Search

Nine new cembrane diterpenes, named sarcoglaucins A-I (1–9) along with three known analogues, trochelioid (10), 7α-hydroxy-Δ8(19)-deepoxysarcophine (11), and (−)-sartrochine (12), were isolated from the soft coral Sarcophyton glaucum collected at Xisha Islands in the South China Sea. The structures of all the compounds were established by extensive spectroscopic analysis. The absolute configurations of sarcoglaucins A and B with an unusual [10.3.2.1] cage-type structure were determined using X-ray diffraction and quantum chemical calculation methods. Sarcoglaucin B (2), sarcoglaucin E (5) and compounds 10–12 showed strong antifouling activity against the barnacle Balanus amphitrite.

Four new cembrane diterpenes, 1,13-di-epi-13-acetoxy launine P (1), 13-oxo-thunbergol (2), isocrassumol B (3) and 7α, 8α-sarcophine (4), together with two known launine P (5) and sarcophytonin B (6), were isolated from the extract of the South China Sea soft coral Sarcophyton trocheliophorum. The structures were elucidated by spectroscopic analysis, ECD analysis and comparison with literature data. All compounds were tested for their antimicrobial activity and antiviral activity. Compounds 1, 2 and 5 were found to exhibit weak antibacterial activity, while 6 showed strong inhibition activity against Staphylococcus aureus and Bacillus subtilis (MIC＜0.5 µg/mL). Compounds 2 showed moderate inhibitory effect against influenza A viruses H1N1 with IC50 of 17.8 μM.

Eleven new cembrane diterpenes, namely, sarcoehrenins A-J (1-9, 11) and (2S,11S,12S)-isosarcophytoxide (10), along with six known compounds, gibberosene B (12), (13S)-cembra-1,3,7,11-tetraen-13-ol (13), (+)-sarcophtol (14), cembrene-C (15), (1R,4R,2E,7E,11E)-cembra-2,7,11-trien-4-ol (16) and (1S,4R,2E,7E,11E)-cembratrien-4-ol (17) were isolated from the soft coral Sarcophyton ehrenbergi collected from Weizhou Island, Beibu Gulf, South China Sea. The structures of these compounds were elucidated by a combination of detailed spectroscopic analyses, chemical methods, and comparison with reported data. The absolute configuration of compound 2 was established by the modified Mosher's method in association with TDDFT ECD calculation, while the absolute configuration of compound 3 was assigned by TDDFT ECD approach. In in vitro bioassays, compounds 13 and 17 showed potent TNF-α inhibitory activities being similar to that of positive control dexamethasone. A preliminary structural-activity relationship was also described.

Three new cembrane diterpenes, nephthecrassocolides A-B (1–2) and 6-acetoxy nephthenol acetate (3) along with three known compounds, 6-acetoxy-7,8-epoxy nephthenol acetate (4), epoxy nephthenol acetate (5) and nephthenol (6) were isolated from one population of Nephthea sp. Their structures were elucidated based on spectroscopic data analysis and the antifungal activities of compounds 1–6 were evaluated.

Cembrane-type diterpenoids are a large and structurally varied group of natural products isolated from both terrestrial and marine organisms. The present paper reviews all the metabolites of cembrane diterpenes, reported up to 2010. The natural products discussed in this review can be divided into several different structural families featuring a variety of ring sizes and oxidation patterns. The currently known biological activities will be presented as well.

6ϵ‐hydroxysinulariolide (3), 11‐dehydrosinulariolide (4), R(‐)‐cembrene A (10) and 3,4,11,12‐diepoxycembrene A (13) have been isolated from the soft coral Sinularia flexibilis. Copyright © 1976 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim

A chemical investigation of the Taiwanese soft coral Sinularia flexibilis has resulted in the isolation of three new cembrane diterpenes designated sinuladiterpenes G–I (1–3, resp.). The structures of 1–3 were determined on the basis of spectroscopic analyses, especially 2D-NMR and HR-ESI-MS.

Two new cembrane diterpenes, sinulaparvalides A and B (1 and 2, resp.), which contain an intriguing seven-membered lactone moiety, along with the four known related cembranoids 3-6, were isolated from the Hainan soft coral Sinularia parva. The structures of compounds I and 2 were established by spectroscopic methods, mainly on the basis of 2D-NMR techniques, and were confirmed by single-crystal X-ray diffraction analysis. The in vitro cytotoxic activities of these compounds were tested on human colon carcinoma (HCT-116), human promyelocytic leukemia (HL-60), and human lung carcinoma (A-549) tumor cell lines.

Four new cembrane diterpenes, 19-hydroxy-sarcocrassolide (1), 18-deacetyldeepoxy lobolide (2), 13-hydroxy-sinularial A (3) and 16-hydroxy-sinulariol C (4), along with four related known compounds (5-8), were isolated front the Hainan soft coral Lobophytum sp. Their structures, including relative stereochemistry, were elucidated by detailed analyses of spectroscopic data and by comparison with the data reported in literature.

Six new cembrane diterpenes, lobophytolides A-F (1-6, resp.), along with six known related cembranoids, 7-12, were isolated from the Hainan soft coral Lobophytum sp. Their structures, including their relative configuration, were elucidated by extensive analyses of the spectroscopic data and by comparison with related known compounds.

New cembranoids 4-carbomethoxyl-10-epigyrosanoldie E (1), 7-acetylsinumaximol B (2), diepoxycembrene B (6), dihydromanaarenolide I (8), and isosinulaflexiolide K (9), along with 11 known related metabolites, were isolated from cultured soft corals Sinularia sandensis and Sinularia flexibilis. The structures were elucidated by means of infrared, mass spectrometry, and nuclear magnetic resonance techniques, and the absolute configurations of 1, 4, 9, and 15 were further confirmed by single-crystal X-ray diffraction analysis. The absolute configurations of these coral metabolites and comparison with known analogues showed that one hypothesis (that cembrane diterpenes possessing an absolute configuration of an isopropyl group at C1 obtained from Alcyonacean soft corals belong to the α series, whereas analogues isolated from Gorgonacean corals belong to the β series) is not applicable for a small number of cembranoids. An in vitro anti-inflammatory study using LPS-stimulated macrophage-like cell line RAW 264.7 revealed that compounds 9-14 significantly suppressed the accumulation of pro-inflammatory proteins, iNOS and COX-2. Structure-activity relationship analysis indicated that cembrane-type compounds with one seven-membered lactone moiety at C-1 are potential anti-inflammatory agents. This is the first culture system in the world that has successfully been used to farm S. sandensis.

The chemical study of the gorgonian Lophogorgia peruana collected at the Gulf of California has led to the isolation of the new diterpenes lophodienone (2), lophodiol A (3), lophodiol B (4), 17-acetoxylophotoxin (5), 15,16-epoxylophotoxin (6), 17-acetoxy-15,16-epoxylophotoxin (7), and isoepoxylophodione (8), together with the known compounds lophotoxin (1), rubifolide (9), lopholide (10), deoxylophotoxin (11), and the lophotoxin analogues 12 and 13. The structures of the new metabolites have been established by spectroscopic techniques and chemical correlation. The in vitro cytotoxicity has been tested against three tumor cell lines.

Cembrane-type diterpenoids are a large and structurally varied group of natural products isolated from both terrestrial and marine organisms. From a biomedical perspective, cytotoxicity is the most remarkable property of this class of diterpenoids, respresented by sarcophytol A. The present paper reviews all the cytotoxic metabolites of cembrane diterpenes, reported up to 2013. The natural products discussed in this review can be divided into several different structural families featuring a variety of ring sizes and oxidation patterns. The currently hypothetical biosynthesis and total syntheses of some representative cembrane diterpenoids will be presented as well.

Three new norditerpenes, chabrolols A–C, were isolated along with three cembrane diterpenes from the soft coral Nephthea chabroli collected from the South China Sea. Their structures were determined on the basis of spectral data and confirmed by X-ray crystallographic analysis.

The new cembrane diterpenes leptodienone A (2) and leptodienone B (3) and the known compounds lopholide, lophodiol B, lophodione, and lophotoxin (1) have been isolated from the gorgonian Leptogorgia laxa collected in the Gulf of California. The structures of the new metabolites have been established by spectroscopic techniques. The in vitro cytotoxicity of the new compounds has been tested against three human tumor cell lines.

Two new cembrane diterpenes, sicrassarines A and B (compounds 1 and 2), were isolated from the Taiwanese soft coral Sinularia crassa. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis, particularly mass spectroscopy and 2D NMR (1H–1H COSY, HMQC, HMBC, and NOESY) spectroscopy.

Four new cembrane diterpenes (1—4) and fifteen known cembranoids (5—19) were isolated from an Okinawan soft coral Lobophytum crassum. The structures of these four new cembranoids were determined on the basis of spectroscopic evidence. In particular, the absolute stereochemistry of 1, 2, 5 and 6 were elucidated by the application of the modified Mosher's method and circular dichroism (CD) spectral data. The inhibitory effects of some isolates were evaluated on nitric oxide (NO) production against a murine macrophage-like cell line (Raw 264.7). Cembranoids consisting of α-methylene-γ-lactone, exhibited the significant effect on NO production.

The soft coral Sinularia ovispiculata collected on the coasts of the Andaman and Nicobar Islands of the Indian Ocean yielded two new metabolites, (2E,7E)-4, 11-dihydroxy-1,12-oxidocembra-2,7-diene [4] and (2E,7E) -4, 11-dihydroxy-1,1 2-oxidocembra-2,7,15-triene [7], in addition to three known cembrane diterpenes 1-3, four polyhydroxysterols, (24S)-24-methylcholestane-3β,5α,6β,25-tetraol, (24S)-24-methylcholestane-3β,5α,6β,25-tetraol 25-monoacetate, 24-methylenecholest-5-ene-3β,7β,16β-triol-3-O-α-L-fucopyranoside, and 24-methylenecholestane-1α,3β,5α,6β-tetraol (numersterol A), and pregnenolone. Structural elucidation of all compounds was carried out through spectral analysis and chemical reactions

A chemical investigation of the Taiwanese soft coral Sinularia flexibilis has resulted in the isolation of three new cembrane diterpenes designated sinuladiterpenes G–I (1–3, resp.). The structures of 1–3 were determined on the basis of spectroscopic analyses, especially 2D-NMR and HR-ESI-MS.

Four new cembrane diterpenes (1-4) and fifteen known cembranoids (5-19) were isolated from an Okinawan soft coral Lobophytum crassum. The structures of these four new cembranoids were determined on the basis of spectroscopic evidence. In particular, the absolute stereochemistry of 1, 2, 5 and 6 were elucidated by the application of the modified Mosher's method and circular dichroism (CD) spectral data. The inhibitory effects of some isolates were evaluated on nitric oxide (NO) production against a murine macrophage-like cell line (Raw 264.7). Cembranoids consisting of alpha-methylene-gamma-lactone, exhibited the significant effect on NO production.

Three new norditerpenes, chabrolols A–C, were isolated along with three cembrane diterpenes from the soft coral Nephthea chabroli collected from the South China Sea. Their structures were determined on the basis of spectral data and confirmed by X-ray crystallographic analysis.

Two new cembrane diterpenes have been isolated from an unidentified species of soft coral of the genus Sarcophyton, collected along the South coast of Madagascar. Their structures were elucidated on the basis of detailed NMR spectroscopic data.

International audience; Preliminary biol. investigation of a collection of Comorian soft corals resulted in the selection of two specimens, one of Sarcophyton and the other of Lobophytum, on the basis of their toxicity on larvae of the brine shrimp (Artemia salina) and inhibition of acetylcholinesterase, resp. Bioassay-guided fractionations provided a known antitumor promoter cembrane diterpenoid, (+)-sarcophytol-A (1), along with a new lobane diterpenoid, carbomethoxyfuscol (2), from Sarcophyton sp., and a new cembranoid, crassumolide E (3), from Lobophytum sp. The structures of compds. 1-3 were detd. by spectroscopic anal. and by comparison of the spectral data with previously reported values. The cembranoid 3 was found to exhibit a moderate inhibitory effect on acetylcholinesterase.

Chromatographic investigation of the octocoral Sinularia flexibilis afforded six new cembrane diterpenes, sinuladiterpenes A-F (1-6, resp.), in addition to four known cembranolides, 11-episinulariolide acetate, 11-dehydrosinulariolide, 11-episinulariolide, and sinulariolide. Their structures were elucidated by spectroscopic analysis, especially 2D-NMR and HR-ESI-MS. Compound 2 exhibited significant in vitro cytotoxic activity against human colon adenocarcinoma (WiDr) cell line.

Two new cembrane diterpenes, sinulaparvalides A and B (1 and 2, resp.), which contain an intriguing seven-membered lactone moiety, along with the four known related cembranoids 3-6, were isolated from the Hainan soft coral Sinularia parva. The structures of compounds I and 2 were established by spectroscopic methods, mainly on the basis of 2D-NMR techniques, and were confirmed by single-crystal X-ray diffraction analysis. The in vitro cytotoxic activities of these compounds were tested on human colon carcinoma (HCT-116), human promyelocytic leukemia (HL-60), and human lung carcinoma (A-549) tumor cell lines.

Four new cembrane diterpenes, 19-hydroxy-sarcocrassolide (1), 18-deacetyldeepoxy lobolide (2), 13-hydroxy-sinularial A (3) and 16-hydroxy-sinulariol C (4), along with four related known compounds (5-8), were isolated front the Hainan soft coral Lobophytum sp. Their structures, including relative stereochemistry, were elucidated by detailed analyses of spectroscopic data and by comparison with the data reported in literature.

Six new cembrane diterpenes, lobophytolides A-F (1-6, resp.), along with six known related cembranoids, 7-12, were isolated from the Hainan soft coral Lobophytum sp. Their structures, including their relative configuration, were elucidated by extensive analyses of the spectroscopic data and by comparison with related known compounds.

Two new cembrane diterpenes (+)-polydactylide (1) and (+)-7alpha,8beta-dihydroxydeepoxysarcophine (2) together with (+)-sarcophine (3) and (+)-sarcophytoxide (4) have been isolated from the soft coral Sinularia polydactyla. The new cembrane diterpene (-)-7beta-hydroxy-8alpha-methoxydeepoxysarcophine (5) has been obtained from the soft coral Sarcophyton trocheliophorum and the known briarane diterpene briaexcavatolide W (6) from the gorgonian coral Briareum sp.The structures were determined primarily by NMR spectroscopy. The assignment of NMR signals was performed by means of (1)H-(1)H COSY, ROESY, HMQC and HMBC experiments.

Four new cembrane diterpenes, sarcophytonolides E-H (1-4), were isolated from the Hainan soft coral Sarcophyton latum. Their structures were elucidated by detailed spectroscopic (IR, MS, 2D NMR) analysis and by comparison with related known compounds. The absolute stereochemistry of sarcophytonolide H (4) was determined by applying the modified Mosher's method.

An investigation of the Caribbean octocoral Eunicea tourniforti collected along the southwest coast of Barbados afforded four new cembrane diterpenes, 1, 2, 4, and 5, along with the known cembranolide 3. The structures of all metabolites were determined by spectroscopic methods. Seasonal effects on the secondary metabolite content of the specimens collected were also observed.

Two new cembrane diterpenes have been isolated from an unidentified species of soft coral of the genus Sarcophyton, collected along the South coast of Madagascar. Their structures were elucidated on the basis of detailed NMR spectroscopic data.

Two cytotoxic cembranoid diterpenes, (+)-isosarcophytoxide (1) and ( + )-isosarcophine (2), were isolated from the soft coral Sarcophyton trocheliophorum by cytotoxicity-guided fractionation. These two compounds demonstrated potent cytotoxicity against P-388 and HL-60 cells.

One new cembrane diterpene, 2 R,7 R,8 R-dihydroxydeepoxysarcophine (1), together with three known compounds, 7α,8β-dihydroxy-deepoxysarcophine (2), 7β-acetoxy-8α-hydroxydeepoxysarcophine (3), and sarcophine (4), have been isolated from the Red Sea soft coral Sarcophyton glaucum. Their structures were determined using 1D and 2D NMR spectroscopy. 7β-Acetoxy-8α-hydroxydeepoxysarcophine (3) exhibits cytotoxic activity against HepG2, HCT-116, and HeLa cells with IC50 values of 3.6, 2.3, and 6.7 μg/mL, respectively.

Two new cembrane diterpenes, 17-hydroxysarcophytoxide (1) and 7β-acetoxy-8α-hydroxydeepoxysarcophine (2), together with 7β,8α-dihydroxydeepoxysarcophine (3), sarcophytonin A (4) and (-)-β-elemene (5) have been isolated from the soft coral Sarcophyton sp. 7β-Hydroxy-8α-methoxydeepoxysarcophytoxide (6) and 7α,8β-dihydroxydeepoxysarcophytoxide (7) have been obtained from the soft coral Sarcophyton glaucum. The structures were determined primarily by NMR spectroscopy.

The combination of liquid chromatography coupled to high resolution mass spectrometry (LC-HRESMS)-based dereplication and antiproliferative activity-guided fractionation was applied on the Red Sea-derived soft coral Sarcophyton sp. This approach facilitated the isolation of five new cembrane-type diterpenoids (1–5), along with two known analogs (6 and 7), as well as the identification of 19 further, known compounds. The chemical structures of the new compounds were elucidated while using comprehensive spectroscopic analyses, including one-dimensional (1D) and two-dimensional (2D) NMR and HRMS. All of the isolated cembranoids (1–7) showed moderate in vitro antiproliferative activity against a human breast cancer cell line (MCF-7), with IC50 ranging from 22.39–27.12 µg/mL. This class of compounds could thus serve as scaffold for the future design of anticancer leads.

Two new cembrane diterpenes, related to sarcophine, have been isolated from a soft coral (Sarcophyton sp.). Structures were solved primarily by spectral methods. The pharmacological profile of one metabolite (5) is briefly discussed.

The isolation and structural elucidation of five new cembrane diterpenes from two Eremophila species is reported. (1R,3S,4S,7E,11Z)-3,15-Epoxy-19-oxocembra-7,11-dien-18-oic acid (3) and (1R,3S,4S,7Z,11Z)-3,15-epoxycembra-7,11-dien-18-oic acid (7) were isolated from E. granitica, and dimethyl(1R,3S,4S,7E,11Z)-3,15-epoxycembra-7,11-diene-18,19-dioate (16), (1R,3S,4S,8R,11Z)-3,15-epoxycembr-11-ene-18,19-dioic acid (14) and its dimethyl ester were isolated from E. abietina. Structural studies on the diol derived from (14) were carried out by single-crystal X-ray diffraction analysis.