Cytotoxic Diterpenoids from the Brown Alga Dilophus ligulatus

Abstract

A new xenicane-type diterpene, dilopholide [5], and four known diterpenoids, acetoxycrenulide [1], acetylcoriacenone [2], and its epimer isoacetylcoriacenone [3], and hydroxyacetyldictyolal [4], have been isolated from the brown alga Dilophus ligulatus [syn. spiralis (Montagne) Hamel]. The structure of dilopholide [5] was elucidated by spectroscopic methods, including the concerted application of a number of 2D nmr techniques, including 1H-1H COSY, heteronuclear proton-carbon chemical shift correlation (HETCOSY), and long-range HETCOSY. The cytotoxic activity of compounds 1-5 has been examined against several types of mammalian cells: human nasopharynx carcinoma cells (KB), human lung carcinoma cells (NSCLC-N6), murine leukemia cells (P-388), and murine leukemia cells expressing the multi-drug-resistance gene, mdr (P-388/DOX).

Diterpenes From the Marine Brown Algae of the Genus Dilophus

“…Two cytotoxic diterpenes possessing a cyclobutenone moiety [4,5], named acetylcoriacenone (118) and isoacetylcoriacenone (119), have been isolated from the brown alga D. ligulatus collected from the Bay of Villefranche-sur-Mer, France. 9 Compound 118 exhibits powerful cytotoxic activity against P-388 and NSCLC-N6 cells with ED 50 values of 4.4 and 5.4 µg/mL, respectively. Compound 119 shows cytotoxic activity against P-388 and NSCLC-N6 cells with ED 50 values of 6 and 6.82 µg/mL, respectively.…”

Cytotoxic Xenicane Diterpenes from the Brown Alga Padina pavonia (L.) Gaill.

“…Xenicanes are a class of diterpenes and norditerpenes (Faulkner, 1993) which have been isolated not only from many brown algae belonging to the family Dictyotaceae (Finer et al, 1979;Enoki et al, 1982;Shono and Kashimura, 1983;Pathirana and Andersen, 1984;Ishitsuka et al, 1982Ishitsuka et al, , 1988Norte et al, 1990;König et al, 1991aKönig et al, , 1991bBouaïcha et al, 1993aBouaïcha et al, , 1993bPatil et al, 1993;Siamopoulou et al, 2004) but also from soft corals and gorgonians (Faulkner, 2000). Some of them showed interesting biological activities including cytotoxicity (Ishitsuka et al, 1988;Bouaïcha et al, 1993aBouaïcha et al, , 1993bRho et al, 2001) and antimicrobial (Iwagawa et al, 1996).…”

“…Some of them showed interesting biological activities including cytotoxicity (Ishitsuka et al, 1988;Bouaïcha et al, 1993aBouaïcha et al, , 1993bRho et al, 2001) and antimicrobial (Iwagawa et al, 1996). Some constituents have been isolated from the brown alga Padina pavonia (L.) Gaill.…”

Slightly polar secondary metabolites from the far-eastern brown alga Dictyota dichotoma

“…They were identified as 18-hydroxy-3,7-dolabelladiene (1) [3], dictyolactone (2) [4], dilopholide (3) [5], and dictyotin B (4) [6]. Diterpenoids 2 and 3 were isolated for the first time from D. dichotoma.…”

“…Diterpenoids 2 and 3 were isolated for the first time from D. dichotoma. They were previously known as secondary metabolites of the algal-toxic mollusk Aplysia depilans [4] and brown alga Dilophus ligulatus [5], respectively. Recently 2 was isolated from the alga Dilophus okamurae [7].…”