Wei Hsien Wang

Survey of briarane-type diterpenoids - Part IV

The structures, names, biological activities, and references of 137 briarane-type diterpenoids are summarized. All briaranes mentioned in this review article were obtained from various octocorals including the specimens belonging to the genus Briareum, Ellisella, Gorgonella, Junceella, Subergorgia, Renilla, and Pachyclavularia.

Klysimplexins I–T, eunicellin-based diterpenoids from the cultured soft coral Klyxum simplex

New eunicellin-base diterpenoids, klysimplexins I-T (1-12), were isolated from a cultured soft coral Klyxum simplex. Their structures were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The absolute stereochemistry of 4 was determined by Moshers method. Compounds 9 and 12 have been shown to exhibit cytotoxicity toward a limited panel of cancer cell lines. Compounds 2-6, 10 and 11 were found to display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein. Compounds 10 and 11 also could effectively reduce the level of COX-2 protein.

Cladielloides A and B: New Eunicellin-Type Diterpenoids from an Indonesian Octocoral Cladiella sp.

Two new eunicellin-type diterpenoids, cladielloides A (1) and B (2), which were found to possess a 2-hydroxybutyroxy group in their structures, were isolated from an Indonesian octocoral identified as Cladiella sp. The structures of eunicellins 1 and 2 were elucidated by spectroscopic methods. Cladielloide B (2) exhibited moderate cytotoxicity toward CCRF-CEM tumor cells and this compound displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils.

Excavatoids E and F: discovery of two new briaranes from the cultured octocoral Briareum excavatum.

Two new briarane-related diterpenoids, designated as excavatoids E (1) and F (2), were isolated from the cultured octocoral Briareum excavatum. The structures of compounds 1 and 2 were established on the basis of extensive spectral data analysis. Briaranes 1 and 2 were found to exhibit moderate inhibitory effects on elastase release by human neutrophils.

Briarane Diterpenoids Isolated from Gorgonian Corals between 2011 and 2013

The structures, names, bioactivities and references of 138 briarane-type diterpenoids, including 87 new compounds, are summarized in this review. All the briarane-type compounds mentioned in this review article were obtained from gorgonian corals including the genus Briareum, Dichotella, Junceella and Verrucella. Some of these compounds showed potential bioactivities.

Carijoside A, a bioactive sterol glycoside from an octocoral Carijoa sp. (clavulariidae)

A new bioactive sterol glycoside, 3β-O-(3′,4′-di-O-acetyl-β-d-arabinopyranosyl) -25ξ-cholestane-3β,5α,6β,26-tetrol-26-acetate) (carijoside A, 1), was isolated from an octocoral identified as Carijoa sp. The structure of glycoside 1 was established by spectroscopic methods and by comparison with spectral data for the other known glycosides. Carijoside A (1) displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils and this compound exhibited moderate cytotoxicity toward DLD-1, P388D1, HL-60, and CCRF-CEM tumor cells.

Cembrane Derivatives from the Soft Corals, Sinularia gaweli and Sinularia flexibilis

A new norcembranoidal diterpene, 1-epi-sinulanorcembranolide A (1), and a new cembranoidal diterpene, flexibilin D (2), were isolated from the soft corals, Sinularia gaweli and Sinularia flexibilis, respectively. The structures of new metabolites 1 and 2 were elucidated by spectroscopic methods, and compound 2 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 proteins of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. In addition, S. flexibilis yielded a known cembrane, 5-dehydrosinulariolide (3); the structure, including its absolute stereochemistry, was further confirmed by single-crystal X-ray diffraction analysis.

Natural product chemistry of gorgonian corals of genus Junceella--part II.

The structures, names, bioactivities, and references of 81 new secondary metabolites obtained from gorgonian corals belonging to the genus Junceella are described in this review. All compounds mentioned in this review were obtained from sea whip gorgonian corals Junceella fragilis and Junceella juncea, collected from the tropical and subtropical Indo-Pacific Ocean.

Bioactive Compounds from a Gorgonian Coral Echinomuricea sp. (Plexauridae)

A new labdane-type diterpenoid, echinolabdane A (1), and a new sterol, 6-epi-yonarasterol B (2), were isolated from a gorgonian coral identified as Echinomuricea sp. The structures of metabolites 1 and 2 were elucidated by spectroscopic methods. Echinolabdane A (1) possesses a novel tetracyclic skeleton with an oxepane ring jointed to an α,β-unsaturated-γ-lactone ring by a hemiketal moiety, and this compound is the first labdane-type diterpenoid to be obtained from marine organisms belonging to the phylum Cnidaria. 6-epi-Yonarasterol B (2) is the first steroid derivative to be isolated from gorgonian coral belonging to the genus Echinomuricea, and this compound displayed significant inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils.

Rumphellaones B and C, New 4,5-Seco-Caryophyllane Sesquiterpenoids from Rumphella antipathies

Two new 4,5-seco-caryophyllane sesquiterpenoids, rumphellaones B (1) and C (2), which were found to possess unprecedented γ-lactone moieties, were obtained from the gorgonian coral Rumphella antipathies. The structures of 1 and 2 were elucidated by spectroscopic methods and compound 2 was found to display modest inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils at a concentration of 10 μg/mL.