Lipid, fatty acid, protein, amino acid and ash contents in four Brazilian red algae species

Four species of marine benthic algae (Laurencia filiformis, L. intricata, Gracilaria domingensis and G. birdiae) that belong to the phylum Rhodophyta were collected in Espirito Santo State, Brazil and investigated concerning their biochemical composition (fatty acid, total lipid, soluble proteins, amino acid and ash). The total content of lipid (% dry weight) ranged from 1.1% to 6.2%: fatty acid from 0.7% to 1.0%: soluble protein from 4.6% to 18.3%, amino acid from 6.7% to 11.3% and ash from 22.5% to 38.4%. judging from their composition, the four species of algae appear to be potential sources of dietary proteins, amino acids, lipids and essential fatty acids for humans and animals. (C) 2009 Elsevier Ltd. All rights reserved.

A study of the relationship between process conditions and mechanical strength of mineralized red algae in the preparation of a marine-derived bone void filler

Bone void fillers that can enhance biological function to augment skeletal repair have significant therapeutic potential in bone replacement surgery. This work focuses on the development of a unique microporous (0.5-10 mu m) marine-derived calcium phosphate bioceramic granule. It was prepared fro Corallina officinalis, a mineralized red alga, using a novel manufacturing process. This involved thermal processing, followed by a low pressure-temperature chemical synthesis reaction. The study found that the ability to maintain the unique algal morphology was dependent on the thermal processing conditions. This study investigates the effect of thermal heat treatment on the physiochemical properties of the alga. Thermogravimetric analysis was used to monitor its thermal decomposition. The resultant thermograms indicated the presence of a residual organic phase at temperatures below 500 degrees C and an irreversible solid-state phase transition from mg-rich-calcite to calcium oxide at temperatures over 850 degrees C. Algae and synthetic calcite were evaluated following heat treatment in an air-circulating furance at temperatures ranging from 400 to 800 degrees C. The highest levels of mass loss occurred between 400-500 degrees C and 700-800 degrees C, which were attributed to the organic and carbonate decomposition respectively. The changes in mechanical strength were quantified using a simple mechanical test, which measured the bulk compressive strength of the algae. The mechanical test used may provide a useful evaluation of the compressive properties of similar bone void fillers that are in granular form. The study concluded that soak temperatures in the range of 600 to 700 degrees C provided the optimum physiochemical properties as a precursor to conversion to hydroxyapatite (HA). At these temperatures, a partial phase transition to calcium oxide occurred and the original skeletal morphology of the alga remained intact.

A taxonomic study of some red algae commonly growing on the coast of Karachi

Eighteen commonly occurring species of marine benthic red algae, i.e., Asparagopsis taxiformis (Delile) Trevisan, Bangia atropurpurea (Roth) C. Agardh, Centroceras clavulatum (C. Agardh) Montagne, Calliblepharis fimbriata (Greville) Kiitzing, Coelarthrum muelleri (Sonder) B¢rgesen, Cottoniella filamentosa (Howe) B¢rgesen, Gracilariafoliifera (Forsskai) B¢rgesen, Halymenia porphyraeformis (B¢rgesen) Parkinson, Hypnea muscifor:mis (Wulfen) Lamouroux, Hypnea valentiae (Turner) Montagne, Laurencia obtusa (Hudson) Lamouroux, Me!anothamnus somalensis Bomet et Falkenberg, Porphyra vietnamensis Tanaka et Pham-hoang H6, Sarconema filiforme (Sonder) Kylin, Sebdenia flabellata (J. Agardh) Parkinson, Scinaia fascicularis (B¢rgesen) Huisman, Scinaia hatei B¢rgesen, and Solieria robusta (Greville) Kylin were collected from coastal areas near Karachi (Pakistan) and taxonomically investigated. All the investigated seaweeds are taxonomically known species. During this study, Melanothamnus somalensis is reported for the first time from northern Arabian Sea and Asparagopsis taxiformis, Bangia atropurpurea, Cottoniella filamentosa, Gracilaria foliifera, Halymenia porphyraeformis, Melanothamnus somalensis, Sarconema filiforme, Sebdenia flabellata, Scinaia fascicularis, and Solieria robusta are taxonomically described for the first time from the coast of Pakistan.

Evidence for positive selection in phycoerythrin genes of red algae and cyanobacteria Prochlorococcus and Synechococcus

Because of the shortage of phycoerythrin (PE) gene sequences from rhodophytes, peBA encoding beta- and alpha-subunits of PE from three species of red algae (Ceramium boydenn, Halymenia sinensis, and Plocamium telfariae) were cloned and sequenced. Different selection forces have affected the evolution of PE lineages. 8.9 % of the codons were subject to positive selection within the PE lineages (excluding high-irradiance adapted Prochlorococcus). More than 40 % of the sites may be under positive selection, and nearly 20 % sites are weakly constraint sites in high-irradiance adapted Prochlorococcus. Sites most likely undergoing positive selection were found in the chromophore binding domains, suggesting that these sites have played important roles in environmental adaptation during PE diversification. Moreover, the heterogeneous distribution of positively selected sites along the PE gene was revealed from the comparison of low-irradiance adapted Prochlorococcus and marine Synechococcus, which firmly suggests that evolutionary patterns of PEs in these two lineages are significantly different.

An efficient method for DNA isolation from red algae

A simple, inexpensive and efficient method was developed for rapid isolation of total genomic DNA from 15 red algal species. It resulted in 0.1 mug high quality DNA from 1 mg fresh algal material, with an A(260)/A(280) ratio of 1.68 - 1.90. Using this rapidly isolated DNA, the 18S ribosomal RNA genes ( rDNA) and the nuclear ribosomal DNA of the internal transcribed spacer (ITS) regions were amplified. The tested DNA was suitable for restriction endonuclease digestion, genetic marker analysis and polymerase chain reaction (PCR) amplification, and may be valid for other genetic manipulation.

Identification of quinolactin alkaloids from fungi associated to Brazilian red algae Dichotomaria marginata by LC-PDA-MS and LC-MSn

Fungi isolated from marine organisms have been shown to produce several interesting secondary metabolites with important biological activities. Such chemical diversity may be associated to environmental stress conditions and may represent an important source of NCE for bioprospection. Quinolactins belong to a rare fungi-alkaloid class with a unique N-methyl-quinolone moiety fused to a lactam ring and present several bioactivities1. Fungi strain Dm1 was isolated from red alga Dichotomaria marginata, collected from Brazil SE coast, and was grown in sterile rice solid media at 26oC 2, which was then extracted with MeOH. The MeCN fr. from the MeOH extract was chromatographed over Sephadex LH-20 and fr. 4 afforded quinolactin (QL) alkaloids B1, B2 and A, whereas fr. 5 afforded quinolactin D1 after purification by HPLC-DAD. Structural determination of pure compounds was based on HRMS, UV, and NMR spectral analyses, in addition to comparison with literature data and Antimarin® databank. UV data indicated the presence of similar chromophores with λmax at ca. 247 and 320nm. HRMS and tandem MS analyses using both negative and positive ion modes for the isolated compounds indicated their molecular formula and structural features, as for QL B1: C15H16O2N2 [M+H 257], which showed one fragment at m/z 214 [-CHNO]; QL B2: C15H16O3N2 [M+H 273], with product ions at m/z 230 [-CHNO.] and m/z 186 [-C4H9NO.]; for QL A: C16H18N2O2 [M+H 271], which presented one ion at m/z 214, due to loss of fragment (-C4H9) from the molecular ion; and for QL D1: C16H18N2O3 [M+H 287], with product ions at m/z 186 [-CHNO] and m/z 230 [-C4H9]. Such data suggested fragmentation proposals, e.g. for Quinolactin B1 (Fig. 1), which confirmed the structures of the isolated quinolactins, and may represent an important contribution for the sustainable exploration of marine biodiversity.

CHEMICAL CONSTITUENTS FROM RED ALGAE Bostrychia radicans (Rhodomelaceae): NEW AMIDES AND PHENOLIC COMPOUNDS

This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N, 4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family.

Chemical constituents from red algae Bostrychia radicans (Rhodomelaceae): new amides and phenolic compounds

This study describes the isolation and structural determination of two amides, isolated for the first time: N,4-dihydroxy-N-(2'-hydroxyethyl)-benzamide (0.019%) and N,4-dihydroxy-N-(2'-hydroxyethyl)-benzeneacetamide (0.023%). These amides, produced by the red macroalgae Bostrychia radicans, had their structures assigned by NMR spectral data and MS analyses. In addition, this chemical study led to the isolation of cholesterol, heptadecane, squalene, trans-phytol, neophytadiene, tetradecanoic and hexadecanoic acids, methyl hexadecanoate and methyl 9-octadecenoate, 4-(methoxymethyl)-phenol, 4-hydroxybenzaldehyde, methyl 4-hydroxybenzeneacetate, methyl 2-hydroxy-3-(4-hydroxyphenyl)-propanoate, hydroquinone, methyl 4-hydroxymandelate, methyl 4-hydroxybenzoate, 4-hydroxybenzeneacetic acid and (4-hydroxyphenyl)-oxo-acetaldehyde. This is the first report concerning these compounds in B. radicans, contributing by illustrating the chemical diversity within the Rhodomelaceae family.

Physiological Responses to Environmental Variation in Intertidal Red Algae: Does Thallus Morphology Matter?

Morphological variation within and among many species of algae show correlated life history traits. The trade-offs of Life history traits among different morphs are presumed to be determined by morphology. Form-function hypotheses also predict that algae of different morphological groups exhibit different tolerances to physiological stress, whereas algae within a morphological group respond similarly to stress. We tested this hypothesis by comparing photosynthetic and respiratory responses to variation in season, light, temperature, desiccation and freezing among the morphologically similar fronds of Chondrus crispus and Mastocarpus stellatus and the alternate stage crust of M. stellatus. Physiological differences between fronds of the 2 species and crusts and fronds were consistent with their patterns of distribution and abundance in the intertidal zone. However, there was no clear relationship between algal morphology and physiological response to environmental variation. These results suggest that among macroalgae the correlation between Life history traits and morphology is not always causal. Rather, the link between life history traits and morphology is constrained by the extent to which physiological characteristics codetermine these features.