The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
Nehir Unver - One of the best experts on this subject based on the ideXlab platform.
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New skeletons and new concepts in Amaryllidaceae alkaloids
Phytochemistry Reviews, 2007Co-Authors: Nehir UnverAbstract:The Amaryllidaceae alkaloids, represent a group of isoquinoline alkaloids, which are produced almost solely by members of the Amaryllidaceae family. The alkaloids of this family have attracted considerable amount of interest due to some important pharmacological activities they were shown to possess. In the last decade, our phytochemical studies on four Galanthus (Amaryllidaceae) species of Turkish origin have yielded quite a number of new alkaloids with diverse structures. Among these alkaloids, gracilines and plicamines constitute two new subgroups for the Amaryllidaceae alkaloids. The gracilines contain an incorporated 10b,4a-ethanoiminodibenzo[ b , d ]pyrane skeleton. The plicamines are dinitrogenous compounds, where the oxygen atom in position 7 of a tazettine skeleton is replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety. One of the new alkaloids, galanthindole, which possesses a nonfused indole ring, unlike the already known subgroups of Amaryllidaceae alkaloids, may be considered as the prototype of a third new subgroup of the Amaryllidaceae alkaloids. Additionally, two known isoquinoline alkaloids which do not possess one of the established skeletons of the Amaryllidaceae alkaloids, namely ( − )-capnoidine and (+)-Bulbocapnine, have been isolated from a Turkish Galanthus species. Totally, 21 new, 20 known alkaloids and 2 known lignans have been characterized. In this review, the isolation and structure elucidation of these compounds with interesting chemical structures are described.
M. Pirali-hamedani A. Shafiee - One of the best experts on this subject based on the ideXlab platform.
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ANGOLINE AND OTHER ALKALOIDS FROM THE ROOTS OF GLAUCIUM OXYLOBUM BOISS. AND BUHSE
DARU, 1999Co-Authors: A. Hadjiakhoondi, K. Morteza-semnani, H.r. Inanloo, M. Pirali-hamedani A. ShafieeAbstract:Glaucium oxylobum Boiss & Buhse population Golestan forest was shown to contain four major alkaloids, protopine (0.2%), Bulbocapnine (0.1%), corydine (0.3%), isocorydine (0.1%) and three minor alkaloids, dihydrochelerythrine, angoline and isocorytuberine. Glaucium oxylubum Boiss & Buhse population Roodbar was shown to contain two major alkaloids, protopine (0.39%) and dicentrinone (0.2%) and three minor alkaloids, angoline, 8-acetonyl-dihydrosanguinarine and a-allocryptopine. Angoline was detected for the first time in Glaucium.
Mk Lee - One of the best experts on this subject based on the ideXlab platform.
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Inhibitory effects of Bulbocapnine on dopamine biosynthesis in PC12 cells
'Society for Leukocyte Biology', 2019Co-Authors: Js Shin, Kt Kim, Mk LeeAbstract:The effects of Bulbocapnine, an aporphine isoquinoline alkaloid, on dopamine biosynthesis in PC12 cells were investigated. Bulbocapnine showed 45.2% inhibition on dopamine content in PC12 cells at a concentration of 20 mu M for 12 h. The IC50 value of Bulbocapnine was 26.7 mu M. Bulbocapnine at concentrations up to 80 mu M was not cytotoxic towards PC12 cells. Tyrosine hydroxylase (TH) activity was inhibited by the treatment of Bulbocapnine ir PC12 cells (24.4% inhibition at 20 mu M). Bulbocapnine at 20 mu M also decreased the intracellular Ca2+ concentration by 12.9% inhibition relative to control in PC12 cells. However, TH mRNA level was not altered by Bulbocapnine treatment. These results suggest that the inhibition of TH activity by Bulbocapnine might be involved in at least one component of the reduction of dopamine biosynthesis in PC12 cells. (C) 1998 Elsevier Science Ireland Ltd.X12
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Inhibitory effects of Bulbocapnine on dopamine biosynthesis in PC12 cells
'Elsevier BV', 2019Co-Authors: Js Shin, Kt Kim, Mk LeeAbstract:The effects of Bulbocapnine, an aporphine isoquinoline alkaloid, on dopamine biosynthesis in PC12 cells were investigated. Bulbocapnine showed 45.2% inhibition on dopamine content in PC12 cells at a concentration of 20 mu M for 12 h. The IC50 value of Bulbocapnine was 26.7 mu M. Bulbocapnine at concentrations up to 80 mu M was not cytotoxic towards PC12 cells. Tyrosine hydroxylase (TH) activity was inhibited by the treatment of Bulbocapnine ir PC12 cells (24.4% inhibition at 20 mu M). Bulbocapnine at 20 mu M also decreased the intracellular Ca2+ concentration by 12.9% inhibition relative to control in PC12 cells. However, TH mRNA level was not altered by Bulbocapnine treatment. These results suggest that the inhibition of TH activity by Bulbocapnine might be involved in at least one component of the reduction of dopamine biosynthesis in PC12 cells. (C) 1998 Elsevier Science Ireland Ltd.X1124sciescopu
Quetin-leclercq Joëlle - One of the best experts on this subject based on the ideXlab platform.
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Alkaloids from Cassytha filiformis and related aporphines: antitrypanosomal activity, cytotoxicity, and interaction with DNA and topoisomerases
GeorgThieme Verlag, 2004Co-Authors: Hoet Sara, Stévigny Caroline, Block Sébastien, Opperdoes Frederik, Colson Pierre, Baldeyrou Brigitte, Lansiaux Amélie, Bailly Christian, Quetin-leclercq JoëlleAbstract:Cassytha filiformis (Lauraceae), a widely distributed parasitic plant, contains several aporphine alkaloids and is often used in African folk medicine to treat cancer, African trypanosomiasis and other diseases. In a previous investigation, we showed that the alkaloid plant extract and the isolated aporphines possessed in vitro cytotoxic properties. In this paper, we evaluated the in vitro activity of the alkaloid extract (IC50 = 2.2 microg/mL) and its three major aporphine alkaloids (actinodaphnine, cassythine, and dicentrine) on Trypanosoma brucei brucei as well as four related commercially available aporphines (Bulbocapnine, glaucine, isocorydine, boldine). Only the three alkaloids from Cassytha filiformis were active on the trypanosomes in vitro (IC50 = 3-15 microM). Additionally, we compared the cytotoxicity of these seven compounds on HeLa cells. Glaucine was the most cytotoxic compound on HeLa cells (IC50 = 8.2 microM) in the series. In order to elucidate their mechanism of action, the binding mode of these molecules to DNA was studied by UV absorption, circular and linear dichroism spectroscopy. The results of the optical measurements indicated that all seven aporphines effectively bind to DNA and behave as typical intercalating agents. Biochemical experiments showed that actinodaphnine, cassythine and dicentrine also interfere with the catalytic activity of topoisomerases in contrast to the four other aporphines. These interactions with DNA may explain, at least in part, the effects observed on cancer cells and on trypanosomes
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Alkaloids from Cassytha filiformis and related aporphines :antitrypanosomal activity, cytotoxicity and interaction with DNA and topoisomerases
'Georg Thieme Verlag KG', 2004Co-Authors: Hoet Sara, Stévigny Caroline, Block Sébastien, Opperdoes Frederik, Colson Pierre, Baldeyrou Brigitte, Lansiaux Amélie, Bailly Christian, Quetin-leclercq JoëlleAbstract:Cassytha filiformis (Lauraceae), a widely distributed parasitic plant, contains several aporphine alkaloids and is often used in African folk medicine to treat cancer, African trypanosomiasis and other diseases. In a previous investigation, we showed that the alkaloid plant extract and the isolated aporphines possessed in vitro cytotoxic properties. In this paper, we evaluated the in vitro activity of the alkaloid extract (IC50 = 2.2 μg/mL) and its three major aporphine alkaloids (actinodaphnine, cassythine, and dicentrine) on Trypanosoma brucei brucei as well as four related commercially available aporphines (Bulbocapnine, glaucine, isocorydine, boldine). Only the three alkaloids from Cassytha filiformis were active on the trypanosomes in vitro (IC50 = 3 - 15 μM). Additionally, we compared the cytotoxicity of these seven compounds on HeLa cells. Glaucine was the most cytotoxic compound on HeLa cells (IC50 = 8.2 μM) in the series. In order to elucidate their mechanism of action, the binding mode of these molecules to DNA was studied by UV absorption, circular and linear dichroism spectroscopy. The results of the optical measurements indicated that all seven aporphines effectively bind to DNA and behave as typical intercalating agents. Biochemical experiments showed that actinodaphnine, cassythine and dicentrine also interfere with the catalytic activity of topoisomerases in contrast to the four other aporphines. These interactions with DNA may explain, at least in part, the effects observed on cancer cells and on trypanosomes.info:eu-repo/semantics/publishe
Robert M. Snapka - One of the best experts on this subject based on the ideXlab platform.
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Topoisomerase II inhibition by aporphine alkaloids.
Biochemical pharmacology, 1999Co-Authors: Sung Ho Woo, Nan-jun Sun, John M. Cassady, Robert M. SnapkaAbstract:Abstract The aporphine alkaloids (+)-dicentrine and (+)-Bulbocapnine are non-planar molecules lacking features normally associated with DNA binding by intercalation or minor groove binding. Surprisingly, dicentrine showed significant activity as a topoisomerase II (EC 5.99.1.3) inhibitor and also was active in a DNA unwinding assay. The DNA unwinding suggests DNA intercalation, which could explain the inhibition of topoisomerase II. Bulbocapnine, which differs from dicentrine only by the presence of a hydroxyl group at position 11 and the absence of a methoxyl group at position 9, was inactive in all assays. Molecular modeling showed that dicentrine can attain a relatively planar conformation, whereas Bulbocapnine cannot, due to steric interaction between the 11-hydroxyl group and an oxygen of the methylenedioxy ring. These observations suggest that dicentrine is an “adaptive” DNA intercalator, which can bind DNA only by adopting a somewhat strained planar conformation. The requirement of a suboptimal conformation to achieve DNA binding appears to make dicentrine a weaker topoisomerase II inhibitor than the very planar oxoaporphine alkaloid liriodenine. These results suggest that it may be possible to modulate DNA binding and biologic activity of drugs by modifications affecting their ability to adopt planar conformations.
