The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Michael L. Shuler - One of the best experts on this subject based on the ideXlab platform.
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Taxol production in suspension cultures of Taxus baccata
Plant Cell Tissue and Organ Culture, 1996Co-Authors: Thomas J. Hirasuna, Luis J. Pestchanker, Venkatesh Srinivasan, Michael L. ShulerAbstract:The response of Taxus baccata (PC2) to basic manipulations of culture conditions is described. Suspension cultures of Taxus baccata (PC2) were maintained at 25°C on a modified B5 medium with two-week transfers. Under these conditions, no taxol^® is formed. However, if the cells are left in the same medium for 7 or more additional days, taxol is produced and released (ca. 90%) into the extracellular medium. Levels as high as 13 mg 1^−1 extracellular taxol were achieved in shake flask cultures and taxol was the primary taxane formed representing between 50 and 80% of total taxane in the medium. The cells are sensitive to changes in culture conditions and cultures cycle through periods of high (13 mg 1^−1) and low (
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taxol production in suspension cultures of Taxus baccata
Plant Cell Tissue and Organ Culture, 1996Co-Authors: Thomas J. Hirasuna, Luis J. Pestchanker, Venkatesh Srinivasan, Michael L. ShulerAbstract:The response of Taxus baccata (PC2) to basic manipulations of culture conditions is described. Suspension cultures of Taxus baccata (PC2) were maintained at 25°C on a modified B5 medium with two-week transfers. Under these conditions, no taxol® is formed. However, if the cells are left in the same medium for 7 or more additional days, taxol is produced and released (ca. 90%) into the extracellular medium. Levels as high as 13 mg 1−1 extracellular taxol were achieved in shake flask cultures and taxol was the primary taxane formed representing between 50 and 80% of total taxane in the medium. The cells are sensitive to changes in culture conditions and cultures cycle through periods of high (13 mg 1−1) and low (<0.1 mg 1−1) levels of taxol production during extended culture. Picloram was the most effective of the auxins tested with respect to cell growth but it suppressed taxol production. Addition of fructose to moderately-productive cultures (ca. 4 mg 1−1) improved taxol production, but cultures in a high producing state did not respond. Glucose suppressed taxane production. Two isoprenoids (geraniol and pinene) had a modest effect on taxol production when added to cultures at 10 mg 1−1.
Bilge Sener - One of the best experts on this subject based on the ideXlab platform.
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Biological activities of lignans from Taxus baccata L. growing in Turkey
Journal of Medicinal Plants Research, 2010Co-Authors: Nurgün Küçükboyacı, Bilge SenerAbstract:Phytochemical investigation of Taxus baccata L. (Taxaceae) by successive chromatographic methods resulted in the isolation of the lignans; lariciresinol (1), taxiresinol (2), 3'-demethylisolariciresinol-9'-hydroxyisopropylether (3), isolariciresinol (4) and 3-demethylisolariciresinol (5) as well as taxoids. Compounds 1 - 5 were evaluated for their several biological activities such as anti-inflammatory, antinociceptive, anti-ulcerogenic, antimicrobial, cytotoxic, and antioxidant as well as acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and lipoxygenase (LOX) inhibitory activities. In this review, the diverse biological activity profiles of lignan derivative compounds (1 - 5) obtained from T. baccata growing in Turkey will be discussed. Key words: Taxus baccata, taxaceae, lignans, anti-inflammatory, antinociceptive, anti-ulcerogenic, antimicrobial, cytotoxicity, enzyme inhibitory,antioxidant.
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Bioactivity of Lignans from Taxus baccata.
Zeitschrift fur Naturforschung. C Journal of biosciences, 2004Co-Authors: Nurgun Erdemoglu, Bilge Sener, M. Iqbal ChoudharyAbstract:Three lignan derivatives, (-)-taxiresinol (1), (-)-3'-demethylisolariciresinol-9'-hydroxyisopropylether (2) and (-)-3-demethylisolariciresinol (3), previously isolated from the heart-wood of Taxus baccata L. (Taxaceae) were investigated for cytotoxicity against the Oncology Cell Line Panel (breast, colon, ovary, prostate, lung and a normal adult bovine aortic endothelial cell line) as well as for antimicrobial activities. Besides, a chloroform-soluble portion of the ethanol extract from the heartwood of T. baccata was also tested for antimicrobial activities. Compounds 1 - 3 did not demonstrate much cytotoxic potency according to the reference drug etoposide. With the exception of compound 2, the other two lignans (1 and 3) and the chloroform extract were shown to possess antifungal activity, whereas only the chloroform extract exhibited antibacterial activity against Pseudomonas aeruginosa.
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Anti-ulcerogenic lignans from Taxus baccata L.
Zeitschrift fur Naturforschung. C Journal of biosciences, 2004Co-Authors: Ilhan Gurbuz, Erdem Yesilada, Nurgun Erdemoglu, Bilge Sener, Nurgun Erdemoglu, Bilge SenerAbstract:Four lignan type compounds, lariciresinol, taxiresinol, isolariciresinol and 3-demethyl-iso-lariciresinol, were isolated from the heartwood of Taxus baccata L. (Taxaceae) growing in Turkey through chromatographic techniques. In vivo anti-ulcerogenic potency of these compounds was investigated on ethanol-induced ulcerogenesis model in rats at two different doses, 50 and 100 mg/kg. All compounds were shown to possess significant anti-ulcerogenic activity at both doses. However, the effect of taxiresinol was the most prominent.
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Pharmacological Activity of Taxus baccata
Pharmaceutical Biology, 2004Co-Authors: Nurgun Erdemoglu, Bilge Sener, Che-ming TengAbstract:Crude extracts prepared from the heartwood of Taxus baccata L. were evaluated for their antiplatelet and vasorelaxing effect. The ethanol extract of the heartwood of T. baccata (1) and their fractions, CHCl3 (2) and CHCl3 nonsoluble extract (3) were preincubated with platelets, and then thrombin, arachidonic acid (AA), collagen or plateletactivating factor (PAF) was added for testing antiplatelet activity. In other set of experiments, all extracts were tested on high potassium or norepinephrine (NE) depolarized isolated rat thoracic aorta for investigating the vasorelaxing effect. All tested extracts showed a significant inhibitory effect on platelet aggregation induced by AA, collagen and PAF at a concentration of 400 mg/ml, but not thrombin. However, not all extracts relaxed NE-induced vasocontraction, extracts 1 and 2 showed a weak inhibitor effect on high potassium depolarized smooth muscle. To the best of our knowledge, this is the first report on antiplatelet activity and vasorelaxing effect of the heartwood of T. baccata.
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Antimycobacterial Activity of Taxus baccata
Pharmaceutical Biology, 2003Co-Authors: Nurgun Erdemoglu, Bilge Sener, Prasit PalittapongarnpimAbstract:Crude extracts prepared from various parts of Taxus baccata L. have been evaluated for their antimycobacterial activity. A CHCl3 fraction of the heartwood and ethanol extract of the leaves exhibited a minimum inhibitory concentration value (MIC) against Mycobacterium tuberculosis H37Ra strain of 200 µg/ml.
Thomas J. Hirasuna - One of the best experts on this subject based on the ideXlab platform.
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Taxol production in suspension cultures of Taxus baccata
Plant Cell Tissue and Organ Culture, 1996Co-Authors: Thomas J. Hirasuna, Luis J. Pestchanker, Venkatesh Srinivasan, Michael L. ShulerAbstract:The response of Taxus baccata (PC2) to basic manipulations of culture conditions is described. Suspension cultures of Taxus baccata (PC2) were maintained at 25°C on a modified B5 medium with two-week transfers. Under these conditions, no taxol^® is formed. However, if the cells are left in the same medium for 7 or more additional days, taxol is produced and released (ca. 90%) into the extracellular medium. Levels as high as 13 mg 1^−1 extracellular taxol were achieved in shake flask cultures and taxol was the primary taxane formed representing between 50 and 80% of total taxane in the medium. The cells are sensitive to changes in culture conditions and cultures cycle through periods of high (13 mg 1^−1) and low (
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taxol production in suspension cultures of Taxus baccata
Plant Cell Tissue and Organ Culture, 1996Co-Authors: Thomas J. Hirasuna, Luis J. Pestchanker, Venkatesh Srinivasan, Michael L. ShulerAbstract:The response of Taxus baccata (PC2) to basic manipulations of culture conditions is described. Suspension cultures of Taxus baccata (PC2) were maintained at 25°C on a modified B5 medium with two-week transfers. Under these conditions, no taxol® is formed. However, if the cells are left in the same medium for 7 or more additional days, taxol is produced and released (ca. 90%) into the extracellular medium. Levels as high as 13 mg 1−1 extracellular taxol were achieved in shake flask cultures and taxol was the primary taxane formed representing between 50 and 80% of total taxane in the medium. The cells are sensitive to changes in culture conditions and cultures cycle through periods of high (13 mg 1−1) and low (<0.1 mg 1−1) levels of taxol production during extended culture. Picloram was the most effective of the auxins tested with respect to cell growth but it suppressed taxol production. Addition of fructose to moderately-productive cultures (ca. 4 mg 1−1) improved taxol production, but cultures in a high producing state did not respond. Glucose suppressed taxane production. Two isoprenoids (geraniol and pinene) had a modest effect on taxol production when added to cultures at 10 mg 1−1.
Stevan Miletic - One of the best experts on this subject based on the ideXlab platform.
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Fatal poisoning by ingestion of Taxus baccata leaves.
Forensic science international, 2018Co-Authors: Vladimir Pilija, Maja Djurendic-brenesel, Stevan MileticAbstract:In this report we describe a first suicide case in Serbia related to ingestion of Taxus baccata leaves. A 30-year old woman was found dead, and the green plant material in a plastic bag was found near her bed. Autopsy revealed dark green needle-like leaves in the stomach, similar to that contained in the plastic bag, and both were botanically identified as Taxus baccata, also known as yew. Using gas chromatography-mass spectrometry (GC-MS), 3,5-dimethoxyphenol (3,5-DMP) as toxicological evidence for the ingestion of yew leaves, was detected in biological samples. As the autopsy showed unspecific findings, and also the routine toxicological examination, based upon 3,5-DMP identification, the cause of death was determined to be suicide, caused by yew poisoning.
Robert Verpoorte - One of the best experts on this subject based on the ideXlab platform.
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geranylgeranyl diphosphate synthase activity and taxane production in Taxus baccata cells
Phytochemistry, 1999Co-Authors: Gregory Laskaris, Mondher El Jaziri, Camiel F De Jong, Robert Van Der Heijden, Georgios Theodoridis, Robert VerpoorteAbstract:Abstract A Taxus baccata cell line has been characterized for growth, nutrient uptake, taxane production and for GGPP synthase activity. The enzyme is extracted by inclusion of non-ionic detergent and its activity parallels taxane production for the first three days. The enzyme activity reaches its peak at day 3 of culture growth, while total taxane formation rises until day 9, when the maximum taxane accumulation in the cells is observed (∼0.004% dry wt). After this day the taxane excretion in the medium increases, reaching its maximum at day 19.
