Pachyclavulariaenones D−G, New Diterpenoids from the Soft Coral <i>Pachyclavularia violacea</i>

Four new diterpenoids, pachyclavulariaenones D−G (1−4), have been isolated from the soft coral Pachyclavularia violacea. The structures and relative stereochemistry of metabolites 1−4 were established on the basis of extensive NMR studies and chemical methods. The structure, including the relative configuration of pachyclavulariaenone F (3), was further confirmed by a single-crystal X-ray analysis. Pachyclavulariaenone G (4) has been shown to exhibit significant cytotoxicity toward P-388 and HT-29 cancer cells

Pachyclavulariolides M−R, Six Novel Diterpenoids from a Taiwanese Soft Coral <i>Pachyclavularia violacea</i>

Six novel diterpenoids, pachyclavulariolides M−R (1−6), have been isolated from a Taiwanese soft coral Pachyclavularia violacea. The structures and relative stereochemistry of compounds 1−6 were established by spectroscopic analyses. Compound 1 has been shown to exhibit significant cytotoxicity toward P-388 cancer cells. Biosynthesis of 4−6 is discussed

Nanolobatolide, a New C₁₈ Metabolite from the Formosan Soft Coral <i>Sinularia nanolobata</i>

Nanolobatolide (1), possessing a novel C18 molecular structure, was isolated from the Formosan soft coral Sinularia nanolobata. The structure of 1 was established by extensive spectroscopic study and confirmed by X-ray diffraction analysis. A plausible biosynthetic pathway of 1 was proposed. Nanolobatolide (1) has been found to possess significant anti-neuroinflammatory and neuroprotective activities

Nanolobatolide, a New C₁₈ Metabolite from the Formosan Soft Coral <i>Sinularia nanolobata</i>

Nanolobatolide (1), possessing a novel C18 molecular structure, was isolated from the Formosan soft coral Sinularia nanolobata. The structure of 1 was established by extensive spectroscopic study and confirmed by X-ray diffraction analysis. A plausible biosynthetic pathway of 1 was proposed. Nanolobatolide (1) has been found to possess significant anti-neuroinflammatory and neuroprotective activities

New Polyoxygenated Briarane Diterpenoids, Briaexcavatolides O−R, from the Gorgonian <i>Briareum excavatum</i>

Four new polyoxygenated briarane-type diterpenoids, briaexcavatolides O−R (1−4), have been isolated from a gorgonian octocoral Briareum excavatum. Their structures were determined using spectroscopic and chemical methods. Metabolites 1−3 were found to contain oxygenated substituents at C-2, C-3, and C-4, and the relative configurations were assigned as 2R*,3R*,4R* at these three positions. Briaranes containing this type of stereochemistry are reported for the first time. The structures of metabolites 1 and 2 were further confirmed by single-crystal X-ray analyses. Compound 2 has been shown to exhibit significant cytotoxicity toward P-388 and HT-29 cancer cells

Sinulochmodins A−C, Three Novel Terpenoids from the Soft Coral <i>Sinularia lochmodes</i>

An unprecedented C,C-linked dimeric norcembranoid (sinulochmodin A, 1), a novel isocembranoid (sinulochmodin B, 2), and a novel yonarane norditerpenoid (sinulochmodin C, 3) were isolated from the soft coral Sinularia lochmodes. The structures of these metabolites were elucidated by extensive spectroscopic analysis and on the basis of the absolute structures of two related norditerpenoids (4 and 5), which were determined for the first time by a modified Mosher method. A plausible pathway for the biosynthesis of 1 and 3−5 from 2 was postulated

Nanolobatolide, a New C₁₈ Metabolite from the Formosan Soft Coral <i>Sinularia nanolobata</i>

Nanolobatolide (1), possessing a novel C18 molecular structure, was isolated from the Formosan soft coral Sinularia nanolobata. The structure of 1 was established by extensive spectroscopic study and confirmed by X-ray diffraction analysis. A plausible biosynthetic pathway of 1 was proposed. Nanolobatolide (1) has been found to possess significant anti-neuroinflammatory and neuroprotective activities

Cytotoxic and Anti-inflammatory Cembranoids from the Soft Coral <i>Lobophytum crassum</i>

Five new cembranoids, namely, crassumolides A and B and D−F (1 and 2 and 4−6), along with four known metabolites, 7−10, were isolated from the soft coral Lobophytum crassum. Crassumolide C (3) was isolated for the first time from a natural source. The structures of these compounds were elucidated by extensive spectroscopic analysis and comparison of the NMR data with those of known analogues. The absolute stereochemistry of 1 was determined using the modified Mosher’s method. Chemical transformation of 7 into the corresponding methyl ester 3 revealed the absolute stereochemistry of 3. Compounds 1, 3, and 7 were cytotoxic toward Ca9-22 cancer cells, and 10 was broadly cytotoxic toward all six test cancer cell lines used. Compounds 1, 3, 7, and 10 were found to inhibit the accumulation of the pro-inflammatory proteins iNOS and COX-2 at 10 μM

Paraminabeolides A−F, Cytotoxic and Anti-inflammatory Marine Withanolides from the Soft Coral <i>Paraminabea acronocephala</i>

Six new withanolides, paraminabeolides A−F (1−6), along with five known compounds, minabeolides-1, -2, -4, -5, and -8 (7−11), were isolated from a Formosan soft coral, Paraminabea acronocephala. The structures of these compounds were elucidated by extensive spectroscopic analysis and chemical transformation. The absolute configuration of 4 was determined by the application of Mosher’s method. Compounds 1 and 7 were cytotoxic toward Hep G2 cancer cells. Compounds 1−4 and 7−10 were found to significantly inhibit the accumulation of the pro-inflammatory iNOS protein. Compounds 7−10 also could effectively reduce the expression of COX-2 protein

Paraminabeolides A−F, Cytotoxic and Anti-inflammatory Marine Withanolides from the Soft Coral <i>Paraminabea acronocephala</i>

Six new withanolides, paraminabeolides A−F (1−6), along with five known compounds, minabeolides-1, -2, -4, -5, and -8 (7−11), were isolated from a Formosan soft coral, Paraminabea acronocephala. The structures of these compounds were elucidated by extensive spectroscopic analysis and chemical transformation. The absolute configuration of 4 was determined by the application of Mosher’s method. Compounds 1 and 7 were cytotoxic toward Hep G2 cancer cells. Compounds 1−4 and 7−10 were found to significantly inhibit the accumulation of the pro-inflammatory iNOS protein. Compounds 7−10 also could effectively reduce the expression of COX-2 protein