Chlorogenic acid in curly hop (humulus lupulus): analysis of the quantitative content by season and biological role

Osinkina Tatyana Vladimirovna

The purpose of this study was to analyze the content of chlorogenic acid in the plant material of climbing hop (Húmulus lúpulus) during the growing season. Sample preparation of plant raw materials was carried out in accordance with the standard method, the exact weight of raw materials was obtained by quartering. The content of chlorogenic acid was determined by the spectrophotometric method on a PEVI 5300 instrument at a wavelength of 327 nm in a cuvette with a layer thickness of 10 mm. The reference solution was 95% ethanol. Two peaks were recorded in the content of chlorogenic acid in the leaves of climbing hop: in June (1.1372%) and in October (1.459%). During the growing season from April to October, in general, an increase in the indicator was observed: the content of chlorogenic acid increased by 6.56 times by October. In seedlings, the maximum accumulation was established in July (1.061%) during the period of preparation for flowering and the flowering period of the plant. The content of chlorogenic acid in leaves exceeded that in seedlings by 1.4 times. In all samples of plant tissues from April to October, a variable content of hydroxycinnamic acids in terms of chlorogenic acid was found, the highest in June (in leaves), in July (in cones). The results obtained generally reflect the plant's response to environmental factors and can also be used in the search for available natural sources of biologically active compounds.

Keywords:chlorogenic acid; biological activity; seasonal dynamics; antioxidant activity; hop seedlings; hydroxycinnamic acids; phenolic radical; curly hops; quantitative content; vegetative organs of a plant.