, 40), helifolen-15-als (38/39), acora-2,4(15)-dien-11-ol (44), (E)-sesquithujen-12-al (47) and -12-ol (54), italicen-15-al (2,11-cycloacor-3-en-15-al, 52), the 6,10-epoxybisabolen-12-als 49, 50, 53, 58, 60/61, ar-curcumen-15-al (62) and its 10,11-epoxides 76/77, epi-α-bisabolone (69), methyl (E)-trans-α-bergamota-2,10-dien-12-oate (74) and its 2,3-epoxide 80. The so-called helifolen-12-als 35, 36, 42, 43, which were trace constituents of the Iranian Pulicaria gnaphalodes oil, belong to the main constituents (together 7.2%) of the Lantana oil. NaBH4 reduction of 35, 36, 42, 43 yielded the helifolen-12-ols A–D. Their structure was elucidated by NOED and HMBC experiments and an X-ray analysis of the p-bromobenzenesulphonate of helifolen-12-ol D. The helifolen-12-ols A–D are racemates. Therefore, a biogenetic pathway via a bisaboladienyl and an acorenyl cation to the helifolen-12- (35, 36, 42, 43) and -15-als (38/39) is proposed. Copyright

Analysis of the polar fraction of Haitian vetiver oil

The polar part of commercial Haitian vetiver oil was converted to the methyl ethers, and this product separated by distillation and repeated flash chromatography (FC). The following new (nor-) sesquiterpene alcohols were isolated as their methyl ethers and identified by their 1H- and 13C-NMR spectra: 12-nor-ziza-6(13)-en-2β- (2) and -2α-ol (3), eudesma-4(15),7-dien-3β- (7) and -2β-ol (18), eudesma-3,5-dien-1α-ol (26), eremophila-1(10),4(15)-dien-2α-ol (31), eremophila-1(10),11-dien-2α-ol (nootkatol, 38), guaia-1(5),11-dien-3-ol (11), spirovetiva-3,7(11)-dien-12-ol (42), preziza-7(15)-en-3α-ol (14) and helifol-1-en-14-ol (syn. khusien-14-ol, 12). Furthermore, the hemi-acetal 7,10-epoxy-salvialan-10-ol (8) was identified. The structure of some artefacts formed by alkylation of β-vetivone 52 (→M 39, M 43) and of 11,12,13-tri-nor-eudesmenone (→16, 17) was also elucidated. Copyright

Constituents of the essential oil from the rhizomes of Hedychium gardnerianum Roscoe

The essential oil from the rhizomes of Hedychium gardnerianum Roscoe (‘Kahili ginger’) contains about 30% of sesquiterpenes, mainly cadinane derivatives. The following new sesquiterpenes were identified by their NMR and MS data: α-corocalene epoxide (104); 1,10;7,10-bisepoxy-1,10-seco-calamenene (68); 6,7;7,10-bisepoxy-6,7-seco-calamenene (74); 7-epi-trans- (60) and 7-epi-cis-sesquisabinene hydrate (69); 10-epi-cubenol (78); and ar-curcumen-1,10-diol (108). Copyright

Constituents of the essential oil of Tanacetum (syn. Chrysanthemum) fruticulosum Ledeb. from Iran

The essential oil of Tanacetum (syn. Chrysanthemum) fruticulosum Ledeb. from Iran was investigated by GC, GC–MS and NMR spectroscopy. The oil is characterized by photo-oxidation products of lavandulol and nerolidol. Ninety-seven components, representing 93% of the oil, could be identified. The oil contains mainly monoterpenes [1,8-cineole (8), camphor (12), lavandulol (13), lavandulyl acetate (25)]. The new 5-isopropenyl-2,2-dimethyltetrahydrofuran-3-yl-methyl acetates (30, 31) are trace constituents. Some new farnesyl derivatives [3,6;6,9-bisepoxyfarnesa-1,7(14),10-trienes (43, 44, 48, 49), 7,10-epoxyfarnesa-1,5,11-trien-3-ols (63, 64), 6,9-epoxyfarnesa-1,7(14)10-trien-3-ols (80–83)] were identified by their NMR spectra. Copyright

CAMEROONANE, PRENOPSANE AND NOPSANE, THREE NEW TRICYCLIC SESQUITERPENE SKELETONS

The strong patchouli-like and woody smelling essential oil of the rhizomes of Echinops giganteus var. lelyi C. D. Adams (Compositae) contains only sesquiterpenes, which are mainly triquinanes. Besides the known tricyclic compounds, silphiperfol-5- (1, 3) and -6-ene (4), modhephen-2-ene (5), α- (6) and β-isocomene (7), silphiperfolan-7β-ol (12), presilphiperfolan-8-ol (13), silphiperfol-6-en-5-one (14) and 7-epi-silphiperfolan-6β-ol (20), the following compounds, three of which (15, 17, 18) have new skeletons, were found, for the first time, occurring naturally: presilphiperfol-7-ene (2), cameroonan-7-ol (15), an 11(78)-abeo-presilphiperfolan-7-ol, prenopsan-8-ol (17), a 1(87)-abeo-cameroonan-8-ol, and nopsan-4-ol (18), a 3(48)-abeo-prenopsan-4-ol, three diastereomers of silphiperfolan-6-ol (19, 21, 22), modheph-2-en-8-ol (23) and silphiperfola-4,7(14)-diene (24). All structures were elucidated by NMR spectroscopy. A biogenetic pathway from a presilphiperfolane cation C to the cameroonane K, prenopsane L and nopsane M cations is shown. Cameroonanol (15) and prenopsanol (17) are the main contributors to the fragrance of the total oil.

1,7‐Cyclogermacra‐1(10),4‐dien‐15‐al, a sesquiterpene with a novel skeleton, and other sesquiterpenes from Haitian vetiver oil

A medium polar part of commercial Haitian vetiver oil was investigated, particularly with regard to carbonyl compounds. The following new natural compounds were characterized by their NMR data: 1,7-cyclogermacra-1(10),4-dien-15-al (1); 10-epi-acor-3-en-5-one (3); 10-epi-acora-3,11-dien-15-al (4); (E)-opposita-4(15),7(11)-dien-12-al (6); 13-nor-opposit-4(15)-en-11-one (8); 7-epi-cis-dracunculifoliol (ax-4(15)-en-7-ol, 11); elema-1,11-dien-15-al (2 epimers, 12a,b); 6,12-epoxyelema-1,3-diene (14); eremophila-1(10), 6-dien-12-al (2 epimers, 15a,b); 15-nor-funebran-3-one (24); 7,15-epoxyprezizaane (31); 15-nor-prezizaan-7-one (33); 12-nor-preziza-7(15)-en-2-one (35, presumable structure); prezizaan-15-al (46); cyclocopacamphan-12-al (2 epimers, 57a,b); 5,6-seco-6,7-furoeudesman-5-one (59); 11,12,13-tri-nor-cis-eudesm-5-en-7-one (61a); 11,12,13-tri-nor-cis-eudesma-5,8-dien-7-one (62); 13-nor-eudesm-5-en-11-one (2 epimers, 63a,b); and 13-nor-trans-eudesma-4(15),7-dien-11-one (67). Two oxiranes, 13-nor-4,5-epoxyeudesm-6-en-11-one (66) and 13-nor-7,8-epoxy-trans-eudesm-4(15)-en-11-one (68), which were also isolated, might be artefacts. The polar part of the oil was converted to the methyl ethers. Distillative and chromatographic separation furnished, among others, β-funebrenyl methyl ether 23′, prezizaenyl methyl ether 50′, khusimyl methyl ether 51′, and cyclocopacamphanyl methyl ethers 58a′,b′ (epimers). Thus, the existence of the new alcohols β-funebren-14-ol (23) and prezizaen-12-ol (50) was established. The formerly described configurations of the prezizaane derivatives jinkohol, jinkohol II and jinkoholic acid are formulated as the 2-epi-compounds 45, 48 and 49. Copyright

Constituents of the essential oil of Pulicaria gnaphalodes (Vent.) Boiss. from Iran

The essential oil of Pulicaria gnaphalodes (Vent.) Boiss. from Iran was investigated by GC, GC–MS and NMR spectroscopy. Typical for this oil are pinane [chrysanthenone (23), cis-chrysanthenol (34)], cadinane [cadina-1(10),4-dien-8α-ol (114)] and bisabolane derivatives [nuciferol (118), γ-curcumen-12-ol (119)]. New, naturally occurring compounds are (Z)-3-methylnon-3-en-2-one (43), the so-called helifolen-12-als 94, 95, 98, 99, tricyclic sesquiterpene aldehydes with a helifolane (syn. allo-cedrane or khusiane) skeleton, and the italicen-12-ols 108 and 110. These aldehydes and alcohols are presumably formed by [4+2] resp. [2+2] cycloaddition of the corresponding γ-curcumene derivatives. Copyright

Constituents of the Essential Oil of Achillea eriophora DC.

Ninety constituents (98%) of the essential oil of the leaves and flowers of Achillea eriophora DC. (Compositae) were identified. The main constituents are 1,8-cineole (34%) and the pinenes (13%). The oil contains only 7% of sesquiterpenes, mainly caryophyllene derivatives. Three new farnesol derivatives were isolated as trace constituents. The structures were confirmed by 1H- and 13C-NMR data.