Eunicellin-Based Diterpenoids from the Formosan Soft Coral <i>Klyxum molle</i> with Inhibitory Activity on Superoxide Generation and Elastase Release by Neutrophils

Eleven new eunicellin-based diterpenoids possessing a cladiellane skeleton with a C-2, C-9 ether bridge, klymollins I–S (<b>1</b>–<b>11</b>), have been isolated from the EtOAc extract of the soft coral <i>Klyxum molle</i> from Taiwan waters. The structures of compounds <b>1</b>–<b>11</b> were elucidated by extensive spectroscopic analysis, including 2D NMR spectroscopy (COSY, HSQC, HMBC, and NOESY). Compound <b>5</b> exhibited cytotoxicity toward several cancer cell lines. Compound <b>5</b> is the first eunicellin-based metabolite bearing a phenyl group and displays significant inhibition of both superoxide anion generation and elastase release in <i>N</i>-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced human neutrophils

Anti-inflammatory Cembranoids from the Soft Corals <i>Sinularia querciformis</i> and <i>Sinularia granosa</i>

Four new cembranoids, querciformolides A−D (1−4), along with two known cembranoids, 7 and 8, have been isolated from the soft coral Sinularia querciformis. Furthermore, chemical investigation of Sinularia granosa has afforded three new cembranoids, querciformolide B (2) and granosolides A (5) and B (6). The structures of the new metabolites were elucidated on the basis of extensive spectroscopic methods, and that of 2 was further confirmed by X-ray diffraction analysis. The absolute configurations of 1 and 2 were determined by a modified Mosher’s method. Among these metabolites, 2−6 are rarely found cembranoids possessing a tetrahydrofuran moiety with a 4,7-ether linkage; in addition, 1 is the first ε-lactone cembrane found that possesses a tetrahydropyran moiety with a 4,8-ether linkage. None of these compounds were found to be cytotoxic toward a limited panel of cancer cell lines. However, compounds 3, 7, and 8 significantly inhibited the accumulation of the pro-inflammatory iNOS and COX-2 proteins in LPS-stimulated RAW264.7 macrophage cells

Anti-inflammatory Cembranoids from the Soft Corals <i>Sinularia querciformis</i> and <i>Sinularia granosa</i>

Four new cembranoids, querciformolides A−D (1−4), along with two known cembranoids, 7 and 8, have been isolated from the soft coral Sinularia querciformis. Furthermore, chemical investigation of Sinularia granosa has afforded three new cembranoids, querciformolide B (2) and granosolides A (5) and B (6). The structures of the new metabolites were elucidated on the basis of extensive spectroscopic methods, and that of 2 was further confirmed by X-ray diffraction analysis. The absolute configurations of 1 and 2 were determined by a modified Mosher’s method. Among these metabolites, 2−6 are rarely found cembranoids possessing a tetrahydrofuran moiety with a 4,7-ether linkage; in addition, 1 is the first ε-lactone cembrane found that possesses a tetrahydropyran moiety with a 4,8-ether linkage. None of these compounds were found to be cytotoxic toward a limited panel of cancer cell lines. However, compounds 3, 7, and 8 significantly inhibited the accumulation of the pro-inflammatory iNOS and COX-2 proteins in LPS-stimulated RAW264.7 macrophage cells

Anti-inflammatory Cembranoids from the Soft Corals <i>Sinularia querciformis</i> and <i>Sinularia granosa</i>

Four new cembranoids, querciformolides A−D (1−4), along with two known cembranoids, 7 and 8, have been isolated from the soft coral Sinularia querciformis. Furthermore, chemical investigation of Sinularia granosa has afforded three new cembranoids, querciformolide B (2) and granosolides A (5) and B (6). The structures of the new metabolites were elucidated on the basis of extensive spectroscopic methods, and that of 2 was further confirmed by X-ray diffraction analysis. The absolute configurations of 1 and 2 were determined by a modified Mosher’s method. Among these metabolites, 2−6 are rarely found cembranoids possessing a tetrahydrofuran moiety with a 4,7-ether linkage; in addition, 1 is the first ε-lactone cembrane found that possesses a tetrahydropyran moiety with a 4,8-ether linkage. None of these compounds were found to be cytotoxic toward a limited panel of cancer cell lines. However, compounds 3, 7, and 8 significantly inhibited the accumulation of the pro-inflammatory iNOS and COX-2 proteins in LPS-stimulated RAW264.7 macrophage cells

Halogenated Sesquiterpenoids from the Red Alga <i>Laurencia tristicha</i> Collected in Taiwan

Chemical investigation of the red alga <i>Laurencia tristicha</i> led to the discovery of eight new halogenated chamigrane-type sesquiterpenoids (<b>1</b>–<b>8</b>) and one new bromocuparane-type sesquiterpene (<b>9</b>), along with nine known related metabolites (<b>10</b>–<b>18</b>). Their structures were elucidated on the basis of extensive spectroscopic analyses, and the absolute configurations of <b>1</b>–<b>8</b> were proposed by comparison to the biosynthetically related known compound <b>12</b>. Cytotoxicity, antibacterial, and anti-inflammatory activities of these isolates were also investigated. The results showed that compound <b>11</b> exhibited good antibacterial activity against <i>Serratia marcescens</i> compared to the positive control ampicillin at a dosage of 100 μg/disk. Compound <b>17</b> showed strong inhibition toward elastase release generation at 10 μM

Klymollins A–H, Bioactive Eunicellin-Based Diterpenoids from the Formosan Soft Coral <i>Klyxum molle</i>

Eight new eunicellin-based diterpenoids, klymollins A–H (1–8), were isolated during the chemical investigation of the soft coral Klyxum molle from Taiwan waters. Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of 4 was determined by Mosher’s method. Bioassays of the new metabolites showed that compounds 3–8 displayed significant in vitro anti-inflammatory activity by inhibiting the expression of the iNOS protein, and compounds 3, 4, and 6–8 also could effectively reduce the accumulation of COX-2 protein in LPS-stimulated RAW264.7 macrophage cells

Bioactive Isoprenoid-Derived Natural Products from a Dongsha Atoll Soft Coral Sinularia erecta

Four new isoprenoids, including two norcembranoids sinulerectols A and B (<b>1</b> and <b>2</b>), a cembranoid sinulerectol C (<b>3</b>), and a degraded cembranoid sinulerectadione (<b>4</b>), along with three known isoprenoids, an unnamed norcembrene (<b>5</b>), sinularectin (<b>6</b>), and ineleganolide (<b>7</b>), and a known nitrogen-containing compound (<i>Z</i>)-<i>N</i>-[2-(4-hydroxyphenyl)­ethyl]-3-methyldodec-2-enamide (<b>8</b>), were isolated from an extract of the marine soft coral Sinularia erecta. The structure of sinularectin (<b>6</b>) was revised, too. Compounds <b>3</b>, <b>4</b>, and <b>8</b> exhibited inhibitory activity against the proliferation of a limited panel of cancer cell lines, whereas <b>1</b>, <b>2</b>, and <b>8</b> displayed potent anti-inflammatory activity in fMLP/CB-stimulated human neutrophils

Halogenated Sesquiterpenoids from the Red Alga <i>Laurencia tristicha</i> Collected in Taiwan

Chemical investigation of the red alga <i>Laurencia tristicha</i> led to the discovery of eight new halogenated chamigrane-type sesquiterpenoids (<b>1</b>–<b>8</b>) and one new bromocuparane-type sesquiterpene (<b>9</b>), along with nine known related metabolites (<b>10</b>–<b>18</b>). Their structures were elucidated on the basis of extensive spectroscopic analyses, and the absolute configurations of <b>1</b>–<b>8</b> were proposed by comparison to the biosynthetically related known compound <b>12</b>. Cytotoxicity, antibacterial, and anti-inflammatory activities of these isolates were also investigated. The results showed that compound <b>11</b> exhibited good antibacterial activity against <i>Serratia marcescens</i> compared to the positive control ampicillin at a dosage of 100 μg/disk. Compound <b>17</b> showed strong inhibition toward elastase release generation at 10 μM

Withanolide-Based Steroids from the Cultured Soft Coral <i>Sinularia brassica</i>

Seven novel withanolides, sinubrasolides A–G (<b>1</b>–<b>7</b>), have been isolated from the cultured soft coral <i>Sinularia brassica</i>. The structures of the new metabolites were determined by extensive spectroscopic analyses, and the absolute configuration of <b>1</b> was established by X-ray crystallographic analysis. The cytotoxicities of compounds <b>1</b>–<b>7</b> against a limited panel of cancer cell lines also were determined

Withanolide-Based Steroids from the Cultured Soft Coral <i>Sinularia brassica</i>

Seven novel withanolides, sinubrasolides A–G (<b>1</b>–<b>7</b>), have been isolated from the cultured soft coral <i>Sinularia brassica</i>. The structures of the new metabolites were determined by extensive spectroscopic analyses, and the absolute configuration of <b>1</b> was established by X-ray crystallographic analysis. The cytotoxicities of compounds <b>1</b>–<b>7</b> against a limited panel of cancer cell lines also were determined