Showing results 121 to 133 of 133
   Didéhydro-16,17 isostrychnobiline, nouvel alcaloÏde bisindolinique asymétrique du Strychnos variabilisTits, Monique  ; Angenot, Luc ; in Journal de Pharmacie de Belgique (1983), 38(5), 241-245 We describe a new asymmetrical bisindole alkaloid, 16,17-didehydroisostrychnobiline, that was isolated by reverse phase liquid chromatography from the root barks of Strychnos variabilis. Its structure was ... [more ▼] We describe a new asymmetrical bisindole alkaloid, 16,17-didehydroisostrychnobiline, that was isolated by reverse phase liquid chromatography from the root barks of Strychnos variabilis. Its structure was elucidated from spectral analysis and by acid hydrolysis. Its stereochemistry was established by 300 MHz 1H NMR spectroscopy [less ▲] Detailed reference viewed: 9 (0 ULg)RMN C13 des alcaloïdes des Strychnos : les dérivés de l'usambarine, de la sarpagine et de la mavacurine; Tits, Monique ; Angenot, Luc in Journal de Pharmacie de Belgique (1982), 37(3), 189-194 13C NMR spectra of seven tertiary and quaternary indole alkaloids are recorded and the signals assigned. The data permit classification and identification of these alkaloids. Moreover the similarity of ... [more ▼] 13C NMR spectra of seven tertiary and quaternary indole alkaloids are recorded and the signals assigned. The data permit classification and identification of these alkaloids. Moreover the similarity of nigritanin and 18,19-dihydrousambarine have been confirmed by this study [less ▲] Detailed reference viewed: 38 (4 ULg)Les alcaloides quaternaires majoritaires du Strychnos variabilis du ZaireTits, Monique ; Franz, Michel ; et alin Planta Medica (1981), 42(8), 371-4 Two quaternary alkaloids have been isolated from the root barks of STRYCHNOS VARIABILIS collected in Zaire. The structure of these alkaloids (mavacurine and fluorocurine) could be deduced from spectral ... [more ▼] Two quaternary alkaloids have been isolated from the root barks of STRYCHNOS VARIABILIS collected in Zaire. The structure of these alkaloids (mavacurine and fluorocurine) could be deduced from spectral data: UV, MS, IR and (1)H NMR. Moreover, the stereochemistry could be assigned by (1)H NMR at 360 MHz. [less ▲] Detailed reference viewed: 36 (0 ULg)Isolement d'un Nouvel Alcaloide (O-Acetylretuline) et d'un Triterpenoide (Friedeline) à partir du Strychnos henningsii du ZaireAngenot, Luc ; Tits, Monique in Planta Medica (1981), 41(3), 240-3 A new alkaloid (O-acetylretuline) has been isolated from barks and leaves of two samples of STRYCHNOS HENNINGSII collected in Zaire. A triterpenoid (friedelin) is also present in this African species of ... [more ▼] A new alkaloid (O-acetylretuline) has been isolated from barks and leaves of two samples of STRYCHNOS HENNINGSII collected in Zaire. A triterpenoid (friedelin) is also present in this African species of Strychnos. [less ▲] Detailed reference viewed: 15 (0 ULg)Se soigner par les plantesAngenot, Luc ; ; et alBook published by Association des Consommateurs (1981) Le livre comprend des conseils pour la récolte des plantes médicinales, la description et les usages de 95 plantes dont de très nombreuses présentes en Belgique , la liste des maladies avec indication des ... [more ▼] Le livre comprend des conseils pour la récolte des plantes médicinales, la description et les usages de 95 plantes dont de très nombreuses présentes en Belgique , la liste des maladies avec indication des plantes à consulter et un des lexiques des termes scientifiques [less ▲] Detailed reference viewed: 38 (3 ULg)Alcaloïdes indoliniques du Strychnos variabilisTits, Monique ; ; Angenot, Luc in Phytochemistry (1980), 19(7), 1531-1534 Three new indolinic alkaloids have been isolated from the root bark of Strychnos variabilis: strychnopivotine, unusual because the C17 atom of the curane skeleton is lacking, 16-hydroxyisoretulinal and ... [more ▼] Three new indolinic alkaloids have been isolated from the root bark of Strychnos variabilis: strychnopivotine, unusual because the C17 atom of the curane skeleton is lacking, 16-hydroxyisoretulinal and rosibiline, a derivative of N-desacetylretuline. Their structures were deduced from spectral data and that of rosibiline was confirmed chemically. [less ▲] Detailed reference viewed: 25 (1 ULg)New indole aldehydic alkaloids of Strychnos variabilisTits, Monique ; Angenot, Luc ; in Tetrahedron Letters (1980), 21 Two isomeric pairs of novel indoline aldehydic alkaloids have been isolated from the root barks of Strychnos variabillis. The isomerism finds its origin in the facile isomerisation of C16 and is set up ... [more ▼] Two isomeric pairs of novel indoline aldehydic alkaloids have been isolated from the root barks of Strychnos variabillis. The isomerism finds its origin in the facile isomerisation of C16 and is set up rapidly at room temperature. So, they could be the biogenetic starting point of two series of alkaloids which have a different stereochemistry for C16: the "retuline" series and the epimer "isoretuline" series. [less ▲] Detailed reference viewed: 7 (0 ULg)Alcaloïdes des feuilles du Strychnos variabilisTits, Monique ; Angenot, Luc in Plantes médicinales et phytothérapie (1980), 14(4), 213-217 The two major alkaloids of the leaves of Strychnos variabilis are : acetylisoretuline which is found for the first time from a natural source and isoretuline previously discovered in the root of the same ... [more ▼] The two major alkaloids of the leaves of Strychnos variabilis are : acetylisoretuline which is found for the first time from a natural source and isoretuline previously discovered in the root of the same Strychnos. Moreover the minor alkaloid, retuline, has been isolated. The spectral data (UV,IR,MS,NMR) are recorded for the new compound. [less ▲] Detailed reference viewed: 11 (1 ULg)The 1H NMR spectra of the Strychnos alkaloids Retuline and Isoretuline, and their N-deacetyl compounds; ; Tits, Monique et alin Bulletin de la Société Chimique de Belgique (1978), 87(8), 595-607 The 300 MHz 1H NMR spectra of the title compounds are discussed. The vicinal coupling constants 3J H2,H16 and 3J H16,H15 are about 10Hz and 4 Hz in the iso series, and about 7 Hz and 1 Hz for retuline ... [more ▼] The 300 MHz 1H NMR spectra of the title compounds are discussed. The vicinal coupling constants 3J H2,H16 and 3J H16,H15 are about 10Hz and 4 Hz in the iso series, and about 7 Hz and 1 Hz for retuline series. In isoretuline, the piperidine ring ( ring D) has a chair conformation, but in retuline a boat conformation, with C21 in the tip position, prevails. This conclusion is based on the pattern of allylic and homoallylic couplings around the double bond, and rests also on comparison with the spectrum of strychnine. Evidence is presented for a hydrogen bond between the C17 hydroxymethyl and the N1-COCH3 group in isoretuline. [less ▲] Detailed reference viewed: 27 (1 ULg)Nouveaux alcaloïdes des feuilles de Strychnos usambarensisAngenot, Luc ; ; Tits, Monique in Journal de Pharmacie de Belgique (1978), 33(1), 11-23 Fourteen bis-indole alkaloids have been isolated from Strychnos usambarensis leaves. Nine are described here for the frst time: 18,19-dihydro-usambarine; usambaridines and their dihydroderivatives ... [more ▼] Fourteen bis-indole alkaloids have been isolated from Strychnos usambarensis leaves. Nine are described here for the frst time: 18,19-dihydro-usambarine; usambaridines and their dihydroderivatives; strychnobaridine; strychnopentamine and isomers. The elucidation of structure and the stereochemistry of these new compounds are also discussed. They possess the "usambarane" skeleton; moreover many are phenolic and amongst them, strychnopentamine and isomers are curiuos alkaloids with five nitrogen atoms: a methylpyrrolidine group is joined to the indole ring of the corynane part of the molecule. [less ▲] Detailed reference viewed: 16 (0 ULg)Les alcaloïdes des fruits et des feuilles du Strychnos usambarensisAngenot, Luc ; ; Tits, Monique in Journal de Pharmacie de Belgique (1978), 33(5), 284-286 Fruits of Strychnos usambarensis may be cause of poisoning in Africa. The main alkaloid of an extract with CHCl3 at pH 5 has been isolated and identified as descarbomethoxydihydrogambirtannine; that ... [more ▼] Fruits of Strychnos usambarensis may be cause of poisoning in Africa. The main alkaloid of an extract with CHCl3 at pH 5 has been isolated and identified as descarbomethoxydihydrogambirtannine; that alkaloid is found for the first time in the family of Loganiaceae.The structure of usambaridine Vi, alkaloid previously isolated from leaves, is now elucidated by analysis of NMR and UV spectra. Its structure corresponds to 10-hydroxy-usambarine. [less ▲] Detailed reference viewed: 36 (3 ULg)Nouveaux alcaloïdes bis-indoliques dans l'écorce des racines du Streychnos variabilisTits, Monique ; Angenot, Luc in Planta Medica (1978), 34 New bis-indole alkaloids (strychnobiline and isostrychnobiline) were extracted from roots of Strychnos variabilis. The plane structures of these alkaloids have been elucidated. Nordihydrotoxiferine is ... [more ▼] New bis-indole alkaloids (strychnobiline and isostrychnobiline) were extracted from roots of Strychnos variabilis. The plane structures of these alkaloids have been elucidated. Nordihydrotoxiferine is also present in this African species of Strychnos. [less ▲] Detailed reference viewed: 10 (2 ULg)Alkaloids from Strychnos usambarensis: revised structure for usambarineAngenot, Luc ; ; Tits, Monique et alin Phytochemistry (1978), 17(9), 1687-1689 Detailed reference viewed: 11 (5 ULg) |
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