HPLC determination of patulitrin content in the spreading marigold (Tagetes patula L.) flowers

Introduction. Spreading marigold (Tagetes patula L.) flowers are of interest as a new species of medicinal plant raw materials, since they are one of the promising sources of flavonoids. Objective: to develop a procedure for quantitative determination of patulitrin content in the spreading marigold flowers, by using a HPLC method. Material and methods. The inflorescences of the Mandarin (tangerine) variety of spreading marigolds were harvested in the Samara University Botanical Garden in August-September of 2018 and 2019. Silica gel column chromatography was used to isolate flavonoids. The isolated compounds were identified on the basis of UV, 1H NMR, and 13C NMR spectroscopic data. Thin-layer chromatography was applied to qualitative analysis. A reverse-phase HPLC method on a micro-column liquid chromatograph was used for quantitative determination. Results. A procedure was developed for the quantitative determination of patulitrin in the spreading marigold flowers by HPLC and detection on a UV detector at a wavelength of 360 nm. The error of a single determination of patulitrin in the spreading marigold flowers at a 95% confidence probability was ±3.32%. The content of the dominant flavonoid patulitrin (3,5,7,3’,4’-pentahydroxy-6-methoxyflavone 7-O-β-D-glucopyranoside) in the spreading marigold flowers ranged from 5.11 to 5.64%. Conclusion. The investigation has shown that it is expedient to standardize spreading marigold flowers, by determining the content of the dominant and diagnostically significant flavonoid patulitrin by HPLC.