Soft corals eleutherobin

The natural product eleutherobin (1) was isolated in 1994 by Fenical et al. from a marine soft coral from an Eleutherobia species and its structure was elucidated shortly afterwards (Figure 1) [1]. Eleutherobin is a diterpene glycoside that possesses remarkable cytotoxicity against a wide variety of cancer cells, which is likely to be based on binding to tubulin and stabilization of microtubules [2, 3]. Mitosis is interrupted and the cell division cycle is terminated. The mechanism of action of eleutherobin is comparable to that of highly potent cytostatic agents such as paclitaxel (Taxol), nonataxel, epothilones, and discodermolide. 

The literature of Cnidara includes 2444 articles comprised of 3744 chemical structures.27 Included within this impressive list is the commercially available diterpenoid glycosides, the pseudopterosins,369,370 with remarkable antiinflammatory and analgesic properties, eleutherobin and the sarcodyctins. Figure 6.6 shows that study within Cnidaria has focused on two orders, that of the soft corals, the Alcyonacea and the Gorgonacea. 

Scheme 6.3 illustrates a few of the main structural classes of soft coral compounds. Included in this list are the tubulin interactive agents, eleutherobin 41 and sarcodictyin A 42, which show nanomolar potency against cancer cell lines. Also of interest are the pseudopterosin A 44 terpenoids which reduce inflammation. Two other terpenoids, sarcophytol A 43 and sinulodurin A 45, have shown micromolar activity against BALB/3T3 and mammary epithelial cells respectively. 

The diterpene glycoside eleutherobin 41373 374 was isolated from the soft coral Eleutherobia sp. collected from Bennett s shoal in Western Australia. Eleutherobin, along with the erythrolides A and B, has also been found in the... 

Overman et al. were the first to synthesize the eunicellane carbon skeleton [20]. In contrast to eleutherobin (1), (-)-7-deacetoxyalcyonin acetate (45) from the marine soft coral Cladiella sp. [21] shows the oxygen bridge between C2 and C9 instead of C4 and C7. Starting from 5(+)-carvone, an elegant Prins-pinacol conden-... 

The anti-mitotic diterpene Eleutherobin (35) and Sarcodictyins A - D (36a-d) are structurally related, natural compounds isolated from the marine soft coral Eleutherobia spec, and Sarcodictyon roseum,... 

Eleuthosides. Marine natural products from soft corals (Eleutherobia albiflora) which exhibit stroM cytotoxic and anticancer properties with a taxol -like mechanism of action (tubulin polymerization and microtubule stabilization). Most active is eleutherobin, first isolated in 1994 C35H48N2OK), Mr 656.76, [a] -67° (CH3OH), oil. Closely related are E. A and B from... 

The most fascinating aspect of the chemistry of eleutherobin is that it was shown in 2001 that this molecule (patented, synthesized and entered into in preclinical testing as an antimitotic agent in the past decade) is actually an artifact of the extraction of the soft coral Erythropodium carihaeorum (Britton et al, 2001). Starting... 

Extraction from large quantities of this soft coral yielded, in the less-polar phase, the aglycone of eleutherobin accompanied by three other derivatives, caribaeorane, 15-hydroxycaribaeorane and methylcaribaeorane (Britton... 

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