Über die Alkaloide von Mesembryanthemum tortuosum L.

Bodendorf, K.; Krieger, Werner

doi:10.1002/ardp.19572901002

Cited by 38 publications

(31 citation statements)

References 3 publications

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“…Upon completion (monitored by TLC), the mixture was quenched with 10 mL NH 4 Cl (aq. 1 5, 148.1, 147.0, 144.0, 133.4, 131.4, 129.9, 127.7, 121.0, 108.5, 107.1, 101.2, 58.1, 55.3, 47.4, 45.2, 43.7, 36.4, 22.7, 21.6 Synthesis of ketal compound 13:E thylene glycol (11 mL, 0.10 mmol), pTSA (3.3 mg, 0.02 mmol) and CH(OMe) 3 (11 mL, 0.20 mmol) were added to as olution of compound 12 (40 mg, 0.10 mmol) in dry benzene (5 mL) at room temperature. The combined organic layers were washed with brine, dried over anhydrous Na 2 SO 4 .T he residue was concentrated in vacuo and purified by flash chromatography on silica (eluent: petroleum ether/ethyl acetate 1:1) to affordt he alcohol 9 (72 mg, 8, 144.2, 132.1, 129.8, 129.3, 127.7, 127.0, 124.9, 118.8, 108.4, 105.5, 101.1, 65.0, 60.4, 42.2, 32.7, 29.8, 21.7, 21.6 Synthesis of compound 10:N aBH 3 CN (77 mg, 1.22 mmol) and trifluoroacetic acid (2 mL, 27 mmol) were added to asolution of compound 9 (420 mg, 1.01 mmol) in dry CH 2 Cl 2 (30 mL) at room temperature.…”

Section: Methodsmentioning

confidence: 99%

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Rhodium‐Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine‐Type Amaryllidaceae Alkaloids

Yang

Hou

Cheng

et al. 2017

Chemistry A European J

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Rhodium-catalyzed denitrogenative [3+2] cycloaddition of 1-sulfonyl-1,2,3-triazoles with cyclic silyl dienol ethers has been developed for the synthesis of functionalized hydroindolones or their corresponding silyl ethers. The present method has been employed to construct synthetically valuable bicyclo[3.3.1]alkenone derivatives and pyrrolidine-ring-containing bicyclic indole compounds. As a further synthetic application, a stereoselective synthesis of 5,11-methanomorphanthridin-3-one, which shares a key skeleton with montanine-type Amaryllidaceae alkaloids has been achieved by using this chemistry.

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Section: Methodsmentioning

confidence: 99%

“…), diluted with ethyl acetate (10 mL), extracted with ethyl acetate (2 10 mL). 1 7,143.5,134.9,132.4,129.8,127.3,121.2,108.3,108.2,107.0,101.0,64.4,64.2,59.4,54.4,44.5,43.1,39.0,29.2,21.5,20.1 ppm. The reaction mixture was stirred for 1h.U pon completion (monitored by TLC), the mixture was quenched with 50 mL NaHCO 3 (aq.)…”

Section: Methodsmentioning

confidence: 99%

Rhodium‐Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine‐Type Amaryllidaceae Alkaloids

Yang

Hou

Cheng

et al. 2017

Chemistry A European J

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“…This plant, also known as “kanna”, is a member of the Aizoaceae family and has been used by South African natives as a hallucinogen. Mesembrine is an alkaloid incorporating a pyrrolidine substructure which was elucidated in 1957 by Bodendorf and Krieger . Like related aspidospermine or spirooxindole alkaloids it incorporates an all‐carbon quaternary stereocenter .…”

Section: Introductionmentioning

confidence: 99%

Total Synthesis of Mesembrine – The Construction of Quaternary Stereocenters by Gold‐Catalyzed Diyne Desymmetrization

Czekelius

2018

Israel Journal of Chemistry

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This review gives an overview on synthetic methodology developed for the synthesis of the naturally occurring alkaloid mesembrine. Its all‐carbon‐substituted quaternary stereocenter has fuelled creativity in the application of ex‐chiral‐pool‐synthesis, chiral auxiliaries, and asymmetric catalysis alike. The gold‐catalyzed desymmetrization of 1,4‐diynes has been demonstrated as a selective method for the enantioselective preparation of methylene pyrrolidines incorporating a quaternary stereocenter. The applicability of this method has therefore been demonstrated in the context of a mesembrine total synthesis.

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“…mesembrenone, mesembrenol, mesembrenone, mesembrine, were isolated from several Sceletium plant species whereas Sceletium A 4 was isolated from Sceletium crassicaule (13). Mesembranol and epimesembranol were synthesized by reduction of mesembrine using hydrogen (14) and sodium borohydride respectively (15). The compounds were qualified by respective spectral evaluation -1 H, 13 C and 2D NMR and mass spectroscopy as well as X-ray crystallography for the crystalline compounds, mesembrine hydrochloride and mesembranol, the others being semi-solid/liquids (16).…”

Section: Introductionmentioning

confidence: 99%

Medicinal use of Sceletium: Characterization of Phytochemical Components of Sceletium Plant Species using HPLC with UV and Electrospray Ionization – Tandem Mass Spectroscopy

Patnala

Kanfer

2015

J Pharm Pharm Sci

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-Purpose. Sceletium plants have been used for its medicinal properties for centuries. However, there is a wide range of Sceletium plant species in which various alkaloidal components such as ∆ 7 mesembrenone, mesembrenol, mesembranol, mesembrenone, mesembrine hydrochloride, epimesembranol and, sceletium A 4 differ between species. Hence, to ensure the quality of Sceletium products used as a medicine, it is imperative to identify the appropriate species using both botanical and chemical methods. The chemical approach to identify and characterize the phytochemical composition of a particular species facilitates the choice of species that will provide the purported therapeutic outcome. Hence, specific analytical methods to identify relevant constituents from complex matrices are necessary. Although HPLC-UV detection is commonly used to identify and estimate phytochemical content of medicinal plants, use of mass spectroscopy (MS) and tandem mass spectroscopy (MS/MS) can unequivocally confirm their presence/absence based on characteristic ions and fragmentation patterns. Methods. The various alkaloidal components were characterized by electrospray ionization (ESI) MS and MS/MS using an ionizing medium of 0.1% ammonium hydroxide in water mixed with acetonitrile. Compounds were purified and characterized for use as reference standards to identify the relevant alkaloidal constituents of several Sceletium plant species using HPLC with on-line UV-MS detection. Results. ESI-MS provided the [M+H]+ ions with respective m/z values that related to the respective molecular weights 287, 289, 291, 287, 289, 324 and 291 for the above mentioned alkaloids, whereas, ESI MS/MS provided the characteristic fragment ions to confirm the structural identity of the individual alkaloids and subsequently used to confirm the presence and/or absence of specific alkaloids in various Sceletium plant samples. Conclusions. Whilst HPLC-UV detection has been a widely-used conventional analytical technique for both qualitative and quantitative analyses, the results highlight the necessity of ESI-MS detection to avoid erroneous identification of phytochemical components, particularly with mesembrine-type compounds which have closely related chemical structures.

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Über die Alkaloide von Mesembryanthemum tortuosum L.

Cited by 38 publications

References 3 publications

Rhodium‐Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine‐Type Amaryllidaceae Alkaloids

Rhodium‐Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine‐Type Amaryllidaceae Alkaloids

Total Synthesis of Mesembrine – The Construction of Quaternary Stereocenters by Gold‐Catalyzed Diyne Desymmetrization

Medicinal use of Sceletium: Characterization of Phytochemical Components of Sceletium Plant Species using HPLC with UV and Electrospray Ionization – Tandem Mass Spectroscopy

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