Terracinolides A and B, Two Bishomoditerpene Lactones with a Novel Carbon Framework from Euphorbia terracina

Abstract

A methanolic extract of Euphorbia terracina L. has been shown to contain two peracylated polyhydroxy terpenoid lactones with a novel C(22) carbon framework. These metabolites, which have been named terracinolides A (1) and B (2), are based on the same parent compound, but differ in the nature of one of the acyl residues. This novel skeletal system is formally derived from the jatrophane framework by addition of a two-carbon fragment on C-17 (jatrophane numbering).

Jatrophane diterpenes from Euphorbia spp. as modulators of multidrug resistance in cancer therapy

“…ROESY spectra determined the location of a acetate and a isobutyrate at C-2 and C-6, respectively. The relative configuration of terracinolide J (11) was investigated by measurement of scalar and dipolar couplings as well as by comparison with literature data (Appendino et al 1998;Marco et al 1996Marco et al , 1997, and has been found identical to that of all known terracinolides isolated to date.…”

“…Compounds 14-17 and 19-20 were identified as the known terracinolides B, C, F, H, and 13a-OH terracinolide B and G, respectively, previously isolated from E. terracina and E. segetalis (Marco et al 1996(Marco et al , 1997(Marco et al , 1999. Compounds 11-20 are based on a 17-ethyl bis-homojatrophane framework, a skeleton previously found in E. terracina diterpenes (Marco et al 1996), from which it takes the name. Preliminary MS and NMR data of terracinolide J (11) suggested that this compound was a diterpenoid polyester with seven ester carbonyls, four acetates and two isobutyrates.…”

“…6). The segetane diterpenoids are the main constituents of Euphorbia segetalis ), a species that gave the name to the entire skeletal class, and have been previously isolated only from E. portlandica (Madureira et al 2006), and E. paralias collected in Turkey (Ö ksüz et al 1997), Spain (Marco et al 1996) and Egypt (Abdelgaleil et al 2001). Among the isolated compounds, pre-segetanin (42) has an unprecedented carbon skeleton, whose isolation provides a first insight into the biosynthesis of diterpenoids with a segetane skeleton.…”

Diterpenes from European Euphorbia Species Serving as Prototypes for Natural‐Product‐Based Drug Discovery

“…Phytochemical investigation of E. salicifolia resulted in the isolation of salicinolide ( 13 ), a new bishomojatrophane containing a C‐6–C‐9‐bonded eight‐membered lactone ring as a new structural feature. Structurally similar C 22 diterpenes, based on the 17‐ethyljatrophane skeleton, were isolated from other Euphorbia species ( E. terracina , E. segetalis and E. dendroides )18,54,55 but in these compounds (terracinolides and isoterracinolides) the lactones are formed through C‐5–OH and C‐3–OH, respectively.…”

Daphnane-Type Diterpene Orthoesters and their Biological Activities

“…T [29] x Stellera chamaejasme L. T [67] x Pimelea simplex F. Muell. T [72,78] x alkyldaphnanes, it is limited to acetyl residues, as in terracinolides from Euphorbia terracina L. [91]. From a structural standpoint, the occasional reduction of the 3-ketogroup is also noteworthy, and reminiscent of ingenane derivatives.…”