Comparative Determinations of Antioxidant Free Radical Scavenging Polyphenols in Certain Natural Products by HPLC Methods and UV-Vis Spectrophotometry

Hawthorn (Crataegus oxiacantha) flowers, Passiflora (Passiflora incarnata) whole plant Rosmarinus (Rosmarinus officinalis) leaves and the apiarian product propolis are rich in polyphenol derivates, well known, for their antioxidant free-radical scavenging capacity. For that reason these products are a raw material of interest in the obtaining of the natural food supplement used in the treatment of degenerative –cardiovascular diseases. The accumulation of free radicals are considered the main cause of these troubles. The present article represents a comparative study concerning the contents of polyphenol derivatives mentioned extracts, using UV-Vis spectrophotometry and HPLC methods. The performed determination by UV-Vis spectrophotometry emphasized the contents of polyphenolcarboxylic acids between 0.4-6 % (in cafeic acid) and in flavone derivatives between 1.7-4.6 % (in rutin) in the studied products. Depending the product nature were identified by HPLC various polyphenols, flavone and antocyan derivatives, natural condensed tannins, using the retention time and the UV-Vis absorbtion spectra.