rozenn trepos - Academia.edu (original) (raw)

Papers by rozenn trepos

Biotechnology Annual Review, 2000

The current study reports the first comprehensive evaluation of a class of allelopathic terrestri... more The current study reports the first comprehensive evaluation of a class of allelopathic terrestrial natural products as antifoulants in a marine setting. To investigate the antifouling potential of the natural dihydrostilbene scaffold, a library of 22 synthetic dihydrostilbenes with varying substitution patterns, many of which occur naturally in terrestrial plants, were prepared and assessed for their antifouling capacity. The compounds were evaluated in an extensive screen against 16 fouling marine organisms. The dihydrostilbene scaffold was shown to possess powerful general antifouling effects against both marine microfoulers and macrofoulers with inhibitory activities at low concentrations. The species of microalgae examined displayed a particular sensitivity toward the evaluated compounds at low ng/mL concentrations. It was shown that several of the natural and synthetic compounds exerted their repelling activities via nontoxic and reversible mechanisms. The activities of the most active compounds such as 3,5-dimethoxybibenzyl (5), 3,4-dimethoxybibenzyl (9), and 3hydroxy-3′,4,5′-trimethoxybibenzyl (20) were comparable to the commercial antifouling booster biocide Sea-nine, which was employed as a positive control. The investigation of terrestrial allelopathic natural products to counter marine fouling represents a novel strategy for the design of "green" antifouling technologies, and these compounds offer a potential alternative to traditional biocidal antifoulants.

Cryptogamie Algologie, 2007

Biofouling is a potential problem for any surface immersed in the sea. For algae this can lead to... more Biofouling is a potential problem for any surface immersed in the sea. For algae this can lead to its death; they have therefore developed biofouling defence mechanisms to prevent biofouling. Grateloupia turuturu was chosen as a model to isolate some structures with antifouling properties. The aims of our study were then (1) to identify and describe in G. turuturu structures similar to gland-cells observed in a variety of species from the order Bonnemaisoniales and (2) to determine their variability in relation to site, stages of development, and the presence of epiphytes. Fluorescent and confocal microscopy was used to highlight structures similar to gland-cells. Using epifluorescence microscopy, the number of "gland cells-like structures" was determined on individuals sampled from three sites in French Brittany (Callot Island, Pointe du Diable, and Fort Bloqué), characterized by different hydrodynamic and fouling exposure conditions, and from three life history phases (gametophyte, tetrasporophyte and carposporophyte). Isolated and grouped fluorescent structures were detected and characterized. Significant variations in the density of those fluorescent structures were found between site and life-history stages. Individuals from the Pointe du Diable had significantly more fluorescent structures than thalli from the two other sites, and they were more numerous on carposporic plants than on either tetrasporophytes or immature gametophytes. More "gland cells-like structures" were also present on plants bearing epiphytes.

Biofouling, 2015

A series of 13 short synthetic amphiphilic cationic micropeptides, derived from the antimicrobial... more A series of 13 short synthetic amphiphilic cationic micropeptides, derived from the antimicrobial iron-binding innate defence protein lactoferrin, have been evaluated for their capacity to inhibit the marine fouling process. The whole biofouling process was studied and microfouling organisms such as marine bacteria and microalgae were included as well as the macrofouling barnacle Balanus improvisus. In total 19 different marine fouling organisms (18 microfoulers and one macrofouler) were included and both the adhesion and growth of the microfoulers were investigated. It was shown that the majority of the peptides inhibited barnacle cyprid settlement via a reversible nontoxic mechanism, with IC50 values as low as 0.5 μg ml(-1). Six peptides inhibited adhesion and growth of microorganisms. Two of these were particularly active against the microfoulers with MIC-values ranging between 0.01 and 1 μg ml(-1), which is comparable with the commercial reference antifoulant SeaNine.

Methods in Molecular Biology, 2015

The development of novel environmentally friendly antifouling (AF) solutions is a very active fie... more The development of novel environmentally friendly antifouling (AF) solutions is a very active field in fundamental and applied research. An attractive option in producing such material resides in biomimetic studies: living organisms have evolved well-adapted structures and materials over geological times through natural selection. In this chapter, we explain the experimental procedure to be followed for the preparation of macroalgal extracts and to assess their AF efficiency towards key species. All bioassays described here have the advantage of being fast, reliable, and standardized.

: examples of small halogenated natural antifouling (AF) compounds produced by sessile marine org... more : examples of small halogenated natural antifouling (AF) compounds produced by sessile marine organisms that have been evaluated as new "green" AF compounds in biomimetic AF solutions. leAF prOjeCT : Marine bioprospecting provides access to marine organims that are studied for the ability to produce AF compounds as well as compounds that can be developed into pharmaceuticals.

Among the great variety of marine-derived compounds, indole alkaloids have emerged as an importan... more Among the great variety of marine-derived compounds, indole alkaloids have emerged as an important structural class based upon their high degree of biological activities (including antimicrobial, antiviral and antitumor properties). These metabolites are generated by various marine organisms and represent the largest number and most complicated of the marine alkaloids . In this work, we have focused on a family of natural bioactive 3-(2-aminopyrimidine)-indoles : meridianins A-G , initially isolated from the ascidian Aplidium meridianum. For this study, the two meridianins C and G , together with thirty-one of their analogues, have been synthesized for the evaluation of their antifouling activity ( anti-settlement and anti-bacterial assays) and their toxicity against larvae of B. amphitrite.

Tetrahedron Letters, 2014

Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated ... more Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated from the Mediterranean sponge Tethya aurantium, yielded a new tryptophan derived alkaloid, 3- , and a new meroterpenoid, austalide R (2), together with three known compounds (3-5). The structures of the new compounds were unambiguously elucidated on the basis of extensive one and twodimensional NMR ( 1 H, 13 C, COSY, HMBC, and ROESY) and mass spectral analysis. Interestingly, the compounds exhibited antibacterial activity when tested against a panel of marine bacteria, with 1 selectively inhibiting Vibrio species and 2 showing a broad spectrum of activity. In contrast, no significant activity was observed against terrestrial bacterial strains and the murine cancer cell line L5178Y.

ChemInform, 2014

Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated ... more Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated from the Mediterranean sponge Tethya aurantium, yielded a new tryptophan derived alkaloid, 3- , and a new meroterpenoid, austalide R (2), together with three known compounds (3-5). The structures of the new compounds were unambiguously elucidated on the basis of extensive one and twodimensional NMR ( 1 H, 13 C, COSY, HMBC, and ROESY) and mass spectral analysis. Interestingly, the compounds exhibited antibacterial activity when tested against a panel of marine bacteria, with 1 selectively inhibiting Vibrio species and 2 showing a broad spectrum of activity. In contrast, no significant activity was observed against terrestrial bacterial strains and the murine cancer cell line L5178Y.

Marine Biotechnology, 2014

The inhibition of marine biofouling by the bromotyrosine derivative ianthelline, isolated from th... more The inhibition of marine biofouling by the bromotyrosine derivative ianthelline, isolated from the Arctic marine sponge Stryphnus fortis, is described. All major stages of the fouling process are investigated. The effect of ianthelline on adhesion and growth of marine bacteria and microalgae is tested to investigate its influence on the initial microfouling process comparing with the known marine antifoulant barettin as a reference. Macrofouling is studied via barnacle (Balanus improvisus) settlement assays and blue mussel (Mytilus edulis) phenoloxidase inhibition. Ianthelline is shown to inhibit both marine micro-and macrofoulers with a pronounced effect on marine bacteria (minimum inhibitory concentration (MIC) values 0.1-10 μg/mL) and barnacle larval settlement (IC 50 =3.0 μg/ mL). Moderate effects are recorded on M. edulis (IC 50 = 45.2 μg/mL) and microalgae, where growth is more affected than surface adhesion. The effect of ianthelline is also investigated against human pathogenic bacteria. Ianthelline displayed low micromolar MIC values against several bacterial strains, both Gram positive and Gram negative, down to 2.5 μg/mL. In summary, the effect of ianthelline on 20 different representative marine antifouling organisms and seven human pathogenic bacterial strains is presented.

Journal of Natural Products, 2014

The current study describes the antifouling properties of four members belonging to the recently ... more The current study describes the antifouling properties of four members belonging to the recently discovered synoxazolidinone and pulmonarin families, isolated from the sub-Arctic sessile ascidian Synoicum pulmonaria collected off the Norwegian coast. Four simplified synthetic analogues were also prepared and included in the study. Several of the studied compounds displayed MIC values in the micro-nanomolar range against 16 relevant marine species involved in both the microand macrofouling process. Settlement studies on Balanus improvisus cyprids indicated a deterrent effect and a low toxicity for selected compounds. The two synoxazolidinones displayed broad activity and are shown to be among the most active natural antifouling bromotyrosine derivatives described. Synoxazolidinone C displayed selected antifouling properties comparable to the commercial antifouling product Sea-Nine-211. The pulmonarins prevented the growth of several bacterial strains at nanomolar concentrations but displayed a lower activity toward microalgae and no effect on barnacles. The linear and cyclic synthetic peptidic mimics also displayed potent antifouling activities mainly directed against bacterial adhesion and growth.

Biotechnology Annual Review, 2000

The current study reports the first comprehensive evaluation of a class of allelopathic terrestri... more The current study reports the first comprehensive evaluation of a class of allelopathic terrestrial natural products as antifoulants in a marine setting. To investigate the antifouling potential of the natural dihydrostilbene scaffold, a library of 22 synthetic dihydrostilbenes with varying substitution patterns, many of which occur naturally in terrestrial plants, were prepared and assessed for their antifouling capacity. The compounds were evaluated in an extensive screen against 16 fouling marine organisms. The dihydrostilbene scaffold was shown to possess powerful general antifouling effects against both marine microfoulers and macrofoulers with inhibitory activities at low concentrations. The species of microalgae examined displayed a particular sensitivity toward the evaluated compounds at low ng/mL concentrations. It was shown that several of the natural and synthetic compounds exerted their repelling activities via nontoxic and reversible mechanisms. The activities of the most active compounds such as 3,5-dimethoxybibenzyl (5), 3,4-dimethoxybibenzyl (9), and 3hydroxy-3′,4,5′-trimethoxybibenzyl (20) were comparable to the commercial antifouling booster biocide Sea-nine, which was employed as a positive control. The investigation of terrestrial allelopathic natural products to counter marine fouling represents a novel strategy for the design of "green" antifouling technologies, and these compounds offer a potential alternative to traditional biocidal antifoulants.

Cryptogamie Algologie, 2007

Biofouling is a potential problem for any surface immersed in the sea. For algae this can lead to... more Biofouling is a potential problem for any surface immersed in the sea. For algae this can lead to its death; they have therefore developed biofouling defence mechanisms to prevent biofouling. Grateloupia turuturu was chosen as a model to isolate some structures with antifouling properties. The aims of our study were then (1) to identify and describe in G. turuturu structures similar to gland-cells observed in a variety of species from the order Bonnemaisoniales and (2) to determine their variability in relation to site, stages of development, and the presence of epiphytes. Fluorescent and confocal microscopy was used to highlight structures similar to gland-cells. Using epifluorescence microscopy, the number of "gland cells-like structures" was determined on individuals sampled from three sites in French Brittany (Callot Island, Pointe du Diable, and Fort Bloqué), characterized by different hydrodynamic and fouling exposure conditions, and from three life history phases (gametophyte, tetrasporophyte and carposporophyte). Isolated and grouped fluorescent structures were detected and characterized. Significant variations in the density of those fluorescent structures were found between site and life-history stages. Individuals from the Pointe du Diable had significantly more fluorescent structures than thalli from the two other sites, and they were more numerous on carposporic plants than on either tetrasporophytes or immature gametophytes. More "gland cells-like structures" were also present on plants bearing epiphytes.

Biofouling, 2015

A series of 13 short synthetic amphiphilic cationic micropeptides, derived from the antimicrobial... more A series of 13 short synthetic amphiphilic cationic micropeptides, derived from the antimicrobial iron-binding innate defence protein lactoferrin, have been evaluated for their capacity to inhibit the marine fouling process. The whole biofouling process was studied and microfouling organisms such as marine bacteria and microalgae were included as well as the macrofouling barnacle Balanus improvisus. In total 19 different marine fouling organisms (18 microfoulers and one macrofouler) were included and both the adhesion and growth of the microfoulers were investigated. It was shown that the majority of the peptides inhibited barnacle cyprid settlement via a reversible nontoxic mechanism, with IC50 values as low as 0.5 μg ml(-1). Six peptides inhibited adhesion and growth of microorganisms. Two of these were particularly active against the microfoulers with MIC-values ranging between 0.01 and 1 μg ml(-1), which is comparable with the commercial reference antifoulant SeaNine.

Methods in Molecular Biology, 2015

The development of novel environmentally friendly antifouling (AF) solutions is a very active fie... more The development of novel environmentally friendly antifouling (AF) solutions is a very active field in fundamental and applied research. An attractive option in producing such material resides in biomimetic studies: living organisms have evolved well-adapted structures and materials over geological times through natural selection. In this chapter, we explain the experimental procedure to be followed for the preparation of macroalgal extracts and to assess their AF efficiency towards key species. All bioassays described here have the advantage of being fast, reliable, and standardized.

: examples of small halogenated natural antifouling (AF) compounds produced by sessile marine org... more : examples of small halogenated natural antifouling (AF) compounds produced by sessile marine organisms that have been evaluated as new "green" AF compounds in biomimetic AF solutions. leAF prOjeCT : Marine bioprospecting provides access to marine organims that are studied for the ability to produce AF compounds as well as compounds that can be developed into pharmaceuticals.

Among the great variety of marine-derived compounds, indole alkaloids have emerged as an importan... more Among the great variety of marine-derived compounds, indole alkaloids have emerged as an important structural class based upon their high degree of biological activities (including antimicrobial, antiviral and antitumor properties). These metabolites are generated by various marine organisms and represent the largest number and most complicated of the marine alkaloids . In this work, we have focused on a family of natural bioactive 3-(2-aminopyrimidine)-indoles : meridianins A-G , initially isolated from the ascidian Aplidium meridianum. For this study, the two meridianins C and G , together with thirty-one of their analogues, have been synthesized for the evaluation of their antifouling activity ( anti-settlement and anti-bacterial assays) and their toxicity against larvae of B. amphitrite.

Tetrahedron Letters, 2014

Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated ... more Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated from the Mediterranean sponge Tethya aurantium, yielded a new tryptophan derived alkaloid, 3- , and a new meroterpenoid, austalide R (2), together with three known compounds (3-5). The structures of the new compounds were unambiguously elucidated on the basis of extensive one and twodimensional NMR ( 1 H, 13 C, COSY, HMBC, and ROESY) and mass spectral analysis. Interestingly, the compounds exhibited antibacterial activity when tested against a panel of marine bacteria, with 1 selectively inhibiting Vibrio species and 2 showing a broad spectrum of activity. In contrast, no significant activity was observed against terrestrial bacterial strains and the murine cancer cell line L5178Y.

ChemInform, 2014

Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated ... more Chromatographic separation of a crude extract obtained from the fungus Aspergillus sp., isolated from the Mediterranean sponge Tethya aurantium, yielded a new tryptophan derived alkaloid, 3- , and a new meroterpenoid, austalide R (2), together with three known compounds (3-5). The structures of the new compounds were unambiguously elucidated on the basis of extensive one and twodimensional NMR ( 1 H, 13 C, COSY, HMBC, and ROESY) and mass spectral analysis. Interestingly, the compounds exhibited antibacterial activity when tested against a panel of marine bacteria, with 1 selectively inhibiting Vibrio species and 2 showing a broad spectrum of activity. In contrast, no significant activity was observed against terrestrial bacterial strains and the murine cancer cell line L5178Y.

Marine Biotechnology, 2014

The inhibition of marine biofouling by the bromotyrosine derivative ianthelline, isolated from th... more The inhibition of marine biofouling by the bromotyrosine derivative ianthelline, isolated from the Arctic marine sponge Stryphnus fortis, is described. All major stages of the fouling process are investigated. The effect of ianthelline on adhesion and growth of marine bacteria and microalgae is tested to investigate its influence on the initial microfouling process comparing with the known marine antifoulant barettin as a reference. Macrofouling is studied via barnacle (Balanus improvisus) settlement assays and blue mussel (Mytilus edulis) phenoloxidase inhibition. Ianthelline is shown to inhibit both marine micro-and macrofoulers with a pronounced effect on marine bacteria (minimum inhibitory concentration (MIC) values 0.1-10 μg/mL) and barnacle larval settlement (IC 50 =3.0 μg/ mL). Moderate effects are recorded on M. edulis (IC 50 = 45.2 μg/mL) and microalgae, where growth is more affected than surface adhesion. The effect of ianthelline is also investigated against human pathogenic bacteria. Ianthelline displayed low micromolar MIC values against several bacterial strains, both Gram positive and Gram negative, down to 2.5 μg/mL. In summary, the effect of ianthelline on 20 different representative marine antifouling organisms and seven human pathogenic bacterial strains is presented.

Journal of Natural Products, 2014

The current study describes the antifouling properties of four members belonging to the recently ... more The current study describes the antifouling properties of four members belonging to the recently discovered synoxazolidinone and pulmonarin families, isolated from the sub-Arctic sessile ascidian Synoicum pulmonaria collected off the Norwegian coast. Four simplified synthetic analogues were also prepared and included in the study. Several of the studied compounds displayed MIC values in the micro-nanomolar range against 16 relevant marine species involved in both the microand macrofouling process. Settlement studies on Balanus improvisus cyprids indicated a deterrent effect and a low toxicity for selected compounds. The two synoxazolidinones displayed broad activity and are shown to be among the most active natural antifouling bromotyrosine derivatives described. Synoxazolidinone C displayed selected antifouling properties comparable to the commercial antifouling product Sea-Nine-211. The pulmonarins prevented the growth of several bacterial strains at nanomolar concentrations but displayed a lower activity toward microalgae and no effect on barnacles. The linear and cyclic synthetic peptidic mimics also displayed potent antifouling activities mainly directed against bacterial adhesion and growth.