Purpurasol, a highly oxygenated coumarin from Pterocaulon purpurascens

Debenedetti, Sílvia; Nadinic, Elena L.; Gómez, María Celeste; Coussio, J.; Kimpe, Norbert De; Boeykens, Marc

doi:10.1016/0031-9422(92)83498-n

Cited by 21 publications

(5 citation statements)

References 7 publications

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“…Frs 1-38 (1.77 g) were united and repeatedly chromatographed over Si gel using CHCl 3-EtOAc mixtures to give two frs (25 mg and 15 mg) containing a mixture of alkanols C n H 2n-1 OH (n = 18-22), and three frs (385 mg, 15 mg, and 57 mg) of oleanolic acid containing very small amounts of different impurities. Frs 55-69 (193 mg) were reunited; a portion (81 mg) on HPLC (column A, MeOH-H 2 O 1:1, 2 ml min -1 ) gave 4 mg of loliolide (R t 10.5 min), 3.5 mg of 1 (R t 12 min), 4 mg of a 3:2 mixture (R t 19 min) of purpurasolol (2a, Debenedetti et al, 1996) and purpurasol (2b, Debenedetti et al, 1992) identified by 1 H NMR spectrometry (500 MHz, CDCl 3 ); 2a δ8.00 (d, J = 9.5 Hz, H-4), 6.35 (d, J = 10 Hz, H-3), 4.64(dd, J = 11.5, 2.5 Hz, H-2a), 4.12(dd, J = 11.5, 9 Hz, H-2b), 3.96 (dd, J = 9, 2.5 Hz, H-3a), 3.88 (s, 3p, OMe), 1.442 and 1.35 (each s and 3p, H-4 and H-5); 2b, δ7.57 (d, J = 9.5 Hz, H-4), 6.49 s, H-5), 6.29 (d, J = 9.5 Hz, H-3), 4.61 (dd, J = 11.5, 2.5 Hz, H-2a), 4.10 (dd, J = 11.5, 9 Hz, H-2b), 3.97 (dd, J = 9, 2.5 Hz, H-3), 3.90 (s, 3p, OMe), 1.439 and 1.34 (each s and 3p, H-4 and H-5). Rechromatography (Si gel) afforded pure 2a.…”

Section: Extraction and Isolation Of Constituentsmentioning

confidence: 99%

Coumarins and a kaurane from Gochnatia polymorpha ssp. polymorpha from Paraguay

Catalán

Vega

Lopez

et al. 2003

Biochemical Systematics and Ecology

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Section: Extraction and Isolation Of Constituentsmentioning

confidence: 99%

Coumarins and a kaurane from Gochnatia polymorpha ssp. polymorpha from Paraguay

Catalán

Vega

Lopez

et al. 2003

Biochemical Systematics and Ecology

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“…About half of the Pterocaulon species have been analyzed previously and many compounds have been isolated: caffeoylquinic acids from P. virgatum [2]; thiophene acetylenes and flavanols from P. virgatum [3]; polyacetylenes from P. alopecuroides, P. balansae, P. lanatum, and P. rugosum [4]; hydroxy-α-caryophyllene from P. serrulatum [5]; flavonoids from P. sphacelatum [6], P. purpurascens [7], and P. alopecuroides [8]; and coumarins from P. balansae, P. lanatum [4], P. purpurascens [9][10][11], P. redolens [12], P. virgatum [13][14][15][16], P. polystachyum [17], and P. alopecuroides [8]. Several species of the genus are used in folk medicine as insecticides and agents against snake bites [15].…”

Section: And G Von Posermentioning

confidence: 99%

Distribution of coumarins in the tribe Plucheeae, genus Pterocaulon

et al. 2007

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The genus Pterocaulon (Asteraceae) is included in the tribe Plucheeae [1]. About half of the Pterocaulon species have been analyzed previously and many compounds have been isolated: caffeoylquinic acids from P. virgatum [2]; thiophene acetylenes and flavanols from P. virgatum [3]; polyacetylenes from P. alopecuroides, P. balansae, P. lanatum, and P. rugosum [4]; hydroxy-α-caryophyllene from P. serrulatum [5]; flavonoids from P. sphacelatum [6], P. purpurascens [7], and P. alopecuroides [8]; and coumarins from P. balansae, P. lanatum [4], P. purpurascens [9][10][11], P. redolens [12], P. virgatum [13][14][15][16], P. polystachyum [17], and P. alopecuroides [8]. Several species of the genus are used in folk medicine as insecticides and agents against snake bites [15].In this work we investigate the occurrence of coumarins in exudates of the species of Pterocaulon native to Brazil and isolate the most abundant compounds. The taxonomic significance of these compounds is discussed.In Plucheeae the only genus that contains coumarins is Pterocaulon in which 40 different coumarins were previously found in ten species. In this work we analyzed five other species native to South Brazil, and coumarins were found in all of them. These data indicate that these compounds could be considered chemotaxonomic markers for the genus Pterocaulon.Although the species of Pterocaulon exhibit other classes of compounds, coumarins are characteristic of the genus. In Pterocaulon, coumarins can be di-, tri-, or tetraoxygenated, and all of them are 6,7 oxygenated.Pterocaulon alopecuroides and P. polystachyum were studied previously, but in this work we investigated the exudate instead of the extract of the powdered plant. The exudate of P. alopecuroides afforded 5-methoxy-6,7-methylenedioxycoumarin (1) and 7-(2,3-epoxy-3-methyl-3-butyloxy)-6-methoxycoumarin (2), previously found in P. virgatum [13,18]. To our knowledge this is the first report on the occurrence of coumarins 1 and 2 in Pterocaulon alopecuroides. From this plant, the compounds 7-(2,3-dihydroxy-3-methylbutyloxy)-6-methoxycoumarin and 7-(2,3-dihydroxy-3-methylbutyloxy)-5-hydroxy-6-coumarin were previously obtained [8]. This difference could be due to the extraction method employed and to the fact that the plants were collected in different places. Nevertheless, it is worthwhile to state that the plant exudate contained several coumarins of which only the most abundant were isolated.The exudate of P. polystachyum, besides 5-methoxy-6,7-methylenedioxycoumarin (1), afforded three other coumarins, namely ayapin (3), prenyletin (4), and prenyletin methyl-ether (5). These compounds were previously isolated from the chloroform extract of the powdered plant material [17,19].

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“…Pterocaulon genus (Asteraceae) has been demonstrated to be a rich source of oxygenated coumarins, most of them reported by Debenedetti and co-workers [9][10][11]. This genus encompasses 26 species, the majority occuring in South America.…”

Section: Introductionmentioning

confidence: 99%