Laurencia nanhaiense sp. nov. （Rhodomelaceae, Rhodophyta） is described from Hainan and Guangdong Provinces, China. The new species clearly displays one of the defining features of the genus, viz. four periaxial cell...Laurencia nanhaiense sp. nov. （Rhodomelaceae, Rhodophyta） is described from Hainan and Guangdong Provinces, China. The new species clearly displays one of the defining features of the genus, viz. four periaxial cells per vegetative axial segment. It differs from other closely related species in having a combination of features such as terete axes from a basal system composed of a primary discoid holdfast and a secondary attachment to give rise to many short rhizoids, branching oppositely and alternately, irregularly tristichous or subverticillately polystichous, having more curve branches with very sparse, adventitious ultimate branchlets, non-projecting superficial cortical cells at the apices of ultimate branchlets, presence of longitudinally oriented secondary pit-connections between contiguous superficial cortical cells, absence of lenticular thickenings in the walls of medullary cells, parallel arrangement of tetrasporangia along the axis of stichidia, and presence of intercellular spaces between medullary cells.展开更多
Two new bromophenols were isolated from Rhodomela confervoides. Their structrues were elucidated as 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-hydroxymethyldiphenylmethane and 2, 2', 3-tribromo...Two new bromophenols were isolated from Rhodomela confervoides. Their structrues were elucidated as 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-hydroxymethyldiphenylmethane and 2, 2', 3-tribromo-3', 4,4', 5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane by spectroscopie methods including IR, HREIMS, 1D and 2D NMR techniques.展开更多
A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-di...A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde, 2-methyl-3-(2,3-di-bromo-4,5-dihydroxyphenyl) propylaldehyde dimethyl acetal and 3-bromo-4,5-dihydroxybenzoic acid methyl ester by spectroscopic techniques including IR, HRFABMS, ID and 2DNMR experiments.展开更多
Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this specie...Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (1), 3,5-dibromo-4-hydroxybenzoic acid (2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene (3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde (4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane (6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane (7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one (8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.展开更多
A new poly brominated dibenzylphenol named as rhodomevoidin was isolated from Rhodomela confervoides. Its structrue was elucidated as 3-bromo-4, 5-bis (2, 3-dibromo-4, 5- dihydroxybenzyl)pyrocatechol by spectroscopic...A new poly brominated dibenzylphenol named as rhodomevoidin was isolated from Rhodomela confervoides. Its structrue was elucidated as 3-bromo-4, 5-bis (2, 3-dibromo-4, 5- dihydroxybenzyl)pyrocatechol by spectroscopic methods including IR, HRFABMS, 1D and 2D NMR techniques.展开更多
We examined the chemical constitution of the red alga Laurencia saitoi Perestenko,collected from Katsuura,Boso Peninsula,Chiba Prefecture,Japan.This specimen produced a new polyhalogenated acetogenin,named katsuural-l...We examined the chemical constitution of the red alga Laurencia saitoi Perestenko,collected from Katsuura,Boso Peninsula,Chiba Prefecture,Japan.This specimen produced a new polyhalogenated acetogenin,named katsuural-lene(1),which structure was determined by the spectral methods,along with known diterpene,deoxyparguerol(2)and triterpene,thyrsiferol(3).In this paper we describe the structural elucidation of katsuurallene together with some biological activities.展开更多
文摘Laurencia nanhaiense sp. nov. （Rhodomelaceae, Rhodophyta） is described from Hainan and Guangdong Provinces, China. The new species clearly displays one of the defining features of the genus, viz. four periaxial cells per vegetative axial segment. It differs from other closely related species in having a combination of features such as terete axes from a basal system composed of a primary discoid holdfast and a secondary attachment to give rise to many short rhizoids, branching oppositely and alternately, irregularly tristichous or subverticillately polystichous, having more curve branches with very sparse, adventitious ultimate branchlets, non-projecting superficial cortical cells at the apices of ultimate branchlets, presence of longitudinally oriented secondary pit-connections between contiguous superficial cortical cells, absence of lenticular thickenings in the walls of medullary cells, parallel arrangement of tetrasporangia along the axis of stichidia, and presence of intercellular spaces between medullary cells.
基金support from the NNSF(Grant No.99-929-01-26)National“863”Program(Grant No.2001AA620403).
文摘Two new bromophenols were isolated from Rhodomela confervoides. Their structrues were elucidated as 2, 2', 3-tribromo-3', 4, 4', 5-tetrahydroxy-6'-hydroxymethyldiphenylmethane and 2, 2', 3-tribromo-3', 4,4', 5-tetrahydroxy-6'-ethyloxymethyldiphenylmethane by spectroscopie methods including IR, HREIMS, 1D and 2D NMR techniques.
基金support from the NSF(Grant No.99-929-01-26)national“863”program(Grant No.2001AA620403).
文摘A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde, 2-methyl-3-(2,3-di-bromo-4,5-dihydroxyphenyl) propylaldehyde dimethyl acetal and 3-bromo-4,5-dihydroxybenzoic acid methyl ester by spectroscopic techniques including IR, HRFABMS, ID and 2DNMR experiments.
基金Supported by the National Natural Science Foundation (No. 30530080)the Ministry of Science and Technology of China (Nos. 2007AA09Z402, 2007AA09Z403)the Department of Science and Technology of Shandong Province (No. 2006GG2205023)
文摘Previously, we had characterized several structurally interesting brominated phenols from the marine red alga Symphyocladia latiuscula collected from various sites. However, Phytochemical investigations on this species collected from the Weihai coastline of Shandong Province remains blank. Therefore, we characterized the chemical constituents of individuals of this species collected from the region. Eight bromophenols were isolated and identified. Using detailed spectroscopic techniques and comparisons with published data, these compounds were identified as 2,3-dibromo-4,5-dihydroxybenzyl methyl ether (1), 3,5-dibromo-4-hydroxybenzoic acid (2), 2,3,6-tribromo-4,5-dihydroxymethylbenzene (3), 2,3,6-tribromo-4,5-dihydroxybenzaldehyde (4), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (5), bis(2,3,6-tribromo-4,5-dihydroxyphenyl)methane (6), 1,2-bis(2,3,6-tribromo-4,5-dihydroxyphenyl)-ethane (7), and 1-(2,3,6-tribromo-4,5-dihydroxybenzyl)-pyrrolidin-2-one (8). Among these compounds, 1 and 2 were isolated for the first time from S. latiuscula. Each compound was evaluated on the ability to inhibit protein tyrosine phosphatase 1B (PTP1B), which is a potential therapeutic target in the treatment of type 2 diabetes. Bromophenols 5, 6, and 7 showed strong activities with IC50 values of 3.9, 4.3, and 3.5 μmol/L, respectively. This study provides further evidence that bromophenols are predominant among the chemical constituents of Symphyocladia, and that some of these compounds may be candidates for the development of anti-diabetes drugs.
基金The authors are grateful to professor Ablez zeper for mass spectra measurements,and financial support from the NSF(Grant No.99-929-01-26)national“863”program(Grant No.2001AA620403).
文摘A new poly brominated dibenzylphenol named as rhodomevoidin was isolated from Rhodomela confervoides. Its structrue was elucidated as 3-bromo-4, 5-bis (2, 3-dibromo-4, 5- dihydroxybenzyl)pyrocatechol by spectroscopic methods including IR, HRFABMS, 1D and 2D NMR techniques.
基金supported by JSPS KAKENHI Grant Numbers 18K05799 and 21K14904.
文摘We examined the chemical constitution of the red alga Laurencia saitoi Perestenko,collected from Katsuura,Boso Peninsula,Chiba Prefecture,Japan.This specimen produced a new polyhalogenated acetogenin,named katsuural-lene(1),which structure was determined by the spectral methods,along with known diterpene,deoxyparguerol(2)and triterpene,thyrsiferol(3).In this paper we describe the structural elucidation of katsuurallene together with some biological activities.
