The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
R. Van Der Heijden - One of the best experts on this subject based on the ideXlab platform.
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Alkaloid production by a Cinchona officinalis 'Ledgeriana' hairy root culture containing constitutive expression constructs of tryptophan decarboxylase and strictosidine synthase cDNAs from Catharanthus roseus.
Plant cell reports, 1999Co-Authors: Arjan Geerlings, D. Hallard, A. Martinez Caballero, I. Lopes Cardoso, R. Van Der HeijdenAbstract:Cinchona officinalis 'Ledgeriana', former called Cinchona ledgeriana, hairy roots were initiated containing constitutive-expression constructs of cDNAs encoding the enzymes tryptophan decarboxylase (TDC) and strictosidine synthase (STR) from Catharanthus roseus, two key enzymes in terpenoid indole and Quinoline Alkaloid biosynthesis. The successful integration of these genes and the reporter gene gus-int was demonstrated using Southern blotting and the polymerase chain reaction. The products of TDC and STR, tryptamine and strictosidine, were found in high amounts, 1200 and 1950 μg g–1 dry weight, respectively. Quinine and quinidine levels were found to rise up to 500 and 1000 μg g–1 dry weight, respectively. The results show that genetic engineering with multiple genes is well possible in hairy roots of C. officinalis. However, 1 year after analyzing the hairy roots for the first time, they had completely lost their capacity to accumulate Alkaloids.
Minkyun Na - One of the best experts on this subject based on the ideXlab platform.
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antithrombotic and antiplatelet activities of small molecule Alkaloids from scolopendra subspinipes mutilans
Scientific Reports, 2016Co-Authors: Roshan Kulkarni, Jae Sam Hwang, Minkyun NaAbstract:The aim of this study was to discover small-molecule anticoagulants from Scolopendra subspinipes mutilans (SSM). A new acylated polyamine (1) and a new sulfated Quinoline Alkaloid (2) were isolated from SSM. Treatment with the new Alkaloids 1, 2, and indole acetic acid 4 prolonged the activated partial thromboplastin time and prothrombin time and inhibited the activity and production of thrombin and activated factor X. Furthermore, compounds 1, 2, and 4 inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In accordance with these potential in vitro antiplatelet activities, compounds 1, 2, and 4 showed enhanced antithrombotic effects in an in vivo pulmonary embolism and arterial thrombosis model. Compounds 1, 2, and 4 also elicited anticoagulant effects in mice. Collectively, this study may serve as the groundwork for commercializing SSM or compounds 1, 2, and 4 as functional food components for the prevention and treatment of pathogenic conditions and serve as new scaffolds for the development of anticoagulants.
Sutherland K Maciver - One of the best experts on this subject based on the ideXlab platform.
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lunacridine from lunasia amara is a dna intercalating topoisomerase ii inhibitor
Journal of Ethnopharmacology, 2007Co-Authors: Thomas A K Prescott, Ian H Sadler, Robert Kiapranis, Sutherland K MaciverAbstract:Abstract An ethnobotanical survey of plants used to treat tropical ulcers in Papua New Guinea identified Lunasia amara as possessing anti-Staphylococcus aureus activity. Activity-guided fractionation of the aqueous bark extract resulted in the identification of the Quinoline Alkaloid lunacridine as the active principle. Lunacridine tends to cyslise at room temperature but the 2′-O-trifluoroacetyl derivative was found to be stable and therefore more suitable for biological assays. The compound exhibited a minimal inhibitory concentration (MIC) of 64 μg/ml against Staphylococcus aureus NCTC 6571 and activity in the low micromolar range against HeLa and H226 cells; the latter showing signs of caspase-3/7 mediated apoptotic cell death. Experiments with drug resistant strains of Streptococcus pneumoniae suggested topoisomerase as a likely target for the drug in bacteria whilst decatenation assays with human topoisomerase II showed the compound to be a potent inhibitor of this isoform (IC50
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lunacridine from lunasia amara is a dna intercalating topoisomerase ii inhibitor
Journal of Ethnopharmacology, 2007Co-Authors: Thomas A K Prescott, Ian H Sadler, Robert Kiapranis, Sutherland K MaciverAbstract:An ethnobotanical survey of plants used to treat tropical ulcers in Papua New Guinea identified Lunasia amara as possessing anti-Staphylococcus aureus activity. Activity-guided fractionation of the aqueous bark extract resulted in the identification of the Quinoline Alkaloid lunacridine as the active principle. Lunacridine tends to cyslise at room temperature but the 2'-O-trifluoroacetyl derivative was found to be stable and therefore more suitable for biological assays. The compound exhibited a minimal inhibitory concentration (MIC) of 64 micro g/ml against Staphylococcus aureus NCTC 6571 and activity in the low micromolar range against HeLa and H226 cells; the latter showing signs of caspase-3/7 mediated apoptotic cell death. Experiments with drug resistant strains of Streptococcus pneumoniae suggested topoisomerase as a likely target for the drug in bacteria whilst decatenation assays with human topoisomerase II showed the compound to be a potent inhibitor of this isoform (IC(50)<5 micro M) thus explaining the drug's activity against human cell lines. Both lunacridine and 2'-O-trifluoroacetyl lunacridine exhibited mild DNA intercalation activity giving 50% decrease in ethidium DNA fluorescence at 0.22 and 0.6 mM, respectively, placing the drug amongst the DNA intercalating class of topoisomerase II inhibitors.
Ignacio Brouard - One of the best experts on this subject based on the ideXlab platform.
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new Quinoline Alkaloid from ruta graveolens aerial parts and evaluation of the antifertility activity
Natural Product Research, 2014Co-Authors: Josline Y Salib, Sayed A Eltoumy, Emad M Hassan, Nabila H Shafik, Sally M Abdellatif, Ignacio BrouardAbstract:Bioassay-guided isolation of methanol extract of Ruta graveolens L. leaves yielded a new Quinoline Alkaloid, (4S) 1,4-dihydro-4-methoxy-1,4-dimethyl-3-(3-methylbut-2-enyl)Quinoline 2,7-diol, and nine phenolic compounds including rutin as a major compound. Structures of the isolated compounds were determined by using chromatography, UV, HR-ESI-MS and 1D/2D (1)H/(13)C NMR spectroscopy. The uterotonic activity of methanol extract fractions (ethyl acetate, n-butanol and aqueous fraction) as well as the isolated major compounds was tested in the isolated mouse uterus in vitro. The n-butanol-soluble fraction was found to demonstrate the most potent uterotonic activity in a dose-dependent manner, also the major isolated compound rutin revealed the occurrence of an uterotonic response, which was maximum at a concentration level of 0.25 mg/mL, accounting for 68.7% of that exhibited by the chosen concentration of oxytocin.
Arjan Geerlings - One of the best experts on this subject based on the ideXlab platform.
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Alkaloid production by a Cinchona officinalis 'Ledgeriana' hairy root culture containing constitutive expression constructs of tryptophan decarboxylase and strictosidine synthase cDNAs from Catharanthus roseus.
Plant cell reports, 1999Co-Authors: Arjan Geerlings, D. Hallard, A. Martinez Caballero, I. Lopes Cardoso, R. Van Der HeijdenAbstract:Cinchona officinalis 'Ledgeriana', former called Cinchona ledgeriana, hairy roots were initiated containing constitutive-expression constructs of cDNAs encoding the enzymes tryptophan decarboxylase (TDC) and strictosidine synthase (STR) from Catharanthus roseus, two key enzymes in terpenoid indole and Quinoline Alkaloid biosynthesis. The successful integration of these genes and the reporter gene gus-int was demonstrated using Southern blotting and the polymerase chain reaction. The products of TDC and STR, tryptamine and strictosidine, were found in high amounts, 1200 and 1950 μg g–1 dry weight, respectively. Quinine and quinidine levels were found to rise up to 500 and 1000 μg g–1 dry weight, respectively. The results show that genetic engineering with multiple genes is well possible in hairy roots of C. officinalis. However, 1 year after analyzing the hairy roots for the first time, they had completely lost their capacity to accumulate Alkaloids.
