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The use of omics technologies to profile an organism's systemic response to environmental changes can improve the effectiveness of biomonitoring. In cell physiology, the dynamic characteristics of membranes can be used to identify lipid profiles that detect environmental threats and assess the health problems associated with them. The efficacy of this approach was demonstrated by profiling glycerophosphocholines (GPCs, a major membrane lipid class) in the coral Seriatopora caliendrum after exposure to Irgarol 1051. A quantitative biomonitoring model for this photosystem II herbicide was developed by correlating variations in coral lipid profile with herbicide exposure levels and degree of photoinhibition. After 4 days of exposure, the predominant changes correlated with photoinhibition were an increase in lyso-GPCs and saturated GPCs and a decrease in phosphatidylcholines with unsaturated C18 chains or a polyunsaturated C22 chain. A time-course experiment showed that most of these lipid changes occurred opposite to the initial response and that the persistent changes can be attributed to photosynthetic shortages and the membrane accommodation of photoinhibition-induced oxidative conditions. These changes can help predict risk factors leading to coral bleaching. In this study, the application of a lipidomic methodology to characterize the adaptation of coral to ambient contamination serves as a basis for advancing environmental monitoring and assessment.

Coral is commonly selected as a bioindicator of detecting a variety of adverse factors such as photosystem II herbicide Irgarol 1051, through measuring pan-type biomarkers. To improve the effectiveness of biomonitoring, omic technologies have recently been applied to model the systemic changes in an organism. Membrane lipids create a dynamic cell structure based on the physiological state, which offers a distinct lipid profile to specifically detect environmental threats and assess the associated health risk. To demonstrate the potential of a lipidomic methodology for biomonitoring, the glycerophosphocholine (GPC) profiles of the coral Seriatopora caliendrum were observed during 3 days of Irgarol (0.1–2.0 μg/L) exposure. The lipid profile variations were modeled based on the Irgarol dose and the coral photoinhibition levels to develop an excellent quantitative model. The predominant changes correlated with the photoinhibition, decreasing the lyso-GPCs and GPCs with lower unsaturated chains and increasing GPCs with highly polyunsaturated chains, can be related to the consequence of blocking the photosynthetic electron flow based on the associated physiological roles. Other dose-specific lipid changes led to the partial exchange of PC(O-16:0/20:5) for PC(16,0/20:5) as a first-line response to counteract the membrane opening caused by Irgarol. Increased levels of the GPCs with 20:4 or 22:6 chains, which can promote mitochondrial functionality, confirmed an elevated respiration level in the coral exposed to Irgarol levels of >0.5 μg/L. Notably, plasmanylcholines with 20:4 or 22:6 chains and phosphatidylcholines with 22:6 or 22:5 chains, which can alter their membrane material properties to mitigate organelle pre-swelling and swelling in different ways, formed in the coral exposed to the 0.5 and 2.0 μg/L Irgarol levels. Such coral adaptations further predict the health risks associated with altered physiological conditions. In this study, the lipidomic methodology is demonstrated as a potential tool for environmental monitoring and assessment.

Photosystem II herbicides, such as Irgarol 1051, are frequently found as common contaminants in coral reefs and represent a particular threat to coral health due to the effect of photoinhibition on symbiotic algae. Membrane lipids form dynamic structures depending on cell requirements, offering a distinct lipid profile for characterizing ambient condition-induced cellular alterations. To obtain fundamental insight into the effect of herbicides on coral health, the glycerophosphocholine profiles of symbiosomes in a coral, Seriatopora caliendrum, were observed during 4 days of Irgarol exposure (50–200 ng/L). On day 1 of exposure, the predominant changes were an increase in phosphatidylcholines with 2 unsaturated chains, especially PC(22:6/22:6), a saturated plasmanylcholine PC(O-18:0/16:0) and a decrease in polyunsaturated plasmanylcholines. These changes indicated an upregulation of membrane-related functions to cope with physiological disturbances, such as increased H2O2 levels, induced by photoinhibition. However, these changes were mostly inverted or insignificant after day 1of exposure. A decrease in lyso-glycerophosphocholines and an increase in phosphatidylcholines with a polyunsaturated chain were also induced as the exposure time increased. Based on the physicochemical properties, these lipid changes can be considered to counteract lipid oxidation-induced perturbations in membrane structure and to protect against oxidative attack. In addition, the effect of fat-soluble antioxidants on lipid peroxidation was observed in the high-dose (200 ng/L)-treated group, resulting in a change in the lipid profile disproportionate to the dose. This study concludes that coral accommodates the membrane lipid profile of symbiosomes to herbicide-induced photoinhibition dependent on the duration of exposure.

Zinc oxide nanoparticles (nZnOs) released from popular sunscreens used during marine recreation apparently endanger corals; however, the known biological effects are very limited. Membrane lipids constitute the basic structural element to create cell a dynamic structure according to the circumstance. Nano-specific effects have been shown to mechanically perturb the physical state of the lipid membrane, and the cells accommodating the actions of nZnOs can be involved in the alteration of the membrane lipid composition. To gain insight into the effects of nanoparticles on coral, glycerophosphocholine (GPC) profiling of the coral Seriatopora caliendrum exposed to nZnOs was performed in this study. Increasing lyso-GPCs, docosapentaenoic acid-possessing GPCs and docosahexaenoic acid-possessing GPCs and decreasing arachidonic acid-possessing GPCs were the predominant changes responded to nZnO exposure in the coral. A backfilling of polyunsaturated plasmanylcholines was observed in the coral exposed to nZnO levels over a threshold. These changes can be logically interpreted as an accommodation to nZnOs-induced mechanical disturbances in the cellular membrane based on the biophysical properties of the lipids. Moreover, the coral demonstrated a difference in the changes in lipid profiles between intra-colonial functionally differentiated polyps, indicating an initial membrane composition-dependent response. Based on the physicochemical properties and physiological functions of these changed lipids, some chronic biological effects can be incubated once the coral receives long-term exposure to nZnOs.

Scleractinian corals have displayed phenotypic gradients of polyps within a single genotypic colony, and this has profound implications for their biology. The intrinsic polymorphism of membrane lipids and the molecular interactions involved allow cells to dynamically organize their membranes to have physicochemical properties appropriate for their physiological requirements. To gain insight into the accommodation of the cellular membrane during ontogenetic shifts, intra-colony differences in the glycerophosphocholine profiling of a pocilloporid coral, Seriatopora caliendrum, were characterized using a previously validated method. Specifically, several major polyunsaturated phosphatidylcholines showed higher levels in the distal tissue of coral branches. In contrast, the corresponding molecules with 1-2-degree less unsaturation and plasmanylcholines were expressed more highly in the proximal tissue. The lipid profiles of these two colonial positions also contrasted sharply with regard to the saturated, monounsaturated, and lyso-glycerophosphocholine ratios. Based on the biochemical and biophysical properties of these lipids, the associated modulation of cellular membrane properties could be related to the physiological requirements, including coral growth and aging, of the functionally differentiated polyps. In this study, the metabolic regulation of membrane lipids involved in the functional differentiation of polyps within a S. caliendrum colony was identified.

A novel sesquiterpenoid, rumphellaoic acid A (1), was isolated from the gorgonian coral Rumphella antipathies, and was found to possess a carbon skeleton that was obtained for the first time from a natural sources. The structure of 1 was elucidated by spectroscopic methods and this compound and was found to exert a moderate inhibitory effect on the release of elastase by human neutrophils.

Two new marine-derived caryophyllene-type sesquiterpenoids, rumphellols A and B (1 and 2), were obtained from the gorgonian coral, Rumphella antipathies, collected off the waters of Taiwan. Although caryophyllene-type sesquiterpenes are rarely found in marine organisms, compounds of this type could be principal components of R. antipathies. The structures of new Compounds 1 and 2 were determined by analysis of their spectroscopic data, including 1D and 2D NMR experiments. Caryophyllene 1 and 2 were evaluated in terms of their anti-inflammatory activity by examining their inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils.

Previous studies on the chemical constituents of soft corals belonging to the genus Sinularia have led to the isolation of a number of interesting secondary metabolites and some of these were found to possess extensive bioactivities [1–3]. Continuation investigation on the chemical constituents of the marine invertebrates collected off the waters of Taiwan, two new cembrane-type diterpenoids, arbolides A (1) and B (2), and a known steroid, crassarosterol A (3) [4], were isolated from the soft coral Sinularia arborea (family Alcyonacea) (Figure 1). In this paper, we describe the isolation, structure determination and cytotoxicity of compounds 1–3.

A new quinone derivative, flexibilisquinone (1), was isolated from the cultured soft coral Sinularia flexibilis, originally distributed in the waters of Taiwan. The structure of quinone 1 was established by extensive spectroscopic methods, particularly 1D and 2D NMR experiments. In the in vitro anti-inflammatory effects test, quinone 1 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 proteins of the LPS-stimulated RAW264.7 macrophage cells.

Three new clovane-related sesquiterpenoids, rumphellclovanes C–E (1–3), and a new natural clovane, clovan-2,9-dione (4), were isolated from a gorgonian coral Rumphella antipathies. The structures of clovanes 1–4 were elucidated by spectroscopic methods and by comparison of the spectral data with those of related analogues. Rumphellclovane C (1) was proven to be the first clovane-type sesquiterpenoid containing an e-lactone moiety. A plausible biosynthetic pathway between clovanes 1 and 2 was proposed. Clovane 4 displayed significant inhibitory effects on the generation of superoxide anion and the release of elastase by human neutrophils.

A new clerodane-type diterpenoid, echinoclerodane A (1), was isolated from a Formosan gorgonian coral Echinomuricea sp. The structure of 1 was elucidated by spectroscopic methods. Echinoclerodane A (1) is the first clerodane-type compound obtained from the marine organisms belonging to the phylum Cnidaria. Echinoclerodane A (1) exhibited moderate cytotoxicity toward MOLT-4, HL-60, DLD-1 and LoVo tumor cells and inhibitory effects on the generation of superoxide anion and the release of elastase by human neutrophils.

New eunicellin-based diterpenoids, klysimplexins U–X (1–4), were isolated from a cultured soft coral Klyxum simplex. Their structures were elucidated by spectroscopic methods, particularly in 1D an...

Two new briarane-type diterpenoids, fragilides H (1) and I (2), along with a known metabolite, (+)-11β,20β-epoxyjunceellolide D (3), were isolated from the sea whip gorgonian coral Junceella fragil...

Eight new eunicellin-base diterpenoids, klysimplexins A–H (1–8), were isolated from a cultured soft coral Klyxum simplex. Their structures were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The structure of 1 was further confirmed by a single-crystal X-ray diffraction analysis and the application of modified Mosher's method. Metabolites 2 and 8 were found to be cytotoxic toward a limited panel of cancer cell lines.

Two new cembranoids, flexibilisolide A (1) and flexibilisin A (2), along with one known combranoid 5 have been isolated from the cultured soft coral Sinularia flexibilis. Furthermore, two new cembranoids, flexibilisolide B (3) and flexibilisin B (4), along with two known combranoids (5, 6), have been isolated from the wild-type soft coral S. flexibilis. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis and by comparison of NMR data with those of known compounds. The metabolites 5 and 6 have been shown to exhibit weak cytotoxic activity against MCF-7 cancer cell line.

Chemical investigations on the sea whip gorgonian coral Junceella juncea have led to the isolation of five new 8-hydroxybriarane diterpenoids, junceols D-H (1-5). The structures of briaranes 1-5 were determined on the basis of spectroscopic methods and the methylenecyclohexane rings were found to exist in boat form in these new diterpenoids. Junceols D (1) and F-H (3-5) exhibited cytotoxicity toward CCRF-CEM and DLD-1 tumor cells and junceols E-H (2-5) displayed weak inhibitory effects on superoxide anion generation by human neutrophils.

Six new caryophyllane-related natural products, including two carboxylated sesquiterpenoids, rumphellolides A (1) and B (2), and four norsesquiterpene alcohols, rumphellolides C-F (3-6), were isolated from the Formosan gorgonian coral Rumphella antipathies. The structures of the above new natural products were established on the basis of extensive spectral data analysis. Rumphellolides A (1), D (4), E (5), and F (6) showed weak antibacterial activity.

A novel clovane-type sesquiterpenoid derivative, rumphellclovane B (1), which possesses an unprecedented δ-lactone moiety, and a new natural clovane, 9α-hydroxyclovan-2-one (2), were isolated from ...

In the present study, the membrane lipid composition of corals from a region with tidally induced upwelling was investigated. The coral community is subject to strong temperature oscillations yet flourishes as a result of adaptation. Glycerophosphocholine profiling of the dominant pocilloporid coral, Seriatopora caliendrum, was performed using a validated method. The coral inhabiting the upwelling region shows a definite shift in the ratio of lipid molecular species, covering several subclasses. Mainly, the coral possesses a higher percentage of saturated, monounsaturated and polyunsaturated plasmanylcholines and a lower percentage of polyunsaturated phosphatidylcholines. Higher levels of lyso-plasmanylcholines containing saturated or monounsaturated fatty acid chains were also revealed in coral tissue at the distal portion of the branch. Based on the physicochemical properties of these lipids, we proposed mechanisms for handling cellular membrane perturbations, such as tension, induced by thermal oscillation to determine how coral cells are able to spontaneously maintain their physiological functions, in both molecular and physical terms. Interestingly, the biochemical and biophysical properties of these lipids also have beneficial effects on the resistance, maintenance, and growth of the corals. The results of this study suggest that lipid metabolic adjustment is a major factor in the adaption of S. caliendrum in upwelling regions.

A novel 4,5-seco-caryophyllane sesquiterpenoid derivative, rumphellaone A (1), which was found to possess an unprecedented γ-lactone moiety, was isolated from the gorgonian coral Rumphella antipathies. The structure of 1 was elucidated by spectroscopic method. A plausible biosynthetic pathway of compound 1 was proposed.

A novel clovane-related derivative, rumphellclovane A (1), which was found to possess a new carbon skeleton, and a new natural clovane, 2β-hydroxyclovan-9-one (2), were isolated from the gorgonian coral Rumphella antipathies. The structures of metabolites 1 and 2 were elucidated by spectroscopic analysis and by comparison of the spectral data with those of related clovane analogues. A plausible biosynthetic pathway of 1 was proposed.

Three natural clovane-related sesquiterpenoids, 2beta-acetoxyclovan-9alpha-ol (1), 9alpha-acetoxyclovan-2beta-ol (2) and clovan-2beta,9beta-diol (3), were isolated from the gorgonian coral Rumphella antipathies. The structures of clovanes 1-3 were elucidated by spectroscopic methods and by comparison of the spectral data with those of known clovane analogues. This is the first time that clovanes 1-3 have been isolated from a natural source. Clovanes 1 and 2 displayed inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils.

Three new cembrane-type diterpenoids, flexibilins A–C (1–3), along with a known cembrane, (−)-sandensolide (4), were isolated from the soft coral, Sinularia flexibilis. The structures of cembranes 1–4 were elucidated by spectroscopic methods. The structure of 4, including its absolute stereochemistry, was further confirmed by single-crystal X-ray diffraction analysis. Cembrane 2 displayed a moderate inhibitory effect on the release of elastase by human neutrophils.

New eunicellin-based diterpenoids, klysimplexins U–X (1–4), were isolated from a cultured soft coral Klyxum simplex. Their structures were elucidated by spectroscopic methods, particularly in 1D an...

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.

Isolation and structure elucidation of title sesquiterpenoid (I) and the natural clovane (II) are described.

A novel 4,5-seco-caryophyllane sesquiterpenoid derivative, rumphellaone A (1), which was found to possess an unprecedented γ-lactone moiety, was isolated from the gorgonian coral Rumphella antipathies. The structure of 1 was elucidated by spectroscopic method. A plausible biosynthetic pathway of compound 1 was proposed.

New eunicellin-base diterpenoids, klysimplexins I–T (1–12), were isolated from a cultured soft coral Klyxum simplex. Their structures were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The absolute stereochemistry of 4 was determined by Mosher's method. Compounds 9 and 12 have been shown to exhibit cytotoxicity toward a limited panel of cancer cell lines. Compounds 2–6, 10 and 11 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. Compounds 10 and 11 also could effectively reduce the level of COX-2 protein.

Two new cembranoids, flexibilisolide A (1) and flexibilisin A (2), along with one known combranoid 5 have been isolated from the cultured soft coral Sinularia flexibilis. Furthermore, two new cembranoids, flexibilisolide B (3) and flexibilisin B (4), along with two known combranoids (5, 6), have been isolated from the wild-type soft coral S. flexibilis. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis and by comparison of NMR data with those of known compounds. The metabolites 5 and 6 have been shown to exhibit weak cytotoxic activity against MCF-7 cancer cell line.

A novel caryophyllane-related norsesquiterpenoid, rumphellolide I (1), which possessing an unprecedented cyclic ether bridge between C-4 and C-8, was isolated from the gorgonian coral Rumphella antipathies. The structure of 1 was established by spectral data analysis and this compound showed moderate inhibitory effects on elastase release by human neutrophils.

The first chloride-containing caryophyllane-type sesquiterpenoid, designated as rumphellatin D (1), was isolated from gorgonian coral Rumphella antipathies. The structure of 1 was established by sp...

Chemical investigations on the sea whip gorgonian coral Junceella juncea have led to the isolation of five new 8-hydroxybriarane diterpenoids, junceols D-H (1-5). The structures of briaranes 1-5 were determined on the basis of spectroscopic methods and the methylenecyclohexane rings were found to exist in boat form in these new diterpenoids. Junceols D (1) and F-H (3-5) exhibited cytotoxicity toward CCRF-CEM and DLD-1 tumor cells and junceols E-H (2-5) displayed weak inhibitory effects on superoxide anion generation by human neutrophils.

Six new caryophyllane-related natural products, including two carboxylated sesquiterpenoids, rumphellolides A (1) and B (2), and four norsesquiterpene alcohols, rumphellolides C-F (3-6), were isolated from the Formosan gorgonian coral Rumphella antipathies. The structures of the above new natural products were established on the basis of extensive spectral data analysis. Rumphellolides A (1), D (4), E (5), and F (6) showed weak antibacterial activity.

From the ethyl acetate extract of the soft coral Sinularia arborea, a new cembrane-type diterpenoid, arbolide C (1), along with (+)-sarcophytol T (2), an enantiomer of the known cembrane, sarcophytol T, were isolated. The structures of compounds 1 and 2 were established by spectroscopic methods and 1 was found to display an inhibitory effect on the release of elastase by human neutrophils.

A novel caryophyllane-related norsesquiterpenoid, rumphellolide I (1), which possessing an unprecedented cyclic ether bridge between C-4 and C-8, was isolated from the gorgonian coral Rumphella antipathies. The structure of 1 was established by spectral data analysis and this compound showed moderate inhibitory effects on elastase release by human neutrophils.

A new caryophyllane-type tetrahydropyran norsesquiterpenoid, rumphellolide G (1), has been isolated from the gorgonian coral Rumphella antipathies, collected off southern Taiwan coast. The structur...

A new cembranoid, trocheliophorol (1), and a known cembranoid sarcophine have been isolated from the cultured soft coral Sarcophyton trocheliophorum. The structure of 1 was determined on the basis of extensive spectroscopic analysis. Compound 1 is the first α,β-unsaturated-γ-lactone cembrane that was found to possess a tetrahydrofuran moiety with an 8,11-ether linkage in a 14-membered ring.

Two sesquiterpenoid phenols, including a new natural product 1 [(7S, 10R)-(+)-10,11-epoxycurcuphenol] and a known metabolite, (+)-curcuphenol (2), were isolated from a gorgonian coral identified as Echinomuricea sp. The structures of 1 and 2 were elucidated by interpretations of spectral data and by comparison of the related physical and spectral data with those of related metabolites. Compound 2 was found to show significant inhibitory effects on elastase release by human neutrophils.