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At least 19 recordsLinked to original sources
PubMed1992

Anticoagulants from marine algae.

Anticoagulant properties were first described in extracts from marine algae over 50 years ago. Currently over 60 species, representing the three major divisions of marine algae, have been reported to have such properties. The major active components are a variety of sulphated polysaccharides, some of which characterize as proteoglycans. These sulphated polysaccharides/proteoglycans exert antithrombin properties, primarily mediated by heparin cofactor II (HCII). However antithrombin III (ATIII) mediated anticoagulant activities, as well as an element of direct antithrombin activity, have also been observed.

Amino Acid Sequence↗
PubMed1978

Antiviral activity of extracts from marine algae.

Extracts of two species of marine algae, Constantinea simplex and Farlowia mollis, were tested for antiviral activity in tissue culture and in experimental infections of mice. Treatment of confluent mouse embryo fibroblast cell monolayers with either compound before viral inoculation was effective in inhibiting the replication of herpes simplex virus type 1 and type 2, vaccinia virus, and vesicular stomatitis virus, but not encephalomyocarditis virus, Semliki Forest virus, or murine cytomegalovirus. Prophylactic administration of these extracts was effective in reducing final mortality or prolonging the mean day of death of animals inoculated by the intraperitoneal, intracerebral, or intranasal routes with herpes simplex virus type 2. When therapy was initiated after viral inoculation or at a site other than that of viral inoculation, no significant effect on mortality or on mean day of death was observed. Neither preparation was effective in mice inoculated intraperitoneally with encephalomyocarditis virus, Semliki Forest virus, or murine cytomegalovirus or in animals infected intravaginally with herpes simplex virus type 2. The prophylactic but not therapeutic antiviral activity of these preparations seriously limits their potential use in human herpes simplex virus infections.

Animals↗
PubMed1976

Ion transport studies and determination of the cell wall elastic modulus in the marine alga Halicystis parvula.

Using cultured cells of the marine alga, Halicystis parvula, we measured the concentrations of 11 inorganic ions in the vacuolar sap and the electrical potential difference (PD) between the vacuole and the external solution. In normal cells under steady-state conditions a comparison of the electrochemical equilibrium (Nernst) potential for each ion with the PD of -82 mV (inside negative) indicates that Na+ and K+ are actively transported out of the vacuole whereas all anions are pumped into the cell. Although the [K+] in the vacuole is only 9 mM, the cytoplasmic [K+] is about 420 mM, which suggests that the outwardly directed pump is at the tonoplast. Using large Halicystis cells we perfused the vacuole with an artificial seawater and conducted a short-circuit analysis of ion transport. The short-circuit current (SCC) of 299 peq - cm-2-s-1 is not significantly different from the net influx of Cl-. There is a small, but statistically significant net efflux of K+ (less than 1 pmol-cm-2.-1), while the influx and efflux of Na+ are not significantly different. Therefore, the SCC is a good measure of the activity of the Cl- pump. Finally, we measured the volumetric elastic modulus (epsilon) of the cell wall by measuring the change in cell volume when the internal hydrostatic pressure was altered. The value of epsilon at applied pressures between 0 and 0.4 atm is about 0.6 atm, which is at least 100-fold lower than the values of epsilon for all other algae which have been studied.

Biological Transport, Active↗
PubMed1975

Antimicrobial agents from marine algae.

The antimicrobial activity of five compounds extracted from marine algae was tested against Staphylococcus aureus, Salmonella choleraesuis, Mycobacterium smegmatis, Candida albicans, and Escherichia coli. Three of the compounds, cycloeudesmol, laurinterol, and debromolaurinterol, exhibited activity at concentrations approaching that of streptomycin. None of the compounds inhibited all of the organisms tested. There appeared to be selectivity for gram-positive microbes.

Anti-Bacterial Agents↗
PubMed1991

Cytotoxic activity of marine algae and a cytotoxic principle of the brown alga Sargassum tortile.

Partition fractions of hexane, CCl4 and CHCl3 from methanolic extracts of marine algae were each examined for cytotoxic activities against cultured P-388 lymphocytic leukemia cells. Cytotoxic activities were found for partition fractions of 21 species of seaweed. Bioactivity-guided fractionation of the CCl4 partition fraction from Sargassum tortile, exhibiting the most prominent activity, afforded dihydroxysargaquinone (1) and sargatriol (2) previously isolated from this alga. The former was evaluated as a cytotoxic principle, and the latter, showing moderate activity, was suggested to be an artifact derived from 1 during the isolation procedure.

Animals↗
PubMed2026

Vibrio phycocola sp. nov. and Vibrio phycohabitans sp. nov., Isolated from the Phycosphere of Marine Algae.

Two Gram-stain-negative, facultatively aerobic, oxidase- and catalase-positive, motile (by means of a polar flagellum) rod-shaped bacterial strains, designated BS-M-Sm-2T and MA40-2T, were isolated from marine algae. Growth was optimal at pH 7.0-8.0 and 2.0-3.0% (w/v) NaCl, with temperature optima of 25°C for BS-M-Sm-2T and 25-30°C for MA40-2T. Ubiquinone-8 was the sole respiratory quinone. The major fatty acids common to both strains were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c), while BS-M-Sm-2T additionally contained C12:0 and C14:0. The predominant polar lipids were phosphatidylethanolamine and phosphatidylglycerol, with diphosphatidylglycerol also detected in strain MA40-2T. The DNA G+C contents of strains BS-M-Sm-2T and MA40-2T were 44.2 and 39.8 mol%, respectively. The 16S rRNA gene sequence similarity, average nucleotide identity (ANI), and digital DNA-DNA hybridization (dDDH) values between the two strains were 93.8%, 71.4%, and 23.2%, respectively. Phylogenetic and phylogenomic analyses placed both strains within the genus Vibrio, forming distinct lineages. Comparisons with closely related Vibrio type strains yielded ANI and dDDH values below 91.6% and 44.3%, respectively, further supporting their classification as novel species. Genome analyses revealed genes potentially involved in algal symbiosis, including those for polysaccharide degradation and vitamin biosynthesis. Based on comprehensive genomic, phylogenetic, phenotypic, and chemotaxonomic evidence, strains BS-M-Sm-2T and MA40-2T represent two novel species, for which the names Vibrio phycocola sp. nov. (BS-M-Sm-2T =KACC 24066T =DSM 119941T) and Vibrio phycohabitans sp. nov. (MA40-2T =KACC 24064T = DSM 119942T) are proposed.

RNA, Ribosomal, 16S↗
PubMed1992

H(+)-translocating ATPase and Na+/H+ antiport activities in the plasma membrane of the marine alga Platymonas viridis.

Proton transport by the vanadate-sensitive ATPase in plasma membrane (PM) vesicles from the marine unicellular microalga Platymonas viridis was investigated. The ATP-dependent generation of delta pH across the membranes of PM vesicles was followed by the changes in the absorbance of the aminoacridine probe, Acridine orange. Na+ caused the decay of delta pH generated by the ATPase, the rate of the decay being dependent on the concentrations of Na+ added. The phenomenon was specific for Na+. Amiloride inhibited Na(+)-dependent delta pH decay. The experiments support the idea of a Na(+)-extruding mechanism (H(+)-translocating ATPase plus Na+/H+ antiporter) operating in the PM of marine alga Pl. viridis.

Adenosine Triphosphate↗
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↗
PubMed1979

[Anti-inflammatory action of extracts from marine algae collected in the area of Burgas seacoast].

It was established by a series of experiments with white Wistar rats that intraperitoneal injection of water extracts (infusions) of a mixed sample of dried algae (Cystosira barbata, Ulva lactica and Zostera nona) collected at the Bourgas coastal region, respectively leveled to an isotonic solution by use of 0.9% NaCl produces well expressed antiinflammatory effect in Caragina provoked oedema. The mixed sample of algae has LD0--0.250 g dry drug per kg body weight, LD'100--0.500 g/kg b. w. and LD50--0.407 g/kg b. w. The therapeutic index of the algae is relatively high -- LD50/U50+20.

Animals↗
PubMed1991

The toxic action and interactions of copper and cadmium to the marine alga Dunaliella minuta, in both acute and chronic exposure.

The effective concentrations of copper and cadmium which reduced the population growth of Dunaliella minuta by 50% after 96 h of static exposure, were determined to be 7.57 microM Cu and 0.34 microM Cd. Short-term static exposure to both metals indicated that their combined action is antagonistic with respect to growth of this chlorophyte. Additionally, long-term exposure to low levels of Cu or Cd led to the acquisition of tolerance towards Cu and Cd, respectively, and co-tolerance towards Cu.

Cadmium↗
PubMed1975

Osmotic regulation in the marine alga, Codium decorticatum. I. Regulation of turgor pressure by control of ionic composition.

Codium decorticatum regulates its internal ionic composition and osmotic pressure in response to changes in external salinity. Over a salinity range of 23 to 37% (675 to 1120 mosmol/kg) Codium maintains a constant turgor pressure of 95 mosmol/kg (2.3 atm), observed as a constant difference between internal and external osmotic pressures. The changes in internal osmotic pressure are due to changes in intracellular inorganic ions. At 30 0/00 salinity the major intracellular ions are present in the following concentrations (mmol/kg cell H20): K+, 295; Na+, 255; Cl-, 450. At different salinities intracellular ion concentrations remain in constant proportion to the external ion concentrations, and thus the equilibrium potentials are approximately constant. The potential difference between the vacuole and seawater (-76 mV), whici is predominantly a K+ diffusion potential, is also constant with changing salinity. Comparison of the equilibrium potentials with the vacuole potential suggests that Cl- is actively absorbed and Na+ actively extruded, whereas K+ may be passively distributed between the vacuole and seawater. Turgor pressure does not change with environmental hydrostatic pressure, and increasing the external osmotic pressure with raffinose elicits a response similar to that obtained by increasing the salinity. These two results suggest that the stimulus for turgor regulation is a change in turgor pressure rather than a change in internal hydrostatic pressure or ion concentrations.

Chlorophyta↗