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Wook-jae Lee - One of the best experts on this subject based on the ideXlab platform.
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Morphological and molecular characteristics of Homoeostrichus formosana sp. nov. (Dictyotaceae, Phaeophyceae) from Taiwan
Botanical Studies, 2013Co-Authors: Wei-lung Wang, Wook-jae Lee, Ching-su Lin, Shao-lun LiuAbstract:Background In the marine brown macroalgae, the morphological characters are highly similar between two widely distributed genera, Homoeostrichus and Zonaria (Dictyotaceae), thereby resulting in the difficulty of exploring their hidden biodiversity. Owing to the help of the molecular tools, it is now easy for scientists to objectively describe a new species in nature. In this study, we make a description on the Homoeostrichus formosana sp. nov. from Taiwan, Indo-Pacific Ocean based on the morphological evidence and molecular data. Results Our morphological observations revealed that this species has marginal row of apical cells responsible for thallus growth and the thallus with four layers of cells except the marginal regions. The cortical cell lies upon each medullary cell in transverse section, and two cortical cells upon each medullary cell in longitudinal section. Tetrasporangium is developed from cortical cell with stalk cell and singly scattered over the thallus surface, and has no indusia and paraphyses. Molecularly, the phylogenetic trees based on SSU , psaA, psbA, and rbcL gene sequences supported that Homoeostrichus species are closely related to Exallosorus species and clearly separated from each others in addition to Zonaria species. Conclusions Homoeostrichus formosana sp. nov. can now be clearly distinguished from E. harveyanus and Japanese H. flabellatus .
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Morphological and molecular characteristics of Homoeostrichus formosana sp. nov. (Dictyotaceae, Phaeophyceae) from Taiwan
Botanical studies, 2013Co-Authors: Wei-lung Wang, Wook-jae Lee, Ching-su Lin, Shao-lun LiuAbstract:In the marine brown macroalgae, the morphological characters are highly similar between two widely distributed genera, Homoeostrichus and Zonaria (Dictyotaceae), thereby resulting in the difficulty of exploring their hidden biodiversity. Owing to the help of the molecular tools, it is now easy for scientists to objectively describe a new species in nature. In this study, we make a description on the Homoeostrichus formosana sp. nov. from Taiwan, Indo-Pacific Ocean based on the morphological evidence and molecular data. Our morphological observations revealed that this species has marginal row of apical cells responsible for thallus growth and the thallus with four layers of cells except the marginal regions. The cortical cell lies upon each medullary cell in transverse section, and two cortical cells upon each medullary cell in longitudinal section. Tetrasporangium is developed from cortical cell with stalk cell and singly scattered over the thallus surface, and has no indusia and paraphyses. Molecularly, the phylogenetic trees based on SSU, psaA, psbA, and rbcL gene sequences supported that Homoeostrichus species are closely related to Exallosorus species and clearly separated from each others in addition to Zonaria species. Homoeostrichus formosana sp. nov. can now be clearly distinguished from E. harveyanus and Japanese H. flabellatus.
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Morphological Characteristics of Brown Alga Spatoglossum crassum Tanaka (Dictyotaceae, Dictyotales), New to Korea
ALGAE, 2004Co-Authors: Il-ki Hwang, Hyung-seop Kim, Wook-jae LeeAbstract:Morphological and phonological characteristics of brown alga Spatoglossum crassum Tanaka new to Korea were described based on the field and the indoor cultured plants. The taxonomic characteristics of the plants were agreed to those from the type locality-submerged reproductive organs in cortex, anatomical features, and absence of phaeophycean hairs on the surface. But they have rudimentary midrib on lower portion of thallus. We can observe the young plants on November, adult ones in June, and senile ones in August. This species has an annual life-cycle in the field, starting with germ lings in early November. The differentiation of thallus is quite different from other species of genera in tribe Zonarieae, e.g. Zonaria and Homoeostrichus. Three different tissues, meristoderm, cortex and medulla are discerned. The outmost cortical one celled layer as a meristoderm produce cortex by unequal periclinal division. In the apical cell division, the primary inner cells are developed into 3-4 cell layered medulla of thallus. The distribution of this species extends from Korea to Shizuoka Peninsula (34°40`N) Japan, which is the type locality of this species.
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Phylogenetic relationship among several genera of Dictyotaceae (Dictyotales, Phaeophyceae) based on 18S rRNA and partial rbcL gene sequences
Marine Biology, 2002Co-Authors: Wook-jae Lee, Kyung Sook BaeAbstract:The partial sequences of the 18S rRNA gene and the rbcL gene, RuBisCo spacer region of representatives of the Dictyotaceae were determined and compared to resolve their phylogenetic relationships. A total of 1,861 base pairs of 18S rDNA sequences were aligned and examined. There was a high similarity of nucleotide sequences within the tribe Dictyoteae (99.4–99.6%) and the tribe Zonarieae (92.8–99.8%). The largest intergeneric divergence within the Dictyotaceae was 7.31%, between Dilophus and Zonaria. The aligned 422 bases of partial rbcL gene sequences gave a similar phylogenetic relationship among taxa to those of the 18S rDNA sequences, although our alignment covered less than 30% of the whole gene. All genera of Dictyotales consisted of several clades forming a polychotomy in MP trees based on partial rbcL gene sequences and on 18S rDNA sequences. The genera within the tribe Dictyoteae formed a clade, a Dictyota–Phacydictyon–Dilophus clade, while genera of the tribe Zonarieae formed four clades: Padina; Distromium–Lobophora–Zonaria;Spatoglossum–Lobospira; and Dictyopteris–Spatoglossum. All genera of the Dictyotaceae included in these sequence analyses are classified into five groups, which have little phylogenetic resolution among them. The genera classified in the tribe Zonarieae according to Womersley's criteria do not appear to be monophyletic, based on our analyses. Although not all genera of Dictyotaceae were analysed, our data suggest that the status of the meristem cells should not be a criterion for separating tribes within the family Dictyotaceae and that other hierarchical systems should be adopted to properly reflect phylogenetic relationships.
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Note on the Dictyotaceae (Phaeophyta) from Ullungdo Island, Korea
Algae, 1996Co-Authors: Wook-jae Lee, In-kyu LeeAbstract:Taxonomic account is given to the seven species of the Dictyotaceae, Dictyopteris divaricata (Okamura) Okamura, Dictyota dichotoma (Hudson) Lamouroux, Pachydictyon coriaceum (Holm.) Okamura, Padina arborescens Holmes, P. crassa Yamada, Spatoglossum paciflcum Yendo, and Zonaria diesingiana J. Agardh, collected from Ullungdo Island, Korea. Dictyopteris divaricata is distinguished that it has larger, broader and less undulated thallus. Dictyota dichotoma shows much morphological variation according to growing season. Pachydictyon coriaceum is characterized by dichotomous branch, two cell layered cortex and one large rolled medulla. Padina arborescens is distinguished by dark, hard and rarely lobed thallus and has eight to nine medullary cells. P. crassa is characterized by light brown, much lobed thallus and four to six celled medulla. Spatoglossum pacificum has variation in globs morphology according to season. Zomaria diesingiana has much lobed thallus and greenish brown, exuberant fibrous protuberance looks like midribs from cortex in basal part of thallus.
Valéria Laneuville Teixeira - One of the best experts on this subject based on the ideXlab platform.
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The Brown Alga Stypopodium zonale (Dictyotaceae): A Potential Source of Anti-Leishmania Drugs
Marine drugs, 2016Co-Authors: Deivid Costa Soares, Valéria Laneuville Teixeira, Marcella Macedo Szlachta, Angélica Ribeiro Soares, Elvira M. SaraivaAbstract:This study evaluated the anti-Leishmania amazonensis activity of a lipophilic extract from the brown alga Stypopodium zonale and atomaric acid, its major compound. Our initial results revealed high inhibitory activity for intracellular amastigotes in a dose-dependent manner and an IC50 of 0.27 μg/mL. Due to its high anti-Leishmania activity and low toxicity toward host cells, we fractionated the lipophilic extract. A major meroditerpene in this extract, atomaric acid, and its methyl ester derivative, which was obtained by a methylation procedure, were identified by nuclear magnetic resonance (NMR) spectroscopy. Both compounds inhibited intracellular amastigotes, with IC50 values of 20.2 μM (9 μg/mL) and 22.9 μM (10 μg/mL), and selectivity indexes of 8.4 μM and 11.5 μM. The leishmanicidal activity of both meroditerpenes was independent of nitric oxide (NO) production, but the generation of reactive oxygen species (ROS) may be at least partially responsible for the amastigote killing. Our results suggest that the lipophilic extract of S. zonale may represent an important source of compounds for the development of anti-Leishmania drugs.
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4α‐Acetoxyamijidictyol – A New Antifeeding Dolastane Diterpene from the Brazilian Brown Alga Canistrocarpus cervicornis
Chemistry & biodiversity, 2015Co-Authors: Éverson Miguel Bianco, Valéria Laneuville Teixeira, Thiago Martins Francisco, Carlos B. Pinheiro, Rodrigo Bagueira De Vasconcellos Azeredo, Renato Crespo PereiraAbstract:Chemical investigation of the CH2 Cl2 crude extract from the brown alga Canistrocarpus cervicornis (Dictyotaceae) led to isolation of one new (1) and four previously reported dolastane diterpenes (2-5). Their structures were characterized by 1D- and 2D-NMR spectroscopic techniques, including a full single crystal X-ray diffraction analysis for 1, 2, and 4. In addition, the new structure 1 was assayed as chemical defense inhibiting the feeding by the sea urchin Lytechinus variegatus. This study constitutes an additional report broadening the known spectrum of action and defensive roles of secondary metabolites of the C. cervicornis and Dictyotales species.
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10β-Acetoxy-8α,9α-epoxy-14β-hydroxy-7-oxodolastane – A New Diterpene Isolated from the Brazilian Brown Macroalga Canistrocarpus cervicornis
Helvetica Chimica Acta, 2015Co-Authors: Éverson Miguel Bianco, Valéria Laneuville Teixeira, Thiago Martins Francisco, Carlos B. Pinheiro, Rodrigo Bagueira De Vasconcellos Azeredo, Renato Crespo PereiraAbstract:Chemical investigation on the nonpolar extract of the Brazilian brown alga Canistrocarpus cervicornis (Dictyotaceae) has led to the isolation of a new diterpene 1 and four known seco-dolastane diterpenes 2–5. Their chemical structures were elucidated by 1D- and 2D-NMR spectroscopy, and the data was compared with the literature. A full X-ray diffraction analysis confirmed the absolute configuration of 1.
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diterpenes from marine brown alga dictyota guineensis Dictyotaceae phaeophyceae
Revista Brasileira De Farmacognosia-brazilian Journal of Pharmacognosy, 2012Co-Authors: Joel Campos Depaula, Yocie Yoneshiguevalentin, Diana Negrao Cavalcanti, Valéria Laneuville TeixeiraAbstract:The crude extract of the marine brown alga Dictyota guineensis was analyzed by high-resolution gas chromatography-mass spectrometry (HRGC-MS). Five diterpenes were identified: dictyol E (the most abundant diterpene), dictyotadiol, dictyoxide, isopachydictyol A and pachydictyol A, all diterpenes from the chemical group I, i.e., mainly prenylated derivatives of known sesquiterpene skeletons that result from a first cyclization of geranyl-geraniol between positions 1 and 10. These diterpenes are known for their activity against bacteria, fungi and other activities. The results characterize D. guineensis as a species that yields exclusively diterpenes from group I, with low oxidation and low structural complexity. On Brazilian coasts, only D. mertensii provides exclusively prenylated guaiane diterpenes. Although D. guineensis presents alternate branches and fixing by rhizoidal branches, it is easily distinguishable from D. mertensii by the much narrower stem, short stature and flabelliform habit of the former species. On the other hand, both species have been characterized as producers of diterpenes of group I, in particular, prenylated guaiane. However, D. guineensis has a majority dictyol E in the lipophilic extract, while D. mertensii produces more complex prenylated guaianes, like dictyol H.
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Anticoagulation and antiplatelet effects of a dolastane diterpene isolated from the marine brown alga Canistrocarpus cervicornis
Journal of Thrombosis and Thrombolysis, 2011Co-Authors: Laura Andrade Moura, Valéria Laneuville Teixeira, Renato Crespo Pereira, Éverson Miguel Bianco, André Lopes FulyAbstract:Marine brown algae of the family Dictyotaceae are rich sources of monocyclic, bicyclic, and tricyclic diterpenes. These molecules are responsible for a wide range of pharmacological and ecological functions, as antitumor and antiviral. Here, we analyzed the effect of the dolastane diterpene (4 R , 9 S , 14 S )-4α-Acetoxy-9β,14α-dihydroxydolast-1(15),7-diene, isolated from the marine brown alga, Canistrocarpus cervicornis on blood clotting and platelet aggregation. The dolastane diterpene was able to inhibit either plasma or fibrinogen coagulation induced by thrombin as well as delayed coagulation in the recalcification test. The dolastane diterpene impaired, in a concentration-dependent manner platelet aggregation induced by collagen or adenosine diphosphate with no lysis on such cells. Thus, the dolastane diterpene maybe a promising source of natural inhibitors for hemostatic disturbs (clotting and platelet aggregation) leading to the discovery of drugs of potential use as antithrombotic and antiplatelet. In addition, the dolastane diterpene may be used as a molecular model for development of new antithrombotic agents giving new approaches to the management to the treatment of thrombotic disturbs.
Judy E. Sutherland - One of the best experts on this subject based on the ideXlab platform.
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Distribution of the genus Zonaria (Dictyotales: Phaeophyceae) in New Zealand, and description of Zonaria cryptica sp. nov from Stewart Island
New Zealand Journal of Botany, 2018Co-Authors: Wendy A. Nelson, Jaret P. Bilewitch, Judy E. SutherlandAbstract:ABSTRACTThe brown algal genus Zonaria (Dictyotales: Dictyotaceae) is widely distributed in temperate waters. Two species, Zonaria turneriana J.Agardh and Zonaria aureomarginata J.A. Phillips & W.A. Nelson have previously been recorded from mainland New Zealand, and a third species, Zonaria diesingiana, has been recorded from the Kermadec Islands. As part of an ongoing study of the order Dictyotales in New Zealand, we have identified an undescribed species of Zonaria present on Stewart Island in southern New Zealand. The new species, described here as Zonaria cryptica, is very similar in external morphology to Z. turneriana, also found on Stewart Island, but differs both genetically and anatomically from Z. turneriana and from other previously described species in the genus. We present a description of the new species based on morphological and anatomical observations, as well as on DNA sequence data from three plastid markers: psaA, psbA and rbcL. Our analysis also indicates the presence of some biogeogra...
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Distribution of the genus Zonaria (Dictyotales: Phaeophyceae) in New Zealand, and description of Zonaria cryptica sp. nov from Stewart Island
2018Co-Authors: Wendy A. Nelson, Jaret P. Bilewitch, Judy E. SutherlandAbstract:The brown algal genus Zonaria (Dictyotales: Dictyotaceae) is widely distributed in temperate waters. Two species, Zonaria turneriana J.Agardh and Zonaria aureomarginata J.A. Phillips & W.A. Nelson have previously been recorded from mainland New Zealand, and a third species, Zonaria diesingiana, has been recorded from the Kermadec Islands. As part of an ongoing study of the order Dictyotales in New Zealand, we have identified an undescribed species of Zonaria present on Stewart Island in southern New Zealand. The new species, described here as Zonaria cryptica, is very similar in external morphology to Z. turneriana, also found on Stewart Island, but differs both genetically and anatomically from Z. turneriana and from other previously described species in the genus. We present a description of the new species based on morphological and anatomical observations, as well as on DNA sequence data from three plastid markers: psaA, psbA and rbcL. Our analysis also indicates the presence of some biogeographic structuring within Z. turneriana and Z. aureomarginata.
Elvira M. Saraiva - One of the best experts on this subject based on the ideXlab platform.
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The Brown Alga Stypopodium zonale (Dictyotaceae): A Potential Source of Anti-Leishmania Drugs
Marine drugs, 2016Co-Authors: Deivid Costa Soares, Valéria Laneuville Teixeira, Marcella Macedo Szlachta, Angélica Ribeiro Soares, Elvira M. SaraivaAbstract:This study evaluated the anti-Leishmania amazonensis activity of a lipophilic extract from the brown alga Stypopodium zonale and atomaric acid, its major compound. Our initial results revealed high inhibitory activity for intracellular amastigotes in a dose-dependent manner and an IC50 of 0.27 μg/mL. Due to its high anti-Leishmania activity and low toxicity toward host cells, we fractionated the lipophilic extract. A major meroditerpene in this extract, atomaric acid, and its methyl ester derivative, which was obtained by a methylation procedure, were identified by nuclear magnetic resonance (NMR) spectroscopy. Both compounds inhibited intracellular amastigotes, with IC50 values of 20.2 μM (9 μg/mL) and 22.9 μM (10 μg/mL), and selectivity indexes of 8.4 μM and 11.5 μM. The leishmanicidal activity of both meroditerpenes was independent of nitric oxide (NO) production, but the generation of reactive oxygen species (ROS) may be at least partially responsible for the amastigote killing. Our results suggest that the lipophilic extract of S. zonale may represent an important source of compounds for the development of anti-Leishmania drugs.
Edda Lisboa Leite - One of the best experts on this subject based on the ideXlab platform.
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A xylogalactofucan from the brown seaweed Spatoglossum schröederi stimulates the synthesis of an antithrombotic heparan sulfate from endothelial cells.
Planta medica, 2005Co-Authors: Hugo Alexandre Oliveira Rocha, Luana Cristina Lins De Medeiros Bezerra, Ivan Rui Lopes Albuquerque, Leandro Silva Costa, Celina Maria Pinto Guerra, Luiz Diz De Abreu, Helena B. Nader, Edda Lisboa LeiteAbstract:The brown seaweed Spatoglossum schroederi (Dictyotaceae) contains three main fucans (fucans A, B and C) with different mobility in electrophoresis. The fucan with highest mobility (fucan C) was precipitated with 2.0 volumes of acetone, purified using a combination of ion exchange chromatography and electrophoresis. It showed an MW of 24 kDa determined by HPLC and Sephadex G-75 chromatography and migrates as a single band in three distinct electrophoretic systems. This fucan contains fucose, xylose, galactose and sulfate in a molar ratio 1 : 0.6 : 2:2.3. The fucan has neither anticoagulant (from 10 to 100 microg) nor hemorrhagic activities (100 microg/mL). In addition, fucan C is neither cytotoxic nor cytostatic. However, fucan C (100 microg/mL) stimulated the synthesis of an antithrombotic heparan sulfate from endothelial cells of rabbit aorta. The results suggest that fucan C might be used as an antithrombotic therapeutic compound.