Marine Drugs

269 KiB

Open AccessArticle

Preparation of Calibration Standards of N1-H Paralytic Shellfish Toxin Analogues by Large-Scale Culture of Cyanobacterium Anabaena circinalis (TA04)

by Ryuichi Watanabe, Toshiyuki Suzuki and Yasukatsu Oshima

Mar. Drugs 2011, 9(3), 466-477; https://doi.org/10.3390/md9030466 - 22 Mar 2011

Cited by 15 | Viewed by 9562

Abstract

Mouse bioassay is the official testing method to quantify paralytic shellfish toxins (PSTs) in bivalves. A number of alternative analytical methods have been reported. Some methods have been evaluated by a single laboratory validation. Among the different types of methods, chemical analyses are [...] Read more.

Mouse bioassay is the official testing method to quantify paralytic shellfish toxins (PSTs) in bivalves. A number of alternative analytical methods have been reported. Some methods have been evaluated by a single laboratory validation. Among the different types of methods, chemical analyses are capable of identifying and quantifying the toxins, however a shortage of the necessary calibration standards hampers implementation of the chemical analyses in routine monitoring of PSTs in bivalves. In our present study, we studied preparation of major PST analogues as calibrants by large-scale cultivation of toxic freshwater cyanobacteria Anabaena circinalis TA04. The cells were steadily grown in 10 L bottle for 28 days. The primary N1-H toxins, C1/C2, were produced at a concentration of 1.3 ± 0.1 µmol/L. The intracellular and extracellular toxins occupied 80% and 20%, respectively. Over 220 µmol of the toxins was obtained from approximately 200 L of the culture over six months, demonstrating that it is sufficient to prepare saxitoxin analogues. The toxins were chemically converted to six N1-H analogues. Preparation of the analogues was carried out at relatively high yields (50–90%). The results indicate that our preparation method is useful to produce N1-H toxins. In our present study, detailed conditions for preparation of one of the rare N1-H analogues, gonyautoxin-5, were investigated. Full article

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225 KiB

Open AccessReview

Astaxanthin: A Potential Therapeutic Agent in Cardiovascular Disease

by Robert G. Fassett and Jeff S. Coombes

Mar. Drugs 2011, 9(3), 447-465; https://doi.org/10.3390/md9030447 - 21 Mar 2011

Cited by 279 | Viewed by 26697

Abstract

Astaxanthin is a xanthophyll carotenoid present in microalgae, fungi, complex plants, seafood, flamingos and quail. It is an antioxidant with anti-inflammatory properties and as such has potential as a therapeutic agent in atherosclerotic cardiovascular disease. Synthetic forms of astaxanthin have been manufactured. The [...] Read more.

Astaxanthin is a xanthophyll carotenoid present in microalgae, fungi, complex plants, seafood, flamingos and quail. It is an antioxidant with anti-inflammatory properties and as such has potential as a therapeutic agent in atherosclerotic cardiovascular disease. Synthetic forms of astaxanthin have been manufactured. The safety, bioavailability and effects of astaxanthin on oxidative stress and inflammation that have relevance to the pathophysiology of atherosclerotic cardiovascular disease, have been assessed in a small number of clinical studies. No adverse events have been reported and there is evidence of a reduction in biomarkers of oxidative stress and inflammation with astaxanthin administration. Experimental studies in several species using an ischaemia-reperfusion myocardial model demonstrated that astaxanthin protects the myocardium when administered both orally or intravenously prior to the induction of the ischaemic event. At this stage we do not know whether astaxanthin is of benefit when administered after a cardiovascular event and no clinical cardiovascular studies in humans have been completed and/or reported. Cardiovascular clinical trials are warranted based on the physicochemical and antioxidant properties, the safety profile and preliminary experimental cardiovascular studies of astaxanthin. Full article

(This article belongs to the Special Issue Marine Carotenoids (Special Issue))

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2947 KiB

Open AccessReview

Mycosporine-Like Amino Acids: Relevant Secondary Metabolites. Chemical and Ecological Aspects

by Jose I. Carreto and Mario O. Carignan

Mar. Drugs 2011, 9(3), 387-446; https://doi.org/10.3390/md9030387 - 21 Mar 2011

Cited by 316 | Viewed by 21266

Abstract

Taxonomically diverse marine, freshwater and terrestrial organisms have evolved the capacity to synthesize, accumulate and metabolize a variety of UV-absorbing substances called mycosporine-like amino acids (MAAs) as part of an overall strategy to diminish the direct and indirect damaging effects of environmental ultraviolet [...] Read more.

Taxonomically diverse marine, freshwater and terrestrial organisms have evolved the capacity to synthesize, accumulate and metabolize a variety of UV-absorbing substances called mycosporine-like amino acids (MAAs) as part of an overall strategy to diminish the direct and indirect damaging effects of environmental ultraviolet radiation (UVR). Whereas the enzymatic machinery to synthesize MAAs was probably inherited from cyanobacteria ancestors via the endosymbionts hypothesis, metazoans lack this biochemical pathway, but can acquire and metabolize these compounds by trophic transference, symbiotic or bacterial association. In this review we describe the structure and physicochemical properties of MAAs, including the recently discovered compounds and the modern methods used for their isolation and identification, updating previous reviews. On this basis, we review the metabolism and distribution of this unique class of metabolites among marine organism. Full article

(This article belongs to the Special Issue Marine Photoprotective Compounds)

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203 KiB

Open AccessArticle

An Acetylenic Alkaloid from the Calcareous Sponge Leucetta sp.

by Idam Hermawan, Nicole J. De Voogd and Junichi Tanaka

Mar. Drugs 2011, 9(3), 382-386; https://doi.org/10.3390/md9030382 - 21 Mar 2011

Cited by 6 | Viewed by 8045

Abstract

A new acetylenic alkaloid was isolated from the sponge Leucetta sp. The structure was established by analyzing spectroscopic data. The alkaloid showed cytotoxicity IC₅₀ 2.5 mg/mL against NBT-T2 cells. Full article

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425 KiB

Open AccessArticle

Chemical Screening Method for the Rapid Identification of Microbial Sources of Marine Invertebrate-Associated Metabolites

by Fabrice Berrue, Sydnor T. Withers, Brad Haltli, Jo Withers and Russell G. Kerr

Mar. Drugs 2011, 9(3), 369-381; https://doi.org/10.3390/md9030369 - 21 Mar 2011

Cited by 22 | Viewed by 9806

Abstract

Marine invertebrates have proven to be a rich source of secondary metabolites. The growing recognition that marine microorganisms associated with invertebrate hosts are involved in the biosynthesis of secondary metabolites offers new alternatives for the discovery and development of marine natural products. However, [...] Read more.

Marine invertebrates have proven to be a rich source of secondary metabolites. The growing recognition that marine microorganisms associated with invertebrate hosts are involved in the biosynthesis of secondary metabolites offers new alternatives for the discovery and development of marine natural products. However, the discovery of microorganisms producing secondary metabolites previously attributed to an invertebrate host poses a significant challenge. This study describes an efficient chemical screening method utilizing a 96-well plate-based bacterial cultivation strategy to identify and isolate microbial producers of marine invertebrate-associated metabolites. Full article

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584 KiB

Open AccessArticle

Lobophorin C and D, New Kijanimicin Derivatives from a Marine Sponge-Associated Actinomycetal Strain AZS17

by Rong-Bian Wei, Tao Xi, Jing Li, Ping Wang, Fu-Chao Li, Yong-Cheng Lin and Song Qin

Mar. Drugs 2011, 9(3), 359-368; https://doi.org/10.3390/md9030359 - 17 Mar 2011

Cited by 63 | Viewed by 12528

Abstract

Marine sponge Hymeniacidon sp. was collected from coastal waters of the East China Sea to isolate symbiotic microorganisms. The resulting sponge-associated actinomycete, Streptomyces carnosus strain AZS17, was cultivated in a 20 L volume of medium for production of bioactive secondary metabolites. Bioassay-guided isolation [...] Read more.

Marine sponge Hymeniacidon sp. was collected from coastal waters of the East China Sea to isolate symbiotic microorganisms. The resulting sponge-associated actinomycete, Streptomyces carnosus strain AZS17, was cultivated in a 20 L volume of medium for production of bioactive secondary metabolites. Bioassay-guided isolation and purification by varied chromatographic methods yielded two new compounds of kijanimicin derivatives, AS7-2 and AS9-12. Their structures were elucidated by spectroscopy and comparison with literatures. Results showed these two compounds were structurally similar to the previously reported compounds lobophorin A and B, yet differed in specific bond forms, stereochemistry and optical activities. The two novel compounds were named lobophorin C and D. In vitro cytotoxicity investigation by MTT assay indicated their selective activities. Lobophorin C displayed potent cytotoxic activity against the human liver cancer cell line 7402, while lobophorin D showed significant inhibitory effect on human breast cancer cells MDA-MB 435. Full article

(This article belongs to the Special Issue Marine Antibiotics)

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596 KiB

Open AccessArticle

Dynamics of Dissolved and Particulate Polyunsaturated Aldehydes in Mesocosms Inoculated with Different Densities of the Diatom Skeletonema marinoi

by Charles Vidoudez, Jens Christian Nejstgaard, Hans Henrik Jakobsen and Georg Pohnert

Mar. Drugs 2011, 9(3), 345-358; https://doi.org/10.3390/md9030345 - 11 Mar 2011

Cited by 36 | Viewed by 10175

Abstract

A survey of the production of polyunsaturated aldehydes (PUA) of manipulated plankton communities is presented here. PUA are phytoplankton-derived metabolites that are proposed to play an important role in chemically mediated plankton interactions. Blooms of different intensities of the diatom Skeletonema marinoi were [...] Read more.

A survey of the production of polyunsaturated aldehydes (PUA) of manipulated plankton communities is presented here. PUA are phytoplankton-derived metabolites that are proposed to play an important role in chemically mediated plankton interactions. Blooms of different intensities of the diatom Skeletonema marinoi were generated in eight mesocosms filled with water from the surrounding fjord by adding different amounts of a starting culture and nutrients. This set-up allowed us to follow PUA production of the plankton community over the entire induced bloom development, and to compare it with the natural levels of PUA. We found that S. marinoi is a major source for the particulate PUA 2,4-heptadienal and 2,4-octadienal (defined as PUA released upon wounding of the diatom cells) during the entire bloom development. Just before, and during, the decline of the induced diatom blooms, these PUA were also detected in up to 1 nM concentrations dissolved in the water. In addition, we detected high levels of the PUA 2,4-decadienal that was not produced by the diatom S. marinoi. Particulate decadienal correlated well with the cell counts of the prymnesiophyte Phaeocystis sp. that also developed in the fertilized mesocosms. Particulate decadienal levels were often even higher than those of diatom-derived PUA, indicating that PUA sources other than diatoms should be considered when it comes to the evaluation of the impact of these metabolites. Full article

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313 KiB

Open AccessArticle

Cytotoxic and Antimicrobial Activity of Pseudopterosins and seco-Pseudopterosins Isolated from the Octocoral Pseudopterogorgia elisabethae of San Andrés and Providencia Islands (Southwest Caribbean Sea)

by Hebelin Correa, Fabio Aristizabal, Carmenza Duque and Russell Kerr

Mar. Drugs 2011, 9(3), 334-344; https://doi.org/10.3390/md9030334 - 4 Mar 2011

Cited by 51 | Viewed by 10548

Abstract

To expand the potential of pseudopterosins and seco-pseudopterosins isolated from the octocoral Pseudopterogorgia elisabethae of San Andrés and Providencia islands (southwest Caribbean Sea), we report the anti-microbial profile against four pathogenic microorganisms (Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and [...] Read more.

To expand the potential of pseudopterosins and seco-pseudopterosins isolated from the octocoral Pseudopterogorgia elisabethae of San Andrés and Providencia islands (southwest Caribbean Sea), we report the anti-microbial profile against four pathogenic microorganisms (Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans) and report a more complete cytotoxic profile against five human cells lines (HeLa, PC-3, HCT116, MCF-7 and BJ) for the compounds PsG, PsP, PsQ, PsS, PsT, PsU, 3-O-acetyl-PsU, seco-PsJ, seco-PsK and IMNGD. For the cytotoxic profiles, all compounds evaluated showed moderate and non-selective activity against both tumor and normal cell lines, where PsQ and PsG were the most active compounds (GI₅₀ values between 5.8 µM to 12.0 µM). With respect to their anti-microbial activity the compounds showed good and selective activity against the Gram-positive bacteria, while they did not show activity against the Gram-negative bacterium or yeast. PsU, PsQ, PsS, seco-PsK and PsG were the most active compounds (IC₅₀ 2.9–4.5 µM) against S. aureus and PsG, PsU and seco-PsK showed good activity (IC₅₀ 3.1–3.8 µM) against E. faecalis, comparable to the reference drug vancomycin (4.2 µM). Full article

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241 KiB

Open AccessReview

Marine Carotenoids: Biological Functions and Commercial Applications

by Carlos Vílchez, Eduardo Forján, María Cuaresma, Francisco Bédmar, Inés Garbayo and José M. Vega

Mar. Drugs 2011, 9(3), 319-333; https://doi.org/10.3390/md9030319 - 3 Mar 2011

Cited by 239 | Viewed by 19289

Abstract

Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids [...] Read more.

Carotenoids are the most common pigments in nature and are synthesized by all photosynthetic organisms and fungi. Carotenoids are considered key molecules for life. Light capture, photosynthesis photoprotection, excess light dissipation and quenching of singlet oxygen are among key biological functions of carotenoids relevant for life on earth. Biological properties of carotenoids allow for a wide range of commercial applications. Indeed, recent interest in the carotenoids has been mainly for their nutraceutical properties. A large number of scientific studies have confirmed the benefits of carotenoids to health and their use for this purpose is growing rapidly. In addition, carotenoids have traditionally been used in food and animal feed for their color properties. Carotenoids are also known to improve consumer perception of quality; an example is the addition of carotenoids to fish feed to impart color to farmed salmon. Full article

(This article belongs to the Special Issue Marine Carotenoids (Special Issue))

261 KiB

Open AccessArticle

Antinociceptive and Anti-Inflammatory Activity from Algae of the Genus Caulerpa

by Carolina Babosa Brito da Matta, Éverton Tenório De Souza, Aline Cavalcanti De Queiroz, Daysianne Pereira De Lira, Morgana Vital De Araújo, Luiz Henrique Agra Cavalcante-Silva, George Emmanuel C. De Miranda, João Xavier De Araújo-Júnior, José Maria Barbosa-Filho, Bárbara Viviana De Oliveira Santos and Magna Suzana Alexandre-Moreira

Mar. Drugs 2011, 9(3), 307-318; https://doi.org/10.3390/md9030307 - 2 Mar 2011

Cited by 55 | Viewed by 14359

Abstract

Marine natural products have been the focus of discovery for new products of chemical and pharmacological interest. The aim of this study was to evaluate the antinociceptive activity of the methanolic (ME), acetate (AE), hexanic (HE) and chloroform (CE) extracts obtained from Caulerpa [...] Read more.

Marine natural products have been the focus of discovery for new products of chemical and pharmacological interest. The aim of this study was to evaluate the antinociceptive activity of the methanolic (ME), acetate (AE), hexanic (HE) and chloroform (CE) extracts obtained from Caulerpa mexicana, and ME, CE and HE obtained from Caulerpa sertularioides. These marine algae are found all over the world, mainly in tropical regions. Models such as the writhing test, the hot plate test and formalin-induced nociception test were used to evaluate antinociceptive activity in laboratory mice. In the writhing test, all the extracts were administered orally at a concentration of 100 mg/kg, and induced high peripheral antinociceptive activity, with a reduction in the nociception induced by acetic acid above 65%. In the hot plate test, treatment with extracts from C. sertularioides (100 mg/kg, p.o.) did not significantly increase the latency of response, although the ME, AE and HE from C. mexicana showed activity in this model. This result suggests that these extracts exhibit antinociceptive activity. In the formalin test, it was observed that ME, AE and HE obtained from C. mexicana reduced the effects of formalin in both phases. On the other hand only CE from C. sertularioides induced significant inhibition of the nociceptive response in the first phase. To better assess the potential anti-inflammatory activity of the extracts, the carrageenan-induced peritonitis test was used to test Caulerpa spp. extracts on cell migration into the peritoneal cavity. In this assay, all extracts evaluated were able to significantly inhibit leukocyte migration into the peritoneal cavity in comparison with carrageenan. These data demonstrate that extracts from Caulerpa species elicit pronounced antinociceptive and anti-inflamatory activity against several nociception models. However, pharmacological and chemical studies are continuing in order to characterize the mechanism(s) responsible for the antinociceptive action and also to identify the active principles present in the Caulerpa species. Full article

(This article belongs to the Special Issue Biomedicines from Marine Symbioses)

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183 KiB

Open AccessArticle

Isolation of a New Natural Product and Cytotoxic and Antimicrobial Activities of Extracts from Fungi of Indonesian Marine Habitats

by Kustiariyah Tarman, Ulrike Lindequist, Kristian Wende, Andrea Porzel, Norbert Arnold and Ludger A. Wessjohann

Mar. Drugs 2011, 9(3), 294-306; https://doi.org/10.3390/md9030294 - 25 Feb 2011

Cited by 45 | Viewed by 14953

Abstract

In the search for bioactive compounds, 11 fungal strains were isolated from Indonesian marine habitats. Ethyl acetate extracts of their culture broth were tested for cytotoxic activity against a urinary bladder carcinoma cell line and for antifungal and antibacterial activities against fish and [...] Read more.

In the search for bioactive compounds, 11 fungal strains were isolated from Indonesian marine habitats. Ethyl acetate extracts of their culture broth were tested for cytotoxic activity against a urinary bladder carcinoma cell line and for antifungal and antibacterial activities against fish and human pathogenic bacteria as well as against plant and human pathogenic fungi. The crude extract of a sterile algicolous fungus (KT31), isolated from the red seaweed Kappaphycus alvarezii (Doty) Doty ex P.C. Silva exhibited potent cytotoxic activity with an IC₅₀ value of 1.5 µg/mL. Another fungal strain (KT29) displayed fungicidal properties against the plant pathogenic fungus Cladosporium cucumerinum Ell. et Arth. at 50 µg/spot. 2-Carboxy-8-methoxy-naphthalene-1-ol (1) could be isolated as a new natural product. Full article

(This article belongs to the Special Issue Bioactive Compounds from Marine Fungi)

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Mar. Drugs, Volume 9, Issue 3 (March 2011) – 11 articles , Pages 294-477

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