Fatty acids from 11 marine macroalgae of the French Brittany coast

Four species of red marine algae (Rhodophyceae), five species of brown marine algae (Pheophyceae) and two species of green marine algae (Chlorophyceae) were examined for the fatty acid composition of the three lipid groups separated by silica gel column chromatography (neutral lipids, glycolipids, phospholipids). The four red algae had high contents of 16:0 and C20-polyunsaturated fatty acids (PUFA), 20:5n-3 ranging from 18 to 49% of the total fatty acid content and 20:4n-6 from 1.4 to 22.5%, these fatty acids were evenly distributed in all lipid groups. The five brown algae had high contents of 18:1n-9, 18:2n-6 and 18:3n-3 but low content of 20:5n-3. No precise trend was detected for the distribution of these fatty acids in the three lipid groups. The two green algae had high contents of 16:0, 18:1n-7 and 18:3n-3 and a very low content of PUFA. They contained also large amounts of 16:4n-3 together with 16:2n-6 and 16:3n-3. While 16:2n-6 was mainly found in phospholipids, 16:4n-3 was mainly distributed in neutral lipids and glycolipids.Porphyra umbilicalis represents the richest source of 20:5n-3 whileUndaria pinnatifida can be selected when a balanced mixture of (n-6) and (n-3) PUFA is required.Author for correspondence     

Ethnobotany of the wild Mexican Cucurbitaceae

This paper presents the results of a survey on the ethnobotany of the wild Mexican Cucurbitaceae. The sources of information were fieldwork in different regions of Mexico, as well as herbarium specimens and bibliographic references. A total of 34 wild species (26.5% of the 128 wild mexican species) of Cucurbitaceae are reported as used in 24 of the 32 states of Mexico. All of the species are called by one or more local names, and 23 are known by names in native languages. The uses comprise 12 categories, including human medicine (18), food (13), soap substitute (12), fodder (4), toy (3), drink (2), ornate (2), insecticide (1), animal medicine (1), handicrafts (2), container (1), and ceremonial (1), and some uses date back to pre-Hispanic and colonial times.

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Etnobotánica de Especies Mexicanas Silvestres de la Familia Cucurbitaceae

Resumen  Este artículo presenta los resultados de una investigatión etnobotánica de las especies mexicanas silvestres de la familia Cucurbitaceae. Las fuentes de informatión fueron el trabajo de campo en diferentes regiones de México, así como también ejemplares de herbario y referencias bibliográficas. Un total de 34 especies silvestres (26.5% de las 128 especies silvestres mexicanas) de Cucurbitaceae son reportadas como útiles en 24 de los 32 estados de México. Todas las especies son conocidas por uno o más nombres locales y 23 de ellas reciben nombres en lenguas nativas. Los usos registrados abarcan un total de doce categorías, incluyendo medicina humana (18), alimento (13), substituto de jabón (12), forraje (4), juguete (3), bebidas (2), ornato (2), insecticidas (1), medicina animal (1), artesanías (2), contenedores (1) y ceremonial (1), y algunos de los usos parecen remontarse a las épocas pre-Hispánica y colonial.

     

Telomerase inhibiting activity in vitro from natural resources, marine algae extracts

We attempted to screen for telomerase inhibitingactivity in vitro from a total of 304 marine algae samples which were collected from various Japancoasts by nonradioisotope telomeric repeatamplification protocol (Non-RI TRAP) assay using humanleukemia MOLT-4 cells. Ten of the MeOH extracts andtwo of the PBS extracts from those algal samplesshowed telomerase inhibiting activity. In particular,the MeOH extract from a green alga, Caulerpasertularioides strongly inhibited telomerase activitywhen added to MOLT-4 cell culture at a level of 1.25%(v/v), suggesting that it may be possible to developa novel anti-cancer agent in view of its specificanti-telomeric property.     

中国大型海藻的研究现状及其存在的问题

结合最新的研究结果,本文对中国大型海藻区系划分、区系的种类组成、分布特征、研究成果、现状和存在的问题等进行了介绍、总结和分析.目前,中国海藻区系可划分为4个小区,即黄海西区、东海西区、南海北区和南海南区.大型海藻物种数达到1,277种,其中蓝藻门6目21科57属161种(及变种)、红藻门15目40科 169属607种(...     

Selective cytotoxicity of marine algae extracts to several human leukemic cell lines

Extracts from 8 species of marine algae which showed selective cytotoxicity in our previous screening program, were further examined for cytotoxic spectra to five human leukemic cell lines. The extract from a red alga, Amphiroa zonata exhibited strong cytotoxicity to all human leukemic cell lines tested and murine leukemic cells L1210 at the final concentrations from 15 to 375 μg ml−¹. Then the cytotoxicity was not found in normal human fibroblast HDF and murine normal cells NIH-3T3. The active extract fraction from this alga was soluble in higher polar organic solvents and water and heat-stable. The extract from a brown alga Dilophus okamurae with weak selective cytotoxic activity to L1210 cells exhibited not only strong cytotoxicity to L1210, but also to human leukemic cells, HL60 and MOLT-4 at 50 μg ml-¹. While, the extract from a green alga, Cladophoropsis vaucheriaeformis with most selective cytotoxic activity, did not show cytotoxicity to any human leukemic cell lines tested at 50 μg ml-¹. However, this extract showed strong cytotoxicity to two human leukemic cell lines and NIH-3T3 at 100 μg ml−¹. Thus, it was considered that a red alga, Amphiroa zonata might be suitable natural source for development of anti-cancer agents without side-effect. This revised version was published online in June 2006 with corrections to the Cover Date.     

Antioxidant activities in tropical marine macroalgae from the Yucatan Peninsula,Mexico

Extracts from 48 marine macroalgae species (17 Chlorophyta, 8 Phaeophyta and 23 Rhodophyta) from the coasts of Yucatan and Quintana Roo (Mexico) were evaluated for antioxidant activity. The antioxidant activity was measured with the DPPH (2,2-diphenyl-1-picrylhydrasyl) method, and the phenolic content of each extract were also evaluated. All species exhibited a DPPH radical scavenging activity, and three species (Avrainvillea longicaulis, Chondria baileyana and Lobophora variegata) demonstrated great antioxidant potential with very low oxidation index EC₅₀ (1.44 ± 0.01, 2.84 ± 0.07 and 0.32 ± 0.01 mg mL⁻¹, respectively), significantly equivalent to EC₅₀ of some commercial antioxidants such as α-tocopherol, ascorbic acid, BHA and BHT. Moreover, extracts of the most active species exhibited reducing activities, superoxide anion radical scavenging and inhibition of lipid peroxidation. These results suggest that some macroalgae from the Yucatan peninsula have a great antioxidant potential which could be considered for future applications in medicine, food production or cosmetic industry.     

大型海藻的营养盐代谢及其与近岸海域富营养化的关系

大型海藻是近岸海域重要的初级生产者,近年来人们愈来愈认识到大型海藻在近岸海域富营养化生物修复中的重要性,同时,富营养化也可能招致某些机会主义大型海藻种类的爆发生长,因此,进一步理解大型海藻与营养盐供应变化的关系就显得非常重要。本文从大型海藻营养盐代谢与海水中营养盐供应变化(主要是富营养化)的生理生态关系角度对相关问题进行评述,主要包括影响大型海藻营养盐吸收特性的重要因素、海水中营养盐的供应及大型海藻对营养盐的细胞贮存、大型海藻对营养盐的生态需求、大型海藻对近岸海域富营养化的生态响应等问题。文章还对今后的研究提出了展望。     

Clonal architecture in marine macroalgae: ecological and evolutionary perspectives

The study of the ecological and evolutionary consequences of clonal growth in vascular plants has been widely addressed; however, marine macroalgae, which are interesting modular organisms that combine simple morphologies and complex life cycles, have been almost ignored. This paper presents a review and analysis of the ecological and evolutionary consequences of clonality in marine macroalgae, including three main subjects: (1) modular construction (modules and ramets); (2) life cycle and evolutionary perspectives, and (3) ecological perspectives of clonality in marine macroalge. The biological emergent attributes of clonality are present in marine macroalgae e.g. high longevity of the genet by the continual renewal of modules, and variable morphological plasticity of ramets and modules in relation to environmental conditions. However, experimental work is still needed to solve questions such as the effect of crowding on survival rates and use of resources, as well as its effect on sexual or asexual patterns of reproduction. I expect that the study of the evolutionary consequences of the combined presence of alternation of generations and clonal growth in marine macroalgae will make important contributions to clonal plant theory.     

Comparing the potential production and value of high-energy liquid fuels and protein from marine and freshwater macroalgae

The biomass production and biochemical properties of marine and freshwater species of green macroalgae (multicellular algae), cultivated in outdoor conditions, were evaluated to assess the potential conversion into high-energy liquid biofuels, specifically biocrude and biodiesel and the value of these products. Biomass productivities were typically two times higher for marine macroalgae (8.5–11.9 g m⁻² d⁻¹, dry weight) than for freshwater macroalgae (3.4–5.1 g m⁻² d⁻¹, dry weight). The biochemical compositions of the species were also distinct, with higher ash content (25.5–36.6%) in marine macroalgae and higher calorific value (15.8–16.4 MJ kg⁻¹) in freshwater macroalgae. Lipid content was highest for freshwater Oedogonium and marine Derbesia. Lipids are a critical organic component for biocrude production by hydrothermal liquefaction (HTL) and the theoretical biocrude yield was therefore highest for Oedogonium (17.7%, dry weight) and Derbesia (16.2%, dry weight). Theoretical biocrude yields were also higher than biodiesel yields for all species due to the conversion of the whole organic component of biomass, including the predominant carbohydrate fraction. However, all marine species had higher biomass productivities and therefore had higher projected biocrude productivities than freshwater species, up to 7.1 t of biocrude ha⁻¹ yr⁻¹ for Derbesia. The projected value of the six macroalgae was increased by 45–77% (up to US$7700 ha⁻¹ yr⁻¹) through the extraction of protein prior to the conversion of the residual biomass to biocrude. This study highlights the importance of optimizing biomass productivities for high-energy fuels and targeting additional coproducts to increase value.     

Vanadium an essential element for some marine macroalgae

In some marine algae cultivated axenically in the artificial medium ASP6 F2 (pH 8.3) vanadium at 1–100 g l^-1 increases the fresh weight. In the multicellular brown algaFucus spiralis 10 g V I^-1 enhances the fresh weight by about 400% while in the green algaEnteromorpha compressa the yield is increased by 90%. Red algae do not respond to vanadium. InFucus morphological effects are displayed in more frequent branching and/or broader blades. No significant increase in the chlorophyll content could be demonstrated at the early stage at which these morphological effects first appeared. Later the chlorophyll content increased.     

Mechanisms of biosorption of different heavy metals by brown marine macroalgae

The biosorption mechanisms of different heavy metallic cations (Cd, Ni, Pb) to active chemical groups on the cell wall matrix of the nonliving brown marine macroalga, Sargassum vulgaris in its natural form, were examined by the following instrumental and chemical techniques: Fourier-transform infrared (FTIR) analysis, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and extraction of alginic acid and sulfated polysaccharides, which act as metal-binding moieties present in cell wall. From the different techniques used and the known chemical composition of the algal cell wall, it was observed that biosorption of the metallic cations to the algal cell wall component was a surface process. The binding capacities of the different metal cations were between 1 and 1.2 mmol metal/g on a dry weight basis. The main chemical groups involved in the metallic cation biosorption were apparently carboxyl, amino, sulfhydryl, and sulfonate. These groups were part of the algal cell wall structural polymers, namely, polysaccharides (alginic acid, sulfated polysaccharides), proteins, and peptidoglycans. The main cadmium cation sequestration mechanism by the algal biomass was apparently chelation, while the nickel cation sequestration mechanism was mainly ion exchange. Lead cations exhibit higher affinity to the algal biomass, and their binding mechanism included a combination of ion exchange, chelation, and reduction reactions, accompanied by metallic lead precipitation on the cell wall matrix. During the ion exchange process, calcium, magnesium, hydrogen cations, and probably other cations (sodium and potassium) in the algal cell wall matrix were replaced by the tested heavy metals.     

Distribution of carbonic anhydrase in British marine macroalgae

Summary Thirty-four species of marine macroalgae from around St. Andrews, Scotland, have been assayed for their external activity and thirty-three species for their total activity of carbonic anhydrase. Activity was detected in all the Rhodophyta tested apart from Chondrus crispus, but was absent in Codium fragile, Enteromorpha sp. and Monostroma fuscum (Chlorophyta), and Alaria esculenta, Laminaria digitata, L. saccharina and L. hyperborea (Phaeophyta). Total activity of carbonic anhydrase per unit fresh weight tended to be higher in the Rhodophyta than in the Chlorophyta or Phaeophyta. External activity was present in two of the six Chlorophyta, four of the twelve Phaeophyta and four of the sixteen Rhodophyta tested. On average, when present, external carbonic anhydrase activity represented 2.7% of the total activity. A relationship was found between total carbonic anhydrase activity and habitat. Species from the high intertidal and the low-light subtidal habitats had significantly higher activity than species from the mid and low intertidal, rockpools, or high-light region of the subtidal. External carbonic anhydrase activity did not vary significantly with habitat. There appeared to be no strong relationship between carbonic anhydrase activity and the ability of a species to use HCO _- ³ in photosynthesis under water.     

Agglutinins from marine macroalgae of the southeastern United States

Protein extracts from 22 species of marine macroalgae from Florida and North Carolina were compared for their abilities to agglutinate sheep and rabbit erythrocytes. Protein extracts from 21 algal species agglutinated rabbit erythrocytes compared to 19 for sheep erythrocytes. However, agglutination by brown algal extracts was variable. The agglutination produced by protein extracts from Dictyota dichotoma could be blocked by addition of polyvinylpyrrolidone. Protein extracts from North Carolina macroalgae were also tested against five bacterial species. Three of these agglutinated bacterial cells. Ulva curvata and Bryopsis plumosa agglutinated all five species. Protein extracts from five species of Florida algae were tested for their effects on mitogenesis in mouse splenocytes and human lymphocytes. Gracilaria tikvahiae HBOI Strain G-5, Ulva rigida and Gracilaria verrucosa HBOI Strain G-16S stimulated mitogenesis in mouse splenocytes, while Gracilaria tikvahiae HBOI Strain G-16stimulated mitogenesis in human lymphocytes.     

Marine algae from the Gulf of Santa Clara,Sonora, México

Four sites in the Gulf of Santa Clara, northwestern coast of Sonora, Mexico, were sampled seasonally during 1995–1996. A total of 43 species of marine algae were determined, which are recorded for the first time for the area of study. The families with best representation are: Gracilariaceae and Cladophoraceae, each with 5 species; and Corallinaceae, Rhodomelaceae, and Ulvaceae, each with 3. The highest diversity was found in autumn, the lowest in summer. The sites with the low diversity were Piedras del Burro with 7 species and El Tornillal with 18. These places are broad beaches, composed of sand and with few pebbles. The higher diversity was found at Punta Gorda with 34 species and Piedras de La Salina with 26. These localities are characterized by relatively stable rocky substrates, with some intertidal pools. The most common species regardless to distribution and occurrence over time were: Spyridia filamentosa, Dictyota flabellata, Struveopsis robusta, Cladophora microcladioides and Enteromorpha linza. Rosenvingea antillarum and Cladophora vagabunda represent new records for the Gulf of California. Nine epiphytic species were identified, which were frequently observed on Gelidium crinale, Spyridia filamentosa and Dictyota flabellata.