- A combined pathway for the synthesis of nitidine family alkaloids
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Three related alkaloids, oxynitidine, nitidine and 5,6-dihydronitidine, have been afforded by the new synthetic protocols. In this approach, the Ni-catalyzed annulation reaction is indicated as the key step to construct the isoquinolinone core structure. The subsequent transformations lead to the target alkaloids.
- Pallikonda, Gangaram,Hsieh, Chang-Yu,Su, Haw-Lih,Hsieh, Jen-Chieh
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- Compounds from Toddalia asiatica: Immunosuppressant Activity and Absolute Configurations
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In a screening of an extract library from plants used in Traditional Chinese Medicine the MeOH extract of Toddalia asiatica inhibited proliferation of human primary T cells with an IC50 of 25.8 μg/mL. Activity in the extract was tracked by HPLC activity profiling, and a total of 15 compounds were characterized. Three compounds, toddalic acid (6) and both enantiomers (7a and 7b) of toddanolic acid (7), were new natural products, and two recently published compounds, (2′R)-toddalolactone 3′-O-β-d-glucopyranoside (10) and (2′S)-toddalolactone 2′-O-β-d-glucopyranoside (11), were described in detail for the first time. The absolute configurations of compounds 8, 9, 10, 12, 13, and 15 were determined by comparison of experimental and calculated ECD spectra. For glucosides 9 and 10, ECD data and chiral-phase HPLC of the aglycones after enzymatic hydrolysis confirmed the results. Nitidine chloride (4) inhibited proliferation of primary human T cells with an IC50 of 0.4 μM.
- Reinhardt, Jakob K.,Zimmermann-Klemd, Amy M.,Danton, Ombeline,Smie?ko, Martin,Gründemann, Carsten,Hamburger, Matthias
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- Preparation method of nitidine chloride
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The invention discloses a preparation method of nitidine chloride. The method comprises the following steps of 1) catalyzing 4,5-dimethoxy-2-(methoxycarbonyl) phenylboronic acid to react with azobenzene bornene to obtain an intermediate 1 by using a metal palladium/ligand; 2) dissolving the intermediate 1 with an organic solvent, then adding trifluoroacetic acid, and conducting a room temperaturereaction to obtain an intermediate 2; 3) methylating the intermediate 2, oxidizing, reducing, and treating with hydrochloric acid to obtain the nitidine chloride. The synthetic route of the method issimpler, and the total synthesis yield of the nitidine chloride is as high as 72% or more.
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- A chlorinated nitidine synthesis method
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The invention discloses a synthetic method of nitidine chloride. The synthetic method comprises the following steps: 1) dissolving 3,4-dimethoxybenzoic acid in a first organic solvent, adding thionyl chloride to react, evaporating out the solvent from reactants to obtain an intermediate 1; 2) dissolving the intermediate 1 by use of the first organic solvent, adding 3,4-methylenedioxy naphthylamine, and performing nucleophilic substitution reaction to obtain an intermediate 2; 3) dissolving the intermediate 2 in the first organic solvent, adding boron trifluoride diethyl etherate and di(trifluoroacetoxyl) iodobenzene to react, removing the solvent from the reactants, performing column chromatography on obtained residues on silica gel to obtain an intermediate 3; 4) dissolving the intermediate 3 in a second organic solvent, and performing lithium aluminum hydride reduction, dehydration and dimethyl sulfate methylation under an atmosphere protection condition, and then treating with sodium chloride to obtain the target product nitidine chloride. The synthetic method disclosed by the invention is relatively simple in synthesis route and relatively high in yield of the target product and the yield is higher than 27%.
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- Palladium-catalyzed tandem reaction to construct benzo[c]phenanthridine: Application to the total synthesis of benzo[c]phenanthridine alkaloids
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A concise and efficient synthesis of benzo[c]phenanthridines was accomplished by the palladium-catalyzed ring-opening coupling of azabicyclic alkene with o-iodobenzoates, followed by tandem cyclization. The strategy was successfully applied in the total synthesis of benzo[c]phenanthridine alkaloids such as sanguinarine, chelerythrine, nitidine and avicine.
- Lv, Pei,Huang, Kanglun,Xie, Longguan,Xu, Xiaohua
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p. 3133 - 3135
(2011/05/15)
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- Triphosgene: A versatile reagent for Bischler-Napieralski reaction
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Triphosgene causes direct formation of quaternary benzo[c]phenanthridines such as anti-tumor active nitidine (2a) chloride by Bischler-Napieralski reaction of 2-phenyl-1-(N-methylformamido)naphthalenes under heating in acetonitrile.
- Saito, Tatsuru,Yoshida, Makoto,Ishikawa, Tsutomu
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p. 437 - 438
(2007/10/03)
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- Synthesis and cytotoxic activities of a new benzo[c]phenanthridine alkaloid, 7-hydroxynitidine, and some 9-oxygenated benzo[c]phenanthridine derivatives.
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[formula: see text] A new benzo[c]phenanthridine alkaloid, 7-hydroxynitidine, was synthesized by a novel synthetic procedure. The cytotoxic activity of this compound against HeLa S3 cells was strong, but not greater than those of its mother compounds, nitidine and NK109. We also synthesized other 9-oxygenated benzo[c]phenanthridine alkaloids, 7-methoxynitidine, 9-demethylnitidine, nitidine, and fagaronine, and tested their cytotoxic activities. These results suggest that the 7-hydroxy group enhances antitumor activity and an 8- or 9-hydroxy group weakens this activity.
- Nakanishi,Suzuki
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p. 985 - 988
(2008/02/09)
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- A versatile synthesis of fully aromatic benzo[c]phenanthridine alkaloids
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A versatile new approach for the synthesis of benzo[c]phenanthridine alkaloids is described and is illustrated by the preparation of eight different alkaloids. The key steps are Smiles rearrangements, which allow easy access to 2-bromo-1-naphthylamines from 2-bromo-1-naphthols, and the attachment of the D-ring unit by Suzuki coupling.
- Geen, Graham R.,Mann, Inderjit S.,Mullane, M. Valerie,McKillop, Alexander
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p. 9875 - 9894
(2007/10/03)
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- A versatile synthesis of benzo[c]phenanthridine alkaloids
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Suzuki coupling between 2-bromo-1-formamidonaphthalenes and arylboronic acids is the key step in a versatile synthesis of benzo[c]phenanthridine alkaloids, illustrated by the synthesis of norallonitidine, nornitidine, noravicine, allonitidine, nitidine and avicine.
- Geen, Graham R.,Mann, Inderjit S.,Mullane, M. Valerie,McKillop, Alexander
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p. 1647 - 1648
(2007/10/03)
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- TRANSFORMATION OF PROTOBERBERINES INTO BENZOPHENANTHRIDINES A NOVEL AND EFFICIENT SYNTHESIS OF ANTITUMOR BENZOPHENANTHRIDINE ALKALOIDS, FAGARONINE AND NITIDINE
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Antileukemic benzophenanthridine alkaloids, fagaronine (1a) and nitidine (1c) were synthesized from the corresponding protoberberines through C6-N bond fission and subsequent cyclization between C6 and C13 position of the protoberberines.
- Hanaoka, Miyoji,Yamagishi, Hiroshi,Marutani, Mari,Mukai, Chisato
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p. 5169 - 5172
(2007/10/02)
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