Comparative Assessment of the Phytochemical Composition and Biological Activity of Extracts of Flowering Plants of Centaurea cyanus L., Centaurea jacea L. and Centaurea scabiosa L.

Abstract

The data on the phytochemical composition and biological activity for flowering plant extracts of the genus Centaurea (Knapweed)—cornflower (Centaurea cyanus L.), brown knapweed (Centaurea jacea L.), and greater knapweed (Centaurea scabiosa L.), which are typical representatives of the flora in the middle belt of the Russian Federation, were obtained. For the first time, biologically active substances such as pyranone, coumaran (2,3-dihydrobenzofuran), and 5-hydroxymethylfurfural were identified in ethanol and methanol extracts of Centaurea scabiosa L. by gas chromatography–mass spectrometry. Catechol and α-amyrin were the major components of the ethanol extract from Centaurea cyanus L., and flavone was the major component of Centaurea jacea L. flower extract. The greatest antimicrobial activity against phytopathogens was detected in Centaurea scabiosa L. when extracting freshly harvested flower biomass with methyl tert-butyl ether at room temperature: the minimum inhibitory concentrations were 60–120 µg/mL, the minimum fungicidal concentration was 120 µg/mL, and the minimum bactericidal concentration was 250 µg/mL. The low antioxidant activity of the studied plant extracts was established using the maximum values of Centaurea jacea L. Ethanol extract of Centaurea cyanus L. flowers had low antimicrobial and antioxidant activity. The extracts showed no phytotoxicity to garden cress germination but inhibited the growth of juvenile plants, especially roots. The greatest phytotoxic effect was revealed with methyl tert-butyl ether, where the depression of growth indicators was 35% or more.

Antioxidant Potential of Flower Extracts from Centaurea spp. Depends on Their Content of Phenolics, Flavonoids and Free Amino Acids

“…In most studies, herbal raw materials of Centaurea species comprised shoots with leaves collected during flowering [16][17][18]. The properties of extracts obtained from Centaurea flowers alone are less well known [19]. The raw material most widely used in herbal medicine, cosmetology and food industry includes edible flowers of C. cyanus and, more specifically, the upper parts of their capitulum [20].…”

Phytochemical Analysis and Anti-Cancer Properties of Extracts of Centaurea castriferrei Borbás & Waisb Genus of Centaurea L

“…Recent research has focused on the health-promoting effects of apigenin, so it can be used in dietary supplements [ 22 ]. Apigenin has been identified in the past in various species of the genus Centaurea: Centaurea nicaeensis; Centaures urvillei; Centaurea cyanus; Centaurea jacea; or Centaurea scabiosa [ 23 , 24 , 25 , 26 ]. The cytotoxic properties of apigenin against many cancers have been repeatedly described in the literature, including the tumors studied in this research.…”

Qualitative Analysis Related to Palynological Characterization and Biological Evaluation of Propolis from Prespa National Park (Greece)

“…(Asteraceae) and Trifolium sp. (Fabaceae) [ 20 , 22 , 23 ], which are the main resources of pollen grains in the studied species. Furthermore, the flavonoids (pinocembrin, pinobanksin and its 3- O -acetate, chrysin, and galangin) and aromatic acid esters (phenylethyl caffeates) are characterized as typical constituents for the bud exudates of Populus nigra , representing the European type of propolis [ 20 ].…”