Spectrophotometric evaluation of total amount of phenolic compounds and the total amount of flavonoids in cornflower (Centaurea cyanus L.)

Abstract

Cornflower (Centaurea cyanus L.) is the most intensive blue color flower from all in Lithuania growing flowers. It is an annual plant [...]. Because of an intensive blue color the cornflower is used as a dye stuff for textile. Centaurea cyanus L. is used as medicinal plant in folk medicine. Some preliminary studies indicated that cornflower may have anti-inflammatory properties and reduce the recurrence of urinary tract. Phenolic compounds are the secondary plant metabolites, which are synthesized during the normal development and as a response to stress conditions such as infection, wounding, and UV irradiation. Plant phenolics include simple phenols, phenolic acids (benzoic and cinnamic acid derivatives), coumarins, flavonoids, stilbenes, hydrolysable and condensed tannins, lignans, and lignins [...]. Spectrophotometry is a very simple and fast method used for determination of common characteristics of plant extracts, such as total amount of phenolic compounds and total amount of flavonoids. Both Folin–Denis and Folin–Ciocalteu reagents used for determination of total phenolic compounds content are not specific and detect all the phenolic groups found in extracted compounds, including those in the extractable proteins. [...]