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PubMed2004

Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications.

Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (qmax values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in < 2 min and equilibrium reached within the first 30 min of contact. Biosorption of cesium by FASs1 derived from P. australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles.

Adsorption↗

PubMed2004

Peyssonenynes a and B, novel enediyne oxylipins with DNA methyl transferase inhibitory activity from the red marine alga peyssonneliacaulifera.

Two novel omega3 fatty acids, obtained as monoacyl glycerol derivatives, were isolated as DNA methyl transferase inhibitors following bioassay-guided fractionation of the Fijian red marine alga Peyssonnelia caulifera. Both active metabolites, peyssonenynes A (1) and B (2), possess an unusual enediyne motif, whereas an inactive co-metabolite, peyssopyrone (3), contains an unusual gamma-pyrone functionality. The molecular structures of all three compounds were determined by NMR spectroscopy in combination with UV, IR, and MS data analysis. The instability of the enediyne monoacyl glycerol derivatives prevented their complete stereochemical assignments.

DNA Modification Methylases↗

PubMed1993

Kahukuenes, new diterpenoids from the marine alga Laurencia majuscula.

Kahukuenes A [4] and B [5], new diterpenoids possessing an unprecedented prenylated chamigrene structure as part of a decalin ring, were isolated from the Hawaiian marine alga Laurencia majuscula. Spectroscopic methods, including extensive 1D and 2D nmr studies, were used to establish the structure and relative stereochemistry of these two secondary metabolites.

Bridged Bicyclo Compounds↗

PubMed2005

Evidence for dissociation of chlorophyll b from the main light-harvesting complex in the oligomerization state isolated from marine alga, Bryopsis corticulans.

We investigated the composition and organization of chlorophylls in monomers, trimers and oligomers (small aggregates) of the main light-harvesting complex (LHC II) isolated from marine alga, Bryopsis corticulans, using a combination of measurements with reversed-phase high performance liquid chromatography (RP-HPLC) and steady-state spectroscopy of absorption, circular dichroism (CD) and low temperature fluorescence. The composition and organization of the chlorophylls in monomeric and trimeric LHC II were essentially identical to those of LHC II from higher plants. For LHC II oligomers, a large decrease of chlorophyll (Chl) b absorption and of CD signals corresponding to Chl b was consistent with the quantitative analysis of Chl b by RP-HPLC, indicating that oligomerization of the LHC II proteins significantly influenced spectroscopic properties and led to the dissociation of Chl b molecules from LHC II. Our data strongly suggested that protein oligomerization constitutes a structural basis for the decrease of Chl b molecules in LHC II of B. corticulans. The LHC II of B. corticulans might play a photoprotective role with the reduction of the ability of light absorption via alteration of its own structural conformation.

Amino Acid Sequence↗

PubMed2006

Acyl-homoserine lactones modulate the settlement rate of zoospores of the marine alga Ulva intestinalis via a novel chemokinetic mechanism.

Bacteria utilize quorum sensing to regulate the expression of cell density-dependant phenotypes such as biofilm formation and virulence. Zoospores of the marine alga Ulva intestinalis exploit the acyl-homoserine lactone (AHL) quorum sensing system to identify bacterial biofilms for preferential settlement. Here, we demonstrate that AHLs act as strong chemoattractants for Ulva zoospores. Chemoattraction does not involve a chemotactic orientation towards the AHL source. Instead, it occurs through a chemokinesis in which zoospore swimming speed is rapidly decreased in the presence of AHLs. The chemoresponse to AHLs was dependant on the nature of the acyl side chain, with N-(3-oxododecanoyl)-homoserine lactone (30-C12-HSL) being the most effective signal molecule. Mean zoospore swimming speed decreased more rapidly over wild-type biofilms of the marine bacteria Vibrio anguillarum relative to biofilms of the vanM mutant, in which AHL synthesis is disrupted. These data implicate a role for AHL-mediated chemokinesis in the location and preferential settlement of Ulva zoospores on marine bacterial assemblages. Exposure to AHLs did not inhibit the negative phototaxis of Ulva zoospores, indicating that chemoattraction to bacterial biofilms does not preclude the response to a light stimulus in substrate location.

4-Butyrolactone↗

PubMed2006

DNA methyl transferase inhibiting halogenated monoterpenes from the Madagascar red marine alga Portieria hornemannii.

Three new halogenated monoterpenes, 2, 3, and 4, along with the known compounds halomon (1) and two analogues, 5 and 6, were isolated from the Madagascar red marine alga Portieria hornemannii. The structures of all three new compounds were determined by NMR spectroscopy in combination with mass spectrometric data analysis. Two of these monoterpenes (1 and 2) were low micromolar inhibitors of DNA methyl transferase-1.

DNA Modification Methylases↗

PubMed2005

Antiviral activity of the marine alga Symphyocladia latiuscula against herpes simplex virus (HSV-1) in vitro and its therapeutic efficacy against HSV-1 infection in mice.

The antiviral activities of extracts from 5 species of marine algae collected at Haeundae (Pusan, Korea), were examined using plaque reduction assays. Although the activity of a methanol (MeOH) extract of Sargassum ringoldianum (Sargassaceae) was the most potent against several types of viruses, it was also cytotoxic. A MeOH extract of Symphyocladia latiuscula (Rhodomelaceae) and its fractions exhibited antiviral activities against acyclovir (ACV) and phosphonoacetic acid (PAA)-resistant (AP(r)) herpes simplex type 1 (HSV-1), thymidine kinase (TK(-)) deficient HSV-1 and wild type HSV-1 in vitro without cytotoxicity. The major component, 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (TDB) of a CH(2)Cl(2)-soluble fraction was active against wild type HSV-1, as well as AP(r) HSV-1 and TK(-) HSV-1 (IC(50) values of 5.48, 4.81 and 23.3 microg/ml, respectively). The therapeutic effectiveness of the MeOH extract and TDB from S. latiuscula was further examined in BALB/c mice that were cutaneously infected with HSV-1 strain 7401H. Three daily oral administrations of the MeOH extract and TDB significantly delayed the appearance of score 2 skin lesions (local vesicles) and limited the development of further score 6 (mild zosteriform) lesions in infected mice without toxicity compared with controls. In addition, TDB suppressed virus yields in the brain and skin. Therefore TDB should be a promising anti HSV agent.

Acyclovir↗

PubMed2003

Long-term hyposaline and hypersaline stresses produce distinct antioxidant responses in the marine alga Dunaliella tertiolecta.

Tolerance to salinity stress in higher plants correlates to levels of antioxidant enzymes and/or substrates. Do hyperosmotic and hypoosmotic stress induce antioxidant responses in salt tolerant algae, and if so, are these responses the same for both excess and minimal salinity? To answer these questions, cultures of the marine alga Dunaliella tertiolecta (Chlorophyta) were grown in seven salinities covering a 60-fold range from 0.05 to 3.0 mol/L NaCl. Long-term effects of salinity on growth and antioxidant parameters were determined. Growth rates were reduced at the salinity extremes (0.05 mol/L NaCl and 3 mol/L NaCl) indicating the cultures were stressed. The levels of six antioxidant enzymes and three antioxidant substrates were quantified at these growth salinities. Compared to growth at optimum salinities (i.e. 0.2-0.5 mol/L NaCl), high salinities produced a 260% increase in monodehydroascorbate reductase, a doubling of ascorbate peroxidase activity and a three-fold increase in the rate of dark respiration. Cells acclimated to low growth salinities (hyposaline stress, i.e. < 0.2 mol/L NaCl) showed major increases in glutathione and alpha-tocopherol coupled with decreases in Fv/Fm ratios and in total and reduced ascorbate compared to moderate and high external salinities. Cell volumes remained unchanged, except at the lowest salinity where they doubled. Catalase, superoxide dismutase, dehydroascorbate reductase and glutathione reductase activities were not altered by extreme salinities. The involvement of oxidative stress at both salinity extremes is implied by the alterations in antioxidant enzymes and substrates, but the specific changes are very different between hypo and hypersaline stresses.

Ascorbate Peroxidases↗

PubMed1997

Selective antitumor activity in vitro from marine algae from Japan coasts.

In vitro selective antitumor activity was tested as a general screening parameter for biologically active substances from a wide range of species of seaweed, 1446 samples of 306 species of marine algae from Japan's coasts. The algae extracts were prepared successively first by phosphate buffered saline (PBS) and then by methanol, and then tested for in vitro selective antitumor activity against murine lymphoid leukemia L1210 cells and for low cytotoxic activity against NIH-3T3 normal cells. Strong cytotoxic activity against L1210 cells was found in 47 species of algae, also showing similar cytotoxicity to mouse NIH-3T3 normal cells. However, four species of green algae showed strong activity specifically against L1210 cells, with low cytotoxicity to normal cells. Such selective activity was conspicuous in two brown and two green algae extracts. In particular, methanol extracts from the green alga, Cladophoropsis vaucheriaeformis, exhibited high viability (86%) to normal cells, showing selective cytotoxicity to tumor cells. This alga extract was no cytocidalic, but cytostatic against L1210 cells. Furthermore, the results of a cytotoxic spectrum test with 9 cell lines including those of L1210 and NIH-3T3 demonstrated that this extract acted strongly only against leukemic cell lines L1210 and P388.

Animals↗

PubMed2002

[Marine algae of Baja California Sur, Mexico: nutritional value].

The Baja California Peninsula is one of the richest regions of seaweed resources in México. The objective of this study was to determine the chemical composition of some marine algae species of Baja California Sur, with an economical potential due to their abundance and distribution, and to promote their use as food for human consumption and animal feeding. The algae studied were Green (Ulva spp., Enteromorpha intestinalis, Caulerpa sertularoides, Bryopsis hypnoides), Red (Laurencia johnstonii, Spyridia filamentosa, Hypnea valentiae) and Brown (Sargassum herporizum, S. sinicola, Padina durvillaei, Hydroclathrus clathrathus, Colpomenia sinuosa). The algae were dried and ground before analysis. In general, the results showed that algae had a protein level less than 11%, except L. johnstonii with 18% and low energy content. The ether extract content was lower than 1%. However, the algae were a good source of carbohydrates and inorganic matter.

Animals↗

PubMed1995

Binding studies on the combining site of a GalNAc alpha 1-->-specific lectin with Thomsen-Friedenreich activity prepared from green marine algae Codium fragile subspecies tomentosoides.

The combining site of a GalNAc alpha 1-->-specific lectin (CFT) with Thomsen-Friedenreich (T, Gal beta 1-->3-GalNAc alpha 1-->Ser/Thr) activity, purified from the subspecies tomentosoides of green marine algae Codium fragile was studied by quantitative precipitin and precipitin-inhibition assays. Of 27 glycoforms tested, Tn (GalNAc alpha 1-->Ser/Thr) glycoprotein from armadillo submandibular glands, and asialo porcine submandibular glycoprotein, which contains T, Tn and GalNAc alpha 1-->3Gal(A) sequences, completely precipitated the lectin added, and less than 1 microgram glycoprotein was required to precipitate 50% 4.7 micrograms lectin nitrogen. However, CFT precipitated negligibly with Pneumococcus type-XIV polysaccharide and asialo human alpha 1-acid glycoprotein, that contain exclusively the human blood-type-II precursor sequence (II, Gal beta 1-->4GlcNAc) at the nonreducing ends. Among the sugar inhibitors tested, the human blood A-active trisaccharide [Ah, GalNAc alpha 1-->3 (LFuc alpha 1-->2)Gal] was the best inhibitor; it was about twice as active as the T disaccharide. Oligosaccharides without GalNAc alpha 1--> as part of their sequences were inactive, indicating that the acetamido group at C2 of galactose is essential for binding and that GalNAc is the main contributor in the T sequence for binding. From the data provided, it is clear that the combining site of CFT requires an alpha-anomer of GalNAc and recognizes Ah, internal GalNAc alpha 1--> of T and Tn determinants of glycans, but not the blood group I/II (Gal beta 1-->3/4GlcNAc) sequences. Consequently, CFT is a useful reagent for detecting GalNAc alpha 1-->-containing glycoconjugates.

Acetylgalactosamine↗

PubMed1979

The mutagenicity of natural products from marine algae.

5 polyhalogenated hydrocarbon natural products isolated from the marine red alga Plocamium spp. were tested for mutagenicity in the Ames reversion assay. All 5 of the compounds induced revertants in Salmonella typhimurium strains TA100 and TA1535, indicating the mutational events involved base substitutions. One of the compounds, designated cross-conjugated ketone, was shown to be almost 200 times more effective as a mutagen than was ethyl methanesulfonate.

Hydrocarbons, Halogenated↗

PubMed1995

Nonsteroidal human progesterone receptor modulators from the marine alga Cymopolia barbata.

The co-transfection assay is a novel functional assay using cells transiently transfected with plasmids encoding intracellular receptors and corresponding reporter genes. Using this assay, natural product extracts were tested to identify compounds that modulate intracellular receptor activity, measured as changes in reporter gene activity. A crude extract of the marine alga Cymopolia barbata was found to inhibit progesterone-stimulated reporter gene expression in cells transfected with the human progesterone receptor (hPR) and an appropriate reporter construct. Purification of the active constituents of the extract, guided by the co-transfection assay, yielded two diastereomers of cyclocymopol monomethyl ether, possessing opposing pharmacological activities with the hPR. The antagonist (3R)-cyclocymopol monomethyl ether (LG100127) blocked 1 nM progesterone-stimulated reporter gene expression with an IC50 value of 549 +/- 55 nM in the co-transfection assay. The agonist (3S)-cyclocymopol monomethyl ether (LG100128) had efficacy similar to that of progesterone and an EC50 value of 35 +/- 2 nM. Stimulation by progesterone of the hPR in the human breast cancer cell line T-47D results in enhanced expression of alkaline phosphatase; LG100127 blocked alkaline phosphatase expression stimulated either by progesterone or by LG100128, and LG100128 mimicked progesterone in this assay. Both diastereomers displaced [3H]progesterone from baculovirus-expressed hPR. LG100127 and LG100128 each interacted with the human androgen receptor but did not interact with the human glucocorticoid receptor, estrogen receptor, vitamin D receptor, or retinoid receptors. In summary, these in vitro studies describe the first nonsteroidal pharmacophores for the hPR and demonstrate the use of the co-transfection assay in their discovery.

Animals↗

PubMed2006

The interactive effects of binary mixtures of three antifouling biocides and three heavy metals against the marine algae Chaetoceros gracilis.

Three of the most commonly used antifouling booster biocides that are usually combined with copper or copper compounds are Irgarol 1051, Diuron, and Zn pyrithione. This study represents an assessment of the interactive effects of the antifouling biocides combined with each other, and with three heavy metals (Cu, Cd, and Zn) in binary mixtures, on the marine algae Chaetoceros gracilis. Seventy-two hour growth inhibition tests were carried out, and the IC50 values of the chemicals were determined along with growth inhibition (%) for several concentrations. The joint effect of the binary mixtures of all the chemicals was assessed by using two models, concentration addition model and the model of probabilities. The following increasing order of toxicity was obtained: Cd < Zn < Cu < Diuron < Zn pyrithione < Irgarol 1051. The interactive effects of the organic chemicals combined with each other on the growth of Ch. gracilis were firmly synergistic. Irgarol 1051 combined with Cd performed synergistic effects, and Zn pyrithione with copper and cadmium action was strictly antagonistic, and the results of the two models were in agreement in almost all mixtures.

Cadmium↗

PubMed1989

Three new and bioactive icosanoids from the temperate red marine alga Farlowia mollis.

Three new dihydroxyicosanoids, 12(R),13(R)-dihydroxyicosa-5(Z),8(Z),10(E),14(Z)-tetraenoic acid, 12(R),13(R)-dihydroxyicosa-5(Z),8(Z),10(E),14(Z),17(Z)-pentaeno ic acid and 10(R*),11(R*)-dihydroxyoctadeca-6(Z),8(E),12(Z)-trienoic acid, have been isolated from a previously unstudied temperate red marine alga, Farlowia mollis (Cryptonemiales, Rhodophyta). The structures of these new metabolites have been deduced from detailed nuclear magnetic resonance and mass spectrometry analyses on stabilized diacetate-methyl esters and stereochemistry deduced by 1H NMR couplings and CD analysis of a dibenzoate derivative. Collectively, these new natural products modulate fMLP-induced superoxide anion generation in human neutrophils, inhibit the conversion of arachidonic acid to lipoxygenase products by human neutrophils, and inhibit the functioning of the dog kidney Na+/K+ ATPase.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗

PubMed1996

Determination of bioconcentration potential of tetrachloroethylene in marine algae by 13C.

The use of stable isotope of organic-carbon, organic-13C, as a tracer for the determination of the concentration of tetrachloroethylene (PCE), CA, in Heterosigma akashiwo and Skeletonema costatum was examined. CA determined by the 13C and GC methods showed good agreement with each other. This suggests that it is reasonable and reliable to determine the bioconcentration potential of PCE in marine algae. Fitting values of bioconcentration potential parameters, including uptake rate constant k1, elimination rate constant k2 and bioconcentration factor on the basis of dry weight BCFD, were done not only to the time course for PCE uptake by the algae with the bioconcentration model, but also to experimental data for "percent inhibition(%) approximately exposure concentration of PCE approximately time" with the combined bioconcentration and probability model. The values obtained from the bioconcentration model were consistent with those from the combined bioconcentration and probability model. With the parameters (such as k1, k2, growth rate constant kG, critical concentration of HOCs in the organism resulting in growth inhibition CA* and spread factor S) the variability in toxicity (such as EC10, EC50, EC70) can be estimated from the combined bioconcentration and probability model, which fits well with the experimental observations.

Carbon Radioisotopes↗

PubMed2004

Studies on the bioactivity and elementology of marine algae from the coast of Karachi, Pakistan.

Some species of marine benthic algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta collected from different coastal areas of Karachi (Pakistan) were investigated for their antibacterial, antifungal, phytotoxic and insecticidal activities. Brown seaweeds showed greater antibacterial activity than the green and red ones. Botryocladia leptopoda (J. Ag.) Kylin exhibited the greatest antifungal activity and Codium shameelii Nizam. the least. The highest phytotoxic activity (95%) was displayed by Enteromorpha intestinalis (L.) Nees at 100 microg/mL concentration, while Osmundea pinnatifida (Huds.) Stack. showed the low insecticidal activity as compared to the other investigated species. Many elements e.g. Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Na, Pb, Zn were determined quantitatively. Among them Ca, Cr and Pb were found to occur in largest amount in green seaweeds, Co, Cu, Fe and Zn in greatest quantity in brown seaweeds, while Cd, K, Mg and Na in highest proportion in the investigated red seaweeds.

Animals↗

PubMed2001

Peroxynitrite scavenging and cytoprotective activity of 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether from the marine alga Symphyocladia latiuscula.

Peroxynitrite (ONOO(-)), formed from the reaction of superoxide (O(2)*(-)) and nitric oxide (*NO), is a cytotoxic species that can oxidize several cellular components such as proteins, lipids, and DNA. It has been implicated in diseases such as Alzheimer's disease, rheumatoid arthritis, cancer, and atherosclerosis. Due to the lack of endogenous enzymes responsible for ONOO(-) inactivation, developing a specific ONOO(-) scavenger is of considerable importance. The aim of this study was to evaluate the ability of marine natural products to scavenge ONOO(-) and to protect cells against ONOO(-). Methanolic extracts of 17 marine alga were tested for their ONOO(-) scavenging activity. Among them, Symphyocladia latiuscula showed the potent scavenging activity. CH(2)CH(2) fraction was partitioned with CH(2)CH(2) following n-hexanal extraction from the methanol extract of S. latiuscula. It was highly effective for ONOO(-) scavenging activity. Further analysis of the active fractionated extract identified 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (TDB) as a potent ONOO(-) scavenger. The data demonstrated that TDB led to decreased ONOO(-)-mediated nitration of tyrosine through electron donation. TDB showed significant inhibition on nitration of bovine serum albumin and low-density lipoprotein by ONOO(-) in a dose-dependent manner. It also provided cytoprotection from cell damage induced by ONOO(-). TDB can be developed as an effective peroxynitrite scavenger for the prevention of the involved diseases.

Animals↗