Количественная оценка содержания флавоноидов в вегетативных и репродукционных органах десмодиума канадского

Abstract

Quantitative and qualitative analysis of flavonoids in the vegetative and reproductive organs of showy tick trefoil (Desmodium canadense L., Fabaceae family) herbs collected at various stages of vegetation at the Department of Medicinal Herbs of the Kaunas Botanical Garden (Vytautas Magnus University) was performed using HPLC techniques. A total of fifteen flavonoids of the aglicone and glycoside nature were identified, including apigenin, apigenin-7-O-glycoside, luteolin, rutin, vicenin-2, vitexin, isovitexin, vitexin rhamnoside, orientin, homoorientin, quercitrin, quercetin, hyperoside, astragalin, and kaempferol. Among the vegetative organs, the maximum amount of flavonoids was found in leaves, where the total content of flavonoids was 24290.2 μg/g in the pre-flowering (budding) phase and reached a maximum of 25472.71 μg/g (2.55%) at the ripening stage (1.88 times greater than in herbs at the beginning of flowering). In stems, the maximum amount of flavonoids (2318.0 μg/g) was accumulated at the pre-flowering phase, while the minimum (1910.77 μg/g) was found at the beginning of the seed ripening phase. The maximum amount of flavonoids in the reproductive organs was found in inflorescences, where the total content of flavonoids was 8164.1 μg/g in the beginning of the flowering phase, reached a maximum of 15226.39 μg/g as in the full flowering phase, and then gradually decreased. At the beginning of ripening, legumes contained 8892.3 μg/g flavonoids, while seeds in the full ripeness phase contained only 4270.1 μg/g (0.43%) flavonoids. Among the individual flavonoids, orientin and homoorientin predominated in all cases. Thus, not only the inflorescences of showy tick trefoil but also leaves can be used as medicinal raw material. The optimum time of collecting leaves for the raw material is from the pre-flowering phase till the beginning of fruit ripening.