- Total Synthesis of Tetrahydroisoquinoline-Based Bioactive Natural Products Laudanosine, Romneine, Glaucine, Dicentrine, and Their Unnatural Analogues Isolaudanosine and Isoromneine
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Starting from suitably substituted homophthalic acids, total synthesis of titled alkaloids have been demonstrated in very good yields. The obtained natural products laudanosine and romneine were utilized to accomplish synthesis of two isoquinoline-based alkaloids glaucine and dicentrine. Base-induced selective generation of two different types of benzylic carbanions, their coupling reactions with 3,4-dimethoxybenzyl mesylate, and the regioselective iodination followed by intramolecular aryl-aryl coupling reactions to form the fused biaryl systems were the strategic steps.
- Jangir, Ravi,Argade, Narshinha P.
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p. 1655 - 1663
(2017/03/21)
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- Structural optimization of berberine as a synergist to restore antifungal activity of fluconazole against drug-resistant Candida albicans
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We have conducted systematic structural modification, deconstruction, and reconstruction of the berberine core with the aim of lowering its cytotoxicity, investigating its pharmacophore, and ultimately, seeking novel synergistic agents to restore the effectiveness of fluconazole against fluconazole-resistant Candida albicans. A structure-activity relationship study of 95 analogues led us to identify the novel scaffold of N-(2-(benzo[d][1,3]dioxol-5-yl)ethyl)-2- (substituted phenyl)acetamides 7 a-l, which exhibited remarkable levels of in vitro synergistic antifungal activity. Compound 7 d (N-(2-(benzo[d][1,3]dioxol- 5-yl)ethyl)-2-(2-fluorophenyl)acetamide) significantly decreased the MIC 80 values of fluconazole from 128.0 μg mL-1 to 0.5 μg mL-1 against fluconazole-resistant C. albicans and exhibited much lower levels of cytotoxicity than berberine toward human umbilical vein endothelial cells. Build it better: Structural optimization of berberine led to the identification of the novel scaffold of N-(2-(benzo[d][1,3]dioxol-5-yl) ethyl)-2-(substituted phenyl)acetamides 7 a-l, which exhibited remarkable in vitro synergistic antifungal activity against fluconazole-resistant Candida albicans in combination with fluconazole. Compound 7 d exhibited much lower cytotoxicity than berberine toward human umbilical vein endothelial cells. Copyright
- Liu, Hong,Wang, Liang,Li, Yan,Liu, Jiang,An, Maomao,Zhu, Shaolong,Cao, Yongbing,Jiang, Zhihui,Zhao, Mingzhu,Cai, Zhan,Dai, Li,Ni, Tingjunhong,Liu, Wei,Chen, Simin,Wei, Changqing,Zang, Chengxu,Tian, Shujuan,Yang, Jingyu,Wu, Chunfu,Zhang, Dazhi,Liu, Hua,Jiang, Yuanying
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p. 207 - 216
(2014/01/17)
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- Design, synthesis, and biological evaluation of Erythrina alkaloid analogues as neuronal nicotinic acetylcholine receptor antagonists
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The synthesis of a new series of Erythrina alkaloid analogues and their pharmacological characterization at various nicotine acetylcholine receptor (nAChR) subtypes are described. The compounds were designed to be simplified analogues of aromatic erythrinanes with the aim of obtaining subtype-selective antagonists for the nAChRs and thereby probe the potential of using these natural products as scaffolds for further ligand optimization. The most selective and potent nAChR ligand to come from the series, 6,7-dimethoxy-2- methyl-1,2,3,4-tetrahydroisoquinoline (3c) (also a natural product by the name of O-methylcorypalline), displayed submicromolar binding affinity toward the α4β2 nAChR with more than 300-fold selectivity over α4β4, α3β4, and α7. Furthermore, this lead structure (which also has inhibitory activity at monoamine oxidases A and B and at the serotonin and norepinephrine transporters) showed antidepressant-like effect in the mouse forced swim test at 30 mg/kg.
- Crestey, Fran?ois,Jensen, Anders A.,Borch, Morten,Andreasen, Jesper Tobias,Andersen, Jacob,Balle, Thomas,Kristensen, Jesper Langgaard
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supporting information
p. 9673 - 9682
(2014/01/06)
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- Pd-catalyzed ortho-arylation of 3,4-dihydroisoquinolones via C-H bond activation: synthesis of 8-aryl-1,2,3,4-tetrahydroisoquinolines
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An efficient route to synthesize biologically interesting 8-aryl-1,2,3,4-tetrahydroisoquinoline has been developed. It involves the Pd-catalyzed direct arylation of 3,4-dihydroisoquinolones via C-H bond activation with aryl iodides to afford a variety of 8-arylated cross-coupling products, which are subsequently reduced to 8-aryl-1,2,3,4-tetrahydroisoquinolines in good to excellent yields.
- Kim, Junwon,Jo, Mina,So, Wonyoung,No, Zaesung
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scheme or table
p. 1229 - 1235
(2009/05/27)
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- A FACILE ROUTE TO TETRAHYDROISOQUINOLINE ALKALOIDS VIA SULFOXIDE MEDIATED CYCLIZATION
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A facile route to 1,2,3,4-tetrahydroisoquinoline framework has been developed by employing the sulfoxide mediated cyclization reaction.Utilizing the reaction developed some naturally occurring isoquinoline alkaloids have been synthesized.
- Takano, Seiichi,Iida, Hirokazu,Inomata, Kohei,Ogasawara, Kunio
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- Alkaloids of Cryptocarya phyllostemon
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The known alkaloids (-)-antofine (1), dehydroantofine (5), (-)-cryptowoline (6), (-)-cryptowolidine (7), and (-)-cryptowolinol (8), were isolated from the New Caledonian lauraceous plant Cryptocarya phyllostemon, together with five new bases : two secophenanthroindolizidines, (-)-phyllostemine (2) and (-)-phyllosteminine (3), one pyrrolidinylacetophenone, (-)-phyllostone (4), and two quaternary tetrahydrobenzylisoquinolines, (+)-phyllocryptine (9) and (+)-phyllocryptonine (10).Chemical and spectroscopic methods were used for identification and structural investigation.A synthesis of phyllocryptonine has permitted its stereostructure to be determined.
- Cave, Andre,Leboeuf, Michel,Moskowitz, Henri,Ranaivo, Anissa,Bick, I. Ralph C.,et al.
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p. 2243 - 2263
(2007/10/02)
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- Isoquinoline-N-Boranes as Precursors to Substituted Tetrahydroisoquinolines
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A new approach to the syntheses of 1,2-disubstituted 1,2,3,4-tetrahydroisoquinolines from isoquinoline-N-boranes is described.The method is a "one-pot" operation in which substituents are introduced consecutively as electrophiles and nucleophiles with accompanying reduction of the heterocyclic ring.This procedure differs from the classical ones in that both requisite rings are present in the starting material and thus avoids the inefficient cyclizations of phenethylamine derivatives when unactivated substrates would be required.The synthetic utility of this process is demonstrated with several examples including the alkaloids carnegine and hydrohydrastinine.
- Brooks, Donald J.,Dowell, David S.,Minter, David E.,Villarreal, Mark C.
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p. 130 - 133
(2007/10/02)
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- A CONVENIENT SYNTHESIS OF SIMPLE TETRAHYDROISOQUINOLINES
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Various simple tetrahydroisoquinoline alcaloids (Ia,b,c, IIa and IIIa,b,c) have been synthesized by the reaction of appropriate arylethylamines with paraformaldehyde or formaldehyde in formic acid.
- Ruchirawat, S.,Chaisupakitsin, M.,Patranuwatana, N.,Cashaw, J. L.,Davis, V. E.
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p. 1221 - 1228
(2007/10/02)
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