New Sesquiterpene Lactone and Other Constituents from Centaurea sulphurea (Asteraceae)

Abstract

Five known flavonoids (1-5) and three sesquiterpene lactones (6-8) are reported for the first time from the endemic species Centaurea sulphurea Willd. (Asteraceae). Compound 7 is a new heliangolide (6R, 7R, 8S, 3'R)-8α-(3',4'-dihydroxymethylene-2'-butanoyloxy)-15-oxo-helianga-1(10), 4(5), 11(13)-trien-6,12-olide, named as sulphurein.

A New Cardenolide and Other Compounds from Salsola tetragona

“…Previous phytochemical investigations of this genus reported the isolation of flavonoids and other phenolic compounds [6], alkaloids [7], fatty acids [8] and triterpene glycosides [9]. In continuation of our works on plants from Algerian Septentrional Sahara [10][11], we report here the isolation and structural characterization of one new cardenolide, 3-O-β-D-allopyranosylcoroglaucigenin, named salsotetragonin (1), in addition to eleven known compounds from aerial parts of S. tetragona (Figure S1).…”

“…Purification of the n-butanol extract through repeated silica gel columns, flash chromatography and semi-prep HPLC led to the isolation and identification of a new cardenolide (1) and seven known compounds (3, 4, 6-10). The dichloromethane extract was fractionated by silica gel chromatography to give four known compounds (2,5,(11)(12). These compounds were identified by extensive spectroscopic methods including 1D-( 1 H and 13 C) and 2D-NMR (COSY, HSQC, HMBC and NOESY) experiments, as well as HR-ESI-MS analysis and by comparison of their spectral data with the literature.…”

New Cytotoxic Guaianolides from Centaurea Aegyptiaca

“…In addition to the reported flavonoids [4][5][6][7][8][9][10], sesquiterpene lactones [11][12][13][14][15][16][17] represent the most distributed natural products in the genus Centaurea, showing a wide spectrum of biological activities such as cytotoxic, antimicrobial, antifungal and antifeedant properties [16,[18][19][20][21][22][23][24]. C. aegyptiaca has no reported folkloric use, but the closely related species, C. alexandrina, is reported to be used in folk medicine in Egypt as a hypoglycemic agent [25].…”