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The chemical screening of a cultured soft coral, Briareum violaceum, led to the isolation of eight natural, briarane-related diterpenoids, including three unreported metabolites, briavioids E–G (1–3), and five known briaranes, briacavatolides B (4) and C (5), briaexcavatin L (6), briaexcavatolide U (7) and briarenol K (8). The structures of briaranes 1–8 were established using spectroscopic methods. The absolute configuration of briavioid A (9), obtained in a previous study, was reported for the first time in this study by a single-crystal X-ray diffraction analysis using a copper radiation source. The anti-inflammatory activity of briaranes 1 and 2 and briaranes 4–8 was evaluated by screening their inhibitory ability against the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells. [ABSTRACT FROM AUTHOR]

[Display omitted] A novel cembranoid, (1 R ,7 R ,8 R ,11 R ,12 R)-7,8:11,12-bisepoxycembrene A (1), was isolated from an octocoral Sinularia sp. The structure of 1 was elucidated using spectroscopic methods, and its absolute configuration was confirmed by a single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

During the chemical screening of the sea whip octocoral Junceella fragilis , five chlorine-containing briarane-type diterpenoids featuring with an s-cis -Δ3(E),5(16)-diene conjugated diene system, were discovered. Of these compounds, two are entirely novel entities: (−)-frajunolide H (1) and fragilide Y (2). Additionally, three known analogs were identified: fragilide P (3), junceellolide B (4), and junceellolide C (5). To determine the absolute structures of 1 and 3 , single-crystal X-ray diffraction analysis was utilized. On the other hand, 2D NMR experiments in combination with data from the literature enabled accurate verification of the structure of 2. Moreover, an evaluation of the conformations of previously-discovered briaranes such as frajunolide H and junceellolide B and C was carried out. Among these newly-discovered compounds, fragilide Y possessed anti-inflammatory activity that reduced the expression of cyclooxygenase-2 (COX-2) to 88.70% at a concentration of 10 μM. Altogether, this study yielded valuable information about the unique chemistry and promising pharmacological properties of chlorine-containing briarane diterpenoids from sea whip octocoral. [Display omitted] • Two new chlorine-containing briaranes, (−)-frajunolide H and fragilide Y, were isolated from Junceella fragilis. • The structures, including the absolute configurations, of (−)-frajunolide H and fragilide P, were determined by X-ray diffraction analysis. • The conformation of Δ3(E),5(16)-conjugated diene moiety in frajunolide H, junceellolides B and C, were revised. [ABSTRACT FROM AUTHOR]

Three new polyacetoxybriarane diterpenoids, briavioids A–C (1 – 3), as well as two known analogues, briaexcavatin M (4) and excavatolide F (5), were isolated from a cultured soft coral Briareum violaceum. The structures and relative stereochemistry of new metabolites 1 – 3 were assigned on the basis of NMR studies. Single-crystal X-ray diffraction analysis was performed to identify the structure of 1. Briaranes 1 – 5 were assessed in terms of their inflammation activity by screening their inhibition abilities against iNOS protein in LPS-stimulated RAW264.7 macrophage cells. [Display omitted] • Three previously-undescribed briaranes, briavioids A–C (1 – 3), were isolated from a cultured octocoral Briareum violaceum. • The structure of briavioid A was confirmed by a single-crystal X-ray diffraction analysis. • Excavatolide F reduced the release of iNOS. [ABSTRACT FROM AUTHOR]

• A novel sterol was isolated from the soft coral Lobophytum durum. • The absolute configuration of sterol 3 was determined through X-ray analysis. • The soft coral Lobophytum durum is a rich source of marine sterols. Chromatographic investigation on the ethyl acetate extract of the soft coral Lobophytum durum collected from the waters of Guishan Island in northeast Taiwan resulted in the isolation of three sterols 1 – 3 , including one new sterol, 3 β -hydroxy-25-methylene-5-cholesten-7-one (1), and two previously reported sterols, 7-oxogorgosterol (2), and (24 R)-ergostane-3 β ,5 α ,6 β ,25-tetraol 25-monoacetate (3). The structures of sterols 1 – 3 were determined by extensive spectroscopic data analysis and by comparison with literatures. Additionally, the 24 R -configuration of sterol 3 was identified by a single-crystal X-ray diffraction analysis and 13C chemical shifts for first time. The anti-inflammatory activities of sterols 1 – 3 were evaluated by examining their inhibitory effects on the generation of superoxide anions and the release of elastase against activated human neutrophils. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • An uncommon spiroketal steroid, 24-dehydrohippuristaol (1), was isolated from Isis hippuris. • 24-Dehydrohippuristaol is the first Δ24(28)-hippuristanol derivative. • 24-Dehydrohippuristaol showed cytotoxicity towards DLD-1 and LoVo cells. Chemical screening of a Formosan sea bamboo octocoral Isis hippuris have led to the isolation of nine spiroketal steroids, including a new metabolite, 24-dehydrohippuristanol (1), a new natural product, hippuristanol 11-one (2), as well as seven known analogs, hippuristanol (3), 22- epi -hippuristanol (4), hippurin-1 (5), 22- epi -hippurin-1 (6), 3-acetyl-22- epi -hippurin-1 (7), 3α-acetoxy-11β-hydroxy-24-methyl-22,25-epoxy-5α-furostan-18,20β-lactone (8) and (22 S)-3α-acetoxy-11β,18α-dihydroxy-24-methyl-18,20β;22,25-diepoxy-5α-furostane (9). The structures of steroids 1 – 9 were corroborated by 2D NMR experiments and comparison with literature data. The configurations of steroids 3 , 4 , 6 and 9 , obtained in previous studies, were reported for the first time in this study by single-crystal X-ray diffraction analysis. Steroid 1 exhibited cytotoxic effects against DLD-1 and LoVo cancer cells with IC 50 values of 5.54 and 6.89 μM, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rare 7β,8β-epoxybriarane, briavioid D (1), was isolated from Briareum violaceum. • The structure of briarane 1 was determined by a single-crystal X-ray diffraction analysis. • Briavioid D is the first example of briarane analog possessing a 7,8‑epoxy group in the γ-lactone moiety. A rare 7β,8β-epoxybriarane, briavioid D (1), has been isolated from a cultured octocoral Briareum violaceum. The structure of 1 was deduced by extensive 2D NMR studies. Single-crystal X-ray diffraction analysis was performed to identify the structure of 1 and this compound was found to reduce the release of iNOS to 85.77 %, at a concentration of 10 μM. [ABSTRACT FROM AUTHOR]

[Display omitted] • 17,20-epoxysteroids, hippuristeroketal B (1), hippuristerones A (2) and I (3), were isolated from octocoral Isis hippuris. • The absolute stereochemistry of steroids 1 – 3 was determined by single-crystal X-ray diffraction analysis. • Hippuristerone A (2) exhibited cytotoxic effect against HT-29 and DLD-1 cancer cells. Three 17,20-epoxysteroids, including a new metabolite, hippuristeroketal B (1), as well as two known compounds, hippuristerones A (2) and I (3), have been isolated from octocoral Isis hippuris collected off the waters of Taiwan. The structure of steroid 1 was deduced by extensive 1D and 2D NMR studies. The absolute stereochemistry of steroids 1 – 3 was determined by single-crystal X-ray diffraction analysis. Steroid 2 exhibited cytotoxic effect against HT-29 and DLD-1 cancer cells with IC 50 values of 11.39 and 12.86 μM, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two new 8,17-epoxybriaranes, briastecholides K and L, were obtained from octocoral Briareum stechei. • The absolute configuration of excavatolide E was confirmed by single-crystal X-ray diffraction analysis. Octocorals belonging to genus Briareum were proven to be rich sources of briarane-type diterpenoids. Three 8,17-epoxybriaranes, including a known metabolite, excavatolide M (1), as well as two new compounds, briastecholides K (2) and L (3), have been isolated from octocoral Briareum stechei collected off the waters of Taiwan. In this study, the absolute configuration of 1 was determined by single-crystal X-ray diffraction analysis for the first time. Moreover, the structures and stereochemistry of briaranes 2 and 3 were established based on spectroscopic analysis and comparison with those of 1. [ABSTRACT FROM AUTHOR]

Two novel chlorine-containing cembranoids, chlorofurancembranoids A (1) and B (2), were isolated from an octocoral identified as Sinularia sp. The structures of 1 and 2 were elucidated using spectroscopic methods, and the absolute configuration of 1 was further confirmed by single-crystal X-ray diffraction analysis. Cembranoid 2 showed cytotoxicity towards human promyelocytic leukemia HL-60 cells, with an IC 50 value of 3.67 μM. [Display omitted] [ABSTRACT FROM AUTHOR]