Study of phenolic compounds in Zinnia elegans raw materials by HPLC

Abstract

Introduction. Zinnia elegans Jacq. is an ornamental herbaceous plant of the Asteraceae family, native to Mexico and Central America. Today, this plant is widely cultivated due to the wide range of colors and long flowering. Given its simple cultivation and high adaptability to harsh landscape conditions, today Zinnia elegans is being studied as a potential source of secondary metabolites that exhibit pronounced pharmacological activity. Polish and Romanian scientists have found a pronounced antioxidant activity associated with the content of phenolic compounds for methanol extract obtained from Zinnia elegans raw material variety Carousel. It has been proven that phenolic compounds cause antioxidant activity, which is inherent in Zinnia elegans raw materials. The aim of the study was to study phenolic compounds in Zinnia elegans raw materials by HPLC. Materials and methods. The study used leaves, flowers and stems of Zinnia elegant, harvested in the flowering phase in Ukraine in the Kharkiv region in August 2021. The study used a varietal mixture, which included varieties Karusel and Rozhevyi briliant. To remove phenolic compounds, the raw material was extracted as follows: 0.500 g of crushed raw material was placed in a 100 ml conical flask equipped with a reflux condenser, 25 ml of 70% ethanol was added and heated in a water bath for 45 minutes. The resulting solution was then cooled to room temperature and filtered through a red tape filter into a 25.0 ml volumetric flask. The volume of the solution was adjusted to 25.0 ml with 70% ethanol. The chromatographic study of tested herb specimens was performed at a Shimadzu HPLC-system, ser.20 liquid chromatograph equipped with a diode matrix detector under the following conditions: Phenomenex Luna C18 column, dimensions: 250 mm х 4,6 mm, particle size 5 μm; column temperature 350С; detector wavelength 330 nm; mobile phase flow rate 1 ml/min; introduced sample volume 5 μl. The components were identified by their retention time and conformity of their UV spectra to standard substance. Research results. Neochlorogenic, chlorogenic acids and rutin have been identified in Zinnia elegant leaf among phenolic compounds. As a result of chromatographic study of the flowers of the studied plant, neochlorogenic, chlorogenic and caffeic acids were identified. Rutin has been found in the stems of Zinnia elegant. Therefore, in view of the above data, it can be said that among the identified compounds in the studied objects are representatives of hydroxycinnamic acids and flavonoids. Conclusions. Thus, the obtained data are the basis for further phytochemical studies of Zinnia elegant as a promising raw material for the production of herbal medicines.

Keywords: Zinnia elegans Jacq., phenolic compounds, HPLC

DOI: 10.5281/zenodo.6634904