Gorgonian Coral Subergorgia Suberosa Research Articles

Isolation and Structure-Activity Relationship of Subergorgic Acid and Synthesis of Its Derivatives as Antifouling Agent.

In this study, as part of our continuous search for environmentally-friendly antifoulants from natural resources, subergorgic acid (SA) was identified from the gorgonian coral Subergorgia suberosa, demonstrating non-toxic, significant inhibitory effects (EC50 1.25 μg/mL, LC50 > 25 μg/mL) against the settlement of Balanus amphitrite. To further explore the bioactive functional groups of SA and synthesize more potent antifouling compounds based on the lead SA, the structure-activity relationships of SA were studied, followed by rational design and synthesis of two series of SA derivatives (one being benzyl esters of SA and another being SA derivatives containing methylene chains of various lengths). Our results indicated that (1) both the double bond and ketone carbonyl are essential elements responsible for the antifouling effect of SA, while the acid group is not absolutely necessary for maintaining the antifouling effect; (2) all benzyl esters of SA displayed good antifouling effects (EC50 ranged from 0.30 to 2.50 μg/mL) with the most potent compound being 5 (EC50 0.30 μg/mL, LC50 > 25 μg/mL), which was over four-fold more potent than SA; and (3) the introduction of a methylene chain into SA reduces the antifouling potency while the length of the methylene chain may differently influence the antifouling effect, depending on the functional group at the opposite site of the methylene chain. Not only has this study successfully revealed the bioactive functional groups of SA, contributing to the mechanism of SA against the settlement of B. amphitrite, but it has also resulted in the identification of a more potent compound 5, which might represent a non-toxic, high-efficiency antifoulant.

A new sesquiterpene from the South China Sea gorgonian coral Subergorgia suberosa

A new sesquiterpene, namely suberosoid (1), was isolated from the South China Sea gorgonian coral Subergorgia suberosa. The chemical structure of 1 was established as an unusual sesquiterpene containing 4-methylenecyclohex-2-enone system, by extensive analyses of NMR spectroscopy and high-resolution mass spectrometry. Suberosoid (1) exhibited cytotoxic effect against HeLa cell lines with IC50 value being 10.6 μM.

Pregnane steroids from a gorgonian coral Subergorgia suberosa with anti-flu virus effects

Five new pregnane-type steroids namely subergorgols T–X (1–5) and three known analogues (6–8) were isolated from a gorgonian coral Subergorgia suberosa. The structures of new compounds were determined on the basis of extensive spectroscopic (IR, MS, 1D and 2D NMR) data analyses, in association with photochemical transformation and ECD methods for the configurational assignment. Compounds 1–8 were evaluated for the inhibitory effects against H1N1 virus infected in MDCK cells, while subergorgols T–U and 1,2-dehydroprogesterone exerted potent inhibition against A/WSN/33 virus.

ChemInform Abstract: Subergane‐Type Sesquiterpenes from Gorgonian Coral Subergorgia suberosa with Antibacterial Activities.

AbstractEpoxysubergorgic acid (I) is isolated from the gorgonian coral Subergorgia suberosa along with seven known sesquiterpenes.

Subergane‐Type Sesquiterpenes from Gorgonian Coral Subergorgia suberosa with Antibacterial Activities

AbstractA new subergane‐type sesquiterpene, named epoxysubergorgic acid (1), along with seven known sesquiterpenes, were isolated from the gorgonian coral Subergorgia suberosa. The structure of the new compound was determined by extensive spectroscopic analyses. The previously uncertain absolute configuration of the known analogues 2–6 was determined on the basis of CD, Mosher's method, and through chemical conversions. All compounds were evaluated for antibacterial activities.

9,11-Secosteroids with cytotoxic activity from the South China Sea gorgonian coral Subergorgia suberosa

Nine new 9,11-secosterols (1–9), containing the same 3β,6α,11-trihydroxy-9,11-seco-5α-cholest-7-en-9-one steroidal nucleus, whereas possessing an array of structurally diverse side chains, along with fourteen known 9,11-secosterol compounds (10–23), were isolated from the South China Sea gorgonian coral Subergorgia suberosa, of which 3/4, 5/6, 7/8, and the known compounds 11/12, 20/21 were five pairs of inseparable C-24 epimers. Their structures were established by the extensive analyses of 1D and 2D NMR spectra, high-resolution chemical ionization mass spectrometry (HRCIMS), and by the comparison with literature data. Cytotoxic effect of these metabolites against the growth of HeLa cell lines was evaluated. The result showed that the inhibitory effect of compounds 1–23 varied considerably depending on the nature of the side chain in spite of sharing the same steroidal nucleus. Compound 19, featuring both the absence of hydroxyl group and the presence of double bond in the stigmasterol side chain, exhibited the most potent cytotoxicity with IC50 being 15.1μM. The preliminary structure activity relationship studies identified some important structural features considerably influencing the biological effect deserved, providing valuable information for chemists and pharmacologists to design and synthesize more effective antitumor agents bearing the 9,11-secosteroid framework.

Suberosanones A – C, New Metabolites Possessing Cyclopentenone System from the South China Sea Gorgonian Coral Subergorgia suberosa

AbstractTwo unusual novel bicyclic lactones, suberosanones A and B (1 and 2, resp.), characterized by the co‐occurrence of cyclopentenone and butanolide rings within the same molecule, along with one tricyclic cyclopentenone derivative, suberosanone C (3), were isolated from the South China Sea gorgonian coral Subergorgia suberosa. Their structures were unambiguously established by detailed spectroscopic analyses (NMR, IR, and HR‐MS). The absolute configurations of 1 and 2 were determined by quantum‐chemical calculations using the time‐dependent density‐functional theory (TDDFT) method. All compounds showed neither antifouling activity against Balanus amphitrite larvae settlement nor antibacterial activity against a panel of bacterial strains at concentrations up to 25 μg/ml.

Isolation of a new butenolide from the South China Sea gorgonian coral Subergorgia suberosa

Chemical investigation on the South China Sea gorgonian coral Subergorgia suberosa has led to the isolation of one new butenolide (5R)-5-(1-ethoxypropyl)-5-hydroxy-3,4-dimethylfuran-2(5H)-one (1) as a pair of inseparable epimers, along with two known butenolides (S)-5-hydroxy-3,4-dimethyl-5-propylfuran-2(5H)-one (2) and (S)-5-hydroxy-3,4-dimethyl-5-pentylfuran-2(5H)-one (3). Their structures including absolute configurations were determined unambiguously by detailed analyses of spectroscopic data and by comparison with the available literature. Compounds 1–3 exhibited moderate antifouling activities against the settlement of Balanus amphitrite larvae, whereas compound 4, the acetyl derivative of 3, showed no antifouling activity at the concentrations up to 25 μg/mL.

Antifouling steroids from the South China Sea gorgonian coral Subergorgia suberosa

Two new unusual cholestane derivatives, pentacyclic steroid 16,22-epoxy-20β,23S-dihydroxycholest-1-ene-3-one (1) and 20β,23S-dihydroxycholest-1-ene-3,22-dione (2), along with two new pregnane derivatives, 15β,17α-dihydroxypregna-4,6-diene-3,20-dione (3) and 11α-hydroxypregna-4-ene-3,6,20-trione (4), were isolated from the South China Sea gorgonian coral Subergorgia suberosa. Their structures were established based on the extensive analyses of 2D NMR, IR, and HRMS. Antifouling tests against Balanus amphitrite larvae settlement indicated that 1 and 2 exhibited inhibitory effect with EC50 values of 5.3, and 14.5μg/mL, respectively.

Pregnane steroids from the South China Sea gorgonian coral Subergorgia suberosa

Abstract Chemical investigation on gorgonian coral Subergorgia suberosa collected from the South China Sea led to the isolation and identification of eight 17-acetyl pregnane steroids ( 1 – 8 ), of which 1 , 6 and 7 were obtained for the first time from this species, as well as from the genus Subergorgia . Compounds 1 and 7 are new natural products. Compared with other species in the genus Subergorgia , pregnane steroids with 17-acetyl group ( 1 – 8 ) were only achieved from S. suberosa , suggesting that the 17-acetyl pregnane steroids might be characteristic constituents of S. suberosa , and may be useful as chemotaxonomic markers for the species S. suberosa .

Suberosols A−D, Four New Sesquiterpenes with β-Caryophyllene Skeletons from a Taiwanese Gorgonian Coral Subergorgia suberosa

Four new beta-caryophyllene-derived sesquiterpenes alcohols, suberosols A (1), B (2), C (3), and D (4), along with two known beta-caryophyllene-derived sesqueterpene ketones, buddledins C (5) and D (6), were isolated from a Taiwanese gorgonian coral Subergorgia suberosa. The structures of 1-4 were determined on the basis of extensive spectroscopic analyses. Cytotoxicity of these compounds toward various cancer cell lines is also described.

Two new subergane-based sesquiterpenes from a Taiwanese Gorgonian coral Subergorgia suberosa.

Chemical investigation of the ethyl acetate extract of the Taiwanese Gorgonian coral Subergorgia suberosa has resulted in the isolation of two new subergane-based sesquiterpenes, subergorgiol (1) and 2beta-acetoxysubergorgic acid (2), along with four known compounds, subergorgic acid methyl ester (3), 2beta-acetoxy methyl ester of subergorgic acid (4), 2beta-hydroxysubergorgic acid (5), and subergorgic acid (6). The structures of the new metabolites 1 and 2 were determined on the basis of extensive spectral analyses. Subergorgiol (1) may be the biosynthetic precursor of 2-6. Compound 3 was found to exhibit moderate cytotoxicity against the growth of HeLa cancer cells.

Studies on the secondary metabolites from the indian gorgonian subergorgia suberosa: isolation and characterization of four analogues of the cardiotoxin subergorgic acid

Chemical investigation of the methanol extract of the Indian ocean gorgonian coral Subergorgia suberosa resulted in isolation and identification of four novel compounds 2-5. Structural investigation revealed compound 1 to be subergorgic acid and the others its analogues.

Studies on the secondary metabolites from the Indian gorgonian Subergorgia suberosa: isolation and characterization of four analogues of the cardiotoxin subergorgic acid.

Chemical investigation of the methanol extract of the Indian ocean gorgonian coral Subergorgia suberosa resulted in isolation and identification of four novel compounds 2-5. Structural investigation revealed compound 1 to be subergorgic acid and the others its analogues.