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Mar. Drugs, Volume 9, Issue 5 (May 2011), Pages 690-921

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Research

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Open AccessArticle Deoxyuridines from the Marine Sponge Associated Actinomycete Streptomyces microflavus
Mar. Drugs 2011, 9(5), 690-695; doi:10.3390/md9050690
Received: 9 March 2011 / Revised: 3 April 2011 / Accepted: 13 April 2011 / Published: 26 April 2011
Cited by 12 | PDF Full-text (165 KB) | HTML Full-text | XML Full-text
Abstract
One new nucleoside derivative, named 3-acetyl-5-methyl-2′-deoxyuridine (1), along with two known compounds 3,5-dimethyl-2′-deoxyuridine (2) and 3-methyl-2′-deoxyuridine (3), were isolated from the cultures of Streptomyces microflavus. This strain was an associated actinomycete isolated from the marine sponge
[...] Read more.
One new nucleoside derivative, named 3-acetyl-5-methyl-2′-deoxyuridine (1), along with two known compounds 3,5-dimethyl-2′-deoxyuridine (2) and 3-methyl-2′-deoxyuridine (3), were isolated from the cultures of Streptomyces microflavus. This strain was an associated actinomycete isolated from the marine sponge Hymeniacidon perlevis collected from the coast of Dalian (China). Their structures were elucidated by detailed NMR and MS spectroscopic analysis as well as comparison with literature data. Full article
(This article belongs to the Special Issue Biomedicines from Marine Symbioses)
Open AccessArticle Oral Administration of Skin Gelatin Isolated from Chum Salmon (Oncorhynchus keta) Enhances Wound Healing in Diabetic Rats
Mar. Drugs 2011, 9(5), 696-711; doi:10.3390/md9050696
Received: 4 March 2011 / Revised: 12 April 2011 / Accepted: 18 April 2011 / Published: 26 April 2011
Cited by 11 | PDF Full-text (953 KB) | HTML Full-text | XML Full-text
Abstract
Care for diabetic wounds remains a significant clinical problem. The present study was aimed at investigating the effect of skin gelatin from Chum Salmon on defective wound repair in the skin of diabetic rats. Full-thickness excisional skin wounds were made in 48 rats,
[...] Read more.
Care for diabetic wounds remains a significant clinical problem. The present study was aimed at investigating the effect of skin gelatin from Chum Salmon on defective wound repair in the skin of diabetic rats. Full-thickness excisional skin wounds were made in 48 rats, of which 32 were diabetes. The diabetic rats were orally treated daily for 14 days with skin gelatin from Chum Salmon (2 g/kg) or its vehicle. Sixteen non-diabetic control rats received the same amount of water as vehicle-treated non-diabetic rats. Rats were killed to assess the rate of wound closure, microvessel density (MVD), vascular endothelial growth factor (VEGF), hydroxyproline (HP) contents in wound tissues and nitrate in plasma and wound tissue at 7 and 14 days after wounding. Skin gelatin-treated diabetic rats showed a better wound closure, increased MVD, VEGF, hyproxyproline and NO contents and a reduced extent of inflammatory response. All parameters were significant (P < 0.05) in comparison to vehicle-treated diabetic group. In light of our finding that skin gelatin of Chum Salmon promotes skin wound repair in diabetic rats, we propose that oral administration of Chum Salmon skin gelatin might be a beneficial method for treating wound disorders associated with diabetes. Full article
(This article belongs to the Special Issue Marine Functional Food)
Open AccessArticle Effects of Oral Glucosamine Hydrochloride Administration on Plasma Free Amino Acid Concentrations in Dogs
Mar. Drugs 2011, 9(5), 712-718; doi:10.3390/md9050712
Received: 23 March 2011 / Revised: 18 April 2011 / Accepted: 25 April 2011 / Published: 27 April 2011
Cited by 7 | PDF Full-text (191 KB) | HTML Full-text | XML Full-text
Abstract
We examined the effects of oral glucosamine hydrochloride (GlcN), N-acetyl-D-glucosamine (GlcNAc) and D-glucose (Glc) administration on plasma total free amino acid (PFAA) concentrations in dogs. The PFAA concentrations increased in the control group and the GlcNAc group at one hour after feeding,
[...] Read more.
We examined the effects of oral glucosamine hydrochloride (GlcN), N-acetyl-D-glucosamine (GlcNAc) and D-glucose (Glc) administration on plasma total free amino acid (PFAA) concentrations in dogs. The PFAA concentrations increased in the control group and the GlcNAc group at one hour after feeding, and each amino acid concentration increased. On the other hand, in the GlcN group and the Glc group PFAA concentrations decreased at one hour after feeding. A significant decrease in amino acid concentration was observed for glutamate, glycine and alanine. Our results suggest the existence of differences in PFAA dynamics after oral administration of GlcN and GlcNAc in dogs. Full article
(This article belongs to the Special Issue Marine Functional Food)
Open AccessArticle Anti-Phytopathogenic Activities of Macro-Algae Extracts
Mar. Drugs 2011, 9(5), 739-756; doi:10.3390/md9050739
Received: 15 March 2011 / Revised: 7 April 2011 / Accepted: 15 April 2011 / Published: 3 May 2011
Cited by 12 | PDF Full-text (449 KB) | HTML Full-text | XML Full-text
Abstract
Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular
[...] Read more.
Aqueous and ethanolic extracts obtained from nine Chilean marine macro-algae collected at different seasons were examined in vitro and in vivo for properties that reduce the growth of plant pathogens or decrease the injury severity of plant foliar tissues following pathogen infection. Particular crude aqueous or organic extracts showed effects on the growth of pathogenic bacteria whereas others displayed important effects against pathogenic fungi or viruses, either by inhibiting fungal mycelia growth or by reducing the disease symptoms in leaves caused by pathogen challenge. Organic extracts obtained from the brown-alga Lessonia trabeculata inhibited bacterial growth and reduced both the number and size of the necrotic lesion in tomato leaves following infection with Botrytis cinerea. Aqueous and ethanolic extracts from the red-alga Gracillaria chilensis prevent the growth of Phytophthora cinnamomi, showing a response which depends on doses and collecting-time. Similarly, aqueous and ethanolic extracts from the brown-alga Durvillaea antarctica were able to diminish the damage caused by tobacco mosaic virus (TMV) in tobacco leaves, and the aqueous procedure is, in addition, more effective and seasonally independent. These results suggest that macro-algae contain compounds with different chemical properties which could be considered for controlling specific plant pathogens. Full article
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Open AccessArticle Genetic Approach for the Fast Discovery of Phenazine Producing Bacteria
Mar. Drugs 2011, 9(5), 772-789; doi:10.3390/md9050772
Received: 17 February 2011 / Revised: 1 April 2011 / Accepted: 29 April 2011 / Published: 9 May 2011
Cited by 16 | PDF Full-text (523 KB) | HTML Full-text | XML Full-text
Abstract
A fast and efficient approach was established to identify bacteria possessing the potential to biosynthesize phenazines, which are of special interest regarding their antimicrobial activities. Sequences of phzE genes, which are part of the phenazine biosynthetic pathway, were used to design one
[...] Read more.
A fast and efficient approach was established to identify bacteria possessing the potential to biosynthesize phenazines, which are of special interest regarding their antimicrobial activities. Sequences of phzE genes, which are part of the phenazine biosynthetic pathway, were used to design one universal primer system and to analyze the ability of bacteria to produce phenazine. Diverse bacteria from different marine habitats and belonging to six major phylogenetic lines were investigated. Bacteria exhibiting phzE gene fragments affiliated to Firmicutes, Alpha- and Gammaproteobacteria, and Actinobacteria. Thus, these are the first primers for amplifying gene fragments from Firmicutes and Alphaproteobacteria. The genetic potential for phenazine production was shown for four type strains belonging to the genera Streptomyces and Pseudomonas as well as for 13 environmental isolates from marine habitats. For the first time, the genetic ability of phenazine biosynthesis was verified by analyzing the metabolite pattern of all PCR-positive strains via HPLC-UV/MS. Phenazine production was demonstrated for the type strains known to produce endophenazines, 2-hydroxy-phenazine, phenazine-1-carboxylic acid, phenazine-1,6-dicarboxylic acid, and chlororaphin as well as for members of marine Actinobacteria. Interestingly, a number of unidentified phenazines possibly represent new phenazine structures. Full article
Open AccessArticle Bioactivity of Benthic and Picoplanktonic Estuarine Cyanobacteria on Growth of Photoautotrophs: Inhibition versus Stimulation
Mar. Drugs 2011, 9(5), 790-802; doi:10.3390/md9050790
Received: 9 March 2011 / Revised: 28 April 2011 / Accepted: 9 May 2011 / Published: 10 May 2011
Cited by 8 | PDF Full-text (293 KB) | HTML Full-text | XML Full-text
Abstract
Understanding potential biochemical interactions and effects among cyanobacteria and other organisms is one of the main keys to a better knowledge of microbial population structuring and dynamics. In this study, the effects of cyanobacteria from benthos and plankton of estuaries on other cyanobacteria
[...] Read more.
Understanding potential biochemical interactions and effects among cyanobacteria and other organisms is one of the main keys to a better knowledge of microbial population structuring and dynamics. In this study, the effects of cyanobacteria from benthos and plankton of estuaries on other cyanobacteria and green algae growth were evaluated. To understand how the estuarine cyanobacteria might influence the dynamics of phytoplankton, experiments were carried out with the freshwater species Microcystis aeruginosa and Chlorella sp., and the marine Synechocystis salina and Nannochloropsis sp. exposed to aqueous and organic (70% methanol) crude extracts of cyanobacteria for 96 h. The most pronounced effect observed was the growth stimulation. Growth inhibition was also observed for S. salina and M. aeruginosa target-species at the highest and lowest concentrations of cyanobacterial extracts. The methanolic crude extract of Phormidium cf. chalybeum LEGE06078 was effective against S. salina growth in a concentration-dependent manner after 96 h-exposure. All of the cyanobacterial isolates showed some bioactivity on the target-species growth, i.e., inhibitory or stimulating effects. These results indicate that the analyzed cyanobacterial isolates can potentially contribute to blooms’ proliferation of other cyanobacteria and to the abnormal growth of green algae disturbing the dynamic of estuarine phytoplankton communities. Since estuaries are transitional ecosystems, the benthic and picoplanktonic estuarine cyanobacteria can change both freshwater and marine phytoplankton succession, competition and bloom formation. Furthermore, a potential biotechnological application of these isolates as a tool to control cyanobacteria and microalgae proliferation can be feasible. This work is the first on the subject of growth responses of photoautotrophs to cyanobacteria from Atlantic estuarine environments. Full article
Open AccessArticle Antiproliferative Activity of Violaxanthin Isolated from Bioguided Fractionation of Dunaliella tertiolecta Extracts
Mar. Drugs 2011, 9(5), 819-831; doi:10.3390/md9050819
Received: 29 March 2011 / Revised: 27 April 2011 / Accepted: 4 May 2011 / Published: 11 May 2011
Cited by 16 | PDF Full-text (435 KB) | HTML Full-text | XML Full-text
Abstract
Dunaliella tertiolecta (DT) was chemically investigated to isolate molecules inhibiting cancer cell proliferation and inducing apoptosis in vitro. The potency to inhibit cell growth was used for the bio-guided fractionation and isolation of active compounds using chromatographic techniques. The DT
[...] Read more.
Dunaliella tertiolecta (DT) was chemically investigated to isolate molecules inhibiting cancer cell proliferation and inducing apoptosis in vitro. The potency to inhibit cell growth was used for the bio-guided fractionation and isolation of active compounds using chromatographic techniques. The DT dichloromethane extract exhibited a strong anti-proliferative activity on MCF-7 and LNCaP cells, and was further fractionated and sub-fractionated by RP-HPLC. High resolution mass spectrometry and spectrophotometric analysis unequivocally identified violaxanthin as the most antiproliferative molecule present in DT DCM extract. Violaxanthin purified from DT induced MCF-7 dose-dependent growth inhibition in continuous and discontinuous treatments, at concentrations as low as 0.1 µg·mL−1 (0.17 µM). Phosphatidylserine exposure, typical of early apoptosis, was observed after 48 h treatment at 8 µg·mL1 (13.3 µM) but no DNA fragmentation, characteristic of late apoptosis steps, could be detected even after 72 h treatment at 40 µg·mL1 (66.7 µM). Taken together, our results demonstrate the strong antiproliferative activity of violaxanthin on one human mammary cancer cell line, and suggest that studying the pharmacology of violaxanthin and pharmacomodulated derivatives on cancer cells may allow potent antiproliferative drugs to be obtained. Full article
Open AccessArticle Three Bianthraquinone Derivatives from the Mangrove Endophytic Fungus Alternaria sp. ZJ9-6B from the South China Sea
Mar. Drugs 2011, 9(5), 832-843; doi:10.3390/md9050832
Received: 28 March 2011 / Revised: 20 April 2011 / Accepted: 4 May 2011 / Published: 12 May 2011
Cited by 38 | PDF Full-text (332 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Three new bianthraquinone derivatives, alterporriol K (1), L (2) and M (3), along with six known compounds were obtained from extracts of the endophytic fungus Alternaria sp. ZJ9-6B, isolated from the mangrove Aegiceras corniculatum collected in the
[...] Read more.
Three new bianthraquinone derivatives, alterporriol K (1), L (2) and M (3), along with six known compounds were obtained from extracts of the endophytic fungus Alternaria sp. ZJ9-6B, isolated from the mangrove Aegiceras corniculatum collected in the South China Sea. Their structures were elucidated by one- and two-dimensional NMR spectroscopy, MS data analysis and circular dichroism measurements. Compounds 1, 2 and 3 were first isolated alterporriols with a C-2–C-2′ linkage. The crystallographic data of tetrahydroaltersolanol B (7) was reported for the first time. In the primary bioassays, alterporriol K and L exhibited moderate cytotoxic activity towards MDA-MB-435 and MCF-7 cells with IC50 values ranging from 13.1 to 29.1 µM. Full article
(This article belongs to the Special Issue Bioactive Compounds from Marine Microbes)
Open AccessArticle Balticolid: A New 12-Membered Macrolide with Antiviral Activity from an Ascomycetous Fungus of Marine Origin
Mar. Drugs 2011, 9(5), 844-851; doi:10.3390/md9050844
Received: 19 March 2011 / Revised: 27 April 2011 / Accepted: 10 May 2011 / Published: 13 May 2011
Cited by 20 | PDF Full-text (223 KB) | HTML Full-text | XML Full-text
Abstract
A new 12-membered macrolide, balticolid (1) was isolated from the EtOAc extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany. The
[...] Read more.
A new 12-membered macrolide, balticolid (1) was isolated from the EtOAc extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany. The structure of balticolid was determined to be (3R,11R), (4E,8E)-3-hydroxy-11-methyloxacyclododeca-4,8-diene-1,7-dione using extensive spectral data as well as the modified Mosher ester method. Balticolid (1) displayed anti-HSV-1 activity with an IC50 value of 0.45 µM. Full article
Open AccessArticle Anti-Proliferative Activity of Meroditerpenoids Isolated from the Brown Alga Stypopodium flabelliforme against Several Cancer Cell Lines
Mar. Drugs 2011, 9(5), 852-862; doi:10.3390/md9050852
Received: 29 March 2011 / Revised: 30 April 2011 / Accepted: 9 May 2011 / Published: 13 May 2011
Cited by 19 | PDF Full-text (330 KB) | HTML Full-text | XML Full-text
Abstract
The sea constitutes one of the most promising sources of novel compounds with potential application in human therapeutics. In particular, algae have proved to be an interesting source of new bioactive compounds. In this work, six meroditerpenoids (epitaondiol, epitaondiol diacetate, epitaondiol monoacetate, stypotriol
[...] Read more.
The sea constitutes one of the most promising sources of novel compounds with potential application in human therapeutics. In particular, algae have proved to be an interesting source of new bioactive compounds. In this work, six meroditerpenoids (epitaondiol, epitaondiol diacetate, epitaondiol monoacetate, stypotriol triacetate, 14-ketostypodiol diacetate and stypodiol) isolated from the brown alga Stypopodium flabelliforme were tested for their cell proliferation inhibitory activity in five cell lines. Cell lines tested included human colon adenocarcinoma (Caco-2), human neuroblastoma (SH-SY5Y), rat basophilic leukemia (RBL-2H3), murine macrophages (RAW.267) and Chinese hamster fibroblasts (V79). Antimicrobial activity of the compounds was also evaluated against Staphylococcus aureus, Salmonella typhimurium, Proteus mirabilis, Bacillus cereus, Enterococcus faecalis and Micrococcus luteus. Overall, the compounds showed good activity against all cell lines, with SH-SY5Y and RAW.267 being the most susceptible. Antimicrobial capacity was observed for epitaondiol monoacetate, stypotriol triacetate and stypodiol, with the first being the most active. The results suggest that these molecules deserve further studies in order to evaluate their potential as therapeutic agents. Full article
Open AccessArticle Volatile Constituents, Inorganic Elements and Primary Screening of Bioactivity of Black Coral Cigarette Holders
Mar. Drugs 2011, 9(5), 863-878; doi:10.3390/md9050863
Received: 9 April 2011 / Revised: 5 May 2011 / Accepted: 9 May 2011 / Published: 18 May 2011
Cited by 4 | PDF Full-text (308 KB) | HTML Full-text | XML Full-text
Abstract
Black corals (BC) have been used for a long time in Chinese medicine, and may have some pharmaceutical functions when used as material for cigarette holders in southeast China. This study is aimed to investigate the bioactivities of volatile constituents in BC and
[...] Read more.
Black corals (BC) have been used for a long time in Chinese medicine, and may have some pharmaceutical functions when used as material for cigarette holders in southeast China. This study is aimed to investigate the bioactivities of volatile constituents in BC and to explore the folklore behind the use of BC cigarette holders (BCCHs). We extracted the volatile constituents of BC by supercritical fluid extraction (SFE) with carbon dioxide (CO2-SFE), then identified and analyzed the constituents by gas chromatography-mass spectrometry (GC-MS). In total, 15 components were reliably identified in BC and found to be biologically active. These included triethyl phosphate, butylated hydroxytoluene, cedrol, n-hexadecanoic acid, squalene, and cholesterol. Meanwhile 13 inorganic elements (P, Ca, Mg, S, B, Si, Fe, Cu, Zn, Ba, etc.) were determined by inductively coupled plasma spectrometer (ICPS). In the bioactivity tests, the BC extract (BCE) showed a scavenging activity of 2,2-diphenyl-1-picrylhydrazyl free radicals and hydroxyl radicals by phenanthroline-Fe (II) oxidation and moderate inhibition of Gram-positive microorganisms. The antioxidant and antimicrobial activities of BC, which are related to the active chemical composition, may explain the perceived benefit for cigarette smokers who use BCCHs. Full article
Open AccessArticle Bioactive Indole Derivatives from the South Pacific Marine Sponges Rhopaloeides odorabile and Hyrtios sp.
Mar. Drugs 2011, 9(5), 879-888; doi:10.3390/md9050879
Received: 13 April 2011 / Revised: 16 May 2011 / Accepted: 17 May 2011 / Published: 24 May 2011
Cited by 20 | PDF Full-text (339 KB) | HTML Full-text | XML Full-text
Abstract
Indole derivatives including bromoindoles have been isolated from the South Pacific marine sponges Rhopaloeides odorabile and Hyrtios sp. Their structures were established through analysis of mass spectra and 1D and 2D NMR spectroscopic data. Their potential inhibitory phospholipase A2 (PLA2),
[...] Read more.
Indole derivatives including bromoindoles have been isolated from the South Pacific marine sponges Rhopaloeides odorabile and Hyrtios sp. Their structures were established through analysis of mass spectra and 1D and 2D NMR spectroscopic data. Their potential inhibitory phospholipase A2 (PLA2), antioxidant and cytotoxic activities were evaluated. The new derivative 5,6-dibromo-l-hypaphorine (9) isolated from Hyrtios sp. revealed a weak bee venom PLA2 inhibition (IC50 0.2 mM) and a significant antioxidant activity with an Oxygen Radical Absorbance Capacity (ORAC) value of 0.22. The sesquiterpene aureol (4), also isolated from Hyrtios sp., showed the most potent antioxidant activity with an ORAC value of 0.29. Full article
Open AccessArticle Screening of Microorganisms Producing Cold-Active Oxidoreductases to Be Applied in Enantioselective Alcohol Oxidation. An Antarctic Survey
Mar. Drugs 2011, 9(5), 889-905; doi:10.3390/md9050889
Received: 20 April 2011 / Revised: 17 May 2011 / Accepted: 20 May 2011 / Published: 24 May 2011
Cited by 8 | PDF Full-text (389 KB) | HTML Full-text | XML Full-text
Abstract
Several microorganisms were isolated from soil/sediment samples of Antarctic Peninsula. The enrichment technique using (RS)-1-(phenyl)ethanol as a carbon source allowed us to isolate 232 psychrophile/psychrotroph microorganisms. We also evaluated the enzyme activity (oxidoreductases) for enantioselective oxidation reactions, by using derivatives of
[...] Read more.
Several microorganisms were isolated from soil/sediment samples of Antarctic Peninsula. The enrichment technique using (RS)-1-(phenyl)ethanol as a carbon source allowed us to isolate 232 psychrophile/psychrotroph microorganisms. We also evaluated the enzyme activity (oxidoreductases) for enantioselective oxidation reactions, by using derivatives of (RS)-1-(phenyl)ethanol as substrates. Among the studied microorganisms, 15 psychrophile/psychrotroph strains contain oxidoreductases that catalyze the (S)-enantiomer oxidation from racemic alcohols to their corresponding ketones. Among the identified microorganisms, Flavobacterium sp. and Arthrobacter sp. showed excellent enzymatic activity. These new bacteria strains were selected for optimization study, in which the (RS)-1-(4-methyl-phenyl)ethanol oxidation was evaluated in several reaction conditions. From these studies, it was observed that Flavobacterium sp. has an excellent enzymatic activity at 10 °C and Arthrobacter sp. at 15 and 25 °C. We have also determined the growth curves of these bacteria, and both strains showed optimum growth at 25 °C, indicating that these bacteria are psychrotroph. Full article
(This article belongs to the Special Issue Enzymes from the Sea: Sources, Molecular Biology and Bioprocesses)
Open AccessArticle Molecular Evolution of Multiple Arylalkylamine N-Acetyltransferase (AANAT) in Fish
Mar. Drugs 2011, 9(5), 906-921; doi:10.3390/md9050906
Received: 17 February 2011 / Revised: 16 May 2011 / Accepted: 17 May 2011 / Published: 24 May 2011
Cited by 11 | PDF Full-text (449 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Arylalkylamine N-acetyltransferase (AANAT) catalyzes the transfer of an acetyl group from acetyl coenzyme A (AcCoA) to arylalkylamines, including indolethylamines and phenylethylamines. Multiple aanats are present in teleost fish as a result of whole genome and gene duplications. Fish aanat1a and aanat2 paralogs
[...] Read more.
Arylalkylamine N-acetyltransferase (AANAT) catalyzes the transfer of an acetyl group from acetyl coenzyme A (AcCoA) to arylalkylamines, including indolethylamines and phenylethylamines. Multiple aanats are present in teleost fish as a result of whole genome and gene duplications. Fish aanat1a and aanat2 paralogs display different patterns of tissue expression and encode proteins with different substrate preference: AANAT1a is expressed in the retina, and acetylates both indolethylamines and phenylethylamines; while AANAT2 is expressed in the pineal gland, and preferentially acetylates indolethylamines. The two enzymes are therefore thought to serve different roles. Here, the molecular changes that led to their specialization were studied by investigating the structure-function relationships of AANATs in the gilthead seabream (sb, Sperus aurata). Acetylation activity of reciprocal mutated enzymes pointed to specific residues that contribute to substrate specificity of the enzymes. Inhibition tests followed by complementary analyses of the predicted three-dimensional models of the enzymes, suggested that both phenylethylamines and indolethylamines bind to the catalytic pocket of both enzymes. These results suggest that substrate selectivity of AANAT1a and AANAT2 is determined by the positioning of the substrate within the catalytic pocket, and its accessibility to catalysis. This illustrates the evolutionary process by which enzymes encoded by duplicated genes acquire different activities and play different biological roles. Full article
(This article belongs to the Special Issue Enzymes from the Sea: Sources, Molecular Biology and Bioprocesses)
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Review

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Open AccessReview The Biological Deep Sea Hydrothermal Vent as a Model to Study Carbon Dioxide Capturing Enzymes
Mar. Drugs 2011, 9(5), 719-738; doi:10.3390/md9050719
Received: 20 March 2011 / Revised: 14 April 2011 / Accepted: 20 April 2011 / Published: 28 April 2011
Cited by 8 | PDF Full-text (309 KB) | HTML Full-text | XML Full-text
Abstract
Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises
[...] Read more.
Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis) a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO2 from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO2 fixation and assimilation might be very useful. This review describes some current research concerning CO2 fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture. Full article
(This article belongs to the Special Issue Enzymes from the Sea: Sources, Molecular Biology and Bioprocesses)
Open AccessReview Carotenoid β-Ring Hydroxylase and Ketolase from Marine Bacteria—Promiscuous Enzymes for Synthesizing Functional Xanthophylls
Mar. Drugs 2011, 9(5), 757-771; doi:10.3390/md9050757
Received: 21 March 2011 / Revised: 19 April 2011 / Accepted: 26 April 2011 / Published: 6 May 2011
Cited by 11 | PDF Full-text (671 KB) | HTML Full-text | XML Full-text
Abstract
Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C40-type dicyclic carotenoids containing two β-end groups (β rings) that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which
[...] Read more.
Marine bacteria belonging to genera Paracoccus and Brevundimonas of the α-Proteobacteria class can produce C40-type dicyclic carotenoids containing two β-end groups (β rings) that are modified with keto and hydroxyl groups. These bacteria produce astaxanthin, adonixanthin, and their derivatives, which are ketolated by carotenoid β-ring 4(4′)-ketolase (4(4′)-oxygenase; CrtW) and hydroxylated by carotenoid β-ring 3(3′)-hydroxylase (CrtZ). In addition, the genus Brevundimonas possesses a gene for carotenoid β-ring 2(2′)-hydroxylase (CrtG). This review focuses on these carotenoid β-ring-modifying enzymes that are promiscuous for carotenoid substrates, and pathway engineering for the production of xanthophylls (oxygen-containing carotenoids) in Escherichia coli, using these enzyme genes. Such pathway engineering researches are performed towards efficient production not only of commercially important xanthophylls such as astaxanthin, but also of xanthophylls minor in nature (e.g., β-ring(s)-2(2′)-hydroxylated carotenoids). Full article
(This article belongs to the Special Issue Marine Carotenoids (Special Issue))
Open AccessReview Neuroprotective Effects of Marine Algae
Mar. Drugs 2011, 9(5), 803-818; doi:10.3390/md9050803
Received: 25 February 2011 / Revised: 12 April 2011 / Accepted: 28 April 2011 / Published: 10 May 2011
Cited by 60 | PDF Full-text (242 KB) | HTML Full-text | XML Full-text
Abstract
The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Among marine organisms, marine algae have been identified as an under-exploited plant resource, although they have long been recognized as valuable sources of structurally diverse bioactive
[...] Read more.
The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Among marine organisms, marine algae have been identified as an under-exploited plant resource, although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities and neuroprotective effects of marine algae including antioxidant, anti-neuroinflammatory, cholinesterase inhibitory activity and the inhibition of neuronal death. Hence, marine algae have great potential to be used for neuroprotection as part of pharmaceuticals, nutraceuticals and functional foods. This contribution presents an overview of marine algal neuroprotective effects and their potential application in neuroprotection. Full article

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