Saussurea lactone

Rrominalive cyclization. Treatment of either costunolide (I) or deydro-saussurea lactone (2) with NBS in aqueous acetone at 20° results in the cyclized hromo lactones 3, 4, and 5, in approximately the same ratio from both substrates.3... 

A total synthesis of ( )-temisin (439) from the known acetal-ketone (438) (Scheme 43) and n.m.r. analysis at 250 MHz have confirmed the structure and established the stereochemistry of this compound.An interesting new approach to the 2,3-secoeudesmanolide (elemanolide) framework has been sucessfully applied to the synthesis of saussurea lactone (442) cf. Vol. 8, p. 97). 

The synthesis of elemanolides from santonin requires cleavage of the C(2)-C(3) double bond. In a synthesis of saussurea lactone by Ando (Scheme 30) [41], cleavage of this bond was carried out by treatment of epoxymesylate 206 with aluminum isopropoxide, which afforded... 

In the saussurea lactone synthesis by Grieco (Scheme 31) [18], cleavage of the C(2)-C(3) link was carried out by ozonolysis of the C(2)-C(3) double bond in compound 247, obtained regioselectively from tetrahydrosantonin 3b by a Shapiro reaction, to give diol 51. Subsequent elimination of both hycftoxyl groups in several steps yielded saussurea lactone (56). An improvement of tWs procedure, described by our group [17], was based on the transformation of diol 51 into diselenide 52, which could then be transformed directly into saussurea lactone (56) (see Scheme 8). 

Fragmentation of an epoxy mesylate. The key step in a synthesis of the sesquiterpene lactone saussurea lactone (4) involved fragmentation of the epoxy mesylate (I), obtained from -santonin by several steps. When treated with aluminum isopropoxide in boiling toluene (N2, 72 hours), 1 is converted mainly into 3. The minor product (2) is the only product when the fragmentation is quenched after 12 hours. Other bases such as potassium r-butoxide, LDA, and... 

Cope Rearrangements.—Direct rearrangement of costunolide (197) to dehydro-saussurea lactone (198) is not possible because of the thermal instability of these compounds. However, the a-methylene lactone moiety can be protected as its P-dimethylamino derivative, the rearrangement carried out at 205—2I0°C, and the... 

Germacranes with trans,trans 1,5-diene system are thermally labile and undergo Cope rearrangement to give products with elemane skeleton. Thus, costunolide (195) on heating gives saussurea lactone (205), albeit, in low yield. 

Rao A S, Paul A, Sadgopal, Bhattacharyya S C 1961 Terpenoids. XXV. Structure of saussurea lactone. Tetrahedron 13 319-323... 

Saussurea lactone C15H22O2 Frullania inflata J 45) GC-MS Artefact... 

Dehydrosaussurea lactone P-Elemene a-Humulene Saussurea lactone... 

Dehydrocostus lactone Saussurea lappa (castus, mu xiang)... 

Robinson, A., T.V. Kumar, E. Sreedhar, et al. 2008. A new sesquiterpene lactone from the roots of Saussurea lappa Structure-anticancer activity study. Bioorg. Med. Chem. Lett. 18(14) 4015-4017. 

The S. A-E are components of the dried, Chinese Saussurea root (Saussurea costus, syn. 5. lappa) which is used in Chinese and Japanese traditional medicine for stomach complaints. S. A, C20H29NO4, Mr 347.45, mp, 115-117°C, [a]i3 +36.7° (CH3OH), corresponds to the Michael adduct from costunolide and proline S. B and C represent the amino acid conjugates of proline and asparagine, respectively, with the corresponding a, 8-unsaturated dehydrocostus lactone. In animal experiments, S. A exhibits a pronounced protective effect against stress-induced stomach ulcers. 

Sesquiterpene lactone isolated from the Compositae plant Saussurea lappa. Costunolide is present in the plant together with dehydrocostus lactone... 

Dehydrocostus lactone (249), inhibitors of nitric oxide synthases and TNF-a, isolated from Saussurea radix, was incubated with C. echinulata to afford (+) lla,13 diltydrodel drocostuslactone (250a). The epoxide (251) and a Cll reduced compound (250) were obtained by the aforementioned microorganisms (Galal, 2001). 

Costunolide (165), a very unstable sesquiterpene y-lactone, from Saussurea radix, was treated in Aspergillus niger to produce three dihydrocostunolides (166-168) (Clark and Hufford, 1979). Costunolide is easily converted into eudesmanolides (169-172) in diluted acid, thus 166-168 might be biotransformed after being cyclized in the medium including the microorganisms. If the crude... 

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