72057-07-9Relevant articles and documents
Germacrenes from fresh costus roots
De Kraker, Jan-Willem,Franssen, Maurice C.R,De Groot, Aede,Shibata, Toshiro,Bouwmeester, Harro J
, p. 481 - 487 (2001)
Four germacrenes, previously shown to be intermediates in sesquiterpene lactone biosynthesis, were isolated from fresh costus roots (Saussurea lappa). The structures of (+)-germacrene A, germacra-1(10),4,11(13)-trien-12-ol, germacra-1(10),4,11(13)-trien-12-al, and germacra-1(10),4,11(13)-trien-12-oic acid were deduced by a combination of spectral data and chemical transformations. Heating of these compounds yields (-)-β-elemene, (-)-elema-1,3,11(13)-trien-12-ol, (-)-elema-1,3,11(13)-trien-12-al, and elema-1,3,11(13)-trien12-oic acid respectively, in addition to small amounts of their diastereomers. Acid induced cyclisation of the germacrenes yields selinene, costol, costal, and costic acid respectively. It is highly probable that the elemenes reported in literature for costus root oil are artefacts.
Hydroxylation of sesquiterpenes by enzymes from chicory (Cichorium intybus L.) roots
De Kraker, Jan-Willem,Schurink, Marloes,Franssen, Maurice C. R.,K?nig, Wilfried A.,De Groot, Aede,Bouwmeester, Harro J.
, p. 409 - 418 (2007/10/03)
A microsomal enzyme preparation of chicory roots catalyses the hydroxylation of various sesquiterpene olefins in the presence of NADPH. Most of these hydroxylations take place at an isopropenyl or isopropylidene group. The number of products obtained from any of the substrates is confined to one or, in a few cases, two sesquiterpene alcohols. In addition, the conversion of (+)-valencene into nootkatone through β-nootkatol was observed. The involvement of (+)-germacrene A hydroxylase (a cytochrome P450 enzyme) and other enzymes of sesquiterpene lactone biosynthesis in these reactions is discussed.
Functionalization of trans-Decalin. IV. A Stereoselective Synthesis of dl-β-Costol, dl-Arctiol, and the Related Eudesmane Type Sesquiterpenes
Torii, Sigeru,Inokuchi, Tsutomu
, p. 2642 - 2646 (2007/10/02)
The efficient synthetic procedures to dl-β-costol (1a), dl-arctiol (2), and the related eudesmane type sesquiterpenes are described. trans-8,8-Ethylenedioxy-4aβ-methyldecalin-2α-ol (6a), prepared from trans-1,1-ethylenedioxy-4aβ-methyl-Δ6,7-octalin by epoxydation and subsequent reduction of the epoxy ring, was converted into 1a as follows: (1) deacetalization of 6a followed with mesylation, giving 2α-methylsulfonyloxy-4aβ-methyldecalin-8-one (7b), (2) condensation of 7b with methyl sodiomalonate and subsequent Wittig reaction with methylenetriphenylphosphorane affording dimethyl (trans-4aβ-methyl-1-methylene-7β-decalinyl)malonate (9), (3) reduction of sodium salt of 9 with NaAl(OCH2CH2OMe)2H2.Oxidation of 1a with PCC gave dl-β-costal. dl-Arctiol (2), structurally related to 1a, was prepared from trans-5,5-ethylenedioxy-8aβ-methyldecalin-2-one.Introduction of two equatorial substituents, such as hydroxyl and 1-hydroxy-1-methylethyl groups at the C-2 and C-3 carbons of 2, was carried out as follows:(1) methoxycarbonylation followed by methylation of the sodium salt of keto ester with MeLi, (2) subsequent reduction with lithium in liquid NH3, giving trans-5,5-ethylenedioxy-3β-(1-hydroxy-1-methylethyl)-8aβ-methyldecalin-2α-ol (14), and (3) deacetalization of 14 followed by the reaction with methylenetriphenylphosphorane. dl-Eudesma-4(14,7(11)-dien-8-one was also prepared from 2 by oxidation with PCC followed by dehydration and subsequent isomerization of double bond.
