Coumarins IV

Nielsen, B.; Soine, Taito O.

doi:10.1002/jps.2600560206

Cited by 16 publications

(4 citation statements)

References 6 publications

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“…Short alkaline hydrolysis of 4 with ethanolic KOH afforded 4a showing again a 'H-NMR spectrum in agreement with that of the enantiomeric compound obtained from isopteryxin (7). The acidic fraction contained only acetic acid, thus confirming the relative positions of both angeloyl and acetyl groups and the identity of the two coumarins isolated from different sources.…”

Section: Resultssupporting

confidence: 68%

“…The structure of the dextrorotatory compound 4 was substantiated by its 1H-NMR, which was in full agreement with that formerly described for levorotatory isopteryxin [3'angeloyl-4'-acetyl-(3'R, 4'R)-cis-khellactonej4 isolated from Pteryxia terebinthina var. californica (7); the opposite sign of the optical rotation suggested an opposite stereochemistry for 4. In fact, a compound identical to 4 was later isolated together with its racemic mixture by Chen et al (8) from the Chinese drug Bai-Hua Quian-Hu and named respectively (+)-praeruptorin A and (±)-praeruptorin A.…”

Section: Resultsmentioning

confidence: 99%

“…Operating in alcoholic KOH, a Michael-type addition of the alkoxide anion produces the 4'-ether derivative; very mild and short reaction conditions well justify the rather exclusive formation of the more stable trans compound through attack of the nucleophile from the opposite side with respect to the pre-existing 3'-ester group. After prolonged and more drastic conditions, during which also saponification of the 3'-ester group takes place and the 3'-OH group is formed, the equilibrium mixture of both diastereoisomers is generally observed (8,7,11). This is probably due both to the less steric hindrance of the OH and to the formation of hydrogen bonds between the 3'-OH and the alkoxide anion.…”

Section: Resultsmentioning

confidence: 99%

“…No references could be found describing the chemical constituents of this plant; only a few papers reported the study of different species: Adenophora triphylla, Adenophora De Candolle var, japonica (2) and Kurilensis kitamura (3). We have investigated the chemical constituents of Adenophora axilliflora roots and isolated cycloartenol acetate (1), lupenone (2), 3-sitosterol (3), 3-Dglucopyranosyl-(1 -3)-3-sitosterol (7), compound 6 which is the 6-O-palmitoyl derivative of 7; (+)-praeruptorin A (4) and 3'-angeloyl-4'-isovaleryl-(3'S, 4'S)-cis-khellactone (5).…”

Section: Introductionmentioning

confidence: 99%

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Constituents of Shashen (Adenophora axilliflora)

Du¹,

Gariboldi²,

Jommi³

1986

Planta Med

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From the ethyl acetate extract of the Chinese drug "Shashen", the root of Adenophora axilliflora Borb., three triterpenoids, cycloartenol acetate ( 1), lupenone ( 2) and beta-sitosterol ( 3), two triterpenoid derivatives, beta- D-glucopyranosyl-(1-->3)-beta-sitosterol ( 7) and its 6- O-palmitoyl ester ( 6), along with two coumarins, (+)-praeruptorin A ( 4) and 3'-angeloyl-4'-isovaleryl-(3' S, 4' S) CIS-khellactone ( 5) have been isolated. A detailed (1)H-NMR analysis of compounds 6, 7 and their acetates is reported. The structure of the partial hydrolysis product of 5 is revised on the basis of spectroscopic evidences and mechanistic considerations.

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Section: Resultssupporting

confidence: 68%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Constituents of Shashen (Adenophora axilliflora)

Du¹,

Gariboldi²,

Jommi³

1986

Planta Med

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Über die absolute Konfiguration der Visnagane

Bernotat-Wulf

Niggli

Ulrich

et al. 1969

Helvetica Chimica Acta

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18. I V . 69).S~rwmary. ( + )-cis-Khellactone methyl ether (4) and ( -)-traizs-klicllactonc methyl ethcr (6) had earlier been assigncd the absolute configurations 3'-S; 4'-S and 3'-S; 4'-H, respectively, on thc basis of the FREUDENBERG rule. Both compounds together with thcir defunctionalised derivatives (-1.7 and ( + ) -8 ( = (+)-lomatin), obtained from a mixture of (+)-visnadin (1) and (+)-san~idin( 2 ) , were investigated by the HOREAU method. A conformational analytical study showed that the optical yield should rise in the order 4 < 6 < 7, 8. This order was found and the cc-phenylhutyric acid libcrated was always dextrorotatory. The centre 3' of the khellactones and their derivatives must be R-chiral and not S. Treatment of ( -)-6 with pyridinium pcrbromide gave ( -)-trans-3bromokhellactone methyl ether (11) as orthorhombic crystals. The X-ray crystal structure dctermination was made using the anomalous scattering of thc Mo-Kcc radiation by Br. The result,ccntre 3' R-chiral (fig. g) -showed that the HOREAU mcthod was corrcct. Die natiirlich vorkommenden Visnagane stellen Diester des 3', 4'-Dihydroxy-3', 4'dihydro-seselins = Khellacton dar. Als Sauren sind Essigsaure, Isovaleriansaure, cc-Methylbuttersaure, Seneciosaure und Angelicasaure angetroffen worden. Auf Grund cheinischer und NMR.-spektroskopischer Evidenz folgt, dass alle bisher isoIierten Visnagane, mit einer Ausnahme, Derivate des (+)-cis-Khellactons (3) l) darstellen. ES sind dies: (-1-)-Dihydrosamidin [l], (+)-Visnadin (1) [l] [ 2 ] , Suksdorfin [ 3 ] , Pteryxin 131 141, 3'-Acety1-4'-senecioyl-cis-khellacton 14 a], (-t)-Samidin (2) 111 (21, Isopteryxin [4 b], Anomalin [4 b] [4 c] [S], Calipteryxin [4 b] und 3', 4'-Di-senecioyl-cis-khellacton [4 a]. Die Ausnahme reprasentiert das Peuformosin = 3'-Angeloyl-4'-senecioyl-ciskhellacton [4b] [5 a], das sich vom (-)-cis-Khellacton ableitet und den Antipoden des Calipteryxins darsteilt.

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