Flavonoids from Algerian Endemic Centaurea microcarpa and their Chemotaxonomical Significance

Abstract

Six flavonoids, namely 6-methoxykaempferol (1), 6-methoxykaempferol 7-O-glucoside (2), kaempferol 7-O-glucoside (3), 6methoxyluteolin (4), patuletin 7-O-glucoside (5), and hispidulin 7-O-glucoside (6), were isolated from a n-butanolic fraction of Centaurea microcarpa Coss et Dur. flowers. This work describes for the first time the phytochemical composition of this endemic Algerian plant.

Guaianolide Sesquiterpene Lactones from Centaurothamnus maximus

“…Apigenin and luteolin, as well as their glycosides, were the most common flavones in the Centaurea species. The glycosylation of flavones was commonly found at position 7 as 6-methoxykaempferol 7- O -glucoside, kaempferol 7- O -glucoside, along with hispidulin-7- O -glucoside from C. macrocarpa [ 59 ], apigenin 4′-(6′-methylglucuronide) from C. nicaeensis [ 60 ], and apigetrin from C. resupinate [ 61 ]. The flavonol glycosides derivatives were rare; only patuletin-7- O -glucoside was isolated from C. macrocarpa [ 59 ] and nicotiflorin as a flavonol-3- O -glucoside from C. resupinate [ 61 ].…”

“…The methoxylated flavone derivatives were commonly detected in genus Centaurea as 6-mono-methoxyflavones, which are represented as 6-methoxykaempferol and 6-methoxyluteoin from C. macrocarpa [ 59 ], 5,7-dihydroxy-6-methoxyflavone (oroxylin A), and 5,7,4′-trihydroxy-6-methoxyflavone (hispidulin) from C. ragusina [ 62 ]. Other rare methoxylated flavone derivatives include 3′-mono-methoxyflavones, such as chrysoeriol from C. resupinate [ 61 ] and 6,5′-dimethoxyflavones such as jaceosidin from C. nicaeensis [ 60 ].…”

In vitro cytotoxicity of sesquiterpene lactones isolated from Centaurea pullata L. native to Algeria

“…It is well known that sesquiterpene lactones constitute the more distributed natural products in the genus Centaurea L. which display a wide spectrum of biological activity such as antimicrobial, antifeedant, cytotoxic and antifungal (Louaar et al, 2011). We report here on the cytotoxic potential of sesquiterpene lactones possessing an α-methyl γ-lactone moiety isolated from C. pullata L. (Djeddi et al, 2007;Djeddi et al, 2008) using the sulforhodamine B (SRB) assay.…”

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].…”