scholarly journals Chemical defenses of the tropical marine seaweed Canistrocarpus cervicornis against herbivory by sea urchin

2010 ◽  
Vol 58 (3) ◽  
pp. 213-218 ◽  
Author(s):  
Éverson Miguel Bianco ◽  
Valéria Laneuville Teixeira ◽  
Renato Crespo Pereira

This paper reports on the defensive chemical properties of the marine tropical brown seaweed Canistrocarpus cervicornis against herbivory. A natural concentration of dichloromethane crude extract (DCE) obtained from this seaweed significantly inhibited feeding by the sea urchin Lytechinus variegatus. The major metabolite isolated from this active DCE extract was identified as the (4R,7R,14S)-4α,7α-diacetoxy-14-hydroxydolast-1(15),8-diene that strongly inhibited feeding by the same sea urchin. This result suggests that the dolastane diterpenes class may constitute the defensive system of C. cervicornis against herbivory, and probably also of that of other brown seaweeds endowed with a biosynthetic pathway capable of producing compounds of the dolastane-type, a typical skeleton found in Dyctioteae species worldwide. This is the first report showing this compound-type (dolastane diterpenes) as a chemical defense against herbivory in marine seaweeds. This study constitutes an additional report broadening the known spectrum of action and roles of secondary metabolites of the C. cervicornis and Dyctioteae species.

2007 ◽  
Vol 55 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Magui Aparecida Vallim ◽  
Valéria Laneuville Teixeira ◽  
Renato Crespo Pereira

Crude extracts of the brown seaweed Dictyota mertensii (Martius) Kützing collected at two distant and different places on the Brazilian coast, Búzios (Rio de Janeiro) and Fernando de Noronha (PE), were evaluated for defensive chemistry against the crab Pachygrapsus transversus, and the sea urchin Lytechinus variegatus. The extract from Búzios specimens of D. mertensii significantly inhibited the consumption by both P. transversus and L. varigetaus. Fractionation of the extracts of specimens of D. mertensii from Búzios and F. de Noronha followed by complementary assays revealed one active fraction from each location, which contained distinct defensive secondary metabolites. In each active fractions prenylated guaiane diterpenes were the major compounds. Dictyol H and epoxypachydictyol A were the most abundant compounds in Búzios and F. de Noronha, respectively, followed by minor components. Our results show a differential production of secondary metabolites in the two distant and different populations of D. mertensii along the Brazilian coast. This suggests that defensive chemicals from this seaweed are not qualitatively absolute characteristics of the species, but may represent an ecological specialization to successfully prevent herbivory.


2017 ◽  
Vol 41 (2) ◽  
pp. 296-304
Author(s):  
Fredy A. Ortiz-Ramírez ◽  
Magui Aparecida Vallim ◽  
Diana Negrão Cavalcanti ◽  
Valéria Laneuville Teixeira

Marine organisms are rich sources of natural products that, among other activities, help to maintain the species equilibrium. Samples of the marine brown alga Canistrocarpus cervicornis (Kützing) De Paula & De Clerck were collected in Búzios, Rio de Janeiro, Brazil, in June 2006. The extract was obtained in CH2Cl2 and subjected to fractionation by chromatographic methods in order to isolate and purify the compound (4R, 7R, 14S)-4α, 7α-diacethoxy-14-hydroxydolastane-1(15), 8-dien. Then, the effects of the extract and the dolastane diterpene on zygotes and gametes of the sea urchin Lytechinus variegatus were evaluated. The exposure of male and female gametes to the C. cervicornis extract promoted, respectively, a reduction of 10-30% in fertilization and a 20 to 70% decrease in the number of eggs. Furthermore, the exposure of zygotes to the extract inhibited their development up to 86.7 ± 1.6% (at a concentration of 250 µg mL-1), as well as generating abnormalities in 39-50% of zygotes. The results of the dolastane diterpene showed no evidence of inhibition in the zygotes’ development, thought it was proved to induce anomalies. At higher concentrations (25 and 50 µg mL-1), it was possible to observe cell lyses.


Aquaculture ◽  
2006 ◽  
Vol 254 (1-4) ◽  
pp. 483-495 ◽  
Author(s):  
Hugh Hammer ◽  
Stephen Watts ◽  
Addison Lawrence ◽  
John Lawrence ◽  
Renee Desmond

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 714
Author(s):  
Enver Keleszade ◽  
Michael Patterson ◽  
Steven Trangmar ◽  
Kieran J. Guinan ◽  
Adele Costabile

Metabolic syndrome (MetS) is a global public health problem affecting nearly 25.9% of the world population characterised by a cluster of disorders dominated by abdominal obesity, high blood pressure, high fasting plasma glucose, hypertriacylglycerolaemia and low HDL-cholesterol. In recent years, marine organisms, especially seaweeds, have been highlighted as potential natural sources of bioactive compounds and useful metabolites, with many biological and physiological activities to be used in functional foods or in human nutraceuticals for the management of MetS and related disorders. Of the three groups of seaweeds, brown seaweeds are known to contain more bioactive components than either red and green seaweeds. Among the different brown seaweed species, Ascophyllum nodosum and Fucus vesiculosus have the highest antioxidant values and highest total phenolic content. However, the evidence base relies mainly on cell line and small animal models, with few studies to date involving humans. This review intends to provide an overview of the potential of brown seaweed extracts Ascophyllum nodosum and Fucus vesiculosus for the management and prevention of MetS and related conditions, based on the available evidence obtained from clinical trials.


2018 ◽  
Vol 2 ◽  
Author(s):  
K.K. Asanka Sanjeewa ◽  
You-Jin Jeon

Seaweeds play a vital role as a source of food and ingredients in traditional Korean medicine. Koreans consume seaweed as fresh vegetables, salad, soups, or snacks. There are several edible brown seaweed species are abundant along the shores of the Korean peninsula, such as Ecklonia cava, Hizikia fusiforme, Laminaria japonica, Pelvetia siliquosa, Sargassum fulvellum, and Undaria pinnatifida. With the growing body of scientific evidence, it is clear that these brown seaweeds are not only good substitutes for land vegetables but also a good source of bioactive secondary metabolites. The secondary metabolites identified from edible Korean brown seaweeds (phlorotannins, sulfated polysaccharides, pigments, and sterols) have the potential to be developed as functional food ingredients. However, seaweeds consumption and their industrial level applications as functional materials are limited compared to the land vegetables. Insufficient awareness about health benefits of seaweeds might be the reason for this issue. Thus, in this review health promotion properties associated with edible Korean brown seaweeds are summarized. The present study might therefore increase consumption and industrial use of brown seaweeds.


RSC Advances ◽  
2018 ◽  
Vol 8 (29) ◽  
pp. 15973-15984 ◽  
Author(s):  
Saghya Infant Shofia ◽  
Kannan Jayakumar ◽  
Amitava Mukherjee ◽  
Natarajan Chandrasekaran

Bioactive polysaccharides extracted from brown seaweeds have potent antioxidant, antitumor, antibacterial, antiviral, anti-inflammatory activities and nanomedicine applications.


Development ◽  
1989 ◽  
Vol 106 (2) ◽  
pp. 355-365 ◽  
Author(s):  
G.M. Wessel ◽  
W. Zhang ◽  
C.R. Tomlinson ◽  
W.J. Lennarz ◽  
W.H. Klein

The influence of the extracellular matrix (ECM) on differential gene expression during sea urchin development was explored using cell-type-specific cDNA probes. The ECM of three species of sea urchin, Strongylocentrotus purpuratus, Lytechinus variegatus and Lytechinus pictus, was disrupted with the lathrytic agent beta-aminopropionitrile (BAPN), which inhibits collagen deposition in the ECM and arrests gastrulation (Wessel & McClay, Devl Biol. 121: 149, 1987). The levels of several mRNAs (Spec 1, Spec 2, CyIIa actin, CyIIIa actin and collagen in S. purpuratus, and metallothionine, ubiquitin and LpS3 in L. pictus and L. variegatus) were compared in BAPN-treated and control embryos. These mRNAs accumulated normally during BAPN treatment, even though the embryos did not gastrulate. To determine if the expression of any gene product is sensitive to ECM disruption, a differential cDNA screen compared poly (A+) RNA from BAPN-arrested and control embryos in Lytechinus. A cDNA clone was isolated from this screen that represented a 2.1 kb mRNA that did not accumulate during BAPN treatment. Removal of BAPN resulted in the accumulation of this transcript coincident with the onset of gastrulation. This cDNA clone encodes a L. variegatus homologue of LpS1, recently demonstrated to be an ancestral homologue of the aboral ectoderm-specific Spec 1-Spec 2 gene family in S. purpuratus. Nuclear run-on assays in L. pictus suggested that transcriptional activity of LpS1 was selectively inhibited by BAPN treatment. Thus, although the accumulation of many gene products occurred independently of the embryonic collagenous matrix, the accumulation of LpS1 and LvS1 appeared to be mediated by the ECM.


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