New Anti-Inflammatory Cembranes from the Cultured Soft Coral Nephthea columnaris

Two new cembranes, columnariols A (1) and B (2), were isolated from the cultured soft coral Nephthea columnaris. The structures of cembranes 1 and 2 were elucidated by spectroscopic methods. In the anti-inflammatory effects test, cembranes 1 and 2 were found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 protein of the lipopolysaccharide (LPS)-stimulated RAW264.7 macrophage cells. Compound 1 exhibited moderate cytotoxicity toward LNCaP cells with an IC₅₀ value of 9.80 μg/mL.     

Polyhydroxylated steroids from the bamboo coral Isis hippuris

In previous studies on the secondary metabolites of the Taiwanese octocoral Isis hippuris, specimens have always been collected at Green Island. In the course of our studies on bioactive compounds from marine organisms, the acetone-solubles of the Taiwanese octocoral I. hippuris collected at Orchid Island have led to the isolation of five new polyoxygenated steroids: hipposterone M-O (1-3), hipposterol G (4) and hippuristeroketal A (5). The structures of these compounds were determined on the basis of their spectroscopic and physical data. The anti-HCMV (human cytomegalovirus) activity of 1-5 and their cytotoxicity against selected cell lines were evaluated. Compound 2 exhibited inhibitory activity against HCMV, with an EC(50) value of 6.0 μg/mL.     

New cytotoxic cembranolides from the soft coral Lobophytum michaelae

Six new cembranolides, michaolides L–Q (1–6), and a known cembranolide, lobomichaolide (7) were isolated from the CH₂Cl₂ extract of the soft coral Lobophytum michaelae. Their structures were established by extensive spectral analysis. The anti-HCMV (human cytomegalovirus) activity of 1–7 and their cytotoxicity against selected cell lines were evaluated.     

New cembranolides from the Dongsha Atoll soft coral Lobophytum durum

Chemical investigations of the Dongsha Atoll soft coral Lobophytum durum resulted in the isolation of five new cembranolides, durumolides M–Q (1–5). The structures of compounds 1–5 were characterized by the interpretation of extensive spectroscopic analysis. Compound 4 exhibited cytotoxicity against P-388 (mouse lymphocytic leukemia) cell line with an ED₅₀ of 3.8 μg/mL. Moreover, compound 5 showed significant antiviral activity against human cytomegalovirus with an IC₅₀ of 5.2 μg/mL.     

New Diterpenoids from Soft Coral Sarcophyton ehrenbergi

Continuing chemical investigation on the acetone extracts of the soft coral Sarcophyton ehrenbergi collected off the coast of San-hsian-tai, Taitong County, Taiwan led to the isolation of two new diterpenoids, ehrenbergol C and acetyl ehrenberoxide B (1 and 2). The structures of these isolated metabolites were elucidated through extensive spectroscopic analyses. Moreover, in vitro tests show that compounds 1 and 2 displayed antiviral activity towards human cytomegalovirus, with EC₅₀ of 20 and 8.0 µg/mL, respectively.     

Three New Cembranoids from the Taiwanese Soft Coral Sarcophyton ehrenbergi

In order to search for new bioactive substances from marine organisms, we have investigated the acetone extracts of the soft coral Sarcophyton ehrenbergi collected at San-Hsian-Tai, Taitong County, Taiwan. Chromatographic fractionation of the extracts of the octocoral S. ehrenbergi led to the isolation of three new cembranoids, (+)-12-ethoxycarbonyl-11Z-sarcophine (1), ehrenbergol A and B (2 and 3). The structures of these isolated metabolites were elucidated through extensive spectroscopic analyses. Moreover, metabolites 1-3 were evaluated in vitro for their cytotoxicity towards selected cancer cell lines and antiviral activity against human cytomegalovirus (HCMV).     

Cembranoids from the Dongsha Atoll soft coral Lobophytum crassum

Chemical investigation of the Dongsha Atoll soft coral Lobophytum crassum has afforded four new cembranoids, crassumols A-C (1-3) and 13-acetoxysarcophytoxide (4). The structures of these isolated compounds were elucidated by extensive NMR and HRESIMS experiments. The cytotoxicity and anti-HCMV (Human cytomegalovirus) activities of 1-4 were evaluated in vitro. Compound 4 exhibited cytotoxicity against A-549 (human lung carcinoma) cell line with an ED(50) of 3.6 μg/mL.     

Bioactive cembrane-based diterpenoids from the soft coral Sinularia triangular

Chemical examination of the Taiwanese soft coral Sinularia triangular led to the isolation of five cembrane-based diterpenoids 1-5, including two new metabolites, triangulenes A (1) and B (2). The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis, particularly mass spectroscopy and 2D NMR ((1)H-(1)H COSY, HMQC, HMBC, and NOESY) spectroscopy. Metabolites 3 and 5 exhibited moderate cytotoxicity to human tumor cell lines CCRF-CEM and DLD-1. Furthermore, 3-5 displayed significant in vitro anti-inflammatory activity in lipopolysaccharide-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein. Metabolites 4 and 5 also effectively reduced the expression of the COX-2 protein in the macrophages.     

Simplexins P-S, eunicellin-based diterpenes from the soft coral Klyxum simplex

Four new eunicellin-based diterpenes, simplexins P-S (1-4), and the known compound simplexin A (5), have been isolated from the soft coral Klyxum simplex. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis, particularly 1D and 2D NMR experiments. Compounds 1 and 3-5 were shown to exhibit cytotoxicity against a limited panel of cancer cell lines, 3 being the most cytotoxic.     

Lobocrassins A-E: new cembrane-type diterpenoids from the soft coral Lobophytum crassum

Five new cembrane-type diterpenoids, lobocrassins A-E (1-5), were isolated from the soft coral Lobophytum crassum. The structures of cembranes 1-5 were established by spectroscopic and chemical methods and by comparison of the spectral data with those of known cembrane analogues. Lobocrassin A (1) is the first cembranoid possessing an α-chloromethyl-α-hydroxy-γ-lactone functionality and is the first chlorinated cembranoid from soft corals belonging to the genus Lobophytum. Lobocrassins B (2) and C (3) were found to be the stereoisomers of the known cembranes, 14-deoxycrassin (6) and pseudoplexaurol (7), respectively. Lobocrassin B (2) exhibited modest cytotoxicity toward K562, CCRF-CEM, Molt4, and HepG2 tumor cells and displayed significant inhibitory effects on the generation of superoxide anion and the release of elastase by human neutrophils.     

Capilloquinol: a novel farnesyl quinol from the Dongsha atoll soft coral Sinularia capillosa

Capilloquinol (1), possessing an unprecedented farnesyl quinoid skeleton, was isolated from the Dongsha Atoll soft coral Sinularia capillosa. The structure of capilloquinol was elucidated by extensive analysis of spectroscopic data. The cytotoxicity and antiviral activity against human cytomegalovirus of 1 was evaluated in vitro.     

Steroids from the soft coral Sinularia crassa

One new sterol, crassarosterol A (1), and four new steroidal glycosides, crassarosterosides A-D (2-5) were isolated from the Formosan soft coral Sinularia crassa. The absolute configuration of 1 was determined using the Mosher's method. The absolute configurations for the sugar moieties of 2-5 were determined by HPLC analysis on the o-tolylthiocarbamates derived from the liberated sugar after acid hydrolysis. Compounds 2 and 4 could significantly inhibit the expression of pro-inflammatory iNOS protein at 10 μM. In contrast, 1-3 were found to stimulate the expression of COX-2 protein at this concentration. Steroids 1 and 4 also showed cytotoxicity toward the selected human liver cancer cells.     

Paralemnolide A, an Unprecedented Bisnorsesquiterpene from the Taiwanese Soft Coral Paralemnalia thyrsoides

Paralemnolide A (1), possessing an unprecedented bisnorsesquiterpene skeleton, was isolated from the soft coral Paralemnalia thyrsoides. The structure of paralemnolide A was elucidated by extensive analysis of spectroscopic data. The anti-HCMV (human cytomegalovirus) activity of 1 and its cytotoxicity against selected cell lines were evaluated.     

Briacavatolides A-C, new briaranes from the Taiwanese octocoral Briareum excavatum

In order to search for novel bioactive substances from marine organisms, we have investigated the organic extracts of the Taiwanese octocoral Briareumexcavatum collected at Orchid Island. Three new briarane-type diterpenoids, briacavatolides A-C (1-3) as well as two known briaranes, briaexcavatolide U (4) and briaexcavatin L (5) were isolated from the acetone extract. The structures of these compounds were elucidated by extensive NMR spectroscopic analysis and physical data. The anti-HCMV (human cytomegalovirus) activity of 1-5 and their cytotoxicity against selected cancer cell lines were evaluated.     

Bioactive cembranoids from the soft coral Sinularia crassa

Eight new cembranoids, crassarines A-H (1-8) were isolated from the Formosan soft coral Sinularia crassa. Compounds 1-3 represent the rare cembranoids with a 1,12-oxa-bridged tetrahydrofuran ring, while 4 and 5 are the firstly discovered 1,11-oxa-bridged tetrahydropyranocembranoids. The absolute configuration of 6 was determined using the Mosher's method. Compounds 6 and 8 were found to significantly inhibit the expression of both pro-inflammatory iNOS and COX-2 proteins at 10 μM, respectively, while compounds 4-8 were found to be non-cytotoxic toward the selected human liver cancer cells.     

Tetrahydrofuran cembranoids from the cultured soft coral Lobophytum crassum

Three new cembranoids, culobophylins A-C (1-3), along with two known compounds (4 and 5) were isolated from the cultured soft coral Lobophytum crassum. The structures of these compounds were elucidated on the basis of their spectroscopic data and comparison of the NMR data with those of known analogues. Among these metabolites, 2 is rarely found in cembranoids possessing an isopropyl moiety with an epoxide group. Compound 1 exhibited significant cytotoxic activity against HL60 and DLD-1 cancer cell lines.     

nardosinane-type sesquiterpenoids from the formosan soft coral Paralemnalia thyrsoides

Five new nardosinane-type sesquiterpenoids, paralemnolins Q-U (1-5), along with three known compounds (6-8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher's method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity.     

Sarcocrassocolides M-O, bioactive cembranoids from the Dongsha Atoll soft coral Sarcophyton crassocaule

Three new cembranoids, sarcocrassocolides M-O (1-3), have been isolated from the soft coral Sarcophyton crassocaule. The structures of the metabolites were determined by extensive spectroscopic analysis. Compounds 1-3 were shown to exhibit moderate cytotoxicity toward a limited panel of cancer cell lines and display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein.     

Bioactive cembranoids from the dongsha atoll soft coral Sarcophyton crassocaule

Seven new cembranoids, sarcocrassocolides F-L (1-7), have been isolated from a soft coral Sarcophyton crassocaule. Their structures were determined by extensive spectroscopic analysis. Most new compounds exhibited significant cytotoxic activity against a limited panel of cancer cell lines, and the structure-activity relationship was studied. Compounds 1-7 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. Compound 4 was also found to effectively reduce the level of COX-2 protein.     

Four New Sulfated Polar Steroids from the Far Eastern Starfish Leptasterias ochotensis: Structures and Activities

Three new sulfated steroid monoglycosides, leptaochotensosides A–C (1–3), and a new sulfated polyhydroxylated steroid (4) were isolated from the alcoholic extract of the Far Eastern starfish Leptasterias ochotensis. The structures of compounds 1–4 were established by extensive nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESIMS) analyses and chemical transformations. Although the isolated compounds did not show any apparent cytotoxicity against melanoma RPMI-7951 and breast cancer T-47D cell lines, leptaochotensoside A (1) demonstrated inhibition of T-47D cell colony formation in a soft agar clonogenic assay at nontoxic doses. In addition, this compound decreased the epidermal growth factor (EGF)-induced colony formation of mouse epidermal JB6 Cl41 cells. The cancer preventive action of 1 is realized through regulation of mitogen-activated protein kinase (MAPK) signaling pathway.