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The Catharanthus roseus leaf epidermome to model alkaloid biosynthesis and cellular specialization in plants
S182
Abstracts / Comparative Biochemistry and Physiology, Part A 150 (2008) S180–S185
inform LCA studies as indicated above, and, in addition, the spatially explicit nature of the results also allows the refinement that such studies (and associated decisions) may be specifically conducted at the regional level. doi:10.1016/j.cbpa.2008.04.485
P2.9 A systematic review of life cycle assessments of bioenergy chains for heat, power and liquid transportation fuel R. Rowe (University of Southampton); J. Chapman (University of Southampton); J. Whittaker (Centre for Ecology and Hydrology, Lancaster University); D. Howard (Centre for Ecology and Hydrology, Lancaster University); G. Taylor (University of Southampton)
Life cycle assessments (LCAs) have been used broadly throughout the bioenergy sector, primarily to assess greenhouse gas emissions and energy balances of various energy production chains. However, variations in methodology and reporting of LCAs often make results incomparable. To compare LCA results, it is necessary to dismantle each individual LCA and reassemble it using set units and stating precise system boundaries. This has been done for numerous biomass-to-energy chains, including biomass for heat, power and liquid transport fuels. Summarising these reassembled LCAs into production-chain specific diagrams allows simple comparison between production chains, but more importantly highlights the process steps with the greatest impact or variation.
P2.11 Antioxidant activity of extracts of three Algerian medicinal plants: Clematis flammula, Populus nigra and Ulmus campestris D. Nadjet, B. Hania, A. Dina, C. Nassima, A. Djebbar (University of Bejaia, Algeria)
The beneficial effects of plant extracts as antioxidant agents, based on their reactions with reactive oxygen species became the target of recent research. In this study, the potential scavenging activity by extracts of the leaves of Clematis flammula, flower buds of Populus nigra and bark of Ulmus campestris against the radical, 1,1, diphenylpicrylhydrazil (DPPH) and hydrogen peroxide (H2O2) was assessed in vitro. Our results indicate that the scavenger activity against DPPH is dose-dependant. The best rates of scavenging activity were obtained by ethanol extracts (87.27 ± 0.14%, IC50 = 3.904) of U. campestris as well as hexane and chloroform aqueous extracts of C. flammula (79.44 ± 0.17% and 89.31 ± 0.11%, IC50 = 50.06 and 25.02, respectively). In the case of P. nigra, only the chloroform aqueous extract displayed a significant scavenging activity (65.81 ± 2.11% and IC50 = 24.61). The highest H2O2 scavenging activities are exhibited by all U. campestris extracts especially the ethanol extract with a rate of 92.16 ± 0.86%. Concerning P. nigra, again only the aqueous chloroform extract gave a moderate inhibition (47.51 ± 0.86%) while those of C. flammula showed insignificant activities. The observed antioxidant activity, notably that displayed by the extracts of U. campestris present a strong positive correlation with polyphenols(R2 = 0.90), suggesting that polyphenols are probably responsible for this activity. doi:10.1016/j.cbpa.2008.04.488
doi:10.1016/j.cbpa.2008.04.486
P2.10 The Catharanthus roseus leaf epidermome to model alkaloid biosynthesis and cellular specialization in plants V. De Luca, J. Murata, J. Roepke, D. Levac (Brock University) The Madagascar periwinkle (Catharanthus roseus) has become an important model system to study plant alkaloid metabolism, since much is known about its alkaloid chemistry, biochemistry and molecular biology. In the case of Catharanthus, it remains the only source of the monoterpenoid indole alkaloids (MIAs), vindoline and catharanthine, components of the commercially important anticancer dimers, vinblastine and vincristine. While numerous steps in the biosynthesis of MIAs have been characterized, much remains to be discovered about MIA pathways, their regulation and their compartmentation. Recently techniques to isolate particular cell types within Catharanthus leaves have shown that the leaf epidermis is the primary site of MIA, flavonoid, wax and triterpenoid biosynthesis. This specialized biochemistry of leaf epidermis is complemented with appropriate mechanisms for distributing end-products to the plant vacuole, to the inside of the leaf or to the leaf surface depending on their biological roles. The secretory nature of the leaf ‘epidermome’ of C. roseus and its complex cell biology will be discussed as a model system for cellular specialization and as a discovery tool for various biotechnological applications. doi:10.1016/j.cbpa.2008.04.487
P2.12 Marine metabolites as pharmacophores and biomedical research tools M. Jaspars (University of Aberdeen); F. Folmer (University of Aberdeen); M. Schumacher (University of Aberdeen/Laboratoire de Recherche sur le Cancer et les Maladies du Sang); J. Tabudravu (University of the South Pacific); R. Scott (University of Aberdeen); W. Houssen (University of Aberdeen); Z. Lu (University of Aberdeen); K. Feussner (University of the South Pacific); M. Diederich (Laboratoire de Recherche sur le Cancer et les Maladies du Sang) Nuclear factor kB (NF-kB) is a family of transcription factors involved in a wide variety of diseases, including cancer and inflammation, and it has hence become a major target for drug discovery. Despite the abundance of marine natural products reported to have pharmaceutical activity, very little research has been performed to date on NF-kB inhibitory activity of marine natural products. A large number of marine species were screened using a luciferase reporter gene assay out of which ca. 9% showed strong NF-kB inhibitory activity. Organisms chosen for further study were the sponge Rhabdastrella globostellata, the soft corals Sinularia sp and Lobophytum sp, and the crinoid Comanthus sp. In all cases the compounds responsible were isolated, structurally characterised and details of their mechanism of action were determined. Often potent bioactives don't make it into the clinic due to a variety of factors, but these compounds make great tools for biomedical research. I will present marine natural products from our laboratory that have been used to investigate cell signalling and membrane processes. The main
Abstracts / Comparative Biochemistry and Physiology, Part A 150 (2008) S180–S185
inform LCA studies as indicated above, and, in addition, the spatially explicit nature of the results also allows the refinement that such studies (and associated decisions) may be specifically conducted at the regional level. doi:10.1016/j.cbpa.2008.04.485
P2.9 A systematic review of life cycle assessments of bioenergy chains for heat, power and liquid transportation fuel R. Rowe (University of Southampton); J. Chapman (University of Southampton); J. Whittaker (Centre for Ecology and Hydrology, Lancaster University); D. Howard (Centre for Ecology and Hydrology, Lancaster University); G. Taylor (University of Southampton)
Life cycle assessments (LCAs) have been used broadly throughout the bioenergy sector, primarily to assess greenhouse gas emissions and energy balances of various energy production chains. However, variations in methodology and reporting of LCAs often make results incomparable. To compare LCA results, it is necessary to dismantle each individual LCA and reassemble it using set units and stating precise system boundaries. This has been done for numerous biomass-to-energy chains, including biomass for heat, power and liquid transport fuels. Summarising these reassembled LCAs into production-chain specific diagrams allows simple comparison between production chains, but more importantly highlights the process steps with the greatest impact or variation.
P2.11 Antioxidant activity of extracts of three Algerian medicinal plants: Clematis flammula, Populus nigra and Ulmus campestris D. Nadjet, B. Hania, A. Dina, C. Nassima, A. Djebbar (University of Bejaia, Algeria)
The beneficial effects of plant extracts as antioxidant agents, based on their reactions with reactive oxygen species became the target of recent research. In this study, the potential scavenging activity by extracts of the leaves of Clematis flammula, flower buds of Populus nigra and bark of Ulmus campestris against the radical, 1,1, diphenylpicrylhydrazil (DPPH) and hydrogen peroxide (H2O2) was assessed in vitro. Our results indicate that the scavenger activity against DPPH is dose-dependant. The best rates of scavenging activity were obtained by ethanol extracts (87.27 ± 0.14%, IC50 = 3.904) of U. campestris as well as hexane and chloroform aqueous extracts of C. flammula (79.44 ± 0.17% and 89.31 ± 0.11%, IC50 = 50.06 and 25.02, respectively). In the case of P. nigra, only the chloroform aqueous extract displayed a significant scavenging activity (65.81 ± 2.11% and IC50 = 24.61). The highest H2O2 scavenging activities are exhibited by all U. campestris extracts especially the ethanol extract with a rate of 92.16 ± 0.86%. Concerning P. nigra, again only the aqueous chloroform extract gave a moderate inhibition (47.51 ± 0.86%) while those of C. flammula showed insignificant activities. The observed antioxidant activity, notably that displayed by the extracts of U. campestris present a strong positive correlation with polyphenols(R2 = 0.90), suggesting that polyphenols are probably responsible for this activity. doi:10.1016/j.cbpa.2008.04.488
doi:10.1016/j.cbpa.2008.04.486
P2.10 The Catharanthus roseus leaf epidermome to model alkaloid biosynthesis and cellular specialization in plants V. De Luca, J. Murata, J. Roepke, D. Levac (Brock University) The Madagascar periwinkle (Catharanthus roseus) has become an important model system to study plant alkaloid metabolism, since much is known about its alkaloid chemistry, biochemistry and molecular biology. In the case of Catharanthus, it remains the only source of the monoterpenoid indole alkaloids (MIAs), vindoline and catharanthine, components of the commercially important anticancer dimers, vinblastine and vincristine. While numerous steps in the biosynthesis of MIAs have been characterized, much remains to be discovered about MIA pathways, their regulation and their compartmentation. Recently techniques to isolate particular cell types within Catharanthus leaves have shown that the leaf epidermis is the primary site of MIA, flavonoid, wax and triterpenoid biosynthesis. This specialized biochemistry of leaf epidermis is complemented with appropriate mechanisms for distributing end-products to the plant vacuole, to the inside of the leaf or to the leaf surface depending on their biological roles. The secretory nature of the leaf ‘epidermome’ of C. roseus and its complex cell biology will be discussed as a model system for cellular specialization and as a discovery tool for various biotechnological applications. doi:10.1016/j.cbpa.2008.04.487
P2.12 Marine metabolites as pharmacophores and biomedical research tools M. Jaspars (University of Aberdeen); F. Folmer (University of Aberdeen); M. Schumacher (University of Aberdeen/Laboratoire de Recherche sur le Cancer et les Maladies du Sang); J. Tabudravu (University of the South Pacific); R. Scott (University of Aberdeen); W. Houssen (University of Aberdeen); Z. Lu (University of Aberdeen); K. Feussner (University of the South Pacific); M. Diederich (Laboratoire de Recherche sur le Cancer et les Maladies du Sang) Nuclear factor kB (NF-kB) is a family of transcription factors involved in a wide variety of diseases, including cancer and inflammation, and it has hence become a major target for drug discovery. Despite the abundance of marine natural products reported to have pharmaceutical activity, very little research has been performed to date on NF-kB inhibitory activity of marine natural products. A large number of marine species were screened using a luciferase reporter gene assay out of which ca. 9% showed strong NF-kB inhibitory activity. Organisms chosen for further study were the sponge Rhabdastrella globostellata, the soft corals Sinularia sp and Lobophytum sp, and the crinoid Comanthus sp. In all cases the compounds responsible were isolated, structurally characterised and details of their mechanism of action were determined. Often potent bioactives don't make it into the clinic due to a variety of factors, but these compounds make great tools for biomedical research. I will present marine natural products from our laboratory that have been used to investigate cell signalling and membrane processes. The main