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Bin-gui Wang - One of the best experts on this subject based on the ideXlab platform.
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nonhalogenated organic molecules from Laurencia algae
Phytochemistry Reviews, 2014Co-Authors: Bin-gui WangAbstract:The marine red algae of the genus Laurencia have produced more 700 secondary metabolites and exhibited high molecular diversity and intriguing bioactivity. Since the halogenated structures have been comprehensively reviewed previously, this review, covering up to the end of 2012, mainly focuses on the source, structure elucidation, and bioactivity of nonhalogenated organic molecules from Laurencia spp. as well as the relationship between nonhalogenated and halogenated products. Overall, 173 new or new naturally occurring compounds with 58 skeletons, mainly including sesquiterpenes, diterpenes, triterpenes, and C15-acetogenins, are described.
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two halosesquiterpenes from Laurencia composita
RSC Advances, 2013Co-Authors: Fengping Miao, Xiaorui Liang, Bin-gui WangAbstract:Two new chamigrane sesquiterpenes, yicterpenes A (1) and B (2) each with an unprecedented halogenation at C-9 and a hemiketal unit at C-10, were isolated from the marine red alga Laurencia composita. The structures and absolute configurations of them were identified by NMR, ECD, and mass spectrometric methods as well as quantum chemical calculations. Compound 1 with a chlorination at C-9 was more active against some tested marine-derived organisms than 2 with a bromination at C-9.
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sesquiterpene and acetogenin derivatives from the marine red alga Laurencia okamurai
Marine Drugs, 2012Co-Authors: Yi Liang, Chuanming Cui, Hong Sun, Bin-gui WangAbstract:In addition to 13 known compounds, four new bisabolane sesquiterpenes, okamurenes A–D (1–4), a new chamigrane derivative, okamurene E (5), and a new C12-acetogenin, okamuragenin (6), were isolated from the marine red alga Laurencia okamurai. The structures of these compounds were determined through detailed spectroscopic analyses. Of these, okamurenes A and B (1 and 2) are the first examples of bromobisabolane sesquiterpenes possessing a phenyl moiety among Laurencia-derived sesquiterpenes, while okamuragenin (6) was the first acetogenin aldehyde possessing a C12-carbon skeleton. Each of the isolated compounds was evaluated for the brine shrimp (Artemia salina) lethal assay and 7-hydroxylaurene displayed potent lethality with LD50 1.8 μM.
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laurenidificin a new brominated c15 acetogenin from the marine red alga Laurencia nidifica
Chinese Chemical Letters, 2010Co-Authors: Xu Liu, Bin-gui WangAbstract:new brominated C-15-acetogenin, namely, laurenidificin, was isolated from the marine red alga Laurencia nidifica. Its structure was determined on the basis of spectroscopic methods. (C) 2010 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
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a new rearranged chamigrane sesquiterpene from Laurencia okamurai
ChemInform, 2009Co-Authors: Yi Liang, Chuanming Cui, Bin-gui WangAbstract:A new rearranged chamigrane sesquiterpene, named laurenokamurin, was isolated from the marine red alga Laurencia okamurai. Its structure was determined on the basis of spectroscopic methods. (C) 2008 Bin Gui Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
D. Christopher Braddock - One of the best experts on this subject based on the ideXlab platform.
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A unifying stereochemical analysis for the formation of halogenated C15-acetogenin medium-ring ethers from Laurencia species via intramolecular bromonium ion assisted epoxide ring-opening and experimental corroboration with a model epoxide.
The Journal of organic chemistry, 2012Co-Authors: Karl J. Bonney, D. Christopher BraddockAbstract:A unifying stereochemical analysis for the formation of the constitutional isomeric halogenated C15-acetogenin medium-ring ether natural products from Laurencia species is presented, where an intramolecular bromonium ion assisted epoxide ring-opening reaction of enantiomerically pure epoxides can account for ring-size, the position of the halogen substituents, and relative and absolute configurations of the known natural products. Experimentally, a model epoxide corroborates the feasibility of this process for concurrent formation of 7-, 8- and 9-ring ethers corresponding to the halogenated medium-ring ethers of known metabolites from Laurencia species.
Karl J. Bonney - One of the best experts on this subject based on the ideXlab platform.
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A unifying stereochemical analysis for the formation of halogenated C15-acetogenin medium-ring ethers from Laurencia species via intramolecular bromonium ion assisted epoxide ring-opening and experimental corroboration with a model epoxide.
The Journal of organic chemistry, 2012Co-Authors: Karl J. Bonney, D. Christopher BraddockAbstract:A unifying stereochemical analysis for the formation of the constitutional isomeric halogenated C15-acetogenin medium-ring ether natural products from Laurencia species is presented, where an intramolecular bromonium ion assisted epoxide ring-opening reaction of enantiomerically pure epoxides can account for ring-size, the position of the halogen substituents, and relative and absolute configurations of the known natural products. Experimentally, a model epoxide corroborates the feasibility of this process for concurrent formation of 7-, 8- and 9-ring ethers corresponding to the halogenated medium-ring ethers of known metabolites from Laurencia species.
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A Unifying Stereochemical Analysis for the Formation of Halogenated C15-Acetogenin Medium-Ring Ethers From Laurencia Species via Intramolecular Bromonium Ion Assisted Epoxide Ring-Opening and Experimental Corroboration with a Model Epoxide
2012Co-Authors: Karl J. Bonney, Christopher D. BraddockAbstract:A unifying stereochemical analysis for the formation of the constitutional isomeric halogenated C15-acetogenin medium-ring ether natural products from Laurencia species is presented, where an intramolecular bromonium ion assisted epoxide ring-opening reaction of enantiomerically pure epoxides can account for ring-size, the position of the halogen substituents, and relative and absolute configurations of the known natural products. Experimentally, a model epoxide corroborates the feasibility of this process for concurrent formation of 7-, 8- and 9-ring ethers corresponding to the halogenated medium-ring ethers of known metabolites from Laurencia species
Minoru Suzuki - One of the best experts on this subject based on the ideXlab platform.
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halogenated metabolites with antibacterial activity from the okinawan Laurencia species
Phytochemistry, 2001Co-Authors: Charles Santhanaraju Vairappan, Minoru Suzuki, Tsuyoshi Abe, Michio MasudaAbstract:The chemical compositions of five species of the red algal genus Laurencia from coastal waters of Okinawa Prefecture, Japan, have been investigated. A halogenated C(15) acetogenin, (12E)-lembyne-A, was isolated from L. mariannensis, and a halogenated sesquiterpene, (6R,9R,10S)-10-bromo-9-hydroxy-chamigra-2,7(14)-diene, was first found from L. majuscula as a naturally occurring compound. Laurencia nidifica yielded previously known laurinterol and isolaurinterol. Samples of L. cartilaginea and L. concreta afforded no halogenated metabolites. The structures of these halogenated metabolites as well as their antibacterial activity against some marine bacteria are reported.
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Diterpenoid feeding-deterrents from Laurencia saitoi
Phytochemistry, 1998Co-Authors: Kazuya Kurata, Kazuya Taniguchi, Yukio Agatsuma, Minoru SuzukiAbstract:Abstract Three new diterpenes and 14 known, brominated and non-brominated diterpenes have been isolated from the red alga Laurencia saitoi collected in ‘Isoyake areas’ in the Sea of Japan. Some of these diterpenes showed significant feeding-deterrent activity against young abalone ( Haliotis discus hannai ) and young sea urchins ( Strongylocentrotus nudus and S. intermedius ), thus suggesting that these metabolites provide a chemical defense against marine herbivorous animals in ‘Isoyake areas’.
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diversity of halogenated secondary metabolites in the red alga Laurencia nipponica rhodomelaceae ceramiales 1 2
Journal of Phycology, 1997Co-Authors: Michio Masuda, Tsuyoshi Abe, Shinji Sato, Teruaki Suzuki, Minoru SuzukiAbstract:Many morphologically similar, but chemically distinct, populations have been found in the marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Ceramiales) growing in Japan. Each chemical type is characterized by a specific end-product of halogenated secondaly metabolite synthesis: chamigrane-type sesquiterpenoids such as prepacifenol and halochamigrene epoxide and C15 bromoethers such as laurencin, laureatin, isoprelaurefucin, epilaurallene, and kumausallene. These seven types of secondary metabolite syntheses remained the same in the wild and under various culture conditions. Because bromoethers and terpenoids are probably synthesized by different metabolic pathways, it is virtually certain that different sets of enzymes participate in their synthesis. Prepacifenol- and laureatin-producing populations were selected as representatives of terpenoid and bromoether groups, respectively. F1 tetrasporophytes derived from crosses between reciprocal, female and male gametophytes of prepacifenol- and laureatin-producing strains bore both types of metabolites, suggesting that the genes Producing these enzyme systems are encoded by nuclear genomes. The F1 gametophytes resulting from the reciprocal crosses produced either prepacifenol or laureatin, and the four individuals derived from spore tetrads (a set of tetraspores derived from a single tetrasporangium) produced either prepacifenol or laureatin in a 1:1 ratio, indicating that genes participating in terpenoid synthsis and those participating in bromoether synthesis are on different loci of homologous chromosomes and are segregated at meiosis (tetrasporogenesis). One individual of this interpopulational F1 gamtophyte produced both parental types of metabolite, perhaps indicating the occurrence of a recombination type. Natural hybrid individuals, including such recombination-type gametophytes, were found in a sympatric locality at which these two chemical types occur. F1 tetrasporophytes derived from crosses between respective prepacifenol- and laureatin-producing strains and their F1 gametohytes produced only parental-type metabolite-producing plants. These results indicate that the diverse chemical types can be referred to as races (chemical races).
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scanlonenyne a novel halogenated c15 acetogenin from the red alga Laurencia obtusa in irish waters
Tetrahedron, 1997Co-Authors: Minoru Suzuki, Yoshihide Matsuo, Yoshinori Takahashi, Michael D Guiry, Michio MasudaAbstract:Abstract A novel halogenated acetogenin with a ketonic moiety at C-7, named scanlonenyne, has been isolated from the red alga Laurencia obtusa collected in Irish waters. Its structure was determined by spectroscopic data.
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neoisoprelaurefucin a halogenated c15 non terpenoid compound from Laurencia nipponica
Phytochemistry, 1996Co-Authors: Minoru Suzuki, Yoshihide Matsuo, Yasuhiro Mizuno, Michio MasudaAbstract:Abstract A new C 15 nonterpenoid acetylenic compound, named neoisoprelaurefucin, has been isolated from Laurencia nipponica and its structure deduced from spectroscopic data. Neoisoprelaurefucin is a stereoisomer of (3Z)-isoprelaurefucin, which has previously been isolated from this species.
Michio Masuda - One of the best experts on this subject based on the ideXlab platform.
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halogenated metabolites with antibacterial activity from the okinawan Laurencia species
Phytochemistry, 2001Co-Authors: Charles Santhanaraju Vairappan, Minoru Suzuki, Tsuyoshi Abe, Michio MasudaAbstract:The chemical compositions of five species of the red algal genus Laurencia from coastal waters of Okinawa Prefecture, Japan, have been investigated. A halogenated C(15) acetogenin, (12E)-lembyne-A, was isolated from L. mariannensis, and a halogenated sesquiterpene, (6R,9R,10S)-10-bromo-9-hydroxy-chamigra-2,7(14)-diene, was first found from L. majuscula as a naturally occurring compound. Laurencia nidifica yielded previously known laurinterol and isolaurinterol. Samples of L. cartilaginea and L. concreta afforded no halogenated metabolites. The structures of these halogenated metabolites as well as their antibacterial activity against some marine bacteria are reported.
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diversity of halogenated secondary metabolites in the red alga Laurencia nipponica rhodomelaceae ceramiales 1 2
Journal of Phycology, 1997Co-Authors: Michio Masuda, Tsuyoshi Abe, Shinji Sato, Teruaki Suzuki, Minoru SuzukiAbstract:Many morphologically similar, but chemically distinct, populations have been found in the marine red alga Laurencia nipponica Yamada (Rhodomelaceae, Ceramiales) growing in Japan. Each chemical type is characterized by a specific end-product of halogenated secondaly metabolite synthesis: chamigrane-type sesquiterpenoids such as prepacifenol and halochamigrene epoxide and C15 bromoethers such as laurencin, laureatin, isoprelaurefucin, epilaurallene, and kumausallene. These seven types of secondary metabolite syntheses remained the same in the wild and under various culture conditions. Because bromoethers and terpenoids are probably synthesized by different metabolic pathways, it is virtually certain that different sets of enzymes participate in their synthesis. Prepacifenol- and laureatin-producing populations were selected as representatives of terpenoid and bromoether groups, respectively. F1 tetrasporophytes derived from crosses between reciprocal, female and male gametophytes of prepacifenol- and laureatin-producing strains bore both types of metabolites, suggesting that the genes Producing these enzyme systems are encoded by nuclear genomes. The F1 gametophytes resulting from the reciprocal crosses produced either prepacifenol or laureatin, and the four individuals derived from spore tetrads (a set of tetraspores derived from a single tetrasporangium) produced either prepacifenol or laureatin in a 1:1 ratio, indicating that genes participating in terpenoid synthsis and those participating in bromoether synthesis are on different loci of homologous chromosomes and are segregated at meiosis (tetrasporogenesis). One individual of this interpopulational F1 gamtophyte produced both parental types of metabolite, perhaps indicating the occurrence of a recombination type. Natural hybrid individuals, including such recombination-type gametophytes, were found in a sympatric locality at which these two chemical types occur. F1 tetrasporophytes derived from crosses between respective prepacifenol- and laureatin-producing strains and their F1 gametohytes produced only parental-type metabolite-producing plants. These results indicate that the diverse chemical types can be referred to as races (chemical races).
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scanlonenyne a novel halogenated c15 acetogenin from the red alga Laurencia obtusa in irish waters
Tetrahedron, 1997Co-Authors: Minoru Suzuki, Yoshihide Matsuo, Yoshinori Takahashi, Michael D Guiry, Michio MasudaAbstract:Abstract A novel halogenated acetogenin with a ketonic moiety at C-7, named scanlonenyne, has been isolated from the red alga Laurencia obtusa collected in Irish waters. Its structure was determined by spectroscopic data.
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neoisoprelaurefucin a halogenated c15 non terpenoid compound from Laurencia nipponica
Phytochemistry, 1996Co-Authors: Minoru Suzuki, Yoshihide Matsuo, Yasuhiro Mizuno, Michio MasudaAbstract:Abstract A new C 15 nonterpenoid acetylenic compound, named neoisoprelaurefucin, has been isolated from Laurencia nipponica and its structure deduced from spectroscopic data. Neoisoprelaurefucin is a stereoisomer of (3Z)-isoprelaurefucin, which has previously been isolated from this species.
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enshuol a novel squalene derived pentacyclic triterpene alcohol from a new species of the red algal genus Laurencia
Chemistry Letters, 1995Co-Authors: Yoshihide Matsuo, Minoru Suzuki, Michio MasudaAbstract:The structure of a novel brominated triterpenoid, designated enshuol, from the red alga Laurencia omaezakiana Masuda sp. ined. (Enshu-sozo) was elucidated by spectroscopic analysis and chemical reactions of a degradation product.