Identification de xanthones et de nouveaux arabinosides de C‐glucosides flavoniques dans Swertia perennisL.

Abstract

26. 11'. 76) Sumv~ary. -Identification of xanthoizes and new avabinosides 01flailone C-glucosides from Swertia perennis L.-Seven tetraoxygenated xanthones [l, 3,7, S-tetrahydroxy-xanthone (1) ; 1,8-dihydroxp-3,7-diiiiethoxy-xanthone (2) ; 1,7-dihydroxy-3,S-dimethoxj.-xanthone (3) ; l-hydroxy-3,7,8-trimethoxy-xanthone (4) ; 3,7, S-trihydroxy-xanl.honc-l-O-,L-glucoside ( 5 ) ; 3,7,8-trimethoxy-xanthone-I-0-primeveroside (6) ; S-hydroxy-3,7-diniethoxy-xanthone-l-0-primeveroside (7)l have been isolated chromatographically, using polyainide columns, from roots of Swertia perennis L. From leaves and steins of the same plant, six xanthoncs [l, 5,8-trihyclroxy-3-methoxyxanthone (8) ; 1,5-dihydroxy-3-methoxy-xanthonc-S-0-~-glucosicle (9) ; niangiferin (10) ; 1 ; 4; 51 and four flavone C-glycosides [iso-orientin (11) ; isovitexin (12) ; iso-oricntin-6"-arabinoside (13) ; isovitexiii-6"-arabinoside (14)] have also been isolated. Among these compounds, 7, 13 and 14 were not encountered before in nature. I n the last two compounds, the position of arabinose on the C-glucositle moiety of the flilvone was established by 13C-NMR. spectroscopy.159u ~I E L V I L T I C A

Secoiridoids and Xanthones in the Genus Centaurium

“…In '3C-NMR spectra of mono acylated glycosides the signal of the acylated C-OH of the sugar moiety get a downfield shift of a few ppm and the signal of the carbon next to this carbon an upfield shift in the same order (ortho effect) [11,12,15,16].…”

Contribution à l'Etude du Genre Gentiana

“…pedicellata est importante d'un point de vue chimiotaxinomique. C e composi n'a &ti signalk, jusqu'alors, qu'une seule fois dans le genre: chez G. nivalis[4].Gentiana pedicellata WALL. (section Chondrophylla Bd.)…”

A Xanthone Dixylopyranoside from Swertia thomsonii

“…There was no bathochromic shift induced by the addition of sodium hydroxide. This established that in 4 there is neither a hydroxy group at C-3 nor at C-6 [9,10]. The IR spectrum of the compound showed bands at 1610 cm Ð1 and 3450 cm Ð1 suggesting the presence of carbonyl and hydroxy groups in the molecule [11].…”