Objective: The aim of the study was to determine the content of polyphenols and flavonoids from sixteen selected medicinal plants from the spontaneous Romanian flora and fifteen tinctures obtained with propylene glycol.
Methods: The polyphenols were determined by the Folin-Ciocalteu method while the flavonoids by using a colorimetric method from the 10th edition of the Romanian Pharmacopoeia. The antioxidant activities of the most common nine medicinal plants and fifteen tinctures were determined by DPPH and ABTS methods.
Results: The results highlighted that the phenolic compounds and flavonoids have contributed to their antioxidant activities and the medicinal plants and tinctures included in the study are rich sources of natural antioxidants.
Conclusions: There are a wide variety of extraction methods for the determination of phenolics and flavonoids. The study confirms a correlation between phenolic and flavonoid contents obtained by using the DPPH and ABTS tests.
Tag Archives: flavonoids
The Analysis of Flavonoids from Inula helenium L. Flowers and Leaves
Objective: In this study we investigated the flavonoids in the leaves and flowers of Inula helenium L..
Material and method: Flowers and leaves were harvested from the Medicinal Plant Garden of the University of Medicine and Pharmacy of Tîrgu Mureș. Dried vegetable product was extracted with methanol and in order to investigate aglycones we prepared hydrolised extracts. We screened the vegetable product for flavonoids using a TLC method, then we determined the total flavonoid content by a spectrophotometric method. HPLC-MS and HPLC-UV methods were used to determine polyphenols in methanolic and hydrolised extracts.
Results: Flavonoid content varies from 1.83% in leaves to 1.43% in flowers, equivalent in hyperoside. We identified the flavonols quercetin and kaempferol and the glycosides isoquercitrin, quercitrin and rutoside. Isoquercitrin is the major compound, in a concentration of 0.898 mg/g dry vegetable product.
Conclusions: Our study shows that the leaves and flowers of Inula helenium L. contain a high percentage of flavonoids with pharmacological activities.