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Dayong Shi - One of the best experts on this subject based on the ideXlab platform.
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bos 93 a novel Bromophenol derivative induces apoptosis and autophagy in human a549 lung cancer cells via pi3k akt mtor and mapk signaling pathway
Experimental and Therapeutic Medicine, 2019Co-Authors: Chuanlong Guo, Lijun Wang, Yue Zhao, Bo Jiang, Jiao Luo, Dayong ShiAbstract:The novel Bromophenol derivative, 3-(3-bromo-5-methoxy-4-(3-(piperidin-1-yl)propoxy)benzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (BOS-93), was synthesized in the CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (Qingdao, China). Experimental studies have demonstrated that it could induce apoptosis and autophagy in human A549 lung cancer cells, and it could also inhibit tumor growth in human A549 lung cancer xenograft models. In the present study, the molecular pathways underlying these effects were identified. The results demonstrated that BOS-93 could inhibit cell proliferation in A549 cells and block A549 cells at the G0/G1 phase. Furthermore, BOS-93 could induce apoptosis, activate caspase-3 and poly ADP ribose polymerase, and increase the B cell lymphoma (Bcl)-2 associated X protein/Bcl-2 ratio. Notably, BOS-93 could also induce autophagy in A549 cells. BOS-93-induced autophagy was confirmed by detecting light chain 3 (LC3)-I/LC3-II conversion and increasing expression of beclin1 and autophagy-related gene 14. Notably, BOS-93-induced autophagy could be inhibited by the autophagy inhibitor 3-MA. Flow cytometry, transmission electron microscopy (TEM) and western blot analysis indicated that BOS-93 induced apoptosis and autophagy activities by deactivating phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin and activating the mitogen-activated protein kinase signaling pathway. The present findings indicated that BOS-93 might be a novel anti-cancer agent for treatment of human lung cancer.
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discovery of novel Bromophenol hybrids as potential anticancer agents through the ros mediated apoptotic pathway design synthesis and biological evaluation
Marine Drugs, 2017Co-Authors: Lijun Wang, Yue Zhao, Bo Jiang, Shuju Guo, Shuaiyu Wang, Jiao Luo, Chuanlong Guo, Hua Liu, Dayong ShiAbstract:A series of Bromophenol hybrids with N-containing heterocyclic moieties were designed, and their anticancer activities against a panel of five human cancer cell lines (A549, Bel7402, HepG2, HCT116 and Caco2) using MTT assay in vitro were explored. Among them, thirteen compounds (17a, 17b, 18a, 19a, 19b, 20a, 20b, 21a, 21b, 22a, 22b, 23a, and 23b) exhibited significant inhibitory activity against the tested cancer cell lines. The structure-activity relationships (SARs) of Bromophenol derivatives were discussed. The promising candidate compound 17a could induce cell cycle arrest at G0/G1 phase and induce apoptosis in A549 cells, as well as caused DNA fragmentations, morphological changes and ROS generation by the mechanism studies. Furthermore, compound 17a suppression of Bcl-2 levels (decrease in the expression of the anti-apoptotic proteins Bcl-2 and down-regulation in the expression levels of Bcl-2) in A549 cells were observed, along with activation caspase-3 and PARP, which indicated that compound 17a induced A549 cells apoptosis in vitro through the ROS-mediated apoptotic pathway. These results might be useful for Bromophenol derivatives to be explored and developed as novel anticancer drugs.
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design synthesis and biological evaluation of novel Bromophenol derivatives incorporating indolin 2 one moiety as potential anticancer agents
Marine Drugs, 2015Co-Authors: Lijun Wang, Bo Jiang, Shuaiyu Wang, Baocheng Wang, Jiao Luo, Meng Yang, Shuihua Jin, Dayong ShiAbstract:A series of Bromophenol derivatives containing indolin-2-one moiety were designed and evaluated that for their anticancer activities against A549, Bel7402, HepG2, HeLa and HCT116 cancer cell lines using MTT assay in vitro. Among them, seven compounds (4g-4i, 5h, 6d, 7a, 7b) showed potent activity against the tested five human cancer cell lines. Wound-healing assay demonstrated that compound 4g can be used as a potent compound for inactivating invasion and metastasis by inhibiting the migration of cancer cells. The structure-activity relationships (SARs) of Bromophenol derivatives had been discussed, which were useful for exploring and developing Bromophenol derivatives as novel anticancer drugs.
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design synthesis and biological evaluation of Bromophenol derivatives as protein tyrosine phosphatase 1b inhibitors
ChemInform, 2012Co-Authors: Bo Jiang, Dayong Shi, Yongchao Cui, Shuju GuoAbstract:A variety of Bromophenol derivatives with bicyclic, tricyclic or tetracyclic scaffold is synthesized and evaluated for protein tyrosine phosphatase 1B inhibitory activity.
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Bromophenols as inhibitors of protein tyrosine phosphatase 1b with antidiabetic properties
Bioorganic & Medicinal Chemistry Letters, 2012Co-Authors: Dayong Shi, Bo Jiang, Shuju Guo, Tao WangAbstract:A series of Bromophenol derivatives were synthesized and evaluated as protein tyrosine phosphatase 1B (PTP1B) inhibitors in vitro and in vivo based on Bromophenol 4e (IC50 = 2.42 mu mol/ L), which was isolated from red algae Rhodomela confervoides. The results showed that all of the synthesized compounds displayed weak to good PTP1B inhibition at tested concentration. Among them, highly brominated compound 4g exhibited promising inhibitory activity against PTP1B with IC50 0.68 mu mol/L, which was approximately fourfold more potent than lead compound 4e. Further, compound 4g demonstrated high selectivity against other PTPs (TCPTP, LAR, SHP-1 and SHP-2). More importantly, in vivo antidiabetic activities investigations of compound 4g also demonstrated inspiring results. (C) 2012 Elsevier Ltd. All rights reserved.
Bo Jiang - One of the best experts on this subject based on the ideXlab platform.
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bos 93 a novel Bromophenol derivative induces apoptosis and autophagy in human a549 lung cancer cells via pi3k akt mtor and mapk signaling pathway
Experimental and Therapeutic Medicine, 2019Co-Authors: Chuanlong Guo, Lijun Wang, Yue Zhao, Bo Jiang, Jiao Luo, Dayong ShiAbstract:The novel Bromophenol derivative, 3-(3-bromo-5-methoxy-4-(3-(piperidin-1-yl)propoxy)benzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (BOS-93), was synthesized in the CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (Qingdao, China). Experimental studies have demonstrated that it could induce apoptosis and autophagy in human A549 lung cancer cells, and it could also inhibit tumor growth in human A549 lung cancer xenograft models. In the present study, the molecular pathways underlying these effects were identified. The results demonstrated that BOS-93 could inhibit cell proliferation in A549 cells and block A549 cells at the G0/G1 phase. Furthermore, BOS-93 could induce apoptosis, activate caspase-3 and poly ADP ribose polymerase, and increase the B cell lymphoma (Bcl)-2 associated X protein/Bcl-2 ratio. Notably, BOS-93 could also induce autophagy in A549 cells. BOS-93-induced autophagy was confirmed by detecting light chain 3 (LC3)-I/LC3-II conversion and increasing expression of beclin1 and autophagy-related gene 14. Notably, BOS-93-induced autophagy could be inhibited by the autophagy inhibitor 3-MA. Flow cytometry, transmission electron microscopy (TEM) and western blot analysis indicated that BOS-93 induced apoptosis and autophagy activities by deactivating phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin and activating the mitogen-activated protein kinase signaling pathway. The present findings indicated that BOS-93 might be a novel anti-cancer agent for treatment of human lung cancer.
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a novel Bromophenol derivative bos 102 induces cell cycle arrest and apoptosis in human a549 lung cancer cells via ros mediated pi3k akt and the mapk signaling pathway
Marine Drugs, 2018Co-Authors: Lijun Wang, Yue Zhao, Xiangqian Li, Bo Jiang, Ning WuAbstract:Bromophenol is a type of natural marine product. It has excellent biological activities, especially anticancer activities. In our study of searching for potent anticancer drugs, a novel Bromophenol derivative containing indolin-2-one moiety, 3-(4-(3-([1,4′-bipiperidin]-1′-yl)propoxy)-3-bromo-5-methoxybenzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (BOS-102) was synthesized, which showed excellent anticancer activities on human lung cancer cell lines. A study of the mechanisms indicated that BOS-102 could significantly block cell proliferation in human A549 lung cancer cells and effectively induce G0/G1 cell cycle arrest via targeting cyclin D1 and cyclin-dependent kinase 4 (CDK4). BOS-102 could also induce apoptosis, including activating caspase-3 and poly (ADP-ribose) polymerase (PARP), increasing the Bax/Bcl-2 ratio, enhancing reactive oxygen species (ROS) generation, decreasing mitochondrial membrane potential (MMP, ΔΨm), and leading cytochrome c release from mitochondria. Further research revealed that BOS-102 deactivated the PI3K/Akt pathway and activated the mitogen-activated protein kinase (MAPK) signaling pathway resulting in apoptosis and cell cycle arrest, which indicated that BOS-102 has the potential to develop into an anticancer drug.
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discovery of novel Bromophenol hybrids as potential anticancer agents through the ros mediated apoptotic pathway design synthesis and biological evaluation
Marine Drugs, 2017Co-Authors: Lijun Wang, Yue Zhao, Bo Jiang, Shuju Guo, Shuaiyu Wang, Jiao Luo, Chuanlong Guo, Hua Liu, Dayong ShiAbstract:A series of Bromophenol hybrids with N-containing heterocyclic moieties were designed, and their anticancer activities against a panel of five human cancer cell lines (A549, Bel7402, HepG2, HCT116 and Caco2) using MTT assay in vitro were explored. Among them, thirteen compounds (17a, 17b, 18a, 19a, 19b, 20a, 20b, 21a, 21b, 22a, 22b, 23a, and 23b) exhibited significant inhibitory activity against the tested cancer cell lines. The structure-activity relationships (SARs) of Bromophenol derivatives were discussed. The promising candidate compound 17a could induce cell cycle arrest at G0/G1 phase and induce apoptosis in A549 cells, as well as caused DNA fragmentations, morphological changes and ROS generation by the mechanism studies. Furthermore, compound 17a suppression of Bcl-2 levels (decrease in the expression of the anti-apoptotic proteins Bcl-2 and down-regulation in the expression levels of Bcl-2) in A549 cells were observed, along with activation caspase-3 and PARP, which indicated that compound 17a induced A549 cells apoptosis in vitro through the ROS-mediated apoptotic pathway. These results might be useful for Bromophenol derivatives to be explored and developed as novel anticancer drugs.
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design synthesis and biological evaluation of novel Bromophenol derivatives incorporating indolin 2 one moiety as potential anticancer agents
Marine Drugs, 2015Co-Authors: Lijun Wang, Bo Jiang, Shuaiyu Wang, Baocheng Wang, Jiao Luo, Meng Yang, Shuihua Jin, Dayong ShiAbstract:A series of Bromophenol derivatives containing indolin-2-one moiety were designed and evaluated that for their anticancer activities against A549, Bel7402, HepG2, HeLa and HCT116 cancer cell lines using MTT assay in vitro. Among them, seven compounds (4g-4i, 5h, 6d, 7a, 7b) showed potent activity against the tested five human cancer cell lines. Wound-healing assay demonstrated that compound 4g can be used as a potent compound for inactivating invasion and metastasis by inhibiting the migration of cancer cells. The structure-activity relationships (SARs) of Bromophenol derivatives had been discussed, which were useful for exploring and developing Bromophenol derivatives as novel anticancer drugs.
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design synthesis and biological evaluation of Bromophenol derivatives as protein tyrosine phosphatase 1b inhibitors
ChemInform, 2012Co-Authors: Bo Jiang, Dayong Shi, Yongchao Cui, Shuju GuoAbstract:A variety of Bromophenol derivatives with bicyclic, tricyclic or tetracyclic scaffold is synthesized and evaluated for protein tyrosine phosphatase 1B inhibitory activity.
Lijun Wang - One of the best experts on this subject based on the ideXlab platform.
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bos 93 a novel Bromophenol derivative induces apoptosis and autophagy in human a549 lung cancer cells via pi3k akt mtor and mapk signaling pathway
Experimental and Therapeutic Medicine, 2019Co-Authors: Chuanlong Guo, Lijun Wang, Yue Zhao, Bo Jiang, Jiao Luo, Dayong ShiAbstract:The novel Bromophenol derivative, 3-(3-bromo-5-methoxy-4-(3-(piperidin-1-yl)propoxy)benzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (BOS-93), was synthesized in the CAS Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences (Qingdao, China). Experimental studies have demonstrated that it could induce apoptosis and autophagy in human A549 lung cancer cells, and it could also inhibit tumor growth in human A549 lung cancer xenograft models. In the present study, the molecular pathways underlying these effects were identified. The results demonstrated that BOS-93 could inhibit cell proliferation in A549 cells and block A549 cells at the G0/G1 phase. Furthermore, BOS-93 could induce apoptosis, activate caspase-3 and poly ADP ribose polymerase, and increase the B cell lymphoma (Bcl)-2 associated X protein/Bcl-2 ratio. Notably, BOS-93 could also induce autophagy in A549 cells. BOS-93-induced autophagy was confirmed by detecting light chain 3 (LC3)-I/LC3-II conversion and increasing expression of beclin1 and autophagy-related gene 14. Notably, BOS-93-induced autophagy could be inhibited by the autophagy inhibitor 3-MA. Flow cytometry, transmission electron microscopy (TEM) and western blot analysis indicated that BOS-93 induced apoptosis and autophagy activities by deactivating phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin and activating the mitogen-activated protein kinase signaling pathway. The present findings indicated that BOS-93 might be a novel anti-cancer agent for treatment of human lung cancer.
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a novel Bromophenol derivative bos 102 induces cell cycle arrest and apoptosis in human a549 lung cancer cells via ros mediated pi3k akt and the mapk signaling pathway
Marine Drugs, 2018Co-Authors: Lijun Wang, Yue Zhao, Xiangqian Li, Bo Jiang, Ning WuAbstract:Bromophenol is a type of natural marine product. It has excellent biological activities, especially anticancer activities. In our study of searching for potent anticancer drugs, a novel Bromophenol derivative containing indolin-2-one moiety, 3-(4-(3-([1,4′-bipiperidin]-1′-yl)propoxy)-3-bromo-5-methoxybenzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (BOS-102) was synthesized, which showed excellent anticancer activities on human lung cancer cell lines. A study of the mechanisms indicated that BOS-102 could significantly block cell proliferation in human A549 lung cancer cells and effectively induce G0/G1 cell cycle arrest via targeting cyclin D1 and cyclin-dependent kinase 4 (CDK4). BOS-102 could also induce apoptosis, including activating caspase-3 and poly (ADP-ribose) polymerase (PARP), increasing the Bax/Bcl-2 ratio, enhancing reactive oxygen species (ROS) generation, decreasing mitochondrial membrane potential (MMP, ΔΨm), and leading cytochrome c release from mitochondria. Further research revealed that BOS-102 deactivated the PI3K/Akt pathway and activated the mitogen-activated protein kinase (MAPK) signaling pathway resulting in apoptosis and cell cycle arrest, which indicated that BOS-102 has the potential to develop into an anticancer drug.
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discovery of novel Bromophenol hybrids as potential anticancer agents through the ros mediated apoptotic pathway design synthesis and biological evaluation
Marine Drugs, 2017Co-Authors: Lijun Wang, Yue Zhao, Bo Jiang, Shuju Guo, Shuaiyu Wang, Jiao Luo, Chuanlong Guo, Hua Liu, Dayong ShiAbstract:A series of Bromophenol hybrids with N-containing heterocyclic moieties were designed, and their anticancer activities against a panel of five human cancer cell lines (A549, Bel7402, HepG2, HCT116 and Caco2) using MTT assay in vitro were explored. Among them, thirteen compounds (17a, 17b, 18a, 19a, 19b, 20a, 20b, 21a, 21b, 22a, 22b, 23a, and 23b) exhibited significant inhibitory activity against the tested cancer cell lines. The structure-activity relationships (SARs) of Bromophenol derivatives were discussed. The promising candidate compound 17a could induce cell cycle arrest at G0/G1 phase and induce apoptosis in A549 cells, as well as caused DNA fragmentations, morphological changes and ROS generation by the mechanism studies. Furthermore, compound 17a suppression of Bcl-2 levels (decrease in the expression of the anti-apoptotic proteins Bcl-2 and down-regulation in the expression levels of Bcl-2) in A549 cells were observed, along with activation caspase-3 and PARP, which indicated that compound 17a induced A549 cells apoptosis in vitro through the ROS-mediated apoptotic pathway. These results might be useful for Bromophenol derivatives to be explored and developed as novel anticancer drugs.
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design synthesis and biological evaluation of novel Bromophenol derivatives incorporating indolin 2 one moiety as potential anticancer agents
Marine Drugs, 2015Co-Authors: Lijun Wang, Bo Jiang, Shuaiyu Wang, Baocheng Wang, Jiao Luo, Meng Yang, Shuihua Jin, Dayong ShiAbstract:A series of Bromophenol derivatives containing indolin-2-one moiety were designed and evaluated that for their anticancer activities against A549, Bel7402, HepG2, HeLa and HCT116 cancer cell lines using MTT assay in vitro. Among them, seven compounds (4g-4i, 5h, 6d, 7a, 7b) showed potent activity against the tested five human cancer cell lines. Wound-healing assay demonstrated that compound 4g can be used as a potent compound for inactivating invasion and metastasis by inhibiting the migration of cancer cells. The structure-activity relationships (SARs) of Bromophenol derivatives had been discussed, which were useful for exploring and developing Bromophenol derivatives as novel anticancer drugs.
Hyiseung Lee - One of the best experts on this subject based on the ideXlab platform.
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Bromophenols as Candida albicans isocitrate lyase inhibitors.
Bioorganic & medicinal chemistry letters, 2010Co-Authors: Heung Bae Jeon, Yu-ri Han, Yeon-ju Lee, Jiyoung Park, So-hyoung Lee, Dongsik Yang, Mihyun Kwon, Jongheon Shin, Hyiseung LeeAbstract:Abstract A new series of Bromophenols was synthesized by reactions of corresponding phenol analogs with bromine. The synthesized compounds were tested for inhibitory activity against isocitrate lyase (ICL) of Candida albicans and antimicrobial activity against Gram-positive and, Gram-negative bacteria and fungi. Among the synthesized Bromophenols, bis(3-bromo-4,5-dihydroxyphenyl)methanone (11) and (3-bromo-4,5-dihydroxyphenyl)(2,3-dibromo-4,5-dihydroxyphenyl)methanone (12) displayed potent inhibitory activities against ICL, showing a stronger inhibitory effects than were found with natural Bromophenol 1. The preliminary structure–activity relationships were investigated in order to determine the essential structural requirements for the inhibitory activities of these compounds against ICL of C. albicans.
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antimicrobial activities of the Bromophenols from the red alga odonthalia corymbifera and some synthetic derivatives
Bioorganic & Medicinal Chemistry Letters, 2008Co-Authors: Jihye Lee, Jongheon Shin, Soonchun Chung, Hee Jae Shin, Hyekyeong Kim, Hyiseung LeeAbstract:Abstract A series of Bromophenols was obtained by isolation from red alga Odonthalia corymbifera and by reactions of bis(hydroxyphenyl)methanes with bromine. New Bromophenols including 3,3′,5,5′-tetrabromo-2,2′,4,4′-tetrahydroxydiphenylmethane ( 10 ), a regioisomer of the potent antimicrobial natural product, together with known derivatives were synthesized in high yield. All of the isolated and synthesized compounds were tested for antimicrobial activity against Gram-negative, Gram-positive bacteria and fungi. The preliminary structure–activity relationship, to elucidate the essential structure requirements for antimicrobial activity, has been described. Among the isolated natural products 2,2′,3,3′-tetrabromo-4,4′,5,5′-tetrahydroxydiphenylmethane ( 4 ) was found to be the most active derivative against Candida albicans , Aspergillus fumigatus , Trichophyton rubrum , and Trichophyton mentagrophytes . The synthetic Bromophenols 3,3′-dibromo-6,6′-dihydroxydiphenylmethane ( 13 ) and 3,3′,5,5′-tetrabromo-6,6′-dihydroxydiphenylmethane ( 14 ) showed potent antibacterial effect against Staphylococcus aureus , Bacillus subtilis , Micrococcus luteus , Proteus vulgaris , and Salmonella typhimurium .
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Inhibition of the pathogenicity of Magnaporthe grisea by Bromophenols, isocitrate lyase inhibitors, from the red alga Odonthalia corymbifera.
Journal of agricultural and food chemistry, 2007Co-Authors: Hyiseung Lee, Taehoon Lee, Jihye Lee, C Chae, Soonchun Chung, Dongsun Shin, Jongheon ShinAbstract:Magnaporthe grisea is a fungal pathogen of rice that forms appressoria that penetrate the outer cuticle of the rice plant. Data from recent studies indicate that M. grisea isocitrate lyase (ICL), a key enzyme in the glyoxylate cycle, is highly expressed during appressorium-mediated plant infection. Bromophenols isolated from the red alga Odonthalia corymbifera exhibited potent ICL inhibitory activity and blocked appressoria formation by M. grisea in a concentration-dependent manner. In addition, these compounds protected the rice plants from infection by M. grisea. Rice plants infected with wild-type M. grisea Guy 11 exhibited significantly lower disease severity with Bromophenol treatment than without, and the treatment effect was comparable to the behavior of the Δicl knockout mutant I-10. The protective effect of Bromophenols and their strong inhibition of appressorium formation on rice plants suggest that ICL inhibitors may be promising candidates for crop protection, particularly to protect rice plan...
Bingui Wang - One of the best experts on this subject based on the ideXlab platform.
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new nitrogen containing Bromophenols from the marine red alga rhodomela confervoides and their radical scavenging activity
Food Chemistry, 2012Co-Authors: James B Gloer, Bingui WangAbstract:In addition to nine known Bromophenol derivatives, five new nitrogen-containing Bromophenols were isolated from an ethyl acetate extract of the marine red alga Rhodomela confervoides. By using spectro-scopic methods, the structures of the new compounds were identified as 3-(2,3-dibromo-4,5-dihydroxybenzyl)pyrrolidine-2,5-dione (1), methyl 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoate (2), 4-(2,3-dibromo-4,5-dihydroxybenzylamino)-4-oxobutanoic acid (3), 3-bromo-5-hydroxy-4-methoxybenzamide (4), and 2-(3-bromo-5-hydroxy-4-methoxyphenyl)acetamide (5). All of these Bromophenols showed potent scavenging activity against DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals, with IC50 values ranging from 5.22 to 23.60 mu M. These compounds also displayed moderate activity against ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radicals, with Trolox Equivalent Antioxidant Capacity values (TEAC) ranging from 2.11 to 3.58 mM. The results obtained in this study demonstrate that the Bromophenols obtained from R. confervoides may have potential application in food and/or pharmaceutical fields as natural antioxidants. (C) 2012 Elsevier Ltd. All rights reserved.
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natural Bromophenols from the marine red alga polysiphonia urceolata rhodomelaceae structural elucidation and dpph radical scavenging activity
Bioorganic & Medicinal Chemistry, 2007Co-Authors: Bingui WangAbstract:Three new natural occurring Bromophenols, 3-(3-bromo-4,5-dihydroxyphenyl)-2-(3,5-dibromo-4-hydroxyphenyl)propionic acid (1), (E)-4-(3-bromo-4,5-dihydroxyphenyl)-but-3-en-2-one (2), and (3,5-dibromo-4-hydroxyphenyl) acetic acid butyl ester (3), together with one known Bromophenol, 1,2-bis(3-bromo-4,5-dihydroxyphenyl)ethane (4), were isolated and identified from the marine red alga Polysiphonia urceolata. The structures of these compounds were elucidated by extensive analysis of ID and 2D NMR and IR spectra and MS data. Each of the isolated compounds was evaluated for scavenging alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radical activity and all of them exhibited significant activity with IC50 values ranging from 9.67 to 21.90 mu M, compared to the positive control, a well-known antioxidant butylated hydroxytoluene (BHT), with IC50 83.84 mu M. (C) 2007 Elsevier Ltd. All rights reserved.
