Topic
Catharanthine
About: Catharanthine is a research topic. Over the lifetime, 459 publications have been published within this topic receiving 12047 citations. The topic is also known as: (+)-catharanthine & methyl (2α,5β,6α,18β)-3,4-didehydro-ibogamine-18-carboxylate.
Papers published on a yearly basis
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Papers
Journal Article•
TL;DR: It is found that those cationic agents--verapamil, quinacrine, indole alkaloids, and quinolines--that were lipid soluble at physiologic pH and had similar molar refractivities were best able to enhance the cytotoxicity of the Vinca alkaloid resistance in the authors' multidrug-resistant cells.
Abstract: Multidrug resistance (MDR), typified by resistance to Vinca alkaloids and anthracyclines, is a well characterized experimental phenomenon that may have some clinical correlates. Verapamil, chloroquine, and related drugs have been shown previously to be capable of enhancing anticancer drug cytotoxicity in multi-drug-resistant cells, but the mechanism(s) by which these agents do this is(are) unclear. Since these agents did not seem to have common features, we studied these and other compounds for their ability to "modulate" Vinca alkaloid resistance in order to determine whether they possessed any common chemical or physical features. In addition to verapamil, 24 compounds, consisting of indole alkaloids, lysosomotropic agents, and amines, were tested for their ability to enhance the cytotoxicity of vinblastine and/or vincristine in our human leukemic multidrug-resistant cell line, CEM/VLB100. Seventeen compounds that enhance the cytotoxicity of the Vinca alkaloids by more than 5-fold have been identified. These include quinolines (chloroquine, quinine, chinchonidine, and primaquine), acridines (acridine, acridine orange, and quinacrine), and indole alkaloids (yohimbine, corynanthine, reserpine, physostigmine, and the vindoline and catharanthine moieties of the Vinca alkaloids), as well as other alkaloids and amines (chlorpromazine, propranolol, atropine, and tryptamine). Vindoline, catharanthine, and quinacrine also enhanced the cytotoxicity of doxorubicin and teniposide in these cells, indicating that this "modulation" was not limited to Vinca alkaloids. We examined some well known lysosomotropic compounds (methylamine, epinephrine, suramin, and trypan blue) and found that they were not able to enhance the cytotoxicity of vincristine in the CEM/VLB100 cells, indicating that lysosomotropic activity per se is not required for modulator activity. Three-dimensional computer modeling permitted molecular comparisons of conformationally related congeners of vinblastine, vindoline, and verapamil and revealed three regions of structural homology. We measured the hydrophobicity (by oil/water partitioning) and calculated the molar refractivity (by the additive substituent constant method) of active and inactive compounds. We found that those cationic agents--verapamil, quinacrine, indole alkaloids, and quinolines--that were lipid soluble at physiologic pH and had similar molar refractivities were best able to enhance the cytotoxicity of the Vinca alkaloids in our multidrug-resistant cells.(ABSTRACT TRUNCATED AT 400 WORDS)
474 citations
TL;DR: Preliminary studies of Fe(III)-NaBH(4)/air oxidation reaction illustrate a generalizable trisubstituted olefin scope, identify alternatives to O(2) trap at the oxidized carbon, provide a unique entry into C20' functionalized vinblastines, and afford initial insights into the observed C20’ diastereoselectivity.
Abstract: Full details of the development of a direct coupling of catharanthine with vindoline to provide vinblastine are described along with key mechanistic and labeling studies. Following an Fe(III)-promoted coupling reaction initiated by generation of a presumed catharanthine radical cation that undergoes a subsequent oxidative fragmentation and diastereoselective coupling with vindoline, addition of the resulting reaction mixture to an Fe(III)−NaBH4/air solution leads to oxidation of the C15′−C20′ double bond and reduction of the intermediate iminium ion directly providing vinblastine (40−43%) and leurosidine (20−23%), its naturally occurring C20′ alcohol isomer. The yield of coupled products, which exclusively possess the natural C16′ stereochemistry, approaches or exceeds 80% and the combined yield of the isomeric C20′ alcohols is >60%. Preliminary studies of Fe(III)−NaBH4/air oxidation reaction illustrate a generalizable trisubstituted olefin scope, identify alternatives to O2 trap at the oxidized carbon, p...
347 citations
TL;DR: Two missing enzymes necessary for vinblastine biosynthesis in this plant are identified: an oxidase and a reductase that isomerize stemmadenine acetate into dihydroprecondylocarpine acetates, which is then deacetoxylated and cyclized to either catharanthine or tabersonine via two hydrolases characterized herein.
Abstract: Vinblastine, a potent anticancer drug, is produced by Catharanthus roseus (Madagascar periwinkle) in small quantities, and heterologous reconstitution of vinblastine biosynthesis could provide an additional source of this drug. However, the chemistry underlying vinblastine synthesis makes identification of the biosynthetic genes challenging. Here we identify the two missing enzymes necessary for vinblastine biosynthesis in this plant: an oxidase and a reductase that isomerize stemmadenine acetate into dihydroprecondylocarpine acetate, which is then deacetoxylated and cyclized to either catharanthine or tabersonine via two hydrolases characterized herein. The pathways show how plants create chemical diversity and also enable development of heterologous platforms for generation of stemmadenine-derived bioactive compounds.
323 citations
TL;DR: Several novel MIA pathway candidate genes were identified, as demonstrated by the cloning and functional characterization of loganic acid O-methyltransferase involved in secologanin biosynthesis.
Abstract: Catharanthus roseus is the sole commercial source of the monoterpenoid indole alkaloids (MIAs), vindoline and catharanthine, components of the commercially important anticancer dimers, vinblastine and vincristine. Carborundum abrasion technique was used to extract leaf epidermis-enriched mRNA, thus sampling the epidermome, or complement, of proteins expressed in the leaf epidermis. Random sequencing of the derived cDNA library established 3655 unique ESTs, composed of 1142 clusters and 2513 singletons. Virtually all known MIA pathway genes were found in this remarkable set of ESTs, while only four known genes were found in the publicly available Catharanthus EST data set. Several novel MIA pathway candidate genes were identified, as demonstrated by the cloning and functional characterization of loganic acid O-methyltransferase involved in secologanin biosynthesis. The pathways for triterpene biosynthesis were also identified, and metabolite analysis showed that oleanane-type triterpenes were localized exclusively to the cuticular wax layer. The pathways for flavonoid and very-long-chain fatty acid biosynthesis were also located in this cell type. The results illuminate the biochemical specialization of Catharanthus leaf epidermis for the production of multiple classes of metabolites. The value and versatility of this EST data set for biochemical and biological analysis of leaf epidermal cells is also discussed.
295 citations
TL;DR: Bioinformatics and virus-induced gene silencing (VIGS)-guided gene discovery combined with biochemical enzyme assays show that tabersonine 3-oxygenase (T3O) and tabersonines 3-reductase ( T3R) are required to form 3-hydroxy-16-methoxy-2,3-dihydrotabersonine, an intermediate in the formation of anticancer drug precursor vindoline from tabersonin.
Abstract: Antitumor substances related to vinblastine and vincristine are exclusively found in the Catharanthus roseus (Madagascar periwinkle), a member of the Apocynaceae plant family, and continue to be extensively used in cancer chemotherapy. Although in high demand, these valuable compounds only accumulate in trace amounts in C. roseus leaves. Vinblastine and vincristine are condensed from the monoterpenoid indole alkaloid (MIA) precursors catharanthine and vindoline. Although catharanthine biosynthesis remains poorly characterized, the biosynthesis of vindoline from the MIA precursor tabersonine is well understood at the molecular and biochemical levels. This study uses virus-induced gene silencing (VIGS) to identify a cytochrome P450 [CYP71D1V2; tabersonine 3-oxygenase (T3O)] and an alcohol dehydrogenase [ADHL1; tabersonine 3-reductase (T3R)] as candidate genes involved in the conversion of tabersonine or 16-methoxytabersonine to 3-hydroxy-2,3-dihydrotabersonine or 3-hydroxy-16-methoxy-2,3-dihydrotabersonine, which are intermediates in the vindorosine and vindoline pathways, respectively. Biochemical assays with recombinant enzymes confirm that product formation is only possible by the coupled action of T3O and T3R, as the reaction product of T3O is an epoxide that is not used as a substrate by T3R. The T3O and T3R transcripts were identified in a C. roseus database representing genes preferentially expressed in leaf epidermis and suggest that the subsequent reaction products are transported from the leaf epidermis to specialized leaf mesophyll idioblast and laticifer cells to complete the biosynthesis of these MIAs. With these two genes, the complete seven-gene pathway was engineered in yeast to produce vindoline from tabersonine.
229 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 7 |
| 2020 | 8 |
| 2019 | 9 |
| 2018 | 22 |
| 2017 | 8 |
| 2016 | 16 |