Biologically Important Eremophilane Sesquiterpenes from Alaska Cedar Heartwood Essential Oil and Their Semi-Synthetic Derivatives

Abstract

The essential oil of Alaska cedar heartwood is known to contain compounds which contribute to the remarkable durability of this species. While previous research has identified several compounds, a complete description of this oil has not been undertaken. In this research a profile of the oil is given in which the major components are identified by GC, isolation and spectroscopic techniques. The major components of the steam distilled essential oil were identified as nootkatin, nootkatone, valencene, nootaktene, carvacrol, methyl carvacrol, nootkatol (2), and eremophil-1(10),11-dien-13-ol (3). The last two compounds were isolated for the first time from Alaska cedar in this research. The absolute stereochemistry at C-2 of nootkatol was shown to have the (S) configuration using the Mosher ester method. Assignment of stereochemistry for valencene-13-ol (3) was established by synthesis from valencene (6). Finally, two related sesquiterpenoids were synthesized from nootkatone and valencene. These sesquiterpenoids were nootkatone-1,10-11,12-diepoxide (5) and valencene-13-aldehyde (4), respectively.

Insect Antifeedant and Ixodicidal Compounds from Senecio adenotrichius

“…The positive NOE effect of H a -C(1) with H-C(9) revealed the configuration of H-atoms H a -C(1) and H b -C(1). The NOE effects of H a -C(6) with Me (13) and b-Me (15); H b -C(6) with b-Me (14), allowed to determine the configuration of H-atoms H a -C(6) and H b -C 15.2 ppm), suggesting that the OH-C(7) had an a-configuration in 6 and a b-configuration in 7. Therefore, the structure of 7 was established as 7b-hydroxyeremophila-9,11-dien-8-one, a new natural product.…”

“…½a 20 D = +86.7 (c = 0.25, CHCl 3 ). EI-MS: 234 (100, M + ), 219 (7), 201 (22), 191 (5), 175 (28), 149 (35), 125 (18), 105 (19), 109 (15), 97 (55), 91 (40), 77 (17), 67 (13). HR-EI-MS: 234.1628 (M + , C 15 H 22 O 2 + ; calc.…”

“…½a 20 D = À110 (CHCl 3 ) [36] ). EI-MS: 333 (7, M + ), 316 (1), 289 (7), 274 (2), 246 (9), 220 (6), 150 (5), 138 (43), 136 (79), 120 (100), 108 (12), 106 (15), 95 (43), 94 (62), 93 (62), 80 (34), 53 (23). HR-EI-MS: 333.1521 (M + , C 18 H 23 NO 5 + ; calc.…”

“…Some eremophilanes have been reported as being insecticidal and acaricidal. Specifically, nootkatone, from Alaska cedar wood oil, had strong contact and repellent insecticidal and ixodicidal effects …”

Terpenoids of the Heartwood of Chamaecyparis Nootkatensis

“…Several compounds have been isolated and identified from the heartwood extract of AYC including two tropolone sesquiterpenoids-nootkatin [1,2] and chanootin [3]; four monoterpenoids-chamic acid, chaminic acid, carvacrol, methyl carvacrol [4,5]; and four eremophilane-type sesquiterpenoids-nootkatene, nootkatone, valencene [6,7] and valencene-13-ol [8]. This paper describes the isolation and characterization of two monoterpenoids (1, 2) and sesquiterpenoids (3, 4) from the methanolic extract of AYC heartwood (Table 1).…”