Effects of<Emphasis Type="Italic">Fomitopsis pinicola</Emphasis> extracts on antioxidant and antitumor activities

We investigated the effects ofFomitopsis pinicola extract on biological activity by examining the antioxidant and antitumor activityin vitro andin vivo. When theF. pinicola extract concentration was raised from 60 to 120 μg/mL, the DPPH scavenging rate increased from 50.3 to 88.2% and the superoxide anion radical scavenging rate increased from 45.2 to 85.3% when theF. pinicola extract concentration was raised from 500 to 700 μg/mL. After incubatingF. pinicola extract for 12 h, the linoleic acid scavenging rate increased from 35.5 to 90.5%. A similar finding was observed for butylated hydroxytoluene. The total phenolic content of theF. pinicola extracts were approximately 10- to 16-fold higher than what was observed in theP. nebrodensis andA. camphorate extracts. The glutathione production, using decoctions prepared fromF. pinicola, was 20.0 μM/g of liver, which corresponded to approximately 4.0-fold higher than the control. The glutathione peroxidase activity was 8.3 U/mg of protein, which was approximately 2.8-fold higher than the activity level observed in the control rat livers. The cell viability rates of all the human cancer cells, when 100 μg/mL of ethanol extract was used for the different types of cancer cells, decreased with increasing extract concentrations in comparison to the hot water extract. In particular, when HeLa and Hep3B cells were incubated with 1.000 μg/mL of methanol extract, the cell viability rates were 20 and 25%, respectively, which was approximately 3.0-fold higher than what was observed for the hot water extract. The first two authors contributed equally to this work.     

Comparative evaluation of antioxidant, nitrite scavenging, and antitumor effects of Antrodia camphorata extract

The effects of decoctions prepared from Antrodia camphorata on antioxidant, nitrite scavenging, and antitumor activities were investigated. Glutathione (GSH) production was 18.2 μM/g of rat liver under the influence of a methanol extract, a result similar to with the effect of silymarin administration. GSH peroxidase activity was about 2.0-fold higher than with silymarin administration. Superoxide dismutase activity was 18.9 U/mg protein, about 2.5-fold higher than the control group. The hot water extract (1000 μg/mL) showed the highest nitrite scavenging activity at 98.1%, similar to those observed with BHA and vitamin E. Among a variety of human cancer cell lines, when the concentration of hot water extract was increased from 31 to 500 μg/mL, the viability of Hep3B cell was decreased from 100 to 60.7%. On the other hand, in the case of methanol extract, it was decreased from 98.4 to 10.0%. These results supported the conclusion that the antioxidant, nitrite scavenging, and antitumor activities of this A. camphorata methanol extract indicate a potential source for the development of various health supplements and pharmaceutical and nutraceutical applications.     

Differential growth response of <Emphasis Type="Italic">Ulva lactuca</Emphasis> to ammonium and nitrate assimilation

Controlled cultivation of marine macroalgal biomass such as Ulva species, notably Ulva lactuca, is currently studied for production of biofuels or functional food ingredients. In a eutrophic environment, this macrophyte is exposed to varying types of nutrient supply, including different and fluctuating levels of nitrogen sources. Our understanding of the influences of this varying condition on the uptake and growth responses of U. lactuca is limited. In this present work, we examined the growth response of U. lactuca exposed to different sources of nitrogen (NH₄⁺; NO₃⁻; and the combination NH₄NO₃) by using photo-scanning technology for monitoring the growth kinetics of U. lactuca. The images revealed differential increases of the surface area of U. lactuca disks with time in response to different N-nutrient enrichments. The results showed a favorable growth response to ammonium as the nitrogen source. The NH₄Cl and NaNO₃ rich media (50 μM of N) accelerated U. lactuca growth to a maximum specific growth rate of 16.4 ± 0.18% day⁻¹ and 9.4 ± 0.72% day⁻¹, respectively. The highest biomass production rate obtained was 22.5 ± 0.24 mg DW m⁻²·day⁻¹. The presence of ammonium apparently discriminated the nitrate uptake by U. lactuca when exposed to NH₄NO₃. Apart from showing the significant differential growth response of U. lactuca to different nitrogen sources, the work exhibits the applicability of a photo-scanning approach for acquiring precise quantitative growth data for U. lactuca as exemplified by assessment of the growth response to two different N-sources.     

Synergistic effect between dieckol from <Emphasis Type="Italic">Ecklonia stolonifera</Emphasis> and β-lactams against methicillin-resistant <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

We have been attempting for some time to discover a compound evidencing antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The dieckol isolated from Ecklonia stolonifera has been shown to exhibit antibacterial activity against methicillin-susceptible S. aureus (MSSA) and MRSA. The minimum inhibitory concentrations (MICs) of dieckol were determined in a range of 32 to 64 μg/mL against standard MSSA and MRSA strains. Furthermore, dieckol clearly reversed the high-level ampicillin and penicillin resistance of MRSA. The MICs of ampicillin against two standard strains of MRSA were dramatically reduced from 512 to 0.5 μg/mL in combination with 1/4 MIC of dieckol (16 μg/mL). The fractional inhibitory concentration (FIC) indices of ampicillin and penicillin were measured from 0.066 to 0.266 in combination with 8 or 16 μg/mL of dieckol against all tested MRSA strains, thereby suggesting that dieckol-ampicillin or dieckol-penicillin combinations exert a synergistic effect against MRSA. The results of this study indicate that dieckol, administered in combination with β-lactams, may prove effective in the treatment of MRSA infections. Our finding may also contribute to the development of an alternative phytotherapeutic anti-MRSA agent.     

The optimal growth conditions for the biomass production of Isochrysis galbana and the effects that phosphorus, Zn2+, CO2, and light intensity have on the biochemical composition of Isochrysis galbana and the activity of extracellular CA

The effects of phosphorus, Zn²⁺, CO₂, and light intensity on growth, biochemical composition, and the activity of extracellular carbonic anhydrase (CA) in Isochrysis galbana were investigated. A significant change was observed when the concentration of phosphorus in the medium was increased from 5 μmol/L to 1000 μmol/L affecting I. galbana’s cell density, biochemical composition, and the activity of extracellular CA. Phosphorous concentration of 50 μmol/L to 500 μmol/L was optimal for this microalgae. The Zn²⁺ concentration at 10 μmol/L was essential to maintain optimal growth of the cells, but a higher concentration of Zn²⁺ (≥ 1000 μmol/L) inhibited the growth of I. galbana. High CO₂ concentrations (43.75 mL/L) significantly increased the cell densities compared to low CO₂ concentrations (0.35 mL/L). However, the activity of extracellular CA decreased significantly with an increasing concentration of CO₂. The activity of extracellular CA at a CO₂ concentration of 43.75 mL/L was approximately 1/6 of the activity when the CO₂ concentration was at 0.35 mL/L CO₂. Light intensity from 4.0 mW/cm² to 5.6 mW/cm² was beneficial for the growth, biochemical composition and the activity of extracellular CA. The lower and higher light intensity was restrictive for growth and changed its biochemical composition and the activity of extracellular CA. These results indicate that phosphorus, Zn²⁺, CO₂, and light intensity are important factors that impact growth, biochemical composition and the activity of extracellular CA in I. galbana.     

Bioactive metabolites from <Emphasis Type="Italic">Penicillium</Emphasis> sp., an endophytic fungus residing in <Emphasis Type="Italic">Hopea hainanensis</Emphasis>

The metabolites of endophytic fungus Penicillium sp. from the leaf of Hopea hainanensis were reported for the first time. By bioassay-guided fractionation, the EtOAc extract of a solid-matrix steady culture of this fungus afforded six compounds, which were identified through a combination of spectral and chemical methods (IR, MS, ¹H- and ¹³C-NMR) to be monomethylsulochrin (1), rhizoctonic acid (2), asperfumoid (3), physcion (4), 7,8-dimethyl-iso-alloxazine (5) and 3,5-dichloro-p-anisic acid (6). Compounds 2, 3 and 6 were obtained from Penicillium sp. for the first time. All of the six isolates were subjected to in vitro bioactive assays including antifungal action against three human pathogenic fungi Candida albicans, Trichophyton rubrum and Aspergillus niger and cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line and human liver cancer HepG2 cell line. As a result, compounds 2–4 and 6 inhibited the growth of C. albicans with MICs of 40.0, 20.0, 50.0 and 15.0 μg/ml, respectively and the compound 6 showed growth inhibition against A. niger with MICs of 40.0 μg/ml. In addition, compounds 1–3 and 6 exhibited cytotoxic activity against KB cell line with IC₅₀ value of 30.0, 20.0, 20.0, 5.0 μg/ml, respectively and against HepG2 cell line with IC₅₀ value of 30.0, 25.0, 15.0, 10.0 μg/ml, respectively.     

Uptake of heavy metals by <Emphasis Type="Italic">Stylonychia mytilus</Emphasis> and its possible use in decontamination of industrial wastewater

The heavy metal resistant ciliate, Stylonychia mytilus, isolated from industrial wastewater has been shown to be potential bioremediator of contaminated wastewater. The ciliate showed tolerance against Zn²⁺ (30 μg/mL), Hg²⁺ (16 μg/mL) and Ni²⁺ (16 μg/mL). The metal ions slowed down the growth of the ciliate as compared with the culture grown without metal stress. The reduction in cell population was 46% for Cd²⁺, 38% for Hg²⁺, 23% for Zn²⁺, 39% for Cu²⁺ and 51% for Ni²⁺ after 8 days of metal stress. S. mytilus reduced 91% of Cd²⁺, 90% of Hg²⁺ and 98% of Zn²⁺ from the medium after 96 h of incubation in a culture medium containing 10 μg/mL of the respective metal ions. Besides this, the ciliate could also remove 88% of Cu²⁺ and 73% Ni²⁺ from the medium containing 5 μg/mL of each metal after 96 h. The ability of Stylonychia to take up variety of heavy metals from the medium could be exploited for metal detoxification and environmental clean-up operations.     

Interaction of benzo[c]phenanthridine and protoberberine alkaloids with animal and yeast cells

We compared the effects of four quaternary benzo[c]phenanthridine alkaloids – chelerythrine, chelilutine, sanguinarine, and sanguilutine – and two quaternary protoberberine alkaloids – berberine and coptisine – on the human cell line HeLa (cervix carcinoma cells) and the yeastsSaccharomyces cerevisiae andSchizosaccharomyces japonicus var. versatilis. The ability of alkaloids to display primary fluorescence, allowed us to record their dynamics and localization in cells. Cytotoxic, anti-microtubular, and anti-actin effects in living cells were studied. In the yeasts, neither microtubules nor cell growth was seriously affected even at the alkaloid concentration of 100 μg/ml. The HeLa cells, however, responded to the toxic effect of alkaloids at concentrations ranging from 1 to 50 μg/ml. IC₅₀ values for individual alkaloids were: sanguinarine IC₅₀ = 0.8 μg/ml, sanguilutine IC₅₀ = 8.3 μg/ml, chelerythrine IC₅₀ = 6.2 μg/ml, chelilutine IC₅₀ = 5.2 μg/ml, coptisine IC₅₀ = 2.6 μg/ml and berberine IC₅₀ >10.0 μg/ml. In living cells, sanguinarine produced a decrease in microtubule numbers, particularly at the cell periphery, at a concentration of 0.1 μg/ml. The other alkaloids showed a similar effect but at higher concentrations (5–50 μg/ml). The strongest effects of sanguinarine were explained as a consequence of its easy penetration through the cell membrane owing to nonpolar pseudobase formation and to a high degree of molecular planarity. This revised version was published online in July 2006 with corrections to the Cover Date.     

Study of the Action of Se and Cu on the Growth Metabolism of <Emphasis Type="Italic">Escherichia coli</Emphasis> by Microcalorimetry

The biological effect of Se and Cu²⁺ on Escherichia coli (E. coli) growth was studied by using a 3114/3236 TAM Air Isothermal Calorimeter, ampoule method, at 37°C. From the thermogenesis curves, the thermokinetic equations were established under different conditions. The kinetics showed that a low concentration of Se (1–10 μg/mL) promoted the growth of E. coli, and a high concentration of Se (>10 μg/mL) inhibited the growth, but the Cu²⁺ was always inhibiting the growth of E. coli. Moreover, there was an antagonistic or positive synergistic effect of Se and Cu²⁺ on E. coli in the different culture medium when Se was 1–10 μg/ml and Cu²⁺ was 1–20 μg/ml. There was a negative synergistic effect of Se and Cu²⁺ on E. coli when Se was higher than 10 μg/ml and Cu²⁺ was higher than 20 μg/ml. The antagonistic or synergistic effect between Se and Cu²⁺ on E. coli was related to the formation of Cu–Se complexes under the different experimental conditions chosen.     

Concentration of <Emphasis Type="Italic">Cupriavidus necator</Emphasis> cells by flocculation and sedimentation

Separation and cells concentration constitute important stages in most biotechnological processes. Particularly, use of flocculation/sedimentation can improve significantly the extraction of biopolymers accumulated by microorganisms and the biodegradation of xenobiotic compounds by cell sludge. In this work the use of tannin and aluminum sulphate (Al₂(SO₄)₃) as flocculating agents for concentration of cells of Cupriavidus necator DSM 545 is evaluated. Cells were grown in broth nutrient medium in Erlenmeyer flasks, submitted to orbital agitation of 160 rpm at 30 °C for 21 h. The optimal concentrations of flocculating agents, as determined with a standard jar test method, were equal to 2,800 mg/L for tannin and 800 mg/L for Al₂(SO₄)₃, allowing for recovery of 95% of the cells in both cases. Obtained flocs presented density and average diameter of 1.03 g/mL ± 0.01 g/mL and 158 μm ± 19 μm for tannin and of 1.05 g/mL ± 0.01 g/mL and 146 μm ± 14 μm for Al₂(SO₄)₃, respectively. Batch settling tests were performed in order to determine the operational capacity of continuous settlers to be used for separation of the investigated flocculent suspensions. Finally, cultivation of cells using flocs as inoculum indicated that the cells remained viable after flocculation with usage of the optimum flocculating agent concentrations.     

Polysaccharides isolated from <Emphasis Type="Italic">Phellinus baumii</Emphasis> stimulate murine splenocyte proliferation and inhibit the lipopolysaccharide-induced nitric oxide production in RAW264.7 murine macrophages

Polysaccharides isolated from Phellinus baumii (PBP) significantly enhanced both lipopolysaccharide (LPS)-induced B lymphocyte proliferation and concanavalin A (Con A)-induced T lymphocyte proliferation. However, PBP (12.5–100 μg ml⁻¹) significantly suppressed the LPS-induced nitric oxide (NO) production in RAW264.7 cells in a concentration-dependent manner. The maximal inhibition of PBP on NO production was 37.5% at 100 μg ml⁻¹. These results provide useful in vitro information to explain the immunostimulating activity and anti-inflammatory activity of PBP.     

Effect of<Emphasis Type="Italic">Pleurotus ferulae</Emphasis> extracts on viability of human lung cancer and cervical cancer cell lines

When SiHa cells were incubated for varying periods of time with extracts of PFF and PFM, the cytotoxicity of the ethanol extracts of PFF was higher than those of the other extracts. These results indicated that the extracts from fruiting bodies ofP. ferulae contain antitumor substances. When A549, SiHa and HeLa cells were incubated with different concentrations of PFF and PFM extracts, the ethanol extracts of PFF showed strong cytotoxicity against A549 cells at concentrations over 10 μg/mL and against SiHa and HeLa cells at concentrations over 40 μg/mL. However, the differences in the cytotoxic effects of the hot water and ethanol extracts of PFM and the hot water extracts of PFF on all 3 cancer cells were not significant. Also, the PFF ethanol extracts induced synergistic effects on the TRAIL-induced apoptosis in A549 cells, which were strongly resistant to TRAIL. These results indicated that ethanol extracts of PFF were the most prominent antitumor agents toward lung cancer cells (A549).     

Chemical and physical-chemical characteristics of dietary fibres from Ulva lactuca (L.) Thuret and Enteromorpha compressa (L.) Grev.

Dietary fibres from Ulva lactuca (L.) Thuret (sea lettuce) and Enteromorpha compressa (L.) Grev. (A.O. nori) were measured according to a ‘standard’ method and a ‘physiological’ protocol simulating the gastric and intestinal environments. U. lactuca contained 15.8–8.0% soluble and 24.2–32.6% insoluble fibres according to the ‘standard’ and ‘physiological’ methods, respectively. For E. compressa, these values were 14.9–15.9 and 21.6–28.7%, respectively. For both algae, the composition suggests that the soluble fibres were xylorhamnoglycuronans sulphates and insoluble fibres were essentially composed of glucans. No marked chemical compositional variation was observed between soluble fractions extracted under the simulated gastric and intestinal conditions. Fibres in both algae are hydrophilic but the water holding capacities were higher after extraction of soluble fibres (5.5–9.5 g g⁻¹ for the dry algae; 14.0–16.0 g g⁻¹ for the standard insoluble fibres). Water soluble fibres demonstrated low intrinsic viscosities at 37 °C in buffers, particularly those from E. compressa (36.0–36.5 ml g⁻¹), and was affected by pH for those of U. lactuca (147.5 ml g⁻¹ at pH 3.0 and 175.0 ml g⁻¹ at pH 7.3).     

Perturbation of monovalent cation composition in Ulva lactuca by cadmium, copper and zinc

Discs of thallus cut from the macroalga Ulva lactuca were incubated in filtered seawater containing cadmium, zinc, copper or cobalt (30 m). The metal uptake rates differed for each metal in the order Cu > Zn > Cd > Co. Exposure of the macroalga to metals resulted in a disruption of intracellular monovalent cation composition. Intracellular potassium was irreversibly lost and sodium was accumulated by cadmium- or copper-treated U. lactuca, which was assumed to indicate irreversible disruption of the plasmalemma. Exposure to zinc caused an increase in sodium concentrations, whereas potassium concentrations were not significantly different from the controls, suggesting that the integrity of the plasmalemma had been maintained at the zinc concentration used. Intracellular magnesium was also lost from copper-treated algae, which again indicated a loss of integrity of the cell membrane.     

Nutrient regulation of bacterial growth and production of anti-tumor metabolites in <Emphasis Type="Italic">Stigmatella</Emphasis> WXNXJ-B fermentation

The metabolites produced by Stigmatella WXNXJ-B inhibited the growth of tumor cells. The aims of this research were to evaluate the inhibition potency to different tumor cell lines and to study the effects of ammonium, phosphate and iron salts on bacterial growth and production of bioactive metabolites in Stigmatella WXNXJ-B fermentation. The results showed that the chloroform extract (CE-ME) showed the strongest growth inhibition bioactivity on mouse melanoma cell line (B16), murine colon carcinoma cell line (CT-26), human liver carcinoma cell line (HepG2) and human breast cancer cell line (MDA-MB231) in vitro and the IC₅₀ values were 9.94, 7.33, 11.34 and 11.66 μg ml⁻¹ respectively. The IC₅₀ value was above 700 μg ml⁻¹ on normal mouse spleen cells. Morphology happened changes in B16 cells treated with CE-ME. The anti-tumor metabolites were mainly produced during the stationary phase of the bacterial growth. Cell growth was stimulated at the phosphate concentration below 5 mM, but it was inhibited partly with 10 mM phosphate. The production of bioactive substances was inhibited by the phosphate. Ammonium increased the cell growth by 250% at 5 mM addition. The inhibition rate to B16 cells was increased to 89% at the concentration of 40 mM ammonium. The bacteria showed the best growth with 4 mM iron. Iron had little effect on the production at 2 mM, but bigger inhibition effect at higher iron concentration.     

Cadmium effects on growth and physiology ofUlva lactuca

The chlorophyceanUlva lactuca L. was grown in the laboratory in unialgal culture to sufficient size so that up to 70 discs, 24 mm in diameter, could be punched out of a single plant. Using such discs,U. lactuca was then tested with various concentrations of Cd under continuous-flow conditions. A concentration of 4.5 ppm Cd was lethal toU. lactuca within 6 days. Control discs in unpolluted water increased in diameter at a rate of 8 to 13 % day⁻¹ over a 6-day period. At sublethal concentrations of Cd a sharp reduction in growth rate was observed at increasing concentrations up to approximately 0.3 ppm Cd, whereas from 0.3 ppm Cd to the lethal concentration the reduction of the growth rate was significantly less. Reduction in photosynthetic performance corresponded closely to the reduction in growth rate. At ambient concentrations of 0.8 ppm Cd, the plants concentrated Cd by a factor of approximately 50 in 6 days. Much higher concentration factors were attained in lower ambient concentrations. After removal from Cd-polluted water into flow-through culture in unpolluted water, a subsequent loss of Cd was indicated and the plants recovered rapidly. Plants exposed up to 3 d to 0.7 ppm Cd recovered sufficiently to produce viable gametes 7 days after removal from Cd. Because it has a relatively short life span and apparently loses Cd subsequent to exposure to Cd-polluted water,Ulva lactuca is not recommended as an alga for monitoring in-situ environmental pollution.     

Astaxanthin production by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis> and <Emphasis Type="Italic">Haematococcus pluvialis</Emphasis>: a comparative study

Phaffia rhodozyma (now Xanthophyllomyces dendrorhous) and Haematococcus pluvialis are known as the major prominent microorganisms able to synthesize astaxanthin natural pigment. Important research efforts have been made to determine optimal conditions for astaxanthin synthesis. When the focus is on astaxanthin production, the maximal reported value of 9.2 mg/g cell is obtained within H. pluvialis grown on BAR medium, under continuous illumination (345 μmol photon m⁻² s⁻¹) and without aeration. Whereas fermentation by mutated R1 yeast grown on coconut milk produced 1,850 μg/g yeast. However, when looking at astaxanthin productivity, the picture is slightly different. The figures obtained with P. rhodozyma are rather similar to those of H. pluvialis. Maximal reported values are 170 μg/g yeast per day with a wild yeast strain and 370 μg/g yeast per day with mutated R1 yeast. In the case of H. pluvialis, maximal values ranged from 290 to 428 μg/g cell per day depending on the media (BG-11 or BAR), light intensity (177 μmol photon m⁻² s⁻¹), aeration, etc. The main aim of this work was to examine how astaxanthin synthesis, by P. rhodozyma and H. pluvialis, could be compared. The study is based on previous works by the authors where pigment productions have been reported.     

Improvement of lipid profile and antioxidant of hypercholesterolemic albino rats by polysaccharides extracted from the green alga Ulva lactuca Linnaeus

Sulfated polysaccharides from Ulva lactuca were extracted in hot water and precipitated by ethanol then orally gavaged to rats fed on a hypercholesterolemic diet for 21 days to evaluate the antihypercholesterolemic and antioxidant actions. Atorvastatine Ca (Lipitor) was used as a reference drug. The intragastric administration of U. lactuca extract to hypercholesterolemic rats caused significant decrease of serum total lipids, triglycerides, total cholesterol, LDL-cholesterol and vLDL-cholesterol levels. Whereas, HDL-cholesterol concentration was markedly increased by 180%. Aqueous extract showed a significant ameliorative action on elevated atherogenic index, creatine kinase and lactate dehydrogenase activities of hypercholesterolemic group. Furthermore, serum activities of transaminases and alkaline phosphatase were also improved. High fat diet intake caused a highly significantly elevated serum urea, creatinine concentration. These effects were reversed by oral administration of U. lactuca extract. Sulfates polysaccharides extract of U. lactuca ameliorate hepatic enzymatic (catalase, glutathione peroxidase and superoxide dismutase), non-enzymatic (reduced glutathione & total thiol) antioxidant defenses and thiobarbituric acid reactive substances. In conclusion, the tested U. lactuca polysaccharides extract has potent hypocholesterolemic and antioxidant effects in experimentally-induced hypercholesterolemic animal model.     

Investigation of the antifouling constituents from the brown alga Sargassum muticum (Yendo) Fensholt

One of the most promising alternatives to toxic heavy metal-based paints is offered by the development of antifouling coatings in which the active ingredients are compounds naturally occurring in marine organisms and operating as natural antisettlement agents. Sessile marine macroalgae are remarkably free from settlement by fouling organisms. They produce a wide variety of chemically active metabolites in their surroundings, potentially as an aid to protect themselves against other settling organisms. In this study, a dichloromethane extract from the brown seaweed Sargassum muticum was tested in situ and, after 2 months of immersion, showed less fouling organisms on paints in which the extract was included, compared to paints containing only copper after 2 months of immersion. No barnacles or mussels have been observed on the test rack. Identification by NMR and GC/MS of the effective compound revealed the abundance of palmitic acid, a commonly found fatty acid. Pure palmitic acid showed antibacterial activity at 44 μg mL⁻¹, and also inhibited the growth of the diatom Cylindrotheca closterium at low concentration (EC₅₀ = 45.5 μg mL⁻¹), and the germination of Ulva lactuca spores at 3 μg mL⁻¹. No cytotoxicity was highlighted, which is promising in the aim of the development of an environmentally friendly antifouling paint.