Red Alga Portieria Hornemannii Research Articles

Anti-Inflammatory Halogenated Monoterpenes from the Red Alga Portieria hornemannii.

The chemical investigation of a red alga Portieria hornemannii enabled the identification of three new halogenated monoterpenes (1-3) along with two previously identified metabolites (4 and 5). Their structures were determined by spectroscopic analysis and also by utilizing single-crystal diffraction analysis and quantum chemical calculation, as well as by comparison with literature data. Further corrections for dichloro and dibromo carbons using the sorted training set (STS) method were established in this study to significantly improve the accuracy in GIAO 13C NMR calculation of compounds 1-3. To discover the potential bioactive metabolites from P. hornemannii, the anti-inflammatory activities of all compounds were examined. Compounds 1 and 3-5 showed significant anti-inflammatory activity to inhibit the production of pro-inflammatory cytokines in the LPS-stimulated mature dendritic cells.

Screening of Phytochemicals and Antibacterial Activity of Marine Red Alga Portieria hornemannii (Lyngbye) P. C. Silva

The evaluation of phytochemicals and antimicrobial activities of marine red alga Portieriahornemannii against bacterial pathogens have been established in the present investigation. The quantitative phytochemical screening of the methanol extract of P.hornemannii, showed a maximum number of natural products such as tannins, flavonoids, glycosides, phenols, saponins, terpenoids, etc. The antimicrobial activity of methanol extract of P.hornemannii showed the highest inhibition against Staphylococcusaureus (77.77%) and the chloroform extract showed the lowest activity against Pseudomonasaeruginosa by showing (52.63%) as evaluated by disc diffusion method. Our findings provide the evidence that the methanol extract of P. hornemannii possesses the good antimicrobial activity and hence, the alga proves to be an effective therapeutic agent.

Further studies and biological activities of macromolecular protein R-Phycoerythrin from Portieria hornemannii

In the present study, the purified R-Phycoerythrin (R-PE) from a red alga Portieria hornemannii was subjected to the analysis of stability under the influence of different agents. Among the various inhibitors tested on R-PE EDTA at lower concentrations (<1mM) supported the activity of R-PE. When R-PE was exposed to different organic solvents, ethanol supported the activity at the maximum followed by acetone, ethyl acetate, chloroform and methanol. Citric acid, as a preservative maintained the stability of R-PE both under 0±5°C and 30±5°C with 59.34% and 56.23% respectively, on 30th day. Thermal decomposition of the R-PE began near 60°C. Maximum weight loss was occurred between 150°C and 500°C. Complete weight loss was recorded around 875°C. Thermal denaturation was observed between 19°C and 40°C. Moderate to low antioxidant activities were observed in R-PE in relation to total antioxidant activities. After characterization, R-PE was taken for in vitro anticancer studies against selected cancer cell lines. Further studies involving AO/EB fluorescence staining and phase contrast microscope revealed characteristic apoptotic features like cell shrinkage, membrane blebbing, and nuclear DNA fragmentation, etc. Likewise, FACS analysis revealed the cell cycle distribution pattern of A549 and HepG2 cells.

Isolation and characterization of macromolecular protein R-Phycoerythrin from Portieria hornemannii

R-Phycoerythrin (R-PE) is one of the three phycobiliproteins which are extensively used as fluorescent probes, and it is prepared from red macro-algae. This macromolecular protein has gained importance in many biotechnological applications in food science, immunodiagnostic, therapy, cosmetics, protein and cell labeling, and analytical processes. In the present investigation, R-PE was isolated and purified from a red alga Portieria hornemannii. R-PE extracted and purified through ammonium sulfate precipitation (55%) followed by Q-Sepharose column chromatography had yielded a maximum purity of 5.2%. R-PE exhibited a typical “three-peak” with absorption maxima at 499, 545 and 565nm. CD spectrum of R-PE yielded the following secondary structure data: alpha helix (14.30%), beta helix (28.10%), turn helix (19.20%) and random coil helix (38.40%). The molecular mass of R-PE was 240kDa under Native-PAGE. Three different subunits such as α, β and γ of 16kDa, 21kDa and 39kDa were segregated under SDS-PAGE. On two dimensional gel electrophoresis, one basic and four acidic subunits were detected. Five different tryptic peptides were assigned under MALDI-TOF. The sequences of N-terminus of R-PE of 10 different amino acids are Met Lys Gln Met Trp Asp Arg Met Val Val. The preparative procedures of the R-PE extraction and purification established based on the experiments exhibit advantages and can offer a reference for R-PE preparation from other marine red macro-alga P. hornemannii.

Morphology, vegetative and reproductive development of the red alga Portieria hornemannii (Gigartinales: Rhizophyllidaceae)

Earlier descriptions of the Indo-Pacific red alga Portieria hornemannii lacked detailed information on its vegetative and reproductive development and morphology. An in-depth treatment is presented on the development of the uniaxial thallus and the formation of male, female and tetrasporangial nemathecia. Post fertilization events and carposporophyte development is described, confirming Kylin's presumption on the development of connecting filaments between the carpogonium and the auxiliary cell following fertilization. Phylogenetic analysis using chloroplast encoded rbcL and nuclear ribosomal LSU gene sequences, including members of Rhizophyllidaceae and their close relatives suggests a monophyletic family. Contarinia is resolved as the sister taxon of a clade uniting Nesophila, Ochtodes and Portieria. The relationships among the latter genera remain largely unresolved.

Comparison of TNT removal from seawater by three marine macroalgae

Axenic plantlets derived from three species of marine macroalgae, the temperate green alga Acrosiphonia coalita, the temperate red alga Porphyra yezoensis, and the tropical red alga Portieria hornemannii, all possessed a similar metabolic route to remove the explosive compound 2,4,6-trinitrotolune (TNT) from seawater. At a biomass density of 1.2 g l(-1) and initial TNT concentrations of 10 mg l(-1) or less, TNT removal from seawater was 100% within 72 h for P. hornemannii and P. yezoensis. Specific rate constants for TNT uptake were 0.016-0.018 l g(-1)FWh(-1) for A. coalita filaments, 0.047-0.062 l g(-1)FW h(-1) for P. yezoensis blades, and 0.037-0.049 l g(-1)FW h(-1) for P. hornemannii microplantlets. Only trace amounts of TNT were found within the biomass. All species reduced TNT to 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dintrotoluene, but these products never accounted for more than 20% of the initial TNT.

Antimicrobial activities of extracts from Indo-Pacific marine plants against marine pathogens and saprophytes

This study is the second of two surveys designed to systematically screen extracts from marine plants for antimicrobial effects against ecologically relevant marine microorganisms, and to compare results on a geographical basis. In the preceding survey, extracts from tropical Atlantic marine algae and seagrasses were screened in growth inhibition assays against the pathogenic fungus Lindra thalassiae, the saprophytic fungus Dendryphiella salina, the saprophytic stramenopiles, Halophytophthora spinosa and Schizochytrium aggregatum, and the pathogenic bacterium Pseudoaltermonas bacteriolytica. In this study, the same assay microorganisms were used to examine the antimicrobial effects of lipophilic and hydrophilic extracts from 54 species of marine algae and two species of seagrasses collected from Indo-Pacific reef habitats. Overall, 95% of all species surveyed in this study yielded extracts that were active against one or more, and 77% yielded extracts that were active against two or more assay microorganisms. Broad-spectrum activity against three or four assay microbes was observed in the extracts from 50 to 21% of all species, respectively. Extracts from the green alga Bryopsis pennata and the red alga Portieria hornemannii inhibited the growth of all assay microorganisms. Given that antimicrobial activity was prevalent among extracts of Indo-Pacific marine plants, it is interesting to note that the inhibitory effects of each extract varied considerably between the assay microorganisms. Overall, H. spinosa and D. salina were the most susceptible while L. thalassiae, S. aggregatum, and P. bacteriolytica were the most resistant to the extracts tested. These results provide good evidence that antimicrobial chemical defenses are widespread among Indo-Pacific marine plants. Further, the activity profiles of plant extracts suggest that antimicrobial secondary metabolites can have pathogen-selective or broad-spectrum effects. To confirm these results, chemical studies will be needed to isolate and characterize the compounds responsible for the observed antimicrobial activities.

Chemical defenses in the sea hare Aplysia parvula: importance of diet and sequestration of algal secondary metabolites

Marine algae produce a variety of secondary metabolites that function as herbivore deterrents. Algal metabolites, however, often fail to deter damage by some herbivores such as meso- grazers that both live and feed on their host alga. In addition, the degree to which intraspecific chem- ical variation in an alga affects a mesograzer's feeding behavior and its ability to deter predators is poorly understood. The red alga Portieria hornemannii contains the secondary metabolites apa- kaochtodene A and B, which have been shown to vary in concentration among sites on Guam and act as significant deterrents to fish feeding. On Guam, the sea hare Aplysia parvula preferred and grew best when fed its algal host P. hornemannii. However, high concentrations of P. hornemannii crude extract and the pure compounds apakaochtodene A and B acted as feeding deterrents to A. parvula. Despite differences among sites in the levels of apakaochtodenes A and B, A. parvula showed no sig- nificant preference for P. hornemannii from any one location. Aplysia parvula found on P. horneman- nii sequestered apakaochtodenes, and both whole animals and body parts were unpalatable to reef fishes. Sea hares found on the red alga Acanthophora spicifera, which contains no unpalatable sec- ondary metabolites, had no apakaochtodene compounds and were eaten by fishes. This observation is consistent with the hypothesis that diet-derived algal metabolites in sea hares play a role in deter- ring predation.

Intraspecific variation in the red alga Portieria hornemannii : monoterpene concentrations are not influenced by nitrogen or phosphorus enrichment

The red alga Portieria hornemannii (Lyngbye) Silva was selected to test the effects of enhanced nutrient availability on the production of carbon-based secondary metabolites, because of its notable site-to-site variation in monoterpene production. On Guam, the major secondary metabolite produced by this alga is ochtodene, a cyclic monoterpene. Quantitative high-performance liquid-chromatography analysis of the extracts of P. hornemannii collected from six sites on Guam showed that both ochtodene and triglyceride concentrations differed significantly among sites. Internal nitrogen and phosphorus content of the algae did not correlate with the observed variation in chemistry. Experimental enhancement of N-alone, P-alone or N + P in the field for 5 wk failed to induce a significant change in ochtodene concentrations in the alga, while triglyceride concentrations increased significantly in the N + P treatment. Ochtodene and triglyceride concentrations did not change among similar treatments in shaded (18 d) and unshaded (11 d) fertilization experiments conducted in the laboratory. Variation in ochtodene concentrations in P. hornemannii cannot be attributed to N and P availability; however, the decrease in ochtodene and triglyceride concentrations during the shaded laboratory experiment suggests that light may be a factor influencing monoterpene biosynthesis. The difference in ochtodene concentration between the initial and final sets of field controls collected for the unshaded laboratory experiment suggests that temporal variation might also contribute to differences observed among the algae at the different sites.

Isolation and structure/activity features of halomon-related antitumor monoterpenes from the red alga Portieria hornemannii.

Ten halogenated monoterpenes (2-6 and 8-12) related to the novel antitumor compound halomon (1) or to the carbocyclic analog 7 have been isolated from different geographic collections of the red alga, Portieria hornemannii. Structures were assigned to the basis of spectral analyses (primarily NMR and MS). The absolute configuration of isohalomon (2) was further established by X-ray crystallography. The compounds were comparatively evaluated alongside 1 and 7 in the U.S. National Cancer Institute's in vitro human tumor cell line screening panel. The results provide some interesting initial insights into the structure/activity relationships in this series.

A pentahalogenated monoterpene from the red alga Portieria hornemannii produces a novel cytotoxicity profile against a diverse panel of human tumor cell lines.

A polyhalogenated acyclic monoterpene, 6(R)-bromo-3(S)-(bromomethyl)-7- methyl-2,3,7-trichloro-1-octene (1) was obtained as a major component of the organic extract of the red alga Portieria hornemannii. X-ray diffraction analysis provided the complete structure, including correct placement of the different halogen atoms and determination of the absolute stereochemistry. Detailed NMR analyses provided complete 1H and 13C assignments. Compound 1 exhibited highly differential cytotoxicity against the U.S. National Cancer Institute's new in vitro human tumor cell line screening panel; brain tumor, renal, and colon tumor cell lines were most sensitive to 1, while leukemia and melanoma lines were relatively less sensitive. A second collection of P. hornemanni yielded the novel, monocyclic 2, considerably less cytotoxic and devoid of differential activity. On the basis of its unprecedented cytotoxicity profile in the NCI primary screen, compound 1 has been selected by the NCI Decision Network Committee for preclinical drug development.

Five new monoterpenes from the marine red alga Portieria hornemannii

From the lipophilic extract of the marine red alga Portieria hornemannii (Lyngbye) P. C. Silva fifteen monoterpenes were isolated. Of the fifteen, five were new natural products: (2 Z)-6-bromo-3-chloromethyl-1,7-dichloro-7-methylocta-2-ene ( 1), (2 Z,6 E)-3-chloromethyl-1-chloroocta-2,6-dien-8-al ( 2), 3-methoxymethyl-6-methoxyl-7-methylocta-1,7(10)-dien-3-ol ( 3), (2 Z,6 S)-3-chloromethyl-1-methoxylocta-2,7(10)-dien-6-ol ( 4) and (2 Z,6 S)-3-chloromethyl-6-methoxylocta-2,7(10)-dien-1-ol ( 5). The structures of all isolates were assigned on the basis of their spectroscopic data; 1H and 13C nmr, ir, uv and ms.