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A known polyoxygenated briarane, briaexcavatolide P (1), was isolated from a Formosan octocoral Briareum stechei. Moreover, the same species B. stechei, collected from Okinawan waters, yielded three chlorine-containing briaranes, including two new compounds, briastecholides B (2) and C (3) as well as a known analogue, briarenol R (4). The structures of 1–4 were established using spectroscopic methods. In addition, briarane 1 demonstrated anti-inflammatory activity in lipo-polysaccharide-induced RAW 264.7 mouse macrophage cells by suppressing the expression of inducible nitric oxide synthase (iNOS) protein.

In this review, 170 natural substances, including steroid, diterpenoid, sesquiterpenoid, peptide, prostaglandin, base, chlorolipid, bicyclolactone, amide, piperazine, polyketide, glycerol, benzoic acid, glycyrrhetyl amino acid, hexitol, pentanoic acid, aminoethyl ester, octadecanone, alkaloid, and a 53-kD allergenic component from octocorals belonging to genus Dendronephthya, were listed. Some of these compounds displayed potential bioactivities.

Five 8,17-epoxybriaranes, including three new compounds&mdash, briarenols I&ndash, K (1&ndash, 3), along with two known analogues, briaexcavatolide P (4) and briaexcavatin P (5), were isolated from the octocoral Briareum excavatum. The structures of briaranes 1&ndash, 3 were elucidated by spectroscopic methods, including 1D and 2D NMR studies and (+)-HRESIMS. Briarane 4 exerted inhibition effects on inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) release from RAW 264.7.

Six 6-chlorine-containing briarane analogues, including two new compounds, briarenols U (1) and V (2), as well as four known metabolites, solenolides B (3) and E (4); briaexcavatolide E (5); and brianolide (6) were isolated from an octocoral identified as Briareum stechei. The structures of compounds 1–6 were elucidated by using spectroscopic methods, and the stereochemistry of solenolide B (3) was revised. The absolute configuration of 6 was further determined by a single-crystal X-ray diffraction analysis. Briarane 1 was found to induce significant in vitro inflammatory activity in LPS-induced RAW264.7 macrophage cells by enhancing the expression of iNOS and COX-2 protein.

Chemical investigation of the octocoral Briareum stechei, collected in the Ie Island, Okinawa, Japan, resulted in the isolation of a new briarane-type diterpenoid, briastecholide A (1), as well as the previously reported metabolites, solenolide C (2) and briarenolide S (3). The structures of briaranes 1–3 were characterized through spectroscopic analysis, and the absolute configuration of 2 was corroborated by a single-crystal X-ray diffraction analysis. Briarane 3 exhibited bioactivity against the protein expression of inducible nitric oxide synthase (iNOS).

Chemical examination of Briareum excavatum, collected in the waters of Taiwan, led to the isolation of four briarane diterpenoids, including three known compounds, briarenol G (1), briaviolides Y (2), and Z (3), as well as a new metabolite, briarenol L (4). The absolute configuration of 1 was determined by a single-crystal X-ray diffraction analysis for the first time in this study and the structure of 4 was established on the basis of spectroscopic analysis. Briaranes 2 and 3 exerted inhibition effects on COX-2 and iNOS, respectively, release from RAW 264.7 macrophages.

Two known briarane diterpenoids, excavatolide C (1) and briacavatolide C (5), along with three new polyoxygenated analogues, briarenols F–H (2–4), have been isolated from the supercritical CO2 extraction of an octocoral identified as Briareum excavatum. The absolute configuration of 1 was determined by a single-crystal X-ray diffraction analysis for the first time and the structures of 2–5 were established by spectroscopic methods. Bioactivity study showed that briaranes 1, 4 and 5 showed inhibition effects on iNOS release from RAW264.7.

Three new 8-hydroxybriaranes&mdash, fragilides R&ndash, T (1&ndash, 3) were obtained from a sea whip gorgonian coral Junceella fragilis. The structures of briaranes 1&ndash, 3 were elucidated by using spectroscopic methods, including 1D (1H and 13C NMR), 2D (COSY, HSQC, HMBC, and NOESY experiments) NMR studies, and (+)-HRESIMS. Fragilides S and T (2 and 3) are the only briaranes known to possess 8&alpha, hydroxy and 17&beta, methyl groups, respectively. Briarane 2 exerted an inhibition effect on iNOS release from RAW264.7, a macrophage cell line that originated from a mouse monocyte macrophage, stimulated with lipopolysaccharides.

Two new steroids, dendronesterones D (1) and E (2), featuring with 1,4-dienone moiety, along with three known steroids, methyl 3-oxochola-4,22-diene-24-oate (3), 5&alpha, 8&alpha, epidioxy-24(S)- methylcholesta-6,22-dien-3&beta, ol (4), and 5&alpha, epidioxy-24(S)-methylcholesta-6,9(11),22-trien-3&beta, ol (5), were isolated from an octocoral Dendronephthya sp. The structures of steroids 1 and 2 were elucidated by using spectroscopic methods and steroid 1 was found to exhibit significant in vitro anti-inflammatory activity in lipopolysaccharides (LPS)-induced RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein.