Vomicin aus Strychnin

Rosenmund, Peter; Schmitt, M.; Franke, H

doi:10.1002/jlac.198019800610

Cited by 9 publications

(8 citation statements)

References 20 publications

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“…N -Propylstrychnine bromide ( 4 ) was prepared by quaternization of strychnine using n -propyl bromide as previously reported . 18-Oxostrychnine ( 5 ) was synthesized from strychnine N -oxide using K 2 Cr 2 O 7 according to a modified procedure by Rosenmund and co-workers . The oxime ethers 6a – k were synthesized by O-alkylation of 1 using NaH as a base and an appropriate alkylating agent.…”

Section: Resultsmentioning

confidence: 99%

“…21 18-Oxostrychnine (5) was synthesized from strychnine N-oxide using K 2 Cr 2 O 7 according to a modified procedure by Rosenmund and co-workers. 22 The oxime ethers 6a−k were synthesized by O-alkylation of 1 using NaH as a base and an appropriate alkylating agent.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Water (4 mL) and warm (45 °C) 1 N HCl (10 mL) were added to the residue, and the insoluble brown material was filtered off and subjected to column chromatography (CH 2 Cl 2 –MeOH–25% NH 3 , 100:5:0.5) to give compound 5 (70 mg, 35.3%) as a colorless solid: mp 263 °C (lit. 263 °C); 1 H NMR (400 MHz, CDCl 3 ) δ 8.09–8.01 (1H, m, H-4), 7.82 (1H, dd, J = 7.8, 0.9 Hz, H-1), 7.23–7.15 (1H, m, H-3), 7.00 (1H, dd, J = 5.1, 2.5 Hz, H-2), 5.88 (1H, t, J = 6.2 Hz, H-22), 4.21 (1H, dt, J = 8.4, 3.6 Hz, H-12), 4.09 (1H, dd, J = 13.9, 6.9 Hz, H-23a), 3.98 (1H, dd, J = 13.9, 6.1 Hz, H-23b), 3.85 (1H, dd, H-20a), 3.77 (1H, d, J = 10.6 Hz, H-8), 3.20 (1H, d, J = 11.0 Hz, H-14), 3.18–3.13 (1H, m, H-18a), 3.08–3.00 (1H, m, H-11a), 2.85–2.72 (2H, m, H-18b, H-20b), 2.57 (1H, dd, J = 17.4, 3.6 Hz, H-11b), 2.301–2.162 (2H, m, H-15a, H-17a), 1.831–1.680 (2H, m, H-15b, H-17b), 1.31 (1H, ddd, J = 13.0, 8.2, 4.8 Hz, H-13); 13 C NMR (101 MHz, CDCl 3 ) δ 170.3 (C, CO), 169.0 (C, C-10), 142.0 (C, C-5), 138.9 (C, C-21), 131.8 (C, C-6), 128.7 (CH, C-2), 127.4 (CH, C-3), 124.3 (CH, C-22), 115.7 (CH, C-4), 92.5 (C, C-16), 77.3 (CH, C-12), 65.2 (CH 2 , C-23), 60.4 (CH, C-8), 56.6 (C, C-7), 52.8 (CH 2 , C-20), 48.7 (CH, C-13), 48.4 (CH 2 , C-18), 42.7 (CH 2 , C-11), 39.8 (CH 2 , C-17), 35.0 (CH 2 , C-15), 33.4 (CH, C-14); ESIMS m / z = 350.2 [M] + .…”

Section: Experimental Sectionmentioning

confidence: 99%

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Oxime Ethers of (E)-11-Isonitrosostrychnine as Highly Potent Glycine Receptor Antagonists

Mohsen

Mandour

Sarukhanyan³

et al. 2016

J. Nat. Prod.

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A series of (E)-11-isonitrosostrychnine oxime ethers, 2-aminostrychnine, (strychnine-2-yl)propionamide, 18-oxostrychnine, and N-propylstrychnine bromide were synthesized and evaluated pharmacologically at human α1 and α1β glycine receptors in a functional fluorescence-based and a whole-cell patch-clamp assay and in [H]strychnine binding studies. 2-Aminostrychnine and the methyl, allyl, and propargyl oxime ethers were the most potent α1 and α1β antagonists in the series, displaying IC values similar to those of strychnine at the two receptors. Docking experiments to the strychnine binding site of the crystal structure of the α3 glycine receptor indicated the same orientation of the strychnine core for all analogues. For the most potent oxime ethers, the ether substituent was accommodated in a lipophilic receptor binding pocket. The findings identify the oxime hydroxy group as a suitable attachment point for linking two strychnine pharmacophores by a polymethylene spacer and are, therefore, important for the design of bivalent ligands targeting glycine receptors.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Experimental Sectionmentioning

confidence: 99%

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Oxime Ethers of (E)-11-Isonitrosostrychnine as Highly Potent Glycine Receptor Antagonists

Mohsen

Mandour

Sarukhanyan³

et al. 2016

J. Nat. Prod.

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“…Keywords: alkaloids · Barbier reaction · cascade reaction · indole · samarium diiodide [ Representative examples of Strychnos alkaloids. [9,10] Chem. Eur.…”

Section: Introductionmentioning

confidence: 99%

Towards the Core Structure of Strychnos Alkaloids Using Samarium Diiodide‐Induced Reactions of Indole Derivatives

Beemelmanns

Gross

Reißig

2013

Chemistry A European J

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This report describes the development of a first and second generation approach towards the synthesis of the ABCEG pentacyclic core structure of Strychnos alkaloids. First, we discuss a sequential approach applying a series of functional group transformations to prepare suitable precursors for cyclization reactions. These include attempts of samarium diiodide-induced cyclizations or a Barbier-type reaction of a transient lithium organyl, which successfully led to a tetracyclic key building block earlier used for the synthesis of strychnine. Secondly, we account our first steps towards the development of an atom-economical samarium diiodide-induced cascade reaction using "dimeric" indolyl ketones as cyclization precursors. In this context, we discuss plausible mechanisms for the samarium diiodide-induced cascade reaction as well as transformations of the obtained tetracyclic dihydroindoline derivatives.

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“…Compound 1 was isolated previously in a pure form from Strychnos icaja Baill [11]. Methods for its preparation from strychnine were reported [12]. Crystallographic data and unit-cell constants of 2 were obtained by XSA and searched for in the Cambridge Crystallographic Database [13].…”

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confidence: 99%