Flavonoids from Serratula komarovii Iljin (the Asteraceae Family)

The genus Serratula L. (the Asteraceae family) is represented by two species in the Russia’s Far East: Serratula manshurica Kitag. and Serratula komarovii Iljin, which are potential sources of biologically active compounds (phytoecdysteroids). Using liquid extraction with 70% ethanol and reverse-phase high-performance liquid chromatography (RP HPLC), six representatives of the flavonoid class in the above-ground parts (leaves, stems, and inflorescences) of S. komarovii growing in the Primorskii krai of the Far East of Russia, are identified for the first time: luteolin-7- O -β-D-glucuronopyranoside, apigenin-7- O -β-D-glucuronopyranoside, chrysoeriol-7- O -β-D-glucuronopyranoside, quercetin, luteiolin, and 3-methylquercetin. The structure of the compounds luteolin-7- O -β-D-glucuronopyranoside, apigenin-7- O -β-D-glucuronopyranoside, and chrysoeriol-7- O -β-D-glucuronopyranoside, which are isolated by preparative column chromatography on silica gel using gradient elution with a mixture of carbon tetrachloride and ethanol, is established by UV, 1 H and 13 C NMR, and 1 H− 13 C heteronuclear multiple bond correlation (HMBC) spectroscopies. Luteolin-7- O -β-D-glucuronopyranoside is found to be the major flavonoid in S. komarovii (its content in leaves and stems is 4.92 ± 0.98% and 1.23 ± 0.25%, respectively), and apigenin-7- O -β-D-glucuronopyranoside is the dominant flavonoid found in inflorescences (1.10 ± 0.22%). Total flavonoids in the above-ground organs of S. komarovii are determined by differential spectrophotometry; their content varies from 1.96 to 9.04 wt %. The highest flavonoid content is found in leaves (9.04 ± 0.71%), and the lowest content is found in stems of the plant (1.96 ± 0.20%). As a result, S. komarovii can be a promising and constantly renewable source of not only phytoecdysteroids but also flavonoids for the pharmaceutical industry.