The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown ...The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown alga Eisenia bicyclis (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8’-bieckol) had a deterrent effect against feeding behavior of T. cornutus in the concentration of algal body, respectively. In the case of the examination of 0.1 mM concentration, although fucofuroeckol A and phlorofucofuroeckol A significantly reduced feeding by T. cornutus, phloroglucinol and 8,8’-bieckol did not show any significant influence on feeding behavior, and eckol and dieckol had stimulating activity. 2,4-Dibromophenol and 2,4,6-tribromophenol, which are major components of extracellular secretions from Eisenia and Ecklonia species, caused the death, the torpidity, and the decreased appetite of T. cornutus at the concentration of 0.1 mM. In addition, 2,4-dibromophenol had strong feeding deterrent activity at the concentration of 1 μM. These results indicate that phlorotannins and bromophenols act as chemical defense agents of brown algae against environmental stresses such as the herbivore attack.展开更多
Marine algae contain various bromophenols with a variety of biological activities, including antimicrobial, anticancer, and anti-diabetic effects. Here, we briefly review the recent progress in researches on the bioma...Marine algae contain various bromophenols with a variety of biological activities, including antimicrobial, anticancer, and anti-diabetic effects. Here, we briefly review the recent progress in researches on the biomaterials from marine algae, emphasizing the relationship between the structure and the potential anti-diabetic applications. Bromophenols from marine algae display their hyper- glycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B, ct-glucosidase, as well as other mechanisms.展开更多
Bromophenols are a set of natural products widely distributed in seaweed, most of which exhibit interesting and useful biological activities. To develop a reliable and efficient synthetic route to these natural bromop...Bromophenols are a set of natural products widely distributed in seaweed, most of which exhibit interesting and useful biological activities. To develop a reliable and efficient synthetic route to these natural bromophenols, three of them, 3,4-dibromo-5-(2′-bromo-3′,4′- dihydroxy-6′-methoxymethyl- benzyl)-benzene-1,2-diol (compound 9), 3,4-dibromo-5-(2′-bromo-6′-ethoxy methyl-3′,4′-dihydroxybenzyl)- benzene-1,2-diol (compound 10), and 3-bromo-4-(3′-bromo-4′,5′-dihydroxy benzyl)-5-(ethoxymethyl)- benzene-1,2-diol (compound 14), isolated from red marine algae, have been synthesized in eight steps with an overall yield of 14.4%, 14.4%, and 18.2% respectively, via a practical approach employing bromination, Wolff-Kishner-Huang reduction and a Friedel-Crafts reaction as key steps. The protein tyrosine phosphatase 1B (PTP1B) inhibitory activities of the synthetic compounds were evaluated by the colorimetric assay. The results show that these compounds are moderate PTP1B inhibitors. The synthesis of these bromophenol derivatives makes in vivo studies of their structure-activity relationships and inhibition activity against PTP1B possible.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
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
Four bromophenols were isolated from the extract of marine red alga, Rhodomela confervoides by column chromatography and HPLC methods. By means of spectroscopic methods including IR, MS, 1D, and 2D-NMR techniques, the...Four bromophenols were isolated from the extract of marine red alga, Rhodomela confervoides by column chromatography and HPLC methods. By means of spectroscopic methods including IR, MS, 1D, and 2D-NMR techniques, their structures were elucidated as (1) 3-bromo-4,5-dihydroxy benzoic acid methyl ester; (2) bis (2,3-dibromo-4,5-dihydroxybenzyl) ether; (3) 3,4-dibromo-5-(methoxymethyl)-1,2-benzenediol and (4) 3-bromo-4,5-dihydroxy-benzaldehyde. Compound 1 was first isolated from the algae in nature, and 1, 4 were found to have selective cytotoxic activities against KB, Bel 7402 and A549 cells, 2 showed powerful antibacterial activities against Staphylococcus aurens and Pseudomonas aeruginosa.展开更多
3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosph...3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B （PTP1B）. Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-（2＇-bromo-6＇-（3＂,4＂-dimethoxybenzyl）- 3 ＇,4 ＇-dimethoxybenzyl）-4,5 -dimethoxybenzene （2）, 2,3-dibromo- 1 -（2 ＇-bromo-6＇-（2 ＂-bromo-4＂,5 ＂-dimethoxy- benzyl）-3＇,4＇-dimethoxybenzyl）-4,5-dimethoxybenzene （3）, 3,4-dibromo-5-（2＇-bromo-6＇-（2＂-bromo-4＂,5＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （4） and 3,4-dibromo-5-（2＇-bromo-6＇-（3＂,4＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （5）. PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.展开更多
This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the p...This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate is titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied for the determination of chlordiazepoxide raw materials with satisfactory results. The recovery is between 99.58% and 100.4%, the relative error is less than ± 0.50% . Experiments show that the method gives the same results as the approach using nonaqueous titration (ChP).展开更多
This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering...This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied to the determination of ciprofloxacin lactate raw material with satisfactory results. The recovery was between 99.66% and 100.2%, the relative error was less than ±0.40%. Experiments showed that the method gave the same results as the approach using nonaqueous titration (ChP).展开更多
To investigate the antitumor effect of bromophenol derivatives in vitro and Leathesia nana extract in vivo, six bromophenol derivatives 6-（2,3-dibromo-4,5-dihydroxybenzyl）-2,3-dibromo-4,5-dihydroxy benzyl methyl eth...To investigate the antitumor effect of bromophenol derivatives in vitro and Leathesia nana extract in vivo, six bromophenol derivatives 6-（2,3-dibromo-4,5-dihydroxybenzyl）-2,3-dibromo-4,5-dihydroxy benzyl methyl ether （1）, （＋）-3-（2,3-dibromo-4,5-dihydroxyphenyl）-4-bromo-5,6-dihydroxy-1,3- dihydroisobenzofuran （2）, 3-bromo-4-（2,3-dibromo-4,5-dihydroxybenzyl）-5-methoxymethyl-pyrocatechol （3）, 2,2＇,3,3＇-tetrabromo-4,4＇,5,5＇-tetrahydroxy-diphenylmethane （4）, bis（2,3-dibromo-4,5-dihydroxybenzyl） ether （5）, 2,2＇,3-tribromo-3＇,4,4＇,5-tetrahydroxy-6＇-ethyloxymethyldiphenylmethane （6） were isolated from brown alga Leathesia nana, and their cytotoxicity were tested by MTF assays in human cancer cell lines A549, BGC-823, MCF-7, B16-BL6, HT-1080, A2780, Be17402 and HCT-8. Their inhibitory activity against protein tyrosine kinase （PTK） with over-expression of c-kit was analyzed also by ELISA. The antitumor activity of ethanolic extraction of Leathesia nana （EELN） was evaluated on S180-bearing mice. All compounds showed very potent cytotoxicity against all of the eight cancer cell lines with IC50 below 10 pg/mL. In PTK inhibition study, all bromophenol derivatives showed moderate inhibitory activity and compounds 2, 5 and 6 showed significant bioactivity with the inhibition ratio of 77.5%, 80.1% and 71.4% respectively. Pharmacological studies reveal that EELN could inhibit the growth of Sarcoma 180 tumor and increase the indices of thymus and spleen to improve the immune system remarkably in vivo. Results indicated that the bromophenol derivatives and EELN can be used as potent antitumor agents for PTK over-expression of c-kit and considered in a new therapeutic strategy for treatment of cancer.展开更多
A novel bromophenol was isolated from ethanolic extract of the brown alga Leathesia nana S.et G. The structure was elucidated as (E)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-2-methyl-propenal by spectroscopic methods inclu...A novel bromophenol was isolated from ethanolic extract of the brown alga Leathesia nana S.et G. The structure was elucidated as (E)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-2-methyl-propenal by spectroscopic methods including IR, HREIMS, 1D and 2D NMR techniques.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
Thrombin,the ultimate proteinase of the coagulation cascade,is an attractive target for the treatment of a variety of cardiovascular diseases.A bromophenol derivative named (+)-3-(2,3-dibromo-4,5-dihydroxy-phenyl)-4-b...Thrombin,the ultimate proteinase of the coagulation cascade,is an attractive target for the treatment of a variety of cardiovascular diseases.A bromophenol derivative named (+)-3-(2,3-dibromo-4,5-dihydroxy-phenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroiso-benzofuran 1,isolated from the brown alga Leathesia nana exhibited significant thrombin inhibitory activity.In this study,we investigated the inhibition of human thrombin in vitro with this bromophenol derivative,and its antithrombotic efficacy in vivo using the arteriovenous shunt model and the ferric chloride-induced arterial thrombosis model in rats.The results show that the bromophenol derivative is a potential inhibitor of thrombin (IC50=1.03 nmol/L).In antithrombotic experiments in vivo,the bromophenol derivative also shows good effect comparing with the control group.These data indicate that the bromophenol derivative is a potential drug for prophylaxis and the treatment of thrombotic diseases.展开更多
In this paper the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of Bromophenol Blue using the Z-scan technique with a continuous wave laser beam at wavelengths 488 ...In this paper the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of Bromophenol Blue using the Z-scan technique with a continuous wave laser beam at wavelengths 488 nm and 514 nm are presented. It was observed that the material exhibited reverse saturation absorption and self defocusing behavior. It was found that the increase in solution concentration resulted in linear increase of the nonlinear refractive index. A pump and probe technique was used to obtain the absorption spectrum of triplet state. Furthermore the nonlinear absorption effect was used to demonstrate all optical switching.展开更多
文摘The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown alga Eisenia bicyclis (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8’-bieckol) had a deterrent effect against feeding behavior of T. cornutus in the concentration of algal body, respectively. In the case of the examination of 0.1 mM concentration, although fucofuroeckol A and phlorofucofuroeckol A significantly reduced feeding by T. cornutus, phloroglucinol and 8,8’-bieckol did not show any significant influence on feeding behavior, and eckol and dieckol had stimulating activity. 2,4-Dibromophenol and 2,4,6-tribromophenol, which are major components of extracellular secretions from Eisenia and Ecklonia species, caused the death, the torpidity, and the decreased appetite of T. cornutus at the concentration of 0.1 mM. In addition, 2,4-dibromophenol had strong feeding deterrent activity at the concentration of 1 μM. These results indicate that phlorotannins and bromophenols act as chemical defense agents of brown algae against environmental stresses such as the herbivore attack.
基金supported by the State Innovative Drugs Development Program of China (2009ZX09103-661 and 2009ZX09102)
文摘Marine algae contain various bromophenols with a variety of biological activities, including antimicrobial, anticancer, and anti-diabetic effects. Here, we briefly review the recent progress in researches on the biomaterials from marine algae, emphasizing the relationship between the structure and the potential anti-diabetic applications. Bromophenols from marine algae display their hyper- glycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B, ct-glucosidase, as well as other mechanisms.
基金Supported by the National Major Research Program of China (No.2009ZX09103-148)the National High Technology Research and Development Program of China (863 program) (Nos.2007AA09Z410,2007AA091604)
文摘Bromophenols are a set of natural products widely distributed in seaweed, most of which exhibit interesting and useful biological activities. To develop a reliable and efficient synthetic route to these natural bromophenols, three of them, 3,4-dibromo-5-(2′-bromo-3′,4′- dihydroxy-6′-methoxymethyl- benzyl)-benzene-1,2-diol (compound 9), 3,4-dibromo-5-(2′-bromo-6′-ethoxy methyl-3′,4′-dihydroxybenzyl)- benzene-1,2-diol (compound 10), and 3-bromo-4-(3′-bromo-4′,5′-dihydroxy benzyl)-5-(ethoxymethyl)- benzene-1,2-diol (compound 14), isolated from red marine algae, have been synthesized in eight steps with an overall yield of 14.4%, 14.4%, and 18.2% respectively, via a practical approach employing bromination, Wolff-Kishner-Huang reduction and a Friedel-Crafts reaction as key steps. The protein tyrosine phosphatase 1B (PTP1B) inhibitory activities of the synthetic compounds were evaluated by the colorimetric assay. The results show that these compounds are moderate PTP1B inhibitors. The synthesis of these bromophenol derivatives makes in vivo studies of their structure-activity relationships and inhibition activity against PTP1B possible.
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Supported by National "863" Program (No. 2004AA625030, 2001AA620503), Qingdao marine sciences project (No. 04-2-NN-26) and Key Knowledge Innovative Project of the Chinese Academy of Sciences (KZCX3-SW-215).
文摘Four bromophenols were isolated from the extract of marine red alga, Rhodomela confervoides by column chromatography and HPLC methods. By means of spectroscopic methods including IR, MS, 1D, and 2D-NMR techniques, their structures were elucidated as (1) 3-bromo-4,5-dihydroxy benzoic acid methyl ester; (2) bis (2,3-dibromo-4,5-dihydroxybenzyl) ether; (3) 3,4-dibromo-5-(methoxymethyl)-1,2-benzenediol and (4) 3-bromo-4,5-dihydroxy-benzaldehyde. Compound 1 was first isolated from the algae in nature, and 1, 4 were found to have selective cytotoxic activities against KB, Bel 7402 and A549 cells, 2 showed powerful antibacterial activities against Staphylococcus aurens and Pseudomonas aeruginosa.
基金Supported by the National Major Research Program of China"The Creation for Significant Innovative Drugs"(No.2009ZX09103-148)the Natural Science Foundation of Shandong(No.BS2009YY011)+1 种基金the Natural Science Foundation of Qingdao(No.10-3-4-8-2-JCH)the Program of Qingdao Shinan District(No.2009-HY-2-14)
文摘3-bromo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl）-l,2-benzenediol （1） is a natural bromophenol isolated from the red algae Rhodomela confervoides that exhibits significant inhibition against protein tyrosine phosphatase 1B （PTP1B）. Based on its activity, we synthesized two new synthetic bromophenols and their methoxy derivatives from vanillin using the structure of natural bromophenol 1 as a scaffold. The structures of these bromophenols were elucidated from H NMR, 13C NMR, and high resolution electron ionization mass spectrometry as 2,3-dibromo-1-（2＇-bromo-6＇-（3＂,4＂-dimethoxybenzyl）- 3 ＇,4 ＇-dimethoxybenzyl）-4,5 -dimethoxybenzene （2）, 2,3-dibromo- 1 -（2 ＇-bromo-6＇-（2 ＂-bromo-4＂,5 ＂-dimethoxy- benzyl）-3＇,4＇-dimethoxybenzyl）-4,5-dimethoxybenzene （3）, 3,4-dibromo-5-（2＇-bromo-6＇-（2＂-bromo-4＂,5＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （4） and 3,4-dibromo-5-（2＇-bromo-6＇-（3＂,4＂- dihydroxybenzyl）-3＇,4＇-dihydroxybenzyl）pyrocatechol （5）. PTP1B inhibition activities of these compounds were evaluated using a colorimetric assay, and compounds 3 and 4 demonstrated interesting activity against PTP1B.
文摘This paper describes an effective method for determining chlordiazepoxide. An excess of sodium tetraphenylboron is added to precipitate chlordiazepoxide in HAc NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate is titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied for the determination of chlordiazepoxide raw materials with satisfactory results. The recovery is between 99.58% and 100.4%, the relative error is less than ± 0.50% . Experiments show that the method gives the same results as the approach using nonaqueous titration (ChP).
文摘This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied to the determination of ciprofloxacin lactate raw material with satisfactory results. The recovery was between 99.66% and 100.2%, the relative error was less than ±0.40%. Experiments showed that the method gave the same results as the approach using nonaqueous titration (ChP).
基金Supported by the National High Technology Research and Development Program of China (863 Program, No. 2007AA09Z410)Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-209)
文摘To investigate the antitumor effect of bromophenol derivatives in vitro and Leathesia nana extract in vivo, six bromophenol derivatives 6-（2,3-dibromo-4,5-dihydroxybenzyl）-2,3-dibromo-4,5-dihydroxy benzyl methyl ether （1）, （＋）-3-（2,3-dibromo-4,5-dihydroxyphenyl）-4-bromo-5,6-dihydroxy-1,3- dihydroisobenzofuran （2）, 3-bromo-4-（2,3-dibromo-4,5-dihydroxybenzyl）-5-methoxymethyl-pyrocatechol （3）, 2,2＇,3,3＇-tetrabromo-4,4＇,5,5＇-tetrahydroxy-diphenylmethane （4）, bis（2,3-dibromo-4,5-dihydroxybenzyl） ether （5）, 2,2＇,3-tribromo-3＇,4,4＇,5-tetrahydroxy-6＇-ethyloxymethyldiphenylmethane （6） were isolated from brown alga Leathesia nana, and their cytotoxicity were tested by MTF assays in human cancer cell lines A549, BGC-823, MCF-7, B16-BL6, HT-1080, A2780, Be17402 and HCT-8. Their inhibitory activity against protein tyrosine kinase （PTK） with over-expression of c-kit was analyzed also by ELISA. The antitumor activity of ethanolic extraction of Leathesia nana （EELN） was evaluated on S180-bearing mice. All compounds showed very potent cytotoxicity against all of the eight cancer cell lines with IC50 below 10 pg/mL. In PTK inhibition study, all bromophenol derivatives showed moderate inhibitory activity and compounds 2, 5 and 6 showed significant bioactivity with the inhibition ratio of 77.5%, 80.1% and 71.4% respectively. Pharmacological studies reveal that EELN could inhibit the growth of Sarcoma 180 tumor and increase the indices of thymus and spleen to improve the immune system remarkably in vivo. Results indicated that the bromophenol derivatives and EELN can be used as potent antitumor agents for PTK over-expression of c-kit and considered in a new therapeutic strategy for treatment of cancer.
文摘A novel bromophenol was isolated from ethanolic extract of the brown alga Leathesia nana S.et G. The structure was elucidated as (E)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-2-methyl-propenal by spectroscopic methods including IR, HREIMS, 1D and 2D NMR techniques.
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 the National High Technology Research and Development Program of China (863 Program) (No. 2007AA09Z410)the National Major Research Program of China "The Creation for Significant Innovative Drugs" (No. 2009ZX09103-148)
文摘Thrombin,the ultimate proteinase of the coagulation cascade,is an attractive target for the treatment of a variety of cardiovascular diseases.A bromophenol derivative named (+)-3-(2,3-dibromo-4,5-dihydroxy-phenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroiso-benzofuran 1,isolated from the brown alga Leathesia nana exhibited significant thrombin inhibitory activity.In this study,we investigated the inhibition of human thrombin in vitro with this bromophenol derivative,and its antithrombotic efficacy in vivo using the arteriovenous shunt model and the ferric chloride-induced arterial thrombosis model in rats.The results show that the bromophenol derivative is a potential inhibitor of thrombin (IC50=1.03 nmol/L).In antithrombotic experiments in vivo,the bromophenol derivative also shows good effect comparing with the control group.These data indicate that the bromophenol derivative is a potential drug for prophylaxis and the treatment of thrombotic diseases.
文摘In this paper the results from investigations of the nonlinear refractive index and nonlinear absorption coefficient of Bromophenol Blue using the Z-scan technique with a continuous wave laser beam at wavelengths 488 nm and 514 nm are presented. It was observed that the material exhibited reverse saturation absorption and self defocusing behavior. It was found that the increase in solution concentration resulted in linear increase of the nonlinear refractive index. A pump and probe technique was used to obtain the absorption spectrum of triplet state. Furthermore the nonlinear absorption effect was used to demonstrate all optical switching.
