The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Yingjin Yuan - One of the best experts on this subject based on the ideXlab platform.
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salicylic acid induced taxol production and Isopentenyl Pyrophosphate biosynthesis in suspension cultures of taxus chinensis var mairei
Cell Biology International, 2007Co-Authors: Yandong Wang, Yingjin YuanAbstract:Abstract The influences of salicylic acid (SA) on taxol production and Isopentenyl Pyrophosphate (IPP) biosynthesis pathways in suspension cultures of Taxus chinensis var. mairei were investigated by adding SA and mevastatin (MVS), a highly specific inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase in the mevalonate pathway for IPP biosynthesis, into the culture systems. The cell death and taxol production were induced upon the introduction of SA, and 20 mg/l was proved to be the optimal SA concentration in terms of the less damage to Taxus cells and marked activation of phenylalanine ammonia lyase (PAL). In the coexistence of SA (20 mg/l) and MVS (100 nmol/l), the taxol content (1.626 mg/g dry wt) was higher than that (0.252 mg/g dry wt) of the MVS-treated system but almost equal to that (1.581 mg/g dry wt) of the SA-treated system. It is thus inferred that the activated non-mevalonate pathway should be responsible for the formation of IPP in taxol biosynthesis in the presence of SA.
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translocation of Isopentenyl Pyrophosphate for taxol biosynthesis in suspension cultures of taxus chinensis var mairei
Plant Cell Tissue and Organ Culture, 2003Co-Authors: Yandong Wang, Yingjin YuanAbstract:Two inhibitors of metabolite translocators, sodium Pyrophosphate (NaPP) and D,L-glyceraldehyde (DLG), respectively, were added into suspension cultures of Taxus chinensis var. mairei at the early and late growth phases to investigate the translocation of Isopentenyl Pyrophosphate (IPP) from cytoplasm to plastids for Taxol biosynthesis. NaPP and DLG hardly affected cell biomass and viability regardless of the phases of their introduction. The Taxol content varied less when NaPP or DLG was added at day 7 but decreased obviously when NaPP or DLG was introduced at day 14. It is thus inferred that NaPP and DLG inhibited Taxol biosynthesis by blocking IPP translocation at the late growth phase, suggesting that the translocation of IPP be involved only at the late growth phase of Taxus cells.
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inhibitor studies of Isopentenyl Pyrophosphate biosynthesis in suspension cultures of the yew taxus chinensis var mairei
Biotechnology and Applied Biochemistry, 2003Co-Authors: Yandong Wang, Yingjin Yuan, Jianlan JiangAbstract:Some metabolic inhibitors, mevastatin (MVS), chlorocholine chloride (CCC), sodium Pyrophosphate (NaPP) and D,L-glyceraldehyde (DLG), were respectively added into the suspension cultures of the yew Taxus chinensis var. mairei at the late phase of cell growth to study Isopentenyl Pyrophosphate (IPP) biosynthesis. The content of total taxanes decreased in the cases of MVS, NaPP and DLG addition, regardless of the inhibitor concentration, whereas it increased in the case of CCC addition. It was thus presumed that a mevalonate pathway might exist in IPP biosynthesis at the late growth phase of Taxus cells and that some IPP might transfer from the cytoplasm to the plastids. This presumption was also confirmed by analysing the effects of the inhibitors on taxane content. It was further demonstrated that IPP in the biosynthesis of taxol, baccatin III and 10-deacetylbaccatin III might transfer from the cytoplasm to the plastids, whereas the translocation of IPP might be not involved in cephalomannine biosynthesis. Furthermore, in combination with the results of previous studies, it is very probable that different IPP biosynthesis pathways exist during different growth phases in Taxus cells.
Yandong Wang - One of the best experts on this subject based on the ideXlab platform.
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salicylic acid induced taxol production and Isopentenyl Pyrophosphate biosynthesis in suspension cultures of taxus chinensis var mairei
Cell Biology International, 2007Co-Authors: Yandong Wang, Yingjin YuanAbstract:Abstract The influences of salicylic acid (SA) on taxol production and Isopentenyl Pyrophosphate (IPP) biosynthesis pathways in suspension cultures of Taxus chinensis var. mairei were investigated by adding SA and mevastatin (MVS), a highly specific inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase in the mevalonate pathway for IPP biosynthesis, into the culture systems. The cell death and taxol production were induced upon the introduction of SA, and 20 mg/l was proved to be the optimal SA concentration in terms of the less damage to Taxus cells and marked activation of phenylalanine ammonia lyase (PAL). In the coexistence of SA (20 mg/l) and MVS (100 nmol/l), the taxol content (1.626 mg/g dry wt) was higher than that (0.252 mg/g dry wt) of the MVS-treated system but almost equal to that (1.581 mg/g dry wt) of the SA-treated system. It is thus inferred that the activated non-mevalonate pathway should be responsible for the formation of IPP in taxol biosynthesis in the presence of SA.
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translocation of Isopentenyl Pyrophosphate for taxol biosynthesis in suspension cultures of taxus chinensis var mairei
Plant Cell Tissue and Organ Culture, 2003Co-Authors: Yandong Wang, Yingjin YuanAbstract:Two inhibitors of metabolite translocators, sodium Pyrophosphate (NaPP) and D,L-glyceraldehyde (DLG), respectively, were added into suspension cultures of Taxus chinensis var. mairei at the early and late growth phases to investigate the translocation of Isopentenyl Pyrophosphate (IPP) from cytoplasm to plastids for Taxol biosynthesis. NaPP and DLG hardly affected cell biomass and viability regardless of the phases of their introduction. The Taxol content varied less when NaPP or DLG was added at day 7 but decreased obviously when NaPP or DLG was introduced at day 14. It is thus inferred that NaPP and DLG inhibited Taxol biosynthesis by blocking IPP translocation at the late growth phase, suggesting that the translocation of IPP be involved only at the late growth phase of Taxus cells.
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inhibitor studies of Isopentenyl Pyrophosphate biosynthesis in suspension cultures of the yew taxus chinensis var mairei
Biotechnology and Applied Biochemistry, 2003Co-Authors: Yandong Wang, Yingjin Yuan, Jianlan JiangAbstract:Some metabolic inhibitors, mevastatin (MVS), chlorocholine chloride (CCC), sodium Pyrophosphate (NaPP) and D,L-glyceraldehyde (DLG), were respectively added into the suspension cultures of the yew Taxus chinensis var. mairei at the late phase of cell growth to study Isopentenyl Pyrophosphate (IPP) biosynthesis. The content of total taxanes decreased in the cases of MVS, NaPP and DLG addition, regardless of the inhibitor concentration, whereas it increased in the case of CCC addition. It was thus presumed that a mevalonate pathway might exist in IPP biosynthesis at the late growth phase of Taxus cells and that some IPP might transfer from the cytoplasm to the plastids. This presumption was also confirmed by analysing the effects of the inhibitors on taxane content. It was further demonstrated that IPP in the biosynthesis of taxol, baccatin III and 10-deacetylbaccatin III might transfer from the cytoplasm to the plastids, whereas the translocation of IPP might be not involved in cephalomannine biosynthesis. Furthermore, in combination with the results of previous studies, it is very probable that different IPP biosynthesis pathways exist during different growth phases in Taxus cells.
Adelbert Bacher - One of the best experts on this subject based on the ideXlab platform.
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dimethylallyl Pyrophosphate is not the committed precursor of Isopentenyl Pyrophosphate during terpenoid biosynthesis from 1 deoxyxylulose in higher plants
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: Duilio Arigoni, Wolfgang Eisenreich, Meinhart H Zenk, Christoph Latzel, Silvia Sagner, Tanja Radykewicz, Adelbert BacherAbstract:Cell cultures of Catharanthus roseus were supplied with [2-13C,3-2H]-deoxyxylulose or [2-13C,4-2H]1-deoxyxylulose. Lutein and chlorophylls were isolated from the cell mass, and hydrolysis of the chlorophyll mixtures afforded phytol. Isotope labeling patterns of phytol and lutein were determined by 2H NMR and 1H,2H-decoupled 13C NMR. From the data it must be concluded that the deuterium atom in position 3 of deoxyxylulose was incorporated into both Isopentenyl Pyrophosphate (IPP) and dimethylallyl Pyrophosphate with a rate of 75% (with respect to the internal 13C label). The detected stereochemical signature implies that the label is located preferentially in the (E)-hydrogen atom of IPP. This preferential labeling, in turn, rules out dimethylallyl Pyrophosphate as the compulsory precursor of IPP. In the experiment with [2-13C,4-2H]1-deoxyxylulose, the 13C label was efficiently transferred to the terpenoids whereas the 2H label was completely washed out, most probably after IPP formation as a consequence of the isomerization and elongation process. In addition, the data cast light on the stereochemical course of the dehydrogenation and cyclization steps involved in the biosynthesis of lutein.
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the deoxyxylulose phosphate pathway of terpenoid biosynthesis in plants and microorganisms
Chemistry & Biology, 1998Co-Authors: Wolfgang Eisenreich, Matthias Schwarz, Alain Cartayrade, Duilio Arigoni, Meinhart H Zenk, Adelbert BacherAbstract:Recent studies have uncovered the existence of an alternative, non-mevalonate pathway for the formation of Isopentenyl Pyrophosphate and dimethylallyl Pyrophosphate, the two building blocks of terpene biosynthesis.
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terpenoid biosynthesis from 1 deoxy d xylulose in higher plants by intramolecular skeletal rearrangement
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Duilio Arigoni, Adelbert Bacher, Wolfgang Eisenreich, Christoph Latzel, Silvia Sagner, Meinhart H ZenkAbstract:The incorporation of [1-13C]- and [2,3,4,5-13C4]1-deoxy-d-xylulose into β-carotene, lutein, phytol, and sitosterol in a cell culture of Catharanthus roseus was analyzed by NMR spectroscopy. The labeling patterns of the isoprene precursors, Isopentenyl Pyrophosphate and dimethylallyl Pyrophosphate, were obtained from the terpenes by a retrobiosynthetic approach. 13C Enrichment and 13C13C coupling patterns showed conclusively that 1-deoxy-d-xylulose and not mevalonate is the predominant isoprenoid precursor of phytol, β-carotene, and lutein. Label from 1-deoxyxylulose was also diverted to phytosterols to a minor extent (6% relative to carotene and phytol formation). The data demonstrate that the formation of Isopentenyl Pyrophosphate from pentulose occurs strictly by an intramolecular rearrangement process.
M A Foster - One of the best experts on this subject based on the ideXlab platform.
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the enzymatic incorporation of Isopentenyl Pyrophosphate into polyisoprene in rubber particles from parthenium argentatum gray
Industrial Crops and Products, 2012Co-Authors: C R Benedict, C L Rosenfield, Rachel Goss, Paul J Greer, M A FosterAbstract:Abstract Studies have indicated the presence of both a de novo biosynthesis of new polyisoprene chains and the elongation of pre-existing rubber-PP chains in rubber particles from Ficus elastica Roxb. and small rubber particles from Hevea brasiliensis (Willd. ex A. Juss.) Mull. Arg. In this paper, we have isolated rubber particles from the cortical parenchyma of Parthenium argentatum Gray with an adsorbed Isopentenyl Pyrophosphate isomerase that was competent to form polyisoprene to determine the presence of de novo biosynthesis of polyisoprene and the elongation of pre-existing rubber-PP. The gel filtrated rubber particles were supplied saturating concentrations of [ 14 C]-Isopentenyl Pyrophosphate for 1 h and the resulting concentrations of [ 14 C]-polyisoprene were isolated and analyzed with a Waters 150C Gel Permeation Chromatograph. The mol wt distribution of the [ 14 C]-polyisoprene ranged from 10 3 to 10 6 Da with no formation of high mol wt chains equal to the polyisoprene in the mol wt distribution of natural rubber from P. argentatum . The mol wt distribution of [ 14 C]-polyisoprene following 1 h of incubation of the reaction mixture was similar to the mol wt distribution formed by the bound rubber transferase in washed rubber particles of H. brasiliensis and the time-dependent formation of polyisoprene by washed rubber particles from P. argentatum . The data support the conclusion that the washed rubber particles from P. argentatum contain a bound rubber transferase that initiates the formation of new chains of polyisoprene from the dimethylallyl Pyrophosphate initiator generated from the added Isopentenyl Pyrophosphate isomerase followed by the extensive polymerization of Isopentenyl Pyrophosphate to form a monomodal rubber polymer. There was no evidence in these washed rubber particles of a chain elongation of pre-existing rubber-PP.
Meinhart H Zenk - One of the best experts on this subject based on the ideXlab platform.
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dimethylallyl Pyrophosphate is not the committed precursor of Isopentenyl Pyrophosphate during terpenoid biosynthesis from 1 deoxyxylulose in higher plants
Proceedings of the National Academy of Sciences of the United States of America, 1999Co-Authors: Duilio Arigoni, Wolfgang Eisenreich, Meinhart H Zenk, Christoph Latzel, Silvia Sagner, Tanja Radykewicz, Adelbert BacherAbstract:Cell cultures of Catharanthus roseus were supplied with [2-13C,3-2H]-deoxyxylulose or [2-13C,4-2H]1-deoxyxylulose. Lutein and chlorophylls were isolated from the cell mass, and hydrolysis of the chlorophyll mixtures afforded phytol. Isotope labeling patterns of phytol and lutein were determined by 2H NMR and 1H,2H-decoupled 13C NMR. From the data it must be concluded that the deuterium atom in position 3 of deoxyxylulose was incorporated into both Isopentenyl Pyrophosphate (IPP) and dimethylallyl Pyrophosphate with a rate of 75% (with respect to the internal 13C label). The detected stereochemical signature implies that the label is located preferentially in the (E)-hydrogen atom of IPP. This preferential labeling, in turn, rules out dimethylallyl Pyrophosphate as the compulsory precursor of IPP. In the experiment with [2-13C,4-2H]1-deoxyxylulose, the 13C label was efficiently transferred to the terpenoids whereas the 2H label was completely washed out, most probably after IPP formation as a consequence of the isomerization and elongation process. In addition, the data cast light on the stereochemical course of the dehydrogenation and cyclization steps involved in the biosynthesis of lutein.
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the deoxyxylulose phosphate pathway of terpenoid biosynthesis in plants and microorganisms
Chemistry & Biology, 1998Co-Authors: Wolfgang Eisenreich, Matthias Schwarz, Alain Cartayrade, Duilio Arigoni, Meinhart H Zenk, Adelbert BacherAbstract:Recent studies have uncovered the existence of an alternative, non-mevalonate pathway for the formation of Isopentenyl Pyrophosphate and dimethylallyl Pyrophosphate, the two building blocks of terpene biosynthesis.
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terpenoid biosynthesis from 1 deoxy d xylulose in higher plants by intramolecular skeletal rearrangement
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Duilio Arigoni, Adelbert Bacher, Wolfgang Eisenreich, Christoph Latzel, Silvia Sagner, Meinhart H ZenkAbstract:The incorporation of [1-13C]- and [2,3,4,5-13C4]1-deoxy-d-xylulose into β-carotene, lutein, phytol, and sitosterol in a cell culture of Catharanthus roseus was analyzed by NMR spectroscopy. The labeling patterns of the isoprene precursors, Isopentenyl Pyrophosphate and dimethylallyl Pyrophosphate, were obtained from the terpenes by a retrobiosynthetic approach. 13C Enrichment and 13C13C coupling patterns showed conclusively that 1-deoxy-d-xylulose and not mevalonate is the predominant isoprenoid precursor of phytol, β-carotene, and lutein. Label from 1-deoxyxylulose was also diverted to phytosterols to a minor extent (6% relative to carotene and phytol formation). The data demonstrate that the formation of Isopentenyl Pyrophosphate from pentulose occurs strictly by an intramolecular rearrangement process.
