Quantitative analysis of phenolic compounds of Inula candida (L.) Cass.

Background and Purpose: Some species of the genus Inula L. are used in herbal medicine. Phenolic compounds contribute to many biological activities of the plants. No literature could be found in respect of the determination of the quantities of phenolic compounds of Inula candida. Quantitative analysis of phenolic compounds in different plant parts was therefore performed. Materials and Methods: Plant material was collected from different locations in Croatia. The content of phenolic compounds (flavonoids, phenolic acids, total polyphenols, nontannin polyphenols and tannins) was determined by spectrophotometric methods. Results: The quantity of flavonoids ranged from 0.008 to 0.079%, while the content of phenolic acids varied between 0.411 and 1.423%. The content of total polyphenols ranged from 1.53 to 3.57%. The quantity of polyphenols unadsorbed on hide powder (nontannin polyphenols) was between 0.56 and 1.99%, while the quantity of tannins ranged from 0.96 to 2.22%. The highest contents of all phenolic compounds were found in leaves, whereas stems contained the lowest quantities. Conclusion: The content of all investigated compounds depended on the plant organ investigated, date of collection, and locality.